Vertebral artery dissection in Turner's syndrome: diagnosis by magnetic resonance imaging.

Aortic artery dissection is a rare but well-recognized complication of Turner's syndrome. Isolated carotid or vertebral artery dissection has not previously been reported. The authors report the clinical and magnetic resonance imaging findings in a 30-year-old woman with Turner's syndrome who developed a high cervical spinal cord infarction with a Brown-Sequard syndrome owing to bilateral vertebral artery dissection. The diagnosis and management of the case is reviewed.

Venous architecture of cerebral hemispheric white matter and comments on pathogenesis of medullary venous and other cerebral vascular malformations.

The parenchymal veins, especially the deep medullary veins, of the cerebral hemispheres were studied in detail by analyzing the stereoroentgenograms of multiple brain slices of postmortem injected brain specimens (injected into the internal carotid arteries in 17 cases and into the jugular veins in 12 cases). The presence of four zones--the first (or outer), the second (or candelabra), the third (or palmate) and the fourth (or subependymal) zone--of venous convergence was confirmed within the centrum semiovale, particularly in the frontoparietal area. Other venous convergences such as those related to the optic radiation in the para-atrial area were also found. Arterial branching zones were also observed in the areas similar to those of the medullary veins. It appears that these converging zones are created by rapidly growing crossing nerve fiber tracts, i.e., projection, commissural, and association fibers which grow rapidly during intrauterine and postnatal life. Pathogenesis of medullary venous malformation is also discussed from anatomical viewpoint, venoarchitecture of the pial, parenchymal, and subependymal veins and of the dural venous sinuses. The possibility of a similar mechanism (partial, mild, repetitive venoocclusive disease developing over a long period with fluctuating venous pressure) leading to formation of most (if not all) cases of medullary venous malformation and in some, if not many, cases of cerebral vascular malformations [aside from gene abnormality (chromosome 7) in familial cavernous angiomatosis, particularly in Hispanic American or other familial hereditary conditions] has been postulated.

Cervical epidural hematoma after chiropractic manipulation in a healthy young woman: case report.

OBJECTIVE AND IMPORTANCE: Posttraumatic spinal epidural hematoma is an uncommon entity. We present the first report of spinal epidural hematoma occurring after chiropractic manipulation in a healthy young adult without preexisting cervical disease or any obvious predisposing factors. CLINICAL PRESENTATION: The patient presented with radicular and myelopathic symptoms that developed 15 minutes after chiropractic manipulation. Computed tomography and magnetic resonance imaging were performed. They revealed a cervical epidural hematoma. INTERVENTION: The hematoma was evacuated, and all of the patient's neurological symptoms improved over the course of the next 3 days. CONCLUSION: Although cervical spinal epidural hematoma is a rare clinical entity, it must be considered in patients with pain or neurological deficit after cervical trauma.

Reversible cerebral perfusion abnormalities associated with cyclosporine therapy in orthotopic liver transplantation.

A 60-yr-old woman experienced several episodes of generalized seizures following 2 wk of immunosuppressive therapy with cyclosporine for orthotopic liver transplantation. CT showed low density in the white matter of the parieto-occipital lobes. A 99mTc-HMPAO brain SPECT showed diminished perfusion in the parieto-occipital cortex bilaterally. Although the cyclosporine was discontinued, the patient's neurologic status initially worsened and then improved over the next several days. Repeat perfusion brain SPECT showed resolution of most of the perfusion abnormalities, while repeat CT showed persistent white matter changes in the parieto-occipital lobes. We report the presence of reversible cortical perfusion abnormalities in conjunction with cyclosporine therapy. The findings suggest that perfusion brain SPECT may be a sensitive monitor of cyclosporine-induced neurotoxicity.

Pantopaque simulating thrombosed intracranial aneurysms on MRI.

A patient is presented in whom iophendylate (Pantopaque) within the basal cisterns closely resembled the appearance on MRI of thrombosed aneurysms of the middle cerebral arteries. The sometimes subtle differences between the appearances on MRI of Pantopaque and aneurysmal clot are discussed to permit accurate diagnosis without resorting to more invasive diagnostic tests, such as cerebral angiography.

Symptomatic spinal epidural lipomatosis in a patient with Cushing's disease.

Spinal epidural lipomatosis (SEL) is a rare complication of iatrogenic Cushing's syndrome (CS). There is only one case reported of symptomatic SEL in association with endogenous CS. We present a patient with compressive myeloradiculopathy due to SEL and Cushing's disease and suggest that in SEL of hypercortisolism, the excess of corticosteroids is the stimulus for the growth of adipose tissue in the spinal canal and that treatment should be aimed at correcting the endocrine abnormality.

Progressive multifocal leukoencephalopathy after orthotopic liver transplantation.

