Toxoplasmosis is a disease caused by an obligate intracellular protozoal parasite, Toxoplasma gondii, whose name was derived from the crescent shape of the parasite (toxon is Greek for "arc"), as well as the name of the North African rodent in which it was first observed, Ctenodactylus gundi. Transplacental infection may occur if the mother acquires the parasite acutely or if a latent infection is reactivated during immunosuppression. It is important to differentiate patients with clinical infection from those who are simply seropositive for T gondii via exposure to toxoplasmosis.
T1-weighted axial brain magnetic resonance image at the level of the basal ganglia in a 24-year-old man with human immunodeficiency virus infection.
T1-weighted axial brain magnetic resonance image at the level of the upper lateral ventricles in a 24-year-old man with human immunodeficiency virus infection (same patient as in the previous image).
Transaxial contrast-enhanced computed tomography scan in a 24-year-old man with human immunodeficiency virus infection and central nervous system toxoplasmosis (same patient as in the previous 2 images).
T2-weighted coronal magnetic resonance image at the level of the insulae in a patient with human immunodeficiency virus infection and central nervous system toxoplasmosis (same patient as in the previous 3 images). Congenital toxoplasmosis may be associated with anomalies such as microcephaly, microphthalmia, hydranencephaly, hydrocephalus secondary to aqueduct stenosis, porencephalic cyst, and periventricular calcification.
Magnetic resonance imaging (MRI) is considered superior to computed tomography (CT) scanning in the detection of brain toxoplasmosis. For excellent patient education resources, visit eMedicineHealth's Brain and Nervous System Center. Hemorrhage and calcification may occur following medical treatment, although ring calcification has been described on CT scans at the time of first diagnosis. In 1994, Fellner et al described a case of unilocular toxoplasmosis that simulated intracerebral tumor in a patient without evidence of AIDS.[3] The patient had a single, tumorlike lesion in the right parietal lobe, as shown on CT scan and MRI. In the congenital form of toxoplasmosis, CT scans may reveal diffuse hydrocephalus that is associated with multiple, irregular, nodular, cystlike or curvilinear calcifications in the periventricular areas and the choroid plexus. The characteristic sign of CNS toxoplasmosis is the asymmetrical target sign, which is detectable on CT and MRI scans, although MRI is more sensitive. A study of 31 patients with congenital toxoplasmosis showed a clear relationship among the CNS lesions observed on computed tomography (CT) scans, neurologic deficit, and the date of maternal infection.
Toxoplasmosis is the most common cerebral mass lesion encountered in HIV-infected patients, and its incidence has increased markedly since the beginning of the AIDS epidemic.
Nonenhanced T1-weighted images in a patient infected with human immunodeficiency virus and cerebral toxoplasmosis. T1-weighted gadolinium-enhanced magnetic resonance image at the level of the fourth ventricle in a 32-year-old patient with human immunodeficiency virus infection. T1-weighted axial gadolinium-enhanced magnetic resonance image at the level of the basal ganglia in a 37-year-old patient with human immunodeficiency virus infection. T1-weighted axial gadolinium-enhanced magnetic resonance images at 2 levels through the basal ganglia (same patient as in the previous image). As noted earlier, Fellner et al reported the case of patient without evidence of AIDS, who presented with unilocular toxoplasmosis that simulated an intracerebral tumor.[8] Although the patienta€™s CT scans and MRI showed a single, tumorlike lesion in the right parietal lobe, no tumor was found at surgery. A study by Guerini et al described the importance of periventricular ependymal enhancement in adults,[13] a finding that can signify an underlying pathology that requires prompt medical attention. In a study, Brightbill et al concluded that the appearance of Toxoplasma encephalitis in lesions viewed on T2-weighted MRI scans is so varied that a definitive diagnosis cannot be reached based on signal-intensity characteristics alone.[14] In fact, it appeared that T2-weighted hyperintensity was pathologically correlated with necrotizing encephalitis, whereas T2-weighted isointensity correlated with organizing abscesses. Brightbill et al further surmised that in patients receiving medical therapy, it was possible that the T2-weighted MRI appearance of hyperintensity to isointensity could be a transitional change as a function of a positive response to antibiotic treatment.
Axial fluid-attenuated, inversion recovery brain magnetic resonance image in a patient infected with human immunodeficiency virus and cerebral toxoplasmosis. D'Ercole et al concluded that MRI of the fetal brain can be used to confirm or exclude fetal cerebral defects in cases in which the ultrasonographic results are inconclusive or incomplete.[3] Da€™Ercole et al reviewed 31 cases in which MRI verified ultrasonographic evidence of fetal brain defects. The asymmetrical target sign is highly suggestive of CNS toxoplasmosis, but it is detected in only 30% of patients. CNS lymphoma lesions are often solitary, whereas the nodules of CNS toxoplasmosis more often are multiple. Meningeal or ependymal involvement should provoke a search for other entities, such as lymphoma or other infections.
The positive predictive value for toxoplasmosis was 100% with the combined occurrence of multiple lesions and mass effect or contrast enhancement (23 patients) or in cases in which at least 1 space-occupying or enhancing lesion was located in the basal ganglia or the thalamus (26 patients). Recurrences of brain toxoplasmosis have been reported to correlate with persistent contrast enhancement both on CT scanning and on MRI.[17] The demonstration of such areas of persistent contrast enhancement in patients who have received treatment for initial toxoplasmosis may be a valuable sign that they are at risk for recurrence.
Revel and associates reported the imaging findings of 5 patients with AIDS who had received a previous diagnosis of, and subsequent treatment for, toxoplasmosis.[19] Nonenhanced CT scans obtained approximately 6 months after the CNS infection showed hyperattenuating lesions. In another study of 12 cases of AIDS, the radiologic (MRI and CT scan) and pathologic findings in the brain were correlated.[20] Balakrishnan et al noted 3 cases each of HIV encephalopathy, primary lymphoma, and toxoplasmosis and 1 case each of cryptococcosis, cytomegalovirus infection, and PML. A variety brain lesions occur in the setting of AIDS, including toxoplasmosis, tuberculoma, and primary lymphoma. Mahadevan et al describe a case in which such a sign was correlated with postmortem findings of a 40-year-old man with AIDS-associated cerebral toxoplasmosis. False-positive findings may result from lymphoma, other CNS infections (particularly fungal infections), and CNS metastases. Postnatal ultrasonography can be used to monitor ventricular size in infants up to 18 months of age or following closure of the fontanelles. Ultrasonographic findings combined with maternal serologic results are significantly related to clinical outcome. Abdominal ultrasonography in adult patients with a history of abdominal pain and abnormal results on liver function tests may show hepatosplenomegaly and abdominal lymphadenopathy.
Preliminary research suggests that positron emission tomography (PET) scanning with fluorine-18-fluorodeoxyglucose (FDG) can reliably distinguish CNS infections from CNS malignancies, such as lymphoma, in patients with HIV infection. Thallous chloride (201Tl) and technetium-99m (99mTc) sestamibi (MIBI) brain imaging has also been used to distinguish CNS infections from CNS lymphoma. Larger prospective studies are required to confirm the impression that FDG-PET can reliably differentiate CNS infection from CNS lymphoma.
False-negative scans may occur with both MIBI scanning and 201Tl scanning, as well as in patients following medical treatment for toxoplasmosis.
Immunohistochemical or immunofluorescent techniques can detect the Toxoplasma gondii parasite. Medscape's clinical reference is the most authoritative and accessible point-of-care medical reference for physicians and healthcare professionals, available online and via all major mobile devices.
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Lateral skull radiograph in a child shows a long, linear fracture extending from the midline in the occipital region across the occipital bone into the temporal bone. Lateral skull radiograph in a child shows a long, linear fracture running across the occipital bone.
A high-energy transfer, such as a blow from a baseball bat, may cause a depressed skull fracture, in which bone fragments are driven inward, with or without a breach in the scalp (see the first 2 images). A fracture is clinically significant and requires elevation when a fragment of bone is depressed deeper than the adjacent inner table. Plain radiographs of the head of a 25a€“year-old man who was assaulted with a baseball bat show a curvilinear shadow indicating a depressed fracture.
Axial computed tomography scan demonstrates an open comminuted and depressed frontal bone fracture with clotted blood along the interhemispheric fissure.
Diastatic fractures occur along the suture lines and usually affect newborns and infants in whom suture fusion has not yet happened. Postmortem radiograph in a child with multiple fractures due to nonaccidental trauma show a diastatic fracture of the sagittal suture. Postmortem radiograph in a child with multiple fractures due to nonaccidental trauma shows a diastatic fracture of the sagittal suture. Basilar fractures are the most serious and involve a linear break in the bone at the base of the skull. Occipital condylar fractures are generally the result of high-energy transfer from blunt trauma with axial compression, lateral bending, or rotational injury to the alar ligament.
The ping-pong skull fracture (seen below) is akin to a greenstick fracture of the long bones in children. Lateral computed tomography (CT) scanogram and axial bone-window CT scan demonstrate a temporal fracture.
Caput succedaneum commonly occurs after vaginal delivery and is related to a serosanguineous effusion, which appears as a soft-tissue swelling over the presenting part of the skull. Computed tomography scan of an 8-week-old baby after forceps delivery shows a major insult to the left cerebral hemisphere, which is now atrophic.
Axial computed tomography scan shows a growing skull fracture nicely, depicting the widened fracture on the left and the fluid collection extending from the intracranial cavity into and through the fracture site. The diagnosis is based on clinical and imaging findings; early recognition of growing skull fractures is crucial to prevent long-term neurologic sequelae. Serial conventional radiographs of the skull show evolution of the initial diastatic fracture into a larger defect. Magnetic resonance imaging (MRI) is preferred to CT scanning for depicting dural tears early after the head injury and allows timely surgical intervention and prevention of growth of the fracture. Minor jarring of the intracranial contents may cause concussion and a clinical state of transient loss of consciousness due to temporary neuronal dysfunction.
