Calvarial hemangiomas: report of two cases and review of the literature.

BACKGROUND: Primary hemangiomas of the bone are uncommon tumors, accounting for less than 1.0% of all bone neoplasms. These tumors are mostly found in vertebral bodies. Hemangiomas are rarely seen in the calvarium, where their frequency is 0.2% of all bone neoplasms. Because of their infrequent appearance in the skull, vague symptoms, and absence of prototypical radiological findings, these tumors can be missed in many cases or may be misinterpreted as more ominous lesions like multiple myeloma or osteosarcoma. CASE DESCRIPTION: We report two cases of calvarial hemangiomas: one with a single mass on the right sphenoid wing, and another with two similar lesions on the right occipital and left parietal bones. The diagnoses could be established only by histopathologic analysis. CONCLUSION: Histopathologic confirmation of the tumor is the definitive method for diagnosis of intraosseous hemangiomas. Radiological findings are not always characteristic for calvarial hemangiomas. Due to possible complications and the possibility of effective treatment, this lesion should always be considered in the differential diagnosis of skull lesions.

Needle diameter in outpatient myelography: rates of adverse effects and current practice trends.

Telephone calls were made to 1251 consecutive patients one day following outpatient myelography. Data were available on 518 patients punctured with 22-gauge (g) (large-diameter) and 465 with 25-g (small-diameter) spinal needles. We surveyed 48 academic and private practice groups regarding needle diameter use in myelography; data were obtained from 34 private practice and 14 academic radiology departments. Patients reported adverse effects including mild and severe headache, back pain and nausea. The percentage of total adverse effects was significantly greater in the 22-g than in the 25-g needle group. The percentage of patients with headache was higher in the 22-g than in the 25-g group, but this difference was not statistically significant. Only 19% of private practice groups and 17% of academic centers use 25-g needles; the remainder use 20-g or 22-g needles.

Cerebral atrophy in Cushing's disease.

BACKGROUND: Cushing's disease causes significant pathological changes throughout the body as a result of elevated cortisol levels. Very few systematic investigations have focused on the morphologic effects of hypercortisolism on the central nervous system. The validity of using premature cerebral atrophy as a diagnostic tool for Cushing's disease remains unknown. METHODS: This study includes 63 patients with Cushing's disease who were evaluated and treated at the University of Virginia Medical Center. Radiologists randomly compared these individuals with age- and sex-matched controls in a blinded protocol, assessing the degree of cerebral atrophy on computed tomography and magnetic resonance scans. RESULTS: Patients with Cushing's disease showed significant premature atrophy when compared with controls. This trend continued after subdividing the groups based on age and duration of symptoms except in the following groups: age greater than 60, duration of symptoms less than 1 year, and symptoms lasting between 4-5 years. CONCLUSIONS: Excluding the three aforementioned groups, the hypercortisolemic state manifested in patients with Cushing's disease promotes the premature development of cerebral atrophy, which can be identified on routine radiologic imaging and may assist in the clinical diagnosis of the condition.

Sinus histiocytosis (Rosai-Dorfman disease) of the suprasellar region: MR imaging findings--a case report.

Sinus histiocytosis with massive lymphadenopathy (SHML) is an uncommon disorder that typically manifests as systemic symptoms and lymphadenopathy. Extranodal, intracranial disease is uncommon. The authors report on a 15-year-old adolescent girl who had a suprasellar mass at magnetic resonance imaging. Biopsy results demonstrated lymphophagocytosis consistent with a diagnosis of SHML. The clinical, radiologic, and histologic aspects of the disease are discussed.

Brown-Séquard syndrome of the cervical spinal cord after chiropractic manipulation.

We report a case of increased signal in the left hemicord at the C4 level on T2-weighted MR images after chiropractic manipulation, consistent with contusion. The patient displayed clinical features of Brown-Séquard syndrome, which stabilized with immobilization and steroids. Follow-up imaging showed decreased cord swelling with persistent increased signal. After physical therapy, the patient regained strength on the left side, with residual decreased sensation to pain involving the right arm.

Sinonasal undifferentiated carcinoma: CT and MR imaging of an uncommon neoplasm of the nasal cavity.