Six weeks after liver transplantation, a 51-year-old man developed a slowly progressive hemiparesis with deteriorating mental status and seizures. Successive computed tomography (CT) scans of the brain revealed unilateral nonenhancing white matter lucencies that gradually coalesced and progressed to both hemispheres. Brain biopsy results were consistent with progressive multifocal leukoencephalopathy (PML). We believe this is the first antemortem description of PML after liver transplantation. Herein, we describe the case and review the literature on PML after solid organ transplantation. Early recognition of this central nervous system disease may be important with new advances in therapy of this viral infection of the immunocompromised patient.

Giant intracranial aneurysms with skull base erosion and extracranial masses: CT and MR findings.

OBJECTIVE: To present the CT and MR findings of three patients with giant intracranial aneurysms (GIAs), each of which eroded the skull base and had an extracranial mass component. A literature review of GIAs was also performed. MATERIALS AND METHODS: In the past year the imaging studies of three patients with these unusual GIAs were collected at our institutions. All three patients had had CT, and one patient had had MR on a 1.5 T GE unit. RESULTS: One patient had a 5 cm GIA in the left petrocavernous region, filling the middle cranial fossa and extending into the left sphenoid sinus and the left posterior ethmoid complex. The aneurysm had heterogeneous high attenuation and extensive rim calcification. The second patient had a 5 cm GIA that filled most of the left middle cranial fossa, eroding the floor and lateral wall and extending into the infratemporal fossa and parapharyngeal space. The aneurysm was partially thrombosed and had minimal rim calcification. The third patient had a 4 cm left cavernous GIA that eroded the floor of the middle cranial fossa and extended into the subjacent parapharyngeal space. The lesion was partially thrombosed and had an enhancing lumen. The rim had low signal intensity on MR. None of these patients had a history of trauma. CONCLUSION: Giant intracranial aneurysms can cause significant skull base erosion and extend into the paranasal sinuses, parapharyngeal space, and infratemporal fossa. The CT and MR findings can lead to an accurate diagnosis.

Sinonasal esthesioneuroblastoma with intracranial extension: marginal tumor cysts as a diagnostic MR finding.

PURPOSE: To determine whether the MR finding of cysts along the intracranial margin of sinonasal esthesioneuroblastomas can be considered to suggest this tumor. METHODS: MR scans of 54 patients who had sinonasal lesions with intracranial extension were examined specifically for cysts along the intracranial margins of the lesions. RESULTS: Only 3 of the 54 patients had these cysts, and all 3 of these patients had esthesioneuroblastoma. Surgical pathologic findings of one specimen showed the cyst to be marginally located within the tumor. CONCLUSION: If cysts are seen on MR along the intracranial margin of a sinonasal mass, this finding highly suggests esthesioneuroblastoma.

MRI of lumbar intradural disc herniation.

We present the magnetic resonance imaging (MRI) appearance of a patient with an intradural lumbar disc herniation and discuss this entity. This case demonstrates the role of MRI in comparison to myelography/postmyelogram computed tomography with respect to the diagnosis of intradural disc herniation.

The varied presentations of papillary thyroid carcinoma cervical nodal disease: CT and MR findings.

PURPOSE: To review the varied presentations of metastatic cervical lymph node disease in patients with papillary thyroid carcinoma. METHODS: Thirteen cases were retrospectively collected and their clinical, imaging, surgical, and pathologic material was reviewed. In the cases reviewed there was no clinical or imaging evidence of a primary thyroid mass. RESULTS: On CT, metastatic nodes can have multiple discrete calcifications, appear as benign cysts or hyperplastic or hypervascular nodes, or have areas of high attenuation which reflect intranodal hemorrhage and/or high concentrations of thyroglobulin. On MR, the nodes can have low to intermediate T1- and high T2-weighted signal intensities or high T1- and T2-weighted signal intensities, the latter reflecting primarily a high thyroglobulin content. CONCLUSION: If any of these varied appearances of cervical lymph nodes are identified on CT or MR, especially in a woman between 20 and 40 years of age, the radiologist should suspect the diagnosis of papillary thyroid carcinoma, even in the absence of a thyroid mass.

The significance of sinonasal radiodensities: ossification, calcification, or residual bone?

PURPOSE: To determine whether very radiodense material within a sinonasal soft-tissue mass on CT can be differentiated as calcification, ossification, or residual bone. METHODS: We retrospectively described the radiodensities within 235 sinonasal soft-tissue masses as discrete, solitary or multiple, or as a diffuse process with either a well-defined or poorly defined margin. They were also classified as calcification, ossification, or residual bone. Findings were correlated with pathologic specimens. RESULTS: Residual bone was underdiagnosed; calcification was overdiagnosed. A solitary discrete density was most likely to be calcification within an inflammatory mass. However, multiple discrete densities were as likely to be in a tumor as in an inflammatory lesion. If the process was diffuse with a well-defined margin, it was most likely to be a benign fibroosseous lesion. If the process was diffuse with a poorly defined margin, it was most likely to be a high-grade sarcoma. Densities within inverted papillomas were shown to be residual bone, not calcifications; densities within esthesioneuroblastomas were calcifications. CONCLUSION: Radiodensities may help in refining a CT diagnosis, but one may not know based on CT whether the density is a calcification, ossification, or residual bone.

