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Biomedical subjects

D F Sobel

Publications and source records attributed to D F Sobel.

At least 37 records · Page 2Linked to original sources

Primary myxoma of the posterior fossa.

A rare case of primary intracranial myxoma of the posterior fossa is described in a 32-year old woman. The patient presented with a history of headaches, disequilibrium, nausea and abnormal vision for several months. Computed tomography (CT) showed a well-demarcated hypodense mass. After contrast administration the mass appeared as an inhomogeneously enhancing lesion surrounded by a small rim of edema. The mass was surgically excised with histological examination revealing a true myxoma. Echocardiography revealed no evidence of a cardiac myxoma. The CT appearance of other case reports of non-cardiac myxomas in the literature is reviewed.

Adult↗

Spinal cord pial metastases: MR imaging with gadopentetate dimeglumine.

The purpose of this investigation was to describe gadopentetate-dimeglumine-enhanced MR findings in metastatic disease to the pial lining of the spinal cord. Correlation was made with clinical data, other radiologic studies, and pathologic findings. Eighty-six patients with a known malignancy and unexplained neurologic signs or symptoms were studied with pre- and postcontrast T1-weighted images. In seven of these patients, abnormal enhancement of the pial lining of the cord was seen on the sagittal postcontrast T1-weighted images. This appeared as a thin rim of enhancement along the surface of the cord in six patients and as a focal, thick rim of enhancement in addition to the thin rim of enhancement in the seventh patient. Axial images confirmed the location along the pial lining in each case. Precontrast T1-weighted images in all seven cases and precontrast T2-weighted images in five cases failed to detect any focal abnormalities of the pial lining of the cord. Pathologic confirmation was available in five of the seven patients. Primary malignancies in these patients included breast carcinomas (two), lymphoma (one), leukemia (one), adenocarcinoma of the lung (one), prostate carcinoma (one), and malignant melanoma (one). Three of seven patients had metastatic disease evident only within the CNS, while four patients had widespread disease outside the CNS. We conclude that contrast-enhanced MR imaging is useful in the diagnosis of pial spread of metastatic disease in patients with a known primary malignancy and unexplained neurologic signs or symptoms.

Adult↗

Adverse reactions to iopamidol and iohexol myelography with special attention to headache: role of myelographic technique.

In order to identify those myelographic risk factors associated with a higher incidence of adverse effects, myelographic technique, patient variables and post-myelographic symptoms were prospectively recorded in a group of 152 patients studied with iopamidol and in a second group of 28 patients studied with iohexol. None of the technical factors studied were identified to have a statistically significant relationship with the incidence of adverse reactions. Older patients fared better than younger patients in both groups. Overall, there was a lower incidence of side effects in the iopamidol group (29%) than in the iohexol group (50%). Headache, nausea, and vomiting were the most frequent reactions seen.

Aged↗

Importance of cerebral collateral pathways during carotid endarterectomy.

Before surgery, we evaluated major intracranial collateral pathways using transcranial Doppler ultrasonography (TCD) in 50 patients who then underwent carotid endarterectomy with concurrent multimodality cerebral monitoring. Patients were grouped with respect to collateral pathways demonstrated preoperatively by TCD: Group 1, good collateralization with an anterior and/or posterior communicating artery ipsilateral to the operative carotid lesion (29 patients, 58%); Group 2, collateral pathways present but impeded by other proximal stenoses (nine patients, 18%); and Group 3, no collateralization identified (nine patients, 18%). Three patients (6%) could not be classified. TCD identified major collateral pathways with a sensitivity of 89% and a specificity of 80% when compared with arteriography. During carotid endarterectomy mean middle cerebral artery velocity, pulsatility index, and stump pressure were higher and the decrease in middle cerebral artery velocity with extracranial carotid artery cross clamping was significantly less among Group 1 patients than among Group 2 and 3 patients (p less than 0.05 for both groups). Group 1 patients required fewer intraoperative carotid artery shunts and developed fewer ischemic electroencephalographic abnormalities than did patients in Groups 2 and 3 (p less than 0.05 for both groups). TCD assessment of cerebral collateralization helps predict hemodynamic consequences of cross clamping during carotid endarterectomy.

Aged↗

Moyamoya pattern of vascular occlusion after radiotherapy for glioma of the optic chiasm.

We studied three children who suffered massive strokes 2 to 5 years after intracranial irradiation of optic chiasm gliomas. Arteriography showed moyamoya changes in all three. CTs showed dramatic reduction in tumor size in two patients, but we believe radiotherapy should only be used sparingly to treat optic chiasm gliomas in young children, because its efficacy is unproven, and side effects may be catastrophic.

Arterial Occlusive Diseases↗

Cerebral amyloid angiopathy associated with massive intracerebral hemorrhage.

Characteristic computed tomographic, clinical and pathologic features are discussed in two patients with cerebral amyloid angiopathy (CAA) associated with massive intracerebral hemorrhage. Amyloid angiopathy should be considered in any elderly patient in whom intracerebral hemorrhage occurs at an atypical site. Cortical involvement, multiplicity of hemorrhages, bilaterality, and repeated episodes should further arouse diagnostic suspicion. Clinical management is confined to prevention of systemic hypertension.

Aged↗

Metrizamide CT myelography in cervical myelopathy and radiculopathy: correlation with conventional myelography and surgical findings.