PURPOSE: To determine the computed tomographic (CT) and magnetic resonance (MR) imaging appearance of sinonasal undifferentiated carcinoma. MATERIALS AND METHODS: Findings from 11 patients with histopathologically proved sinonasal undifferentiated carcinoma were retrospectively reviewed. All 11 patients had undergone CT, and six of them had undergone MR imaging. RESULTS: The tumors usually were large (larger than 4 cm in maximum dimension in eight patients), had poorly defined margins, and arose within the ethmoid sinuses and superior nasal cavity. The aggressive nature of the tumor was demonstrated by bone destruction (n = 10) and by invasion of adjacent structures, including paranasal sinuses (n = 10), anterior fossa (n = 7), orbits (n = 4), pterygopalatine fossa (n = 2), parapharyngeal space (n = 1), and cavernous sinus (n = 1). On contrast material-enhanced CT scans, all tumors were enhanced to varying degrees. They tended to be noncalcified (n = 10) and often caused sinus obstruction (n = 10). MR signal intensity of the lesions was isointense to muscle on T1-weighted images in all six patients and iso- to hyperintense on T2-weighted images in five patients. Heterogeneous enhancement of tumors was seen on gadolinium-enhanced images. CONCLUSION: Sinonasal undifferentiated carcinoma cannot be distinguished from other tumors of this region (with the possible exception of melanoma) on the basis of imaging features.

Ownership and utilization of MR imagers in the Commonwealth of Virginia.

PURPOSE: To assess distribution, operation, and ownership of magnetic resonance (MR) imagers in Virginia in 1991. MATERIALS AND METHODS: Questionnaires regarding ownership, location, hours of operation, annual throughput, sources and amounts of revenue, and expenses were mailed to identified providers. Data, specifically regarding ownership and location, were analyzed. RESULTS: Staff from 95% of MR facilities responded. Most facilities were located in and around major metropolitan areas. Population density per imager ranged from one per 76,000 to one per 222,000 persons. Imagers in larger metropolitan areas were operated for longer hours with higher revenues and greater expenses than were those in lower-population-density areas. Imagers owned by physicians in a position to self-refer had the highest patient throughput, the most revenue, and a much lower percentage of revenues from Medicare and Medicaid than did other ownership types. CONCLUSION: Patient access to MR services in Virginia is inhomogeneous. Important aspects of utilization are location and ownership. Ownership by physicians who can self-refer is associated with higher use, greater overall revenues, and less service to the poor and elderly.

Pleomorphic xanthoastrocytoma, a distinctive astroglial tumor: neuroradiologic and pathologic features.

PURPOSE: To analyze and discuss CT and MR features of pleomorphic xanthoastrocytoma (PXA) and present salient histopathologic features of this distinctive astroglial tumor. METHOD: CT, MR, and histopathologic studies on seven patients with the histologic diagnosis of PXA were reviewed retrospectively. RESULTS: All patients were in their first 3 decades of life when first diagnosed and demonstrated peripherally situated supratentorial tumors of varying size involving the superficial cortex and leptomeninges. Five of six cases examined with CT showed areas of mixed attenuation with four demonstrating well-demarcated enhancement. MR demonstrated low or mixed signal intensity on T1-weighted and high or mixed signal intensity on T2-weighted sequences. All five who received gadopentetate dimeglumine showed well-defined enhancement. Three showed cyst formation. Typical histologic features included marked cellular pleomorphism with giant cells, bizarre nuclei, variable cytoplasmic lipidization and positive immunoreactivity for glial fibrillary acidic protein. Necrosis and endothelial-pericytic cell proliferation were absent. CONCLUSION: PXA has a highly suggestive neuroradiologic and distinctive histopathologic appearance.

Limbic encephalitis occurring in association with Alzheimer's disease.

Paraneoplastic limbic encephalitis is a rare cause of subacute dementia. A patient with limbic encephalitis and small-cell lung carcinoma is reported in whom the onset of subacute cognitive impairment was obscured by concurrent Alzheimer's disease. MRI revealed increased T2 signal in medial temporal lobes which corresponded to inflammatory pathology demonstrated at necropsy. High titres of antineuronal antibody (type II, anti-Hu) were present at death. Direct immunofluorescent staining of necropsy tissue revealed IgG bound to most remaining neurons in the temporal lobe. Antineuronal antibody screening and MRI are important in detecting limbic encephalitis.