Coup-type contusion or laceration of the brain surface often occurs at the site of a fracture, especially if it is depressed. Contrecoup-type brain contusions occur when the head strikes a stationary object (eg, when the falling head strikes the ground). Missiles can be subdivided into (1) low-velocity bullets, such as those used in air rifles, nail guns, stun guns (used for animal slaughter), handguns, shotguns, and shrapnel, and (2) high-velocity bullets, such as metal-jacket bullets fired from military weapons. Computed tomography scans of the head show air in the cranium, intracerebral hematoma, and cerebral edema due to a high-velocity gunshot wound.
Missiles produce brain injury by causing laceration and crushing, cavitation, and shock waves. The type of skull fracture sustained and the underlying brain injury depends on the variation in skull thickness and on the strength and angle of the impact.
Most fractures in children are a result of falls and bicycle accidents, but skull fractures in infants may originate from neglect, falls, or abuse.
In an infant, anything but a nonwidely spaced simple linear fracture of the parietal bone should be viewed with suspicion and regarded as a nonaccidental injury until proven otherwise. Margulies and Thibault have shown that the fracture threshold for an infant is approximately 10% that of a child or adult.[11] A special pattern of bilateral skull fractures can occur when crushing forces are applied against the infant skull. Subdural hemorrhages are more common than an epidural hemorrhages, and they are especially common in the elderly, children, and individuals with alcoholism. Subarachnoid hemorrhages may occur as a result of a ruptured intracranial arterial aneurysm or trauma. Intracerebral hemorrhage may occur as a result of a ruptured atheromatous intracerebral arteriole, vasculitis, ruptured intracranial arterial aneurysm, or trauma.
CT scanning is an essential imaging modality in detecting intracranial lesions that require urgent surgical intervention, such as an acute subdural hematoma. CT scanning is increasingly being used to identify minimal and minor head injury in patients who may benefit from observation; clinical criteria have not proven to be consistently reliable for the identification of those with significant intracranial injury. Ultrasonography is a noninvasive technique that may be useful for evaluating growing skull fractures and associated intracranial hemorrhage in infants.
Cerebral angiography may be indicated if a vascular injury is suspected and if the patient is stable, though CT angiography (CTA) or magnetic resonance angiography (MRA) can be used to obtain similar information.
Isotopic bone scans may be useful in children with suspected nonaccidental injury, as the scans may show fractures elsewhere in the body in various stages of healing. Single-photon emission CT (SPECT) scanning, positron emission tomography (PET) scanning, and transcranial Doppler ultrasonography have complementary roles in the assessment of brain injury.
Conventional radiographs do not help in assessing intracranial complications associated with skull fractures. Temporal bone CT scanning requires additional imaging time and patient cooperation, neither of which may be possible in the immediate posttraumatic period.
MRI has limited availability in the acute trauma setting, long imaging times, sensitivity to patient motion, incompatibility with various medical and life-support devices, and relative insensitivity to subarachnoid hemorrhage.
Cisternography with99m Tc DTPA may not be immediately available, as this study is expensive and cumbersome. Lateral skull radiograph shows the importance of having the patient positioned straight for lateral imaging. Anteroposterior (AP) skull radiograph in a child shows the sagittal and lambdoid sutures and a prominent squamous cell suture on the right side.
Lateral skull radiograph shows the normal bilateral squamous temporal sutures, not to be confused with fractures. Frontal skull radiograph shows a persistent metopic suture that has not yet fused; this is not a fracture. Failure to recognize skull fracture has more consequences than the complications resulting from treatment. In infants and children, a simple linear fracture may be associated with a dural tear, which can lead to subepicranial hygroma or a growing skull fracture. A complete and sudden onset of facial palsy at the time of fracture is usually secondary to nerve transection, and patients in this condition have a poor prognosis. The risk of epilepsy after a depressed fracture is low, but the risk increases when patients lose consciousness for longer than 2 hours and when they have associated dural tears. Controversy exists regarding the need to elevate a depressed fracture and whether the choice to elevate a skull fracture is the surgeon's. Skull fractures pose a significant potential risk of underlying direct injury to the brain, CNs, and vessels.
Patients treated surgically for contaminated open depressed skull fractures should be monitored with repeat CT studies to check for abscess formation.
Preoperative angiography with a venous-phase image or MRA is indicated when depressed fractures overlie the dural venous sinuses. In most patients with suspected head injury, radiographs of the lateral cervical spine and chest are obtained in the resuscitation room.
In general, conventional radiography of the skull has a limited role, if any, to play in the management of skull fractures with or without blunt head injury. The following are postmortem radiographs of skull fractures in a child with nonaccidental trauma.
Of the 32 (48%) who underwent head CT scanning, 6 (19%) had evidence of acute intracranial injury despite the presence of minimal depression and stellate, multiple, and diastatic fractures.[18] Of the 20 children with acute neurologic findings, 16 (80%) had positive CT scans, which led to neurosurgical intervention in 9 (of the 20, or 45%).
In fact, routine CT scanning for all patients with skull fractures may be unnecessary, because few patients with minor head injury develop a life-threatening intracranial hematoma that must be rapidly detected and surgically treated.
An initial Glasgow Coma score (GCS) score of 13-15 does not necessarily indicate a trivial head injury, because 3% of patients with such scores require surgery despite initially normal alertness. An abnormal skull radiograph increases the probability of neurosurgical treatment by a factor of 20.
It is unusual for patients with a GCS score of 15 and a normal skull radiograph to have a significant neurosurgical complication. Alternative management schemes that depend on selective use of skull radiographs and CT scans may substantially reduce the cost of caring for patients with minor head injury.
Skull radiographs reveal most linear fractures, show air-fluid levels in the paranasal sinuses and cranium, and delineate the craniocervical junction well.
A false-positive diagnosis may be made when unusual vascular markings and suture lines (as seen below) are found on radiographs. CT scanning is the modality of choice in the evaluation of suspected skull fractures and intracranial injury. Computed tomography scan in a child with a high-impact injury to the frontoethmoid region shows a comminuted fracture in the left frontal bone and disruption of the left orbit with air in the orbital cavity. Computed tomography scans in a child with a high-impact injury to the frontoethmoid region show a comminuted fracture in the left frontal bone and disruption of the left orbit with air in the orbital cavity. Axial fluid-attenuated inversion recovery (FLAIR) magnetic resonance images obtained at 2-year follow-up of a child who had a high-impact injury to the frontoethmoid region demonstrate focal cystic atrophy in the left frontal region (black) and gliosis of the brain (white). Axial proton densitya€“weighted magnetic resonance image obtained at 2-year follow-up of a child who had a high-impact injury to the frontoethmoid region demonstrate focal cystic atrophy in the left frontal region (black) and gliosis of the brain (white).
Axial T2-weighted axial MRI obtained at 2-year follow-up demonstrates focal cystic atrophy in the left frontal region (black) and gliosis of the brain (white). CT images with wide windows (1000-4000 Hounsfield units [HU]) are needed to evaluate skull injuries.
However, a linear or minimally depressed fracture may be easily overlooked on CT scans, particularly when viewed with narrow windows. Advances in radiologic imaging techniques, such as computed tomography (CT) scanning and magnetic resonance imaging (MRI), have improved the ability to predict the success for complete removal of the mass.
Transverse axial CT without and with contrast shows a spoke-wheel pattern within this avidly enhancing meningioma. Subsequent MRI of the previous CT with the following sequences: axial T1 post gadolinium adminsitration and axial T2 sequences.
Neuroradiologists and neurosurgeons must be aware of both the typical and atypical imaging appearances of meningiomas, as there is some correlation with different histologic types of tumor.
Significant factors contributing to recurrence include atypical and malignant histologic types and heterogeneous tumor contrast enhancement on CT scans.
MRI is preferred for the diagnosis and evaluation of brain meningiomas.[7, 10, 11, 12] It more accurately evaluates en plaque and posterior fossa meningiomas, which may be missed on CT scanning.
CT scanning historically had limitations in performing direct imaging in any plane other than axial. The development of catheters and the continued refinement of embolic materials and radiographically controlled interventional procedures have contributed to improved treatment of patients with brain meningiomas. The best available treatment for benign meningiomas is complete surgical resection of the tumor. In a study of the effects of preoperative embolization on overall surgical outcomes after meningioma resection, preembolization and postembolization tumor enhancement patterns on MRI defined as embolization fraction correlated with decreased intraoperative blood loss and better postoperative functional outcomes.
Embolization can be carried out at the same time as the diagnostic angiography session or may occur later if detailed procedural planning is required.
PVA particles ranging in size from 100 to 2000 microns have been used, but the newer class of deformable particles and Bead Block have been shown to be more effective in distal embolotherapy to reach the capillary bed of the meningioma.
A cautious approach should be taken regarding pathologic evaluation of preoperatively embolized meningiomas; one study has suggested that preoperatively embolizing meningiomas may risk overgrading the pathologic specimen if the interpreting pathologist is not aware of the recent procedure. Approximately 2% of patients have complications associated with embolization that result in neurologic deficits. T2-weighted magnetic resonance image shows a hyperintense mass attached to the petrous bone, within the cerebellopontine angle, in keeping with a cerebellopontine angle meningioma. Selective angiogram of right occipital artery shows focal hypervascularity through the auricular artery.
This angiogram demonstrates successful embolization of this cerebellopontine angle meningioma prior to surgery, via embolization of the right occipital artery with polyvinyl alcohol particles.
In most patients, plain skull radiographs are nondiagnostic, with no features to suggest the presence of a meningioma. Transverse axial CT without and with contrast demonstrates the large calcified meningioma that was seen radiographically on the scout image. Calcification within the tumor is a considerably less frequent plain radiographic manifestation; therefore, false-negative results occur. Computed tomography (CT) scanning is frequently utilized in the assessment of meningiomas.[16, 17, 18, 19, 20, 21, 22, 23] Typical features on unenhanced images include a well-circumscribed, smoothly marginated extra-axial mass abutting the dura.
Approximately 70-75% of meningiomas are hyperattenuating to surrounding brain parenchyma, while roughly 25% are isodense. An advantage of CT over MRI is the evaluation of bone.[24] Underlying bone demonstrates hyperostosis in 15-20% of patients. The administration of intravenous contrast in evaluating meningiomas is helpful, as more than 90% of cases will demonstrate intense homogeneous enhancement.