MR appearance of intraocular silicone oil.

A 41-year-old man with AIDS and cytomegalovirus retinitis with retinal detachment was studied with CT and MR. Part of his treatment had been a vitrectomy with intravitreal injection of silicone oil as an attempt to stop further retinal detachment. This form of therapy is being used more frequently and radiologists should be familiar with the imaging appearance of such deposits of silicone oil. In this case the oil was hyperdense to muscle on CT and had a homogeneous intermediate signal intensity on all pulse sequences on MRI.

Imaging the postoperative neck.

The variety of cervical lymphadenectomy and neck reconstructive procedures that have been developed in the past 20 years has led to confusion about nomenclature in the literature. In addition, some of these operations result in gross alteration of the normal anatomy. The authors review the present classification system for cervical lymph nodes and various lymphadenectomy and reconstructive procedures. Examples of typical postoperative images are given. A protocol for postoperative follow-up is presented, which calls for imaging for 5 years after surgery. Finally, the authors review their experience with 400 cases, 276 of which were initially classified as having no clinical evidence of disease. Recurrence developed in 68 of these (in 62 [91%] within 4-18 months of surgery). Imaging findings altered the postoperative salvage plan in 17 (25%). Clinically occult disease was found at sectional imaging in 47 (17%).

Neurosarcoidosis presenting as a tumour of the basal ganglia and brainstem: sequential MRI.

Neurosarcoidosis may spread from the basal leptomeninges via the Virchow-Robin spaces to form intraparenchymal masses. We present a case of sarcoidosis whose first presentation was that of secondary amenorrhoea without other neurological symptoms. Discovery of a mass invading the basal ganglia, hypothalamus, pituitary stalk and midbrain led to a search for systemic involvement. After the diagnosis was proven by mediastinal biopsy, steroids were used effectively to shrink the tumour. Sequential magnetic resonance imaging (MRI) studies demonstrate dramatic reduction in the mass over a six month period. A high index of suspicion for sarcoidosis in intracranial masses, particularly in young adults, is advocated.

The benign fibroosseous lesion: its association with paranasal sinus mucoceles and its MR appearance.

Although fibrous dysplasia and ossifying fibroma of the facial bones may, with some difficulty, be distinguishable pathologically, they are inseparable radiographically. Based on a study of 30 patients, there was no good or reliable imaging correlation with the histology and the degree of ossification or the bone(s) involved. Therefore, "benign fibroosseous lesion" has been proposed by several noted bone authorities as the term for these entities. Eleven patients had MRI and the overall signal intensities were low on both T1-weighted and T2-weighted sequences. Areas of high signal intensity on T2-weighted imaging correlated with either cysts within the lesion or the presence of mucocele, especially in the frontoethmoid region. Four such mucoceles are presented. The coexistence of mucoceles and benign fibroosseous lesions may be more common than previously reported. It is both realistic and appropriate for the radiologist to diagnose these entities as benign fibroosseous lesions and leave the final histologic diagnosis to the pathologist who can diagnose most such cases, albeit with some difficulty. Sites of high signal intensity on T2-weighted imaging in the frontoethmoid area should raise the possibility of a coexistent mucocele.

Eccentric cystic facial schwannoma: CT and MR features.

Facial schwannomas are uncommon lesions with a fairly characteristic range of clinical and radiographic presentations. This report describes an unusual case of facial schwannoma that clinically and radiographically mimicked a cystic skull base lesion extrinsically compressing the facial nerve. The MR findings are presented.

Simulated aggressive skull base erosion in response to benign sinonasal disease.

Benign sinonasal masses and slow-growing neoplasms tend to remodel the nasal vault and facial bones, and this is particularly true of nasal polyps and inverted papillomas. However, when such benign masses press against the floor of the anterior cranial fossa and the walls of the sphenoid sinuses, simulated aggressive bone destruction rather than bone remodeling usually occurs. This type of bone destruction implies to the radiologist that a carcinoma may also be present, and this information could dissuade a surgeon from operating with an attempt at cure. In fact, about 90% of the time with inverted papillomas and in virtually all cases of nasal polyposis, no carcinoma is present. The computed tomographic (CT) scans and magnetic resonance images of 14 patients are used to demonstrate these changes. In addition, the CT scans of three patients with malignancies are shown to illustrate the similarity in the bony skull base changes.

Evidence for arterial embolization in dissecting aneurysm of the cervical vertebral artery.

Ultrasonographic imaging of the right cervical vertebral artery in a 57-year-old man with recurrent episodes of ischemia in the vertebrobasilar territory revealed a dissecting aneurysm with communication of the true and false lumen. This finding demonstrates that arterial dissection can form a nidus for distal embolization and supports the use of anticoagulation in this disorder.