Chordoma of the petrous bone.

We have presented two cases of chordoma arising from an unusual location within the skull. Chordomas in the skull usually arise from within the body of the clivus, reputedly from notochordal remnants. The first case, which was diagnosed both with CT and MRI, had its origin from the petrous bone, with extension into the left cerebellopontine angle. Chordoma was not considered high on the list of differential diagnoses. A right pontine hemorrhage, which was evacuated surgically, was diagnosed in the second case both from its clinical appearance and from that on CT scan. Only when bone windowing technique was used with CT was a lytic lesion of the right petrous bone evident. Chordoma was only diagnosed on autopsy. In reviewing these two cases and the literature, it is evident that chordoma must be considered in the differential diagnosis of erosive lesions of the petrous bone.

Intraventricular central neurocytoma: CT and MR findings.

Primary cerebral neuroblastoma occurring within the ventricles has been called intraventricular central neurocytoma. This lesion is usually calcified and tends to have a better prognosis than primary cerebral neuroblastoma occurring in the hemispheres. This entity must be considered when an intraventricular calcified lesion is encountered. We report the CT and MR findings in a case of this unusual neoplasm.

Relationship between CT attenuation changes and post-traumatic CSF-CKBB-activity after severe head injury in man.

In order to evaluate if it is practically possible to assess the volume of contused brain tissue from the CT pictures, a comparison has been carried out between the size of the cerebral contusion(s)--as estimated from the CT scans--and the post-traumatic CSF-CKBB activity, in a series of 29 patients with severe head injury. A clearance curve for the elimination of CKBB from the CSF was constructed. The relation between contusion volume and CSF-CKBB-activity was not statistically significant, while the relationships between contusion volume and outcome, and between CSF-CKBB, as estimated at 6 hours after from the clearance curve, and outcome, were.

CT in iatrogenic cerebral air embolism.

Three patients with suspected iatrogenic cerebral air embolism had cranial CTs performed within 24 hr of onset of symptoms. One was interpreted as normal, one showed a large, right frontoparietal enhancing lesion, and the third showed evidence of bi-thalamic infarction. Follow-up scans 7 to 10 days later showed either single or multiple enhancing infarcts in all patients. Although CT proved a valuable tool in the diagnosis of this condition, one out of three initial studies were negative, necessitating a follow-up scan.

Large brain metastasis not shown by computerized tomography.

We have described a patient with metastatic small cell carcinoma of the lung in whom cranial CT and contrast-enhanced CT failed to show metastases. When the patient died four days later, two sizable intracerebral metastatic foci were found at autopsy. Reviewing previously reported causes of nonvisualization of lesions, we have speculated on reasons for the lack of CT findings in this case.

Computed tomography in the prediction of outcome in head injury.

To determine the prognostic significance of computed tomographic (CT) findings in head injury, retrospective analysis was performed in 128 randomly selected severe head-injury patients managed with a standardized protocol. The minimal criterion for entry into this study was that the patients were unable to obey simple commands or utter formed words. Serial CT was performed on admission and 3-5 days, 2 weeks, 3 months, and 1 year after injury. A scale of severity of abnormalities was devised taking into account the size of the traumatic lesions on CT. The CT findings using the proposed scale were correlated with the clinical outcome and analyzed using linear logistic regression. Other characteristics such as midline shift, multiplicity, and corpus callosum and brainstem lesions were not included in the analysis either because they did not affect the prognosis or because too few of these lesions were present for statistical analysis. The correct prediction rate of outcome using the proposed scale for CT findings alone was found to be 69.7%. When CT findings were combined with the Glasgow Coma Scale score this rate was increased to 75.8%.

Computed tomography in the evaluation of incidence and significance of post-traumatic hydrocephalus.

Two hundred consecutive patients with severe head injury underwent sequential computed tomography (CT) on admission, after 4, 14, and 90 days, and after one year. Ventricular enlargement was evaluated in the surviving patients, based upon serial CT examinations. Significant ventricular enlargement was further evaluated with radionuclide cisternography. A significant correlation was shown between clinical outcome and presence or absence of ventricular enlargement. Radionuclide cisternography provided an additional means of determining those patients whose recovery was impaired by persistent obstruction of cerebrospinal fluid circulation and who would therefore benefit from cerebrospinal fluid shunting.