After identification on plain radiograph, this calcified intracranial mass was further investigated with CT. Transverse axial and coronal CT images show a large left parieto-occipital calcified meningioma.
Nonenhanced computed tomography scan shows a malignant meningioma in the frontal convexity that appears as a spontaneously hyperattenuating mass. Contrast-enhanced computed tomography scan shows a parietal convexity meningioma, characterized by a round, hyperattenuating, and unilobulated mass. Computed tomography (CT) scanning is the imaging technique most commonly used to evaluate bone changes and calcium in meningiomas. MRI can demonstrate tumor vascularity, arterial encasement, venous sinus invasion, and the relationship between the tumor and surrounding structures. On nonenhanced T1-weighted images, most meningiomas have no signal intensity difference compared with cortical gray matter. Hyperintensity on T2-weighted images indicates soft-tumor consistency and microhypervascularity.
Fluid-attenuated inversion recovery (FLAIR) sequences are useful to assess for associated edema, as well as for the characteristic feature of a dural tail. On MRI and CT, meningiomas exhibit the same enhancement appearance after the injection of contrast medium. A: Noncontrast angio-magnetic resonance image (MRI) on lateral view demonstrates occluded superior sagittal sinus due to meningioma invasion. Nonenhanced T1-weighted sagittal magnetic resonance image demonstrates a typical parasagittal meningioma. Coronal T2-weighted magnetic resonance image demonstrates a typical parasagittal meningioma. Contrast-enhanced T1-weighted axial magnetic resonance image demonstrates a typical parasagittal meningioma. Contrast-enhanced T1-weighted coronal magnetic resonance image shows a typical parasagittal meningioma.
Multisequence MR images, including axial T2 and axial T1 post-gadolinium, demonstrate a large right temporal meningioma with a spoke-wheel pattern, local mass effect, surrounding edema, and underlying hyperostosis.
An MR angiogram was performed on the previous case, with the following sequences: MRA through the level of the middle cerebral arteries, MRA through the level of the petrous segment of the internal carotid arteries, collapsed MRA, and MRA projection. A-D: Coronal T2-weighted and enhanced T1-weighted magnetic resonance images demonstrate quick growth of a convexity mass toward the tentorium and the petrous bone.
MRI images with the following sequences: axial T2, axial T2, coronal FLAIR, and sagittal T1. A: 3-dimensional (3-D)-enhanced T1-weighted magnetic resonance image (MRI) image shows residual meningioma at the cranial base after second surgical removal. Histologic subtypes may have different MRI appearances, but this does not suffice for a histologic diagnosis by using MRI. Most meningiomas can be diagnosed by conventional MRI.[18, 19, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44] However, atypical features can lead to uncertainty in diagnosis. MR spectroscopy (MRS) has been studied to aid in differentiating meningiomas from other mimics.
MRI of the brain with the following sequences: axial T2, coronal T2, coronal FLAIR, and coronal T1 post gadolinium administration.
This MR spectroscopy of the previous MRI demonstrates elevated choline and low NAA levels, typical of meningiomas.
MRI with the following sequences: axial T2, coronal T1 post gadolinium administration, and MR spectroscopy. MRI with the following sequences: axial T1 post gadolinium administration, coronal T1 post gadolinium, sagittal T1, and MR spectroscopy. MRI images with the following sequences: axial T2, coronal FLAIR, coronal T1, coronal T1 post gadolinium administration, sagittal T1 post gadolinium, and MR spectroscopy. Diffusion weighted MRI of the posterior fossa meningioma demonstrates mildly increased signal, in keeping with mild diffusion restriction.
Gadolinium-based contrast agents have been linked to the development of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). An apparent diffusion coefficient (ADC) of 0.85 using diffusion-weighted MRI was found to differentiate grade I meningioma from grade II and III tumors. In general, the sensitivity and specificity of MRI are high in the diagnosis of meningiomas.
The location of intratumoral hemorrhage, cystic changes inside or outside of the tumor mass, calcifications, invasion of the parenchyma by malignant meningiomas, and lobulated or multilobulated masses is demonstrable only with intraoperative ultrasonography. Lateral skull projection of a bone scan shows a small focus of increased uptake that overlying the mid skull. Transverse axial CT at the level of the centrum semiovale on brain and bone windows illustrates a small right posterior frontal meningioma that was detected on bone scan. PET has been studied using18 F-FDG (18 F-fluorodeoxyglucose), with mixed results: some papers have suggested an FDG avidity to differentiate benign from malignant meningiomas, while other papers contradict this finding. Although magnetic resonance angiography (MRA and magnetic resonance venography [MRV]) have decreased the role of classical angiography, the latter remains a powerful tool for embolization and planning surgery. Meningiomas are supplied by meningeal branches of the internal and external carotid artery (see the following images).
This angiogram of the internal carotid artery demonstrates considerable supply of a middle cranial fossa meningioma from a petrous branch. Lateral projection from internal carotid angiography shows multiple opacified tumoral vessels in a radial distribution, characterizing this parasellar meningioma. Tumors that arise along the falx, the sphenoidal ridge, and the convexity are supplied by the middle meningeal artery.
Selective injection of the left middle meningeal artery shows inhomogeneous enhancing tumor, consistent with a parietal-convexity meningioma.
Meningeal arteries penetrate to a meningioma through its dural attachment with inside branches radially distributed like sunrays, creating the typical "sunburst" appearance. In summary, angiography is useful in delineating the blood supply of the external versus internal carotid arteries and can show encasement of intracranial vessels. As an alternative to traditional catheter angiography, 3-D CT angiography may depict the relationship between skull base meningiomas and neighboring bony and vascular structures clearly, quickly, and with minimal risk to the patient. Angiography has a high degree of confidence in recognizing the arterial source of the meningioma.
Acyanotic Increased pulmonary blood flow Atrial septal defect (ASD) is a congenital heart defect in which the wall that separates the upper heart chambers (atria) does not close completely. Ventricular septal defect (VSD)describes one or more holes in the wall that separates the right and left ventricles of the heart. Opening between ventricles A large ventricular septal defect (VSD): a hole in the part of the septum that separatesventricular septal defect the ventricles, the lower chambers of the heart.
Children with TOF may develop "tet spells (acute hypoxia) The precise mechanism of these episodes is in doubt presumably results from a transient In resistance to blood flow to the lungs with flow of desaturated blood to the body characterized by a sudden, marked, increase in cyanosis followed by syncope, and may result in hypoxic brain injury and death, prolonged crying, irritability treatment: Calm infant- hold over shoulder or in knee chest position or have child squat (increases pressure on the left side of the heart, decreaseing the R to L shunt thus decreasing the amount of deoxygenated blood entering systemic circulation) Morphine (to decrease spasm and supress resp center) Oxygen (it is a potent pulmonary vasodilator and systemic vasoconstrictor.
Transposition of the great vessels is a congenital heart defect in which the two major vessels that carry blood away from the heart -- the aorta and the pulmonary artery -- are switched (transposed).
Aortic coarctation is a narrowing of part of the aorta (the major artery leading out of the heart). Disorders of Hematological Function Anemia: The condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood.
Failure to produce (hem)oglobin due to lack of iron Iron containing O2 transport protein that carries O2 from the lungs to the body Iron needed to bind O2 Reduces O2 carrying capacity of the blood O2 state to the tissues: dyspnea on exertion, fatique, fainting, lightheadedness, tinnitus, headache In anemia selective vasoconstriction of blood vessels allows nonvital areas to be bypassed to allow more blood to flow into critical areas. Disorders of Hematological Function Leukemia -ALL (acute lymphoblastic leukemia) uncontrolled proliferation of blast cells,which accumulate in the marrow causing crowding and depression of other cells Hodgkins disease- This is a malignant lymphoma distinguished by painless, progressive enlargement of lymphoid tissue. Disorders of the Immune System Infection with HIV produces Lymphopenia resulting in immunosupression and AIDS Symptoms may not Appear for 1 to 2 yrs Nonspecific clinical manifestations Prevent opportunistic infections Administer prophylactic therapy for P.
Over the past two decades, the way in which trauma surgeons approach a person with multiple severe injuries has undergone an evolution.
Damage-control principles are typically applied to patients who have multiple severe injuries. Although the organ-specific operative techniques are beyond the scope of this article, patients who undergo damage-control celiotomy are at risk for the development of multiple life-threatening complications in the early postoperative period.


Abdominal compartment syndrome (ACS) is a condition that elevates intra-abdominal pressure (IAP), adversely affects end-organ physiology, and disrupts patient homeostasis. ACS is most often encountered during the early postoperative course and is commonly discovered in patients who have undergone damage-control celiotomy with primary fascial closure and intra-abdominal packing for coagulopathy. The aforementioned conditions may lead to decreased blood flow to the abdominal wall and organs. The aforementioned conditions either directly or indirectly increase IAP in patients who are critically ill with ACS. Elevated IAP results in elevated intrathoracic pressure, leading to elevated central venous pressure (CVP) and causing an increase in intracerebral pressure.
This fall in ICP may be transient as well if intrathoracic pressure increases as a consequence of increased IAP.
Abdominal decompression has resulted in a return toward baseline for ICP and an improvement in the CPP.
Increased IAP can cause the rupture of retinal capillaries, resulting in the sudden onset of decreased central vision (Valsalva retinopathy).
The most direct and accurate measurements of IAP are obtained via a cannula placed percutaneously into the peritoneum.
Indirect IAP is monitored through transfemorally placed inferior-caval venous lines, nasogastric tubes, rectal tubes, and, most commonly, Foley catheters.
Leaving the abdominal incision open during surgery prevents abdominal compartment syndrome (ACS).
The techniques of temporary abdominal closure (TAC) are varied, and each has its own advantages and disadvantages. With a damage-control celiotomy, the trauma surgeon must decide to convert to a limited procedure within 5 minutes of starting the operative procedure. The trauma surgeon should be familiar with different TAC techniques, including their indications, their advantages, and their disadvantages. One of the simplest and fastest forms of temporary abdominal closure (TAC) is towel-clipping of the skin edges. Evisceration of the bowel (as illustrated) may occur if towel clips are not placed properly (1 cm from skin edge X 1 cm apart). Open packing of the abdomen is a form of TAC that has been used for more than two decades at the Detroit Receiving Hospital.