Conventional myelography, metrizamide computed tomographic (CT) myelography, and surgical findings were correlated in 30 patients with cervical radiculopathy and/or myelopathy. In 60% of patients, metrizamide CT myelography provided significant additional information including better characterization of the abnormality, lateralization if the conventional myelogram was indeterminate, more definitive demonstration of cord atrophy, foraminal narrowing not appreciated on myelography, and demonstration of abnormalities distal to a myelographic block. In no case was a myelographic abnormality not detected on metrizamide CT myelography. In patients with cervical myelopathy, a cross-sectional diameter of the cord equaling less than 50% of the subarachnoid space is predictive of poor patient response to surgical intervention.

Adult↗

Intraventricular mass lesions.

Determining the precise etiology of an intraventricular mass can be a difficult diagnostic problem. CT and angiographic findings were reviewed in a series of 73 patients who had intraventricular masses. The histologic diagnosis can be suggested preoperatively by an analysis of the frequency of lesions occurring at a given ventricular location, lesion density before and after administration of contrast material, age and sex of the patient, morphologic appearance of the mass, and presence or absence of hydrocephalus. Angiography is useful when meningioma, choroid plexus papilloma and carcinoma, or arteriovenous malformation are considered. The differential features of each diagnostic entity are discussed.

Brain Diseases↗

CT myelography in cervical nerve root avulsion.

Computed tomographic myelography (CTM) with metrizamide was performed in six patients to delineate the CTM appearance of avulsed cervical nerve roots. Twelve cervical nerve root avulsions were found and confirmed by cervical myelography and physical examination. The CTM findings in cervical nerve root avulsion closely matched those found myelographically: outpouchings of metrizamide extending ventrolaterally from the thecal sac into the neural foramen in an expanding or "mushroom-like" manner and separated from the thecal sac proximally by a 1-2 mm thick dural plane. This CTM appearance differs from that seen in such normal variants as dilated nerve root sleeves or root diverticula. We conclude that CTM is as sensitive as myelography. In addition, it can provide useful information regarding bony fragments or contiguous soft tissue injury.

Adolescent↗

Diskogenic vertebral sclerosis: MR imaging.

Magnetic resonance imaging findings in three patients with diskogenic vertebral sclerosis of the lumbar spine are presented. Increased signal intensity within the vertebral bodies was observed on T2-weighted images that corresponded to areas of bony sclerosis on plain radiography. Decreased signal intensity within the disk space on T2-weighted images serves to differentiate diskogenic sclerosis from infectious spondylitis.

Adult↗

Mucocele of the anterior clinoid process: CT and MR findings.

A patient with biopsy-proven primary mucocele of the anterior clinoid process is presented. Gadolinium-DTPA enhanced magnetic resonance imaging revealed a nonenhancing lesion isointense to gray matter. Computed tomography revealed well corticated bony margins without direct involvement of the sphenoid sinus.

Adult↗

Heterotopic brain in the middle ear: CT findings.

A soft tissue mass was found by CT in the mesotympanum of the left middle ear of a 4-year-old boy. This lesion was without radiologic or surgical evidence of associated bony defect or communication with the intracranial cavity. Pathological examination revealed heterotopic brain tissue. Although heterotopic brain tissue in the middle ear is rare, it should be considered in the differential diagnosis of soft tissue middle ear masses.

Brain↗

Spinal cord pial metastases: MR imaging with gadopentetate dimeglumine.

The purpose of this investigation was to describe gadopentetate-dimeglumine-enhanced MR findings in metastatic disease to the pial lining of the spinal cord. Correlation was made with clinical data, other radiologic studies, and pathologic findings. Eighty-six patients with a known malignancy and unexplained neurologic signs or symptoms were studied with pre- and postcontrast T1-weighted images. In seven of these patients, abnormal enhancement of the pial lining of the cord was seen on the sagittal postcontrast T1-weighted images. This appeared as a thin rim of enhancement along the surface of the cord in six patients and as a focal, thick rim of enhancement in addition to the thin rim of enhancement in the seventh patient. Axial images confirmed the location along the pial lining in each case. Precontrast T1-weighted images in all seven cases and precontrast T2-weighted images in five cases failed to detect any focal abnormalities of the pial lining of the cord. Pathologic confirmation was available in five of the seven patients. Primary malignancies in these patients included breast carcinoma (two), lymphoma (one), leukemia (one), adenocarcinoma of the lung (one), prostate carcinoma (one), and malignant melanoma (one). Three of seven patients had metastatic disease evident only within the CNS, while four patients had widespread disease outside the CNS. We conclude that contrast-enhanced MR imaging is useful in the diagnosis of pial spread of metastatic disease in patients with a known primary malignancy and unexplained neurologic signs or symptoms.

Adult↗

MR imaging of orbital and ocular disease.

Magnetic resonance (MR) images of 27 patients with ocular and orbital pathology were reviewed retrospectively and correlated with computed tomography (CT), funduscopic examination, and tissue histology. Disease processes were classified by location into ocular, extraconal, intraconal, optic nerve, and orbital apex. The diagnostic efficacy of MR differed at each location. MR was very sensitive in detecting ocular, extraconal, and intraconal lesions larger than 5 mm but was insensitive in imaging smaller lesions and in detecting pathology of the optic nerve. The limitations of MR were related to 7 mm slice thickness and 2.6 mm interslice gap. The diagnostic accuracy is expected to improve markedly with further developments in thin-section imaging and use of surface coils.

Adolescent↗