Either a conventional zipper or a commercial zipper is sewn to the skin or fascia with a continuous suture of 0 or 2-0 nylon or polypropylene. The approach using the Wittmann Patch (STARSURGICAL, Inc, Burlington, WI) was first reported by Teichman et al,[6] Wittmann et al,[7] and Aprahamian et al.[8] As bowel edema resolves, the excess Velcro-biocompatible patch material is removed and the fascial edges approximated.
The major advantage of this approach is the ease of access for repeated surgical interventions and the capacity for applying tension to the midline fascia, which helps prevent lateral retraction of the aponeurotic edges, permitting definitive delayed primary closure in most cases (see the images below). The polytetrafluoroethylene (PTFE) 2-mm biocompatible prosthetic abdominal wall graft is strong and watertight and creates a bed for granulation tissue, which may be covered with a split-thickness skin graft when the prosthesis is removed.
Gore-Tex 2-mm mesh is sewn to itself and to the skin or fascia (as in this case) to achieve temporary closure. Several authors have reported the use of polypropylene-polyethylene mesh in the setting of a contaminated wound (eg, fasciitis, intra-abdominal sepsis). Although short-term successes have occurred, numerous long-term complications have been reported with this mesh.
As described by Bender et al, the mesh is applied loosely over the abdominal contents and then covered with fine mesh gauze packing, maintaining the bowel below the absorbable mesh and within the abdominal contents.[3] This may decrease bowel wall distention, thinning, and subsequent desiccation, thereby potentially reducing the incidence of enterocutaneous fistula.
The choice between polyglactin mesh and polyglycolic acid mesh is primarily determined by the surgeon's preference. A presterilized (gas) soft 3-L plastic cystoscopy fluid irrigation bag is cut and shaped to cover the abdominal incision and extruded viscera.
An alternative is to apply sterile towels over the silo and to secure them with a Montgomery abdominal wound binder, being careful not to create increased abdominal pressure while securing the dressing.
Example of massive edema of the bowel and liver in a patient who experienced blunt trauma and developed abdominal compartment syndrome (ACS).
Primary delayed facial closure (at 5-10 days) may be attempted if the abdominal cavity can be closed without significant elevation of intra-abdominal pressure (IAP).
Fabian et al published their experience with their eponymous protocol,[13] after which the patients are subsequently brought back for definitive reconstruction, usually within 6-12 months. The Sure-Closure skin-stretching system (MedChem, Woburn, MA) is a patented, disposable, molded device made of stainless steel and plastic parts and used to provide sufficient skin in advance of closures for fasciotomies and trauma repairs of various types, including closure of the open abdomen. The device is attached intraoperatively by first inserting needles parallel to the wound edges.
By using the Sure-Closure skin-stretching system, the surgeon is able to close most cases of skin defects that would more commonly require secondary wound closure techniques, such as myocutaneous flaps or skin grafts. The Sure-Closure device accomplishes skin stretching by using two intradermal needles in conjunction with a tension rod that connects two self-aligning U-arms.
Patient with blunt trauma with nearly healed ventral hernia (subcutaneous flap advancement technique with the Sure-Closure device). Miller et al reported excellent results in the use of this system.[16] They reviewed 646 patients with trauma injuries who underwent laparotomies, of whom 148 required management of an open abdomen over a 5-year period (1996-2001). Fifty-nine patients underwent fascial closure, 37 of them before postoperative day 9 and the remaining 22 on or after postoperative day 9.[16] Mean time to fascial closure in the LATE group was 21 days (range, 9-49 days).
Postoperatively, the patient developed severe abdominal distention and respiratory distress. The open skin over the fascia will be closed either by contraction or by secondary closure.
The management of the severely contaminated abdomen, severe peritonitis, and intra-abdominal sepsis by an open approach has been discussed in the literature.
Fernandez et al described a technique that evolved from their experience with the use of the Silastic silo closure for patients with ACS.[21] They used the extraperitoneal silo in the intraperitoneal (IP) position in selected patients who did not have ACS and whose injuries would benefit from a second-look procedure (see the first image below).
Several techniques in the surgical armamentarium are available to effect temporary closure of the open abdomen. Of the techniques described within this article, the Sure-Closure skin-stretching system has the potential to obviate split-thickness skin grafting in the setting of the open abdomen, particularly if approximation of the skin can be achieved within the first 7-10 days. We've evolved into one of the largest and most respected construction and mining organizations in North America.
T gondii is one of the most successful protozoal parasites; it infects the nucleated cells of virtually all warm-blooded animals.
Consumption of raw or undercooked meat that contains viable tissue cysts (principally lamb and pork), direct ingestion of oocysts from contaminated soil and water, and consumption of unwashed vegetables are common sources of infection. Fetal infection usually occurs in the third trimester, but more severe sequelae may ensue if the fetus is contaminated in the first trimester. In adults, most T gondii infections are subclinical, but severe infection can occur in patients who are immunocompromised, such as those who have acquired immunodeficiency syndrome (AIDS) and malignancies. The image shows hypointense lesions in the region of the thalami (arrows) caused by toxoplasmosis.
This image was obtained after the patient received 20 days of treatment, with resultant clinical improvement, and shows a low-attenuating mass with minor peripheral ring enhancement.
The administration of intravenous (IV) contrast material with either modality improves the diagnostic yield and accuracy.
An exception is congenital toxoplasmosis, in which calcification within the skull can occasionally be depicted. More commonly, following the IV administration of contrast medium, CT scan studies demonstrate thin-walled cavitating lesions with ring enhancement.
Approximately 75% of the nodules are located in the basal ganglia, but others are scattered throughout the brain at the gray mattera€“white matter junction. During neurosurgical intervention, no tumor was found; however, the final diagnosis was based on histopathology. The lesions are bilateral and vary from a few millimeters to 2 cm, and there may be associated hydrocephalus.
This asymmetrical target sign represents a ring-enhancing abscess, which contains other similar ring-enhancing abscesses as well as similarly enhancing, eccentric nodules in the abscess cavity. CT scan findings in these infants are characteristic, depending on the timing of maternal infectiona€”namely, was the mother infected and and did she undergo seroconversion before the 20th week of gestation, was she infected during weeks 20-30 of gestation, or was she infected and did she undergo seroconversion after the 30th week of gestation? There are occasionally unusual appearances of CNS toxoplasmosis that make diagnosis by standard imaging techniques difficult or impossible. Focal nodular or ring enhancement (as shown in the images below) occurs in approximately 70% of patients after gadolinium enhancement.
The image shows 2 complex, ring-enhancing lesions in the basal ganglia on the right, surrounded by notable white matter edema. These images show 2 complex, ring-enhancing lesions in the basal ganglia on the right, with surrounding notable white matter edema. On histologic examination, the asymmetrical target sign, which is detectable on CT and MRI scans, was observed, confirming the diagnosis.
The authors reported the pattern of periventricular contrast enhancement, basing the features they noted on the underlying infectious or tumor etiology. Thus, the signal-intensity change might be a means to determine the effectiveness of medical therapy. Other MRI patterns that are presumably related to the patient's altered immune status are not as specific and may be mimicked by various CNS infections and lymphoma. A diagnosis of toxoplasmosis is favored over a diagnosis of lymphoma when more than 3 lesions or slender, ring-enhancing foci are seen or when marked edema is present. Twenty-nine percent of the observed lesions on the T2-weighted MRIs included the presence of target-shaped lesions with hypointense centers, suggesting the diagnosis of CNS toxoplasmosis. Solitary lesions with mass effect or contrast enhancement were also seen (26 patients), and cerebral toxoplasmosis was the cause in 22 patients (84.6%). Overall, however, histologic changes were more frequent than lesions on MRI, including cases in which conventional MRI did not reveal multiple tuberculous granulomas, multinucleate giant cells, microglial nodules, perivascular cuffing, and cytomegaloviral inclusions. MRI was performed in all cases: in 4 of the 5 patients, the hyperattenuating areas on the CT scans were characterized by high signal intensity on the T1-weighted MRIs. MRI was better than CT scanning at clearly depicting the various cranial lesions; on the basis of MRI characteristics, HIV encephalopathy was distinguishable from other lesions, particularly PML. Differentiation between these lesions can be difficult but is important because of the diverse therapeutic challenges. In adult patients, abdominal ultrasonography may show hepatosplenomegaly and abdominal lymphadenopathy. MIBI imaging appears to be more helpful than 201Tl imaging because of its higher specificity and equal sensitivity.
Prenatal diagnosis of fetal cerebral abnormalities by ultrasonography and magnetic resonance imaging. Neuropathological correlate of the "concentric target sign" in MRI of HIV-associated cerebral toxoplasmosis.
Analysis of cerebral toxoplasmosis in a series of 170 allogeneic hematopoietic stem cell transplant patients. Localised 1H-MR spectroscopy for metabolic characterisation of diffuse and focal brain lesions in patients infected with HIV. Toxoplasmosis and primary central nervous system lymphoma in HIV infection: diagnosis with MR spectroscopy. Differentiation of toxoplasmosis and lymphoma in AIDS patients by using apparent diffusion coefficients. MR of Toxoplasma encephalitis: signal characteristics on T2-weighted images and pathologic correlation. Focal brain lesions in patients with AIDS: aetiologies and corresponding radiological patterns in a prospective study. Persistent enhancement after treatment for cerebral toxoplasmosis in patients with AIDS: predictive value for subsequent recurrence. Hyperdense CT foci in treated AIDS toxoplasmosis encephalitis: MR and pathologic correlation. Acquired immunodeficiency syndrome: correlation of radiologic and pathologic findings in the brain. Topics are richly illustrated with more than 40,000 clinical photos, videos, diagrams, and radiographic images. The articles assist in the understanding of the anatomy involved in treating specific conditions and performing procedures. Check mild interactions to serious contraindications for up to 30 drugs, herbals, and supplements at a time.
Plus, more than 600 drug monographs in our drug reference include integrated dosing calculators.
Each of the flat bones consists of a thick outer table, the spongy diploe, and a thinner inner table. The skull is deformed by localized impact, which may damage the cranial contents even when the skull does not fracture.
However, skull fractures may be associated with intracranial hemorrhage, which may create an intracranial space-occupying lesion. The skull is thick at the glabella, the external occipital protuberance, the mastoid processes, and the external angular process. The middle cranial fossa forms the thinnest part of the skull and thus represents the weakest part, which is further weakened by the presence of multiple foramina.
These fractures are usually the result of low-energy transfer due to blunt trauma over a wide surface area of the skull. The fracture is more radiolucent than the other sutures, has no serration along its edges, and is blind ending.
This fracture is usually comminuted (as exemplified in the third image below), with the bone fragments starting from the point of maximum impact and spreading peripherally. Contusional hemorrhage is present in the left frontal lobe, as is a left-sided temporal extradural hematoma containing a small pocket of air; this finding implies an open fracture. Most basilar fractures occur at 2 specific anatomic locationsa€”namely, the temporal region and the occipital condylar region.
The fracture may run either anterior or posterior to the cochlea and labyrinthine capsule, ending in the middle cranial fossa near the foramen spinosum or in the mastoid air cells. These fractures can be subdivided into 3 types based on the morphology and mechanism of injury,[5] or alternatively, into stable and displaced fractures depending on the presence or absence of ligamentous injury.[6] A type I fracture is due to axial compression injury, which results in a comminuted fracture of the occipital condyle. It occurs in the first few months of life and is usually caused by a fall when the skull hits the edge of a hard blunt object, such as a table. The CT scan shows slight inward bulging of the bone, but the inner and outer tables are intact.
Caput succedaneum is a benign process that generally resolves within 2 weeks and usually does not require any form of imaging.
In addition, a cephalohematoma may be visible on a plain radiograph as a subperiosteal elevation.
This scan shows hypoattenuating areas in the brain parenchyma, with dilatation of the ipsilateral lateral ventricle and a midline shift toward the atrophic side. However, in a small minority of children, a fracture may remain un-united and enlarge to form a growing skull fracture.
Cases related to difficult vacuum extraction and corrective surgery for craniosynostosis have also been described. The mechanism of injury is usually a direct force applied to the cranial vault, resulting in the fracture, with tearing of the dura so that cerebrospinal fluid (CSF) leaks to form a collection. Although plain radiographs are sufficient for diagnosis, brain computed tomography (CT) scanning better defines the exact pathology. Cranial Doppler ultrasonographic studies have also been used to achieve an early diagnosis.
Matsuura et al present a case history of a 2-month-old baby boy who fell from his mother's arms and hit his head on the floor; he underwent radiography, MRI, and CT scanning before cranioplasty with dural plasty. Lacerations are particularly common, as the scalp is readily crushed and split against the underlying bone. A blow to the head when it is free to move accelerates the head and causes cerebral contusion at the point of impact.
The head decelerates abruptly while the intracranial contents continue moving forward to the point of impact. The entry site is the frontal bone; note the intracranial metallic bone attenuations, intracranial air, cerebral edema, and subarachnoid hemorrhage.
The presence of the reversal sign suggests severe brain swelling and probably secondary hypoxic ischemic injury to the brain as a result of the pressure on the brain. The injuries to the skull range from a graze to an entry wound and sometimes an exit hole (penetrating) or a depressed fracture, with results ranging from focal hemorrhage to extensive neuronal damage. A stab wound nearly perpendicular to the skull may cause bone fragments to travel along the same trajectory as that of the penetrating object, it may shatter the skull in an irregular pattern, or it may produce linear fractures that radiate away from the entry site.
Nonaccidental injury or shaken baby syndrome is a major cause of skull fractures and head injury in infants. A fracture at this site may tear the middle meningeal artery as it passes upward within a groove between the inner skull table and the dura. Subdural hemorrhages are not usually associated with skull fractures but may occur after sudden jarring or rotation of the head, a blow to the head, or a fall.
Traumatic subarachnoid hemorrhage is usually associated with brain contusion or laceration. Traumatic intracerebral hemorrhage is usually due to extension of hemorrhage from surface contusions deep into the substance of the brain.
Skull radiography is useful for imaging of calvarial fractures, penetrating injuries, and radiopaque foreign bodies. Skull fractures are detected on plain radiographs in 5% of patients with mild head injuries, but the detection of a skull fracture on a radiograph is regarded as an indication for CT evaluation.
CSF rhinorrhea and otorrhea can be detected and localized by using overpressure cisternography with technetium-99m (99m Tc) diethylenetriaminepentaacetic acid (DTPA). Other disadvantages include the need for MRI-specific monitoring equipment and ventilators and the risk associated with imaging patients with certain indwelling devices or foreign bodies. Cerebral angiography is an invasive procedure and generally performed only in patients in stable condition.
Because the patient is slightly malpositioned, both coronal sutures are seen as separate entities. On the left is an accessory suture, which is seen to extend from the squamous central suture to the lambdoid suture. These markings engrave the inner table of the skull only, are less translucent than fractures, have ill-defined margins, and have symmetrical branching patterns. The fracture is radiolucent and wide, and it courses without interruption across the occipital and parietal bones.
About 15% of patients with skull fractures sustain concomitant injury to the cervical spine; therefore, missing such a fracture has both clinical and medicolegal implications.
This complication may take up to 6 months to develop, and hence, close radiologic follow-up is important in these patients. Moreover, a sphenoid bone fracture may affect cranial nerves III, IV, and VI, and it also may disrupt the internal carotid artery. Dural tears can be recognized on imaging, and therefore, it is important to make this distinction from both the therapeutic and prognostic point of view. However, most skull fractures are linear vault fractures, particularly in children, and are not associated with epidural hematoma. Follow-up CT evaluation is also recommended when complications, such as seizures and infections, occur in association with skull fractures. Skull fractures are detected on plain radiographs in 5% of patients with mild head injuries, but the detection of a skull fracture on a conventional radiograph is regarded as an indication to proceed to CT scanning. However, although fractures at the skull vertex may be missed on CT scans, they may be depicted on plain radiographs.
Because most adult patients have a calcified pineal gland, a skull radiograph may reveal a midline shift due to a mass effect, and patients are treated in light of the plain radiographic results, especially when there is no access to CT scanning.
Once the patient's cardiopulmonary condition has been stabilized, a CT scan of the head should be obtained to determine the extent of intracranial damage and whether there are intracranial metallic fragments in penetrating injuries.
Reformatted 3-dimensional scan of the maxillofacial skeleton nicely shows the fracture on the left, which involves the frontal and ethmoidal bones and the medial plate of the left orbit (ie, this is a complex fracture involving 3 bones).
Reformatted 3-dimensional scans of the maxillofacial skeleton nicely show the fracture on the left, which involves the frontal and ethmoidal bones and the medial plate of the left orbit (ie, this is a complex fracture involving 3 bones). Gliosis is a highly cellular response of the brain to injury and is, in effect, scar tissue. They represent approximately 38% of all intracranial neoplasms in females and 20% in males.[1] Meningiomas are also the most common extra-axial tumors in the brain and the most frequently occurring tumors of mesodermal or meningeal origin. Although this pattern is typically seen angiographically, it can also be noted on cross-sectional imaging.
Most meningiomas grow inward toward the brain as discrete well-defined, dural-based masses and are spherical or lobulated in contour.
CT scanning, however, clearly depicts bony hyperostosis, which may be difficult to appreciate on MRI. However, with modern spiral CT scanning and multisection or multidetector-row CT (MDCT) scanning, the quality of sagittal and coronal images that can be reconstructed from axial data has increased significantly. Nevertheless, interventional neuroradiologists commonly contribute in performing preoperative embolization to reduce the blood supply to the tumor. Distal, homogeneous, and permanent occlusion of the vascular bed by injecting small particles (150-300 microns of polyvinyl alcohol [PVA]) through microcatheters is the goal.
This scout image was for a subsequent CT that demonstrates typical features of a meningioma. Lateral skull radiograph localizes the mass to be arising superior to the cribriform plate. Meningiomas en plaque have diffuse hyperostosis, more frequently observed over the sphenoid wing and pterion. Most patients with brain meningiomas do not undergo radiographic imaging because the diagnosis has been made directly with CT scanning or MRI. A rare group of meningiomas (the lipoblastic subtype) contain fat and are thus hypoattenuating. This transverse axial CT at the level of the superior border of the orbits demonstrates a cribriform plate meningioma.
A, B: Computed tomography (CT) scans depict calcified meningiomas from the parietal convexity. The cystic cavity may be tumor necrosis, old hemorrhage, cystic degeneration, or trapped cerebrospinal fluid. Computed tomography scan of the frontal internal table and diploe shows erosion and bone infiltration.
The contrast-enhancing mass is attached to the major sphenoid wing and was demonstrated only after the intravenous injection of contrast material. Broad-based attachment to the dura is demonstrated, as is intense edema in the subjacent brain.
The main role of CT scanning, as opposed to MRI, is the demonstration of adjacent bone changes and calcification within the lesion. False-positive findings can occur with large dural calcification, which can mimic the disease.
This modality is particularly advantageous in depicting the juxtasellar area and the posterior fossa and in demonstrating the rare presence of disseminated disease via the CSF. The dural tail represents a collar of thickened, enhancing dura that surrounds the tumor's dural attachment. A: Nonenhanced sagittal T1-weighted magnetic resonance image (MRI) shows a solid dural isointense mass with bone invasion and compression against the parietal cortex.
B: MRI reconstruction shows sagittal venous obstruction and 3-dimensional (3-D) appearance of the tumor. Isointense and inhomogeneous tumor without peripheral edema indicates a more fibrous and harder character (ie, a fibroblastic meningioma). High T2 signal rim surrounding the mass is consistent with CSF fluid, confirming the extra-axial location. These images demonstrate an additional finding of the large right temporal meningioma supplied by the middle meningeal artery (a branch off the external carotid arterial system). A: Sagittal T1-weighted magnetic resonance image (MRI) demonstrates posterior fossa and parietal meningiomas. A 47-year-old white male underwent gamma knife surgery due to left convexity meningioma, followed by microsurgical removal of the tumor.
A large left-sided meningioma shows a spoke-wheel pattern within an extra-axial mass with surrounding edema. A, B: Slow growth and surrounding edema is seen on magnetic resonance imaging (MRI) control of this tumor.
Shown is a left frontal meningioma with a spoke-wheel pattern, underlying hyperostosis of the calvarium, and surrounding parenchymal edema. Additional characteristic meningioma MRS features include increased alanine and glutamate-glutamine complex and decreased creatine. Findings of this large meningioma include CSF encompassing the mass, a classic "CSF cleft sign," confirming an extra-axial location. This MRI characterizes the posterior fossa meningioma to be within the cisterna magna, exerting mass effect with superior displacement of the cerebellum. Apparent diffusion coefficients (ADC) have been shown to typically be lower than surrounding brain for high-grade neoplasms. The disease has occurred in patients with moderate to end-stage renal disease after being given a gadolinium-based contrast agent to enhance MRI or MRA scans. MRI has proved to be superior in delineation of the tumor and its relation with surrounding structures. Delineation of acute hemorrhage into tumor with conventional sequences is a disadvantage of MRI and may generate false findings.
Bone windows illustrate typical meningioma features of hyperostosis and cortical irregularity underlying the mass.
One of the major complicating factors of FDG evaluation is the normal high uptake in cerebral cortex.
Basal meningiomas of the anterior and middle cranial fossa and meningiomas of the wings of the sphenoid bone are commonly supplied by the internal carotid artery.
Homogeneous sharp tumor staining is seen early and remains late and, as such, has been called "the mother-in-law sign." Usually, meningiomas do not exhibit drainage veins, although angioblastic types may. A, B: Left external carotid artery shows early and delayed stain of the mass through middle meningeal and superficial temporal arteries.
Angiography shows an arterial map for preoperative embolization with a low false-finding rate. New pathology classification, imagery techniques and prospective trials for meningiomas: the future looks bright.
Use of Diffusion Weighted Imaging in Differentiating Between Maligant and Benign Meningiomas. MRI Pre- and Post-Embolization Enhancement Patterns Predict Surgical Outcomes in Intracranial Meningiomas.
Atypical computed tomography features of intracranial meningioma: radiological-pathological correlation in a series of 131 consecutive cases. A Magnetic Resonance Imaging Technique to Evaluate Tumor-Brain Adhesion in Meningioma: Brain-Surface Motion Imaging. MRI of radiation-induced tumors of the head and neck in post-radiation nasopharyngeal carcinoma. Fusion of magnetic resonance angiography and magnetic resonance imaging for surgical planning for meningioma--technical note.
The application of MR brain surface anatomy scanning in the operation of intracranial parasagittal meningiomas.
Cerebellopontine angle-petromastoid mass lesions: comparative study of diagnosis with MR imaging and CT. Meningiomas: correlation between MRI characteristics and operative findings including consistency. High-resolution MR imaging of juxtasellar meningiomas with CT and angiographic correlation. Distinct peak at 3.8 ppm observed by 3T MR spectroscopy in meningiomas, while nearly absent in high-grade gliomas and cerebral metastases. Metabolic profiles of human brain tumors using quantitative in vivo 1H magnetic resonance spectroscopy. Meningiomas: Their Classification, Regional Behavior, Life History and Surgical End Results.
Ventricular septal defect is one of the most common congenital (present from birth) heart defects. The hole allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood from the right ventricle. The chief complication in the postoperative period is abdominal compartment syndrome (ACS). ACS was described as early as the 1800s; however, only in the past 15-20 years has it been consistently recognized in the surgical and medical patient population. This derangement of cellular perfusion initiates cytokine release, destabilizing cell membranes and ultimately leading to cellular edema and cell death if not reversed.
The Monroe-Kellie doctrine states that this increase in intracranial blood volume results in elevation of intracranial pressure (ICP). As previously mentioned, the increase in intracranial blood volume results in elevation of the ICP (the Monroe-Kellie doctrine).
Head injury and concomitant abdominal injury is a frequently encountered clinical scenario. Valsalva retinopathy has been described in a number of settings where a sudden increase in IAP or intrathoracic pressure has occurred. The most accurate and simple way to determine the IAP is indirectly by measurement of the bladder pressure using a Foley catheter. ACS more commonly presents in the early postoperative period (24-72 hours); however, it can present later than this time frame. This decision is based on the initial physiologic state of the patient and a rapid initial assessment of the internal injuries.


The trauma surgeon must maintain a low index of suspicion for delayed or occult injuries, particularly in patients with blunt polytrauma. This damage degrades the native tissue, decreasing its tensile and elastic capacity, and increases the potential for delayed incisional hernia.
After this time frame, loss of abdominal domain and lateral retraction of the recti and aponeurotic edges tend to be maximal. By using the skin, the fascia is spared and the incidence of postoperative fascial dehiscence may be diminished.
The Velcro-like material can be adjusted to accommodate increased intra-abdominal pressure (IAP), or, as the IAP decreases, it may be trimmed and the incision approximated accordingly. PTFE is expensive, and similar outcomes may be achieved with less costly absorbable mesh or Silastic (silo) dressing changes. These complications include increased incidence of postoperative wound sepsis, increased incidence of enteric fistulas, and significantly decreased survivability of split-thickness skin grafts.
Polyglactin and polyglycolic acid have been in the surgical armamentarium for approximately 25 years. However, Brasel et al have reported some advantage in the use of polyglycolic acid mesh.[11] This mesh has wider interstices that Brasel et al believe may allow for more efficient drainage of intra-abdominal fluid and, thus, may decrease potential delayed complications (eg, abdominal distention, ileus, and abscess). This bag is either stapled or sutured to the skin edges of the wound with a standard (wide) skin stapling device or monofilament, nonabsorbable suture, thus preserving the fascia.
A high index of suspicion for recurrent abdominal compartment syndrome (ACS) must be maintained.
Use of the Sure-Closure system can minimize the need for more extensive secondary wound closure techniques.
The 50-mm device is designed for smaller skin defects with uneven surfaces, whereas the 75-mm device is designed for larger skin defects with relatively flat, even surfaces. They also noted above-average healing of the wounds at 1 month and 3 months, with better cosmesis than was seen in comparable conventionally closed wounds. This avoids the need and attendant operative risks incurred with abdominal wall reconstruction in the future. The polyethylene sheet helps prevent visceral-abdominal wall adhesions that inhibit movement of the abdominal wall. Injury severity scores, admissions base deficit, number of fistulas, number of operations, and mortality were similar between the HERNIA group and the LATE group. The approximate total hospital cost of the silo was $15.94, with an approximate patient cost of $57 (see the second image below). One of the least expensive and most rapid is the use of the gas-sterilized 3-L plastic cystoscopy irrigation bag. This Sure-Closure device facilitates the creation of a ventral hernia that may be repaired at a later date in an elective fashion.
The relative cost of these devices is small in comparison to the potentially decreased associated cost and morbidity of a second, planned abdominal wall reconstructive procedure, which is commonly required in this patient population.
Effects of increased intra-abdominal pressure upon intracranial and cerebral perfusion pressure before and after volume expansion.
The technique of visceral packing: recommended management of difficult fascial closure in trauma patients. Etappenlavage: advanced diffuse peritonitis managed by planned multiple laparotomies utilizing zippers, slide fastener, and Velcro analogue for temporary abdominal closure. Emergency abdominal wall reconstruction with polypropylene mesh: short-term benefits versus long-term complications. Comparative clinical study of the sure-closure device with conventional wound closure techniques.
Prospective evaluation of vacuum-assisted fascial closure after open abdomen: planned ventral hernia rate is substantially reduced. Vacuum pack technique of temporary abdominal closure: a 7-year experience with 112 patients. Systematic review and evidence based recommendations for the use of negative pressure wound therapy in the open abdomen. Both primary and secondary abdominal compartment syndrome can be predicted early and are harbingers of multiple organ failure. At Kiewit, we build quality projects safely, on time and on budget; no matter how large or small. Some species of felines are the definitive host for sexual reproduction of the parasite; however, asexual reproduction occurs in secondary hosts, such as rodents, livestock, birds, and humans, culminating in the formation of tissue cysts, which persist for the lifespan of the secondary host. Affected organs include the gray and white matter of the brain (as shown in the images below), retinas,[1] alveolar lining of the lungs (where the infection may mimic Pneumocystis carinii infection), heart, and skeletal muscle.
Concomitant cerebral atrophy is seen in approximately one third of patients; this is presumably the result of the direct cellular damage caused by the human immunodeficiency virus (HIV). The advent of MR spectroscopy has increased the ability to differentiate between various CNS lesions. The lesions are rarely hemorrhagic; thus, MRI findings depend on the hemorrhagic stage of evolution.
The patient presented with a solitary space-occupying lesion, which was confirmed to be secondary to toxoplasmosis. This appearance is typical of central nervous system toxoplasmosis, which has the propensity for involvement of the basal ganglia.
In addition, the differential diagnosis for each patient was derived from the patient's immune status and response to a trial of therapy, as well as the type of enhancement that was seen on MRI.
By extrapolation, fluid-attenuated inversion recovery (FLAIR) signal alterations that are easer to evaluate can be used in a similar fashion.
Overall, MRI confirmed or further documented the ultrasonographic findings for 20 cases; however, 4 of the 20 cases required fetal autopsy to determine the exact nature of the lesion. In addition, toxoplasmosis is more common subcortically than lymphoma and seldom affects the corpus callosum.
The degree of perilesional edema is correlated directly with the patient's ability to mount an inflammatory response. In 73 (38.8%), the initial CT scans or MRIs showed focal brain lesions, which were assessed prospectively.
On the other hand, 1 common finding on T2-weighted MRIs in 6 cases was punctate or patchy hyperintensity in the basal ganglia.
Although the basal ganglia were found to be the most common sites of involvement in opportunistic infections and primary lymphoma, reliable distinguishing features among lesions in the basal ganglia were not found, with the exception of a unique appearance for cryptococcal lesions. A recently described "concentric target sign" on T2-weighted images with concentric hyperintense and hypointense zones is believed to be more specific in the diagnosis of cerebral toxoplasmosis that has concentric alternating zones of hypointensity and hyperintensity, believed to be more specific than the well-known "eccentric target sign". Customize your Medscape account with the health plans you accept, so that the information you need is saved and ready every time you look up a drug on our site or in the Medscape app. If the force and deformation is excessive, the skull fractures at or near the site of impact. In addition, cerebral edema associated with skull fractures is a common and frequently fatal complication of head injury and may develop within minutes or hours of injury.
Other sites at risk for fracture are the cribriform plate, the roof of orbits in the anterior cranial fossa, and the areas between the mastoid and dural sinuses in the posterior cranial fossa. Most depressed fractures involve the frontoparietal region, because the bones in this area are relatively thin and because this part of the head is particularly prone to an assailant's attack. Compound fractures may be exposed when they are associated with a skin laceration or when the fracture extends into the paranasal sinuses and the middle-ear structures.
These fractures are often associated with dural tears, of which cerebrospinal fluid (CSF) rhinorrhea and otorrhea are known complications. Transverse fractures (5-30%) originate at the foramen magnum and extend through the cochlea and labyrinth, ending in the middle cranial fossa. This is a classic ping-pong ball fracture roughly akin to a greenstick fracture in a long bone. However, a cephalohematoma may develop after an instrumental delivery and represents a subperiosteal hematoma. Most growing skull fractures are located in the calvarium, but rare sites are the basiocciput and the orbital roof. Because the CSF is under pressure and pulsatile, a transmitted pulsation from the subarachnoid space into the extra-axial fluid collection causes pressure enlargement of the fracture. Radiography at admission showed a diastatic fracture with a gap of 8 mm in the right frontal bone and a linear fracture in the right occipital bone. At the primary point of impact, a bruise, abrasion, or laceration of the scalp is often present.
Differentiating between penetrating and perforating skull wounds is important because of their different prognostic implications. Skull penetration most commonly occurs in the thinnest parts of the skull, such as the orbital surfaces and the squamous portion of the temporal bone. Stab wounds occasionally produce a narrow, elongated defect (a slot fracture); this injury is diagnostic when identified. Tangential stab wounds result in complex single defects, with both internal and external beveling of the skull and varying degrees of neurologic injury. The classic syndrome is an infant with a mean age of about 6 months who has retinal hemorrhages, subdural hematomas, and absent or minimal signs of external trauma.
Injuries most often observed in inflicted head trauma are subgaleal hematomas, skull fractures, subarachnoid hemorrhages (SAHs), subdural hematomas, and parenchymal brain injuries. Some researchers believe that falls from a distance less than 3 feet rarely produce any kind of skull fracture and that skull fractures occur only with extremely violent forces. However, accidents usually resulted in single, narrow, linear fractures, most commonly in the parietal bone, with no associated intracranial injury.[12] The results suggest that in young children with skull fracture in whom a minor fall is alleged, it is possible to recognize abuse by considering the fracture alone. A blow to the temporal bone may result in a tear of the temporal artery without a fracture (15%). In rare cases, this type of hemorrhage is due to a direct blow to the side of the neck, which ruptures the vertebral artery as it enters the cranial cavity.
Traumatic intracerebral hemorrhage may also be the result of rupture of small blood vessels deep within the brain due to shearing stress. Therefore, obtaining a radiograph can only delay the diagnosis of an associated intracranial injury. In the assessment of complications, CT may be appropriate; however, MRI is useful in identifying vestibular hemorrhage and delayed complications of head injury. CT scanning does involve exposure to x-ray radiation, but the benefit of an accurate diagnosis far outweighs the risk. Some of these limitations can be overcome by placing the MRI unit close to emergency care areas, with appropriate design and equipment for the management of acutely injured patients.
This problem also applies to the lambdoid sutures; because they are separated, one could be mistaken for a fracture. Although fractures and sutures can be difficult to differentiate, the accessory suture can be identified as such because it connects 2 sutures, has an even caliber and radiopacity throughout, and has slightly serrated edges.
In addition, meningeal grooves taper as they run peripherally, and diploic venous markings are wide.
The other side shows a vascular marking of similar radiolucency, but it is of even caliber and its origin in the occipital region is from another vessel.
In addition, a fracture line crossing a vascular groove may be associated with an epidural hematoma; therefore, recognition of this possibility is important, as the hematoma may need surgical drainage. In rare cases, pseudoaneurysm formation and caroticocavernous fistulas occur as complications.
In addition, basilar skull fractures with CSF leak pose a risk of meningitis if the CSF leak is chronic and not repaired. Some skull fractures are associated with serious neurologic complications, and hence, the medicolegal implications of missing a primary fracture during the diagnostic workup can be serious as well. Therefore, obtaining a radiograph can only delay the diagnosis of associated intracranial injury. When no cross-sectional imaging is available, fractures of the skull base can be diagnosed on clinical grounds aided by associated radiologic signs of pneumocephaly; on conventional radiographs, an air-fluid level may be seen in the frontal or sphenoid sinuses.
When ossification of the skull vault is impaired or premature, the frontal, temporal, and parietal bones form reasonably well but do not meet in the midline. It has high signal intensity partly because of its high cellular content and also because of the absence of normal neural structures. Flat tumors, termed en plaque, infiltrate the dura and grow as a thin carpet or sheet of tumor along the convexity dura, falx, or tentorium. Treatment of meningiomas is benefited by embolization, but especially those with a complex presentation, giant meningiomas, meningiomas exhibiting malignant or angioblastic characteristics, or meningiomas involving the skull base, scalp, or critical vascular structures. Bilateral dural devascularization shortens the surgical resection time and permits total removal of the tumor.
Several meningiomas of the convexity have been embolized with Embospheres in our experience. Features on this image include a sharply defined tumor margin, subtle edema, and mass effect on the fourth ventricle and the brainstem. Although a meningioma could be suspected, this finding is not specific and this intracranial mass was correctly further investigated with CT.
C: Nonenhanced axial CT image shows homogeneous calcified mass attached to the right parietal bone. Pooling of cerebrospinal fluid, subtle edema, homogeneous enhancement, and ventricular dilatation are demonstrated. T2-weighted signal intensity is best correlated with both the histology and the consistency of the meningioma. B: Contrast-enhanced sagittal T1-weighted MRI demonstrates partially intense enhancement of the tumor. B: Gadolinium enhancement on sagittal T1-weighted MRI shows intense enhancing of the masses. Coronal, enhanced-T1 weighted and fluid attenuation inversion recovery (FLAIR) sequences are shown. C: 3-D image on enhanced T1-weighted MRI demonstrates frontal meningioma underlying the orbital right sulcus.
Additional features include significant mass effect with effacement of the left lateral ventricle. However, MRI is unreliable for recognition of tumor calcification, and acute hemorrhage is often difficult to image with this modality.
Other supratentorial meningiomas are supplied by the internal and external carotid arteries. Pulmonary stenosis Pulmonary stenosis : This defect is a narrowing of the pulmonary valve and the passage through which blood flows from the right ventricle to the pulmonary artery. The literature reflects the cumulative experience of trauma surgeons, which confirms that conservative operative techniques and short operating times, even when all organ repairs have not been completed, increase survival in civilian and military patients with multiple trauma. The reported incidence of ACS is 10-15%, and if it is left untreated, it is uniformly fatal. This process is clinically manifested by organ swelling, leading to secondary pressure effects on the respiratory, cardiovascular, and central nervous systems when the IAP rises above a critical level.
During resuscitation and vascular volume expansion, intracerebral pressure and cerebral perfusion pressure (CPP) may increase transiently; however, these pressures will ultimately fall if abdominal pressure continues to increase. The retinal hemorrhage usually resolves within days to months, and no specific treatment is necessary.
No prospective randomized studies are available to compare the effectiveness of these various techniques or to validate the concept of the open-abdomen protocol. Intra-abdominal pressures as high as 50 mm Hg have been obtained with this type of closure technique. This type of prosthetic mesh implant has been used in the repair of traumatic liver, splenic, and renal injuries and in pelvic floor repair in the setting of abdominal peroneal resection of the rectum. Sterile antibiotic-soaked towels (using Kantrex) may be applied over the silo, which is then covered with an iodine-impregnated adhesive plastic drape.
Gauges on the device monitor the applied forces, ensuring a safe and permanent skin stretching.
The Sure-Closure system has a built-in safety clutch mechanism that prevents excessive tension by limiting the total force to 3 kg. The polyurethane sponge, when placed under negative pressure (suction), provides the countertraction required to inhibit abdominal wall retraction and creates an environment where approximation of the abdominal wall may occur. The incidence of abscess, wound dehiscence, and fistula in the LATE group and the HERNIA group were nearly identical. These two devices represent major advances in surgical theory and are welcome additions to the extant surgical doctrine.
AIDS-associated Toxoplasma encephalitis results from reactivation of chronic latent infection in more than 95% of patients.
However, because toxoplasmosis is a treatable condition, therapy is started immediately, and the scan is repeated in 1-2 weeks.
When the dose of contrast agent is doubled and CT scanning is delayed, the detection rate significantly improves. On T1-weighted precontrast MRIs, the lesions are hypointense relative to brain tissue (as demonstrated in the image below). This appearance is typical of central nervous system toxoplasmosis, which has the propensity to involve the basal ganglia. The differential diagnosis included tumors (eg, lymphoma, ependymoma, germ cell tumor, or metastases), viral ependymitis (eg, cytomegalovirus, varicella-zoster virus), toxoplasmosis, and bacterial or tuberculous ventriculitis.
The greater the edema, the greater the inflammatory response, and the better the prognosis.
Miguel et al also noted that the presence of isoattenuating or hyperattenuating lesions on nonenhanced CT scans or irregularly shaped lesions was uncommon in CNS toxoplasmosis and that the appearance of a solitary lesion per se on CT scanning or MRI was not a good criterion for the differential diagnosis of CNS toxoplasmosis. The authors concluded that in the epidemiologic context of the study, specific imaging findings in HIV-1-seropositive patients are highly predictive for cerebral toxoplasmosis. The corresponding histologic changes included calcification of vessels with widened perivascular spaces and mineralized neurons. In the fifth case, pathologic correlation verified the MRI findings that had suggested calcification. The sign has been found more useful in differentiation of cerebral toxoplasmosis from other brain lesions in the context of AIDS. Easily compare tier status for drugs in the same class when considering an alternative drug for your patient.
A shallow subdural space lies between the inner surface of the dura and the thin arachnoid mater that covers the surface of the brain. Uncomplicated skull fractures themselves rarely produce neurologic deficit, but the associated intracranial injury may have serious neurologic sequelae. Cerebral edema may accompany diffuse axonal injury or a space-occupying lesion, such as an intracranial hematoma. Generally, these fractures are of little clinical significance unless they involve a vascular channel, a venous sinus groove, or a suture.
As the name suggests, mixed fractures have components of both longitudinal and transverse fractures. A type II fracture is caused by a direct blow, and although it is an extensive fracture of the basioccipital region, it is regarded as a stable injury because of the preserved alar ligament and tectorial membrane.
The ping-pong skull fracture was first described in a newborn whose head was impinging against the mother's sacral promontory during uterine contractions. This fracture only occurs in children because the skull vault is more elastic and less rigid than it is in adults. Since then, cases of GSF (demonstrated in the images below) continue to appear in the literature, with various names such as a leptomeningeal cyst, traumatic meningocele, cerebrocranial erosion, cephalhydrocele, meningocele, and spuria. Type I is a GSF with a leptomeningeal cyst, which may be seen herniating through the skull defect into the subgaleal space. The diastatic fracture had increased to 25 mm on radiography performed 37 days after injury. When injured, the scalp often becomes markedly edematous, and hematoma formation is common above or below the galeal layer. A poor postsurgical outcome occurs in 50% of patients treated for perforating wounds, as compared with 20% of those with penetrating wounds. However, in some cases in which skull penetration is proven, no radiologic abnormality is identified. Because the parents seldom volunteer a history of nonaccidental injury or shaken baby syndrome, this condition is difficult to document and diagnose. An arterial bleed from a middle meningeal artery accumulates, forming a hematoma between the inner skull table and stripped dura; this is called an extradural hemorrhage, which acts as a space-occupying lesion. Movement of the brain relative to the dura, often associated with widened CSF spaces, causes shears and tears of the small veins that bridge the gap between the dura and the cortical surface of the brain. This phenomenon is called traumatic basal subarachnoid hemorrhage and is most often due to a blow to the side of the chin or jaw in an alcohol-induced fistfight. The effective radiation dose from this procedure is about 2 millisievert (mSv), which is about the same as that which the average person receives from background radiation in 8 months.
The development of wide-bore magnets, fast imaging protocols, and MRI-compatible resuscitation equipment promises a greater role for MRI in the evaluation of closed head injuries. In general, when a fracture connects 2 sutures, the fracture line is wide open or open mouthed at the sutural connection and is narrowest away from the suture. Similarly, a fracture line that crosses over a suture may cause sutural diastasis and a growing fracture.
Many early studies recommended abandoning skull radiographs.[16, 17] In 1981, the Royal College of Radiologists concluded that if CT scans are used judiciously, obtaining plain radiographs of the head has a low diagnostic yield and does not give any additional information that leads to changes in management.
In the developing world, with limited access to CT scanners, plain radiography of the skull is regarded as useful in screening head injuries.
As a result, the outer table of the skull is often not visible on a lateral skull radiograph. In addition, skull sutures can be readily distinguished from fractures by their symmetry and corticated margins. The procedure causes tumor necrosis, expanding the spectrum of meningiomas that can be safely resectioned during surgery.
Hyperintensity on the T2-weighted image indicates a soft tumor consistency and microhypervascularity, which is seen more often in aggressive, angioblastic, or meningothelial meningioma.
Occasionally, the edema is extensive and, as it predominantly affects white matter, can resemble fingers of low attenuation. Cystic components of meningiomas may be present inside the tumor or between the tumor and the adjacent brain (so-called trapped CSF). CT scan features, such as irregular areas of nonenhancing mass and well-defined regions of persistent low attenuation, are common reasons for preoperative misdiagnosis. Although this finding is not specific for meningiomas, it is highly suggestive of the diagnosis.
Gadolinium also enables better visualization of en plaque meningiomas that may be more subtle on unenhanced sequences.
C: T2-weighted coronal MRI shows stable hypointense appearance of the posterior mass after endovascular embolization.
D: Gadolinium-enhanced, axial T1-weighted image shows 1 of the 3 focal hyperintense masses discovered only on this sequence.
Direct meningeal arteries from the cavernous sinus can supply meningiomas of the middle cranial fossa. In pulmonary stenosis, the heart has to work harder than normal to pump blood, and not enough blood reaches the lungs.
These principles hold true for all affected regions of the body, including the abdominal cavity and its contents, which constitute the focus of this article. Because of a concomitant decrease in caval venous return, this will ultimately cause a fall in cardiac output that will negatively impact intracerebral perfusion pressure. Decompressive celiotomy in patients such as these has resulted in a dramatic reduction in ICP.
If a patient with ACS develops visual changes, Valsalva retinopathy should be considered and an appropriate ophthalmic examination performed.
However, retrospective data in the form of case and cohort studies do exist, and these data consistently show that maintaining the open-abdomen protocol in high-risk groups has been effective in reducing mortality in a clinical setting. The incision may then be covered with an adherent plastic drape (eg, Vi-Drape, Steri-Drape). Widely spaced retention-type sutures are placed, encompassing all layers of the abdominal wall, and are tied above the gauze packing. Although early burst strength (at 8 weeks) is comparable to that of permanent mesh, as the mesh is absorbed (at 10-12 weeks), hernias inevitably develop in most patients.
This technique is a variation of the silon (silo) closure used for the repair of gastroschisis and omphalocele.
The device allows the surgeon to take advantage of the inherent viscoelastic properties of the skin by mechanically stretching the skin and allowing it to relax under tension; the surgeon then has sufficient skin to affect a suitable closure. Patients treated with planned hernia (HERNIA group, Fabian protocol) were compared with those undergoing fascial closure 9 or more days after the initial laparotomy (LATE group).
In both groups, the differences were not significant with respect to time in the ICU, total hospital stay, incidence of acute respiratory distress syndrome, multiple organ failure, and death. They also reported one IP silo failure in a patient who developed a small bowel dehiscence; this patient underwent IP silo replacement in the ICU. In the author's opinion, it is the preferred initial method of temporary closure, particularly in patients who may require multiple reoperative interventions. Cardiac involvement, which is rare, may be demonstrated on chest radiographs as cardiomegaly in association with features of pulmonary venous hypertension. However, findings may differ in other parts of the world where cerebral toxoplasmosis may be less prevalent among HIV-1-infected individuals.
The concentric target sign, seen in deep parenchymal lesions, is distinct from the surface-based cortical "eccentric" target sign. A fracture indicates that substantial force has been applied to the head and is likely to have damaged the cranial contents. The diploA« does not form where the skull is covered with muscles, leaving the vault thin and prone to fracture. Thus, complications include epidural hematoma, venous sinus thrombosis, and suture diastasis. A type III fracture is potentially unstable and regarded as an avulsion injury due to forced rotation and lateral bending.
In some cases, associated extradural hematoma,[7] subdural hematoma, or axonal injury is observed. Unlike missile injuries, stab wounds have no concentric zone of coagulative necrosis caused by dissipated energy, and unlike motor vehicle accidents, stab wounds cause no diffuse, shearing brain injury. A stab wound to the temporal fossa is most likely to cause major neurologic injury because of the thinness of the squamous temporal bone and because of the short distance to the brainstem and blood vessels.
Blood from torn vessels accumulates over several hours and usually tracks extensively as a thin film over the surface of the brain.
The degree of traumatic force required to cause a basal subarachnoid is less than reasonably expected.
The detection of skull fractures allows for admission of the patient to the hospital for observation.
Moreover, the sutures appear to be widened, but only because the bone margins have not come together and because of increased intracranial pressure. Because the pia and arachnoid form a membranous barrier between brain and tumor, some meningiomas grow into the subarachnoid space, but invasion of the brain is infrequent. Edema, however, is absent in approximately 50% of cases because of the neoplasm's slow growth. Other minor calcifications on the left cerebral hemisphere are caused by a parasitic disease. Right ventricular hypertrophy Right ventricular hypertrophy : This defect occurs if the right ventricle thickens because the heart has to pump harder than it should to move blood through the narrowed pulmonary valve. Abdominal decompression in these patients has resulted in a return toward baseline for ICP and an improvement in CPP. Covering the incision decreases manipulation of the towel clips while the patient is being transferred. As bowel edema diminishes, the gauze dressing is removed, and the retention sutures are gradually tightened until the incision can be closed.
In hospitals in Colombia, South America, IV bag closure (also known as the BogotA? Bag) has been used extensively and successfully.
The wound was closed by delayed primary closure 12 days after the initial decompression laparotomy.
The histopathological correlate of the latter has been recently described, but that of the concentric target sign is not known. A combination of MRI and CT images enabled the edge of the dural tear to be plotted on a 3-dimensional image of the skull, which was used to estimate the location of the edge of the dural tear on the scalp. Therefore, a backward fall causes contrecoup contusions at the frontal and temporal poles of the brain, whereas a fall on the side of the head causes contrecoup contusions at the opposite temporal lobe.
A small, self-limiting subdural hemorrhage may remain asymptomatic and be an incidental finding. Additionally, this sequence is used to assess for a CSF cleft between the neoplasm and brain parenchyma, confirming an extra-axial location.
D: Contrast-enhanced T1-weighted axial MRI shows hyperintense image located within the bony marrow. Overriding aorta An overriding aorta: the aorta is between the left and right ventricles, directly over the VSD. This technique may be used in the rapid temporary closure of thoracic or groin incisions in patients with trauma injuries who are in unstable condition and in patients undergoing general surgery. Generally, a forward fall does not cause contrecoup contusions on the back of the brain because the interior surface of the skull is smooth at this point.



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