Eric E. Awwad

Asymptomatic versus symptomatic herniated thoracic discs: their frequency and characteristics as detected by computed tomography after myelography.

We retrospectively reviewed the myelograms of 433 patients and identified those who had no symptoms or signs referable to the thoracic cord, roots, or nerves. By post-myelography computed tomographic scan criteria, our frequency of asymptomatic thoracic herniated discs (ATHDs) was calculated. Post-myelography computed tomographic scans of 68 ATHDs were analyzed. Their imaging characteristics were compared with our own series of 5 symptomatic thoracic herniated discs and symptomatic thoracic herniated discs in the literature. We were unable to identify any imaging features that could reliably classify a disc as an ATHD or a symptomatic thoracic herniated disc. Our results call into question the propriety of prophylactic surgery for ATHDs, even when the lesions are radiographically impressive.

The solitary intraspinal vertebral osteochondroma. An unusual cause of compressive myelopathy: features and literature review.

STUDY DESIGN Reports of four patients with compressive myelopathy from solitary intraspinal vertebral osteochondromas. OBJECTIVES To evaluate the clinical presentation and radiographic findings of patients with intraspinal osteochondroma with compressive myelopathy and to review the relevant English-language medical literature. SUMMARY OF BACKGROUND DATA Involvement of the spine by solitary osteochondromas is rare. The addition of the current four cases to those already reported makes a total of 41 published cases of solitary vertebral osteochondromas with spinal cord compression. METHODS Clinical histories, computed tomographic studies, magnetic resonance imaging studies, routine radiographs, and/or myelographic studies of the lesions were reviewed. A review of the English-language medical literature also was done. RESULTS Patients gradually improved or symptoms stopped progressing after surgical removal of the lesions. Although magnetic resonance imaging is the preferred method for localizing the lesion, computed tomography can be more specific, because of its sensitivity, when the diagnosis is in doubt. CONCLUSIONS Osteochondromas represent a hyperplastic-dysplastic disturbance of bone from progressive endochondral ossification. The tumors slowly enlarge, creating insidious but progressive symptoms. Magnetic resonance imaging, computed tomography, and postmyelogram computed tomography are useful in evaluating the size and extent of spinal osteochondromas as a cause of spinal cord compression.

Gemcitabine-associated posterior reversible encephalopathy syndrome: MR imaging and MR spectroscopy findings

A 55 year old female receiving gemcitabine for stage IV non-small cell carcinoma of the lung developed the clinical-radiologic syndrome of posterior reversible encephalopathy syndrome (PRES). She had clinical manifestations of headaches, increasing somnolence and tonic-clonic seizures. The fluid-attentuated inversion recovery (FLAIR) MR imaging sequence conspicuously showed bihemispheric, symmetrical cortical and subcortical white matter hyperintensities that preponderantly involved the parietal and occipital lobes. Diffusion-weighted imaging (DWI) sequence reflected the preponderant existence of vasogenic edema in the involved areas. MR spectroscopy showed no significant N-acetyl aspartate (NAA) depletion or lactate elevation prospectively, indicating the absence of significant neuronal loss and reversibility of the brain parenchymal changes. The clinical and radiologic manifestations essentially resolved completely with discontinuation of the drug.

Computed Tomography of Fatal Cerebral Air Embolism Following Percutaneous Aspiration Biopsy of the Lung

Air embolism complicated a thin needle aspiration performed on a patient with adult respiratory distress syndrome and on positive-pressure ventilation. Computed tomography obtained 30 h following the event demonstrated a considerable quantity of intravascular air within the cranium. Positive-pressure ventilation should be considered a relative contraindication for thin needle lung aspiration.

MR imaging of lumbar juxtaarticular cysts.

Three surgically proven cases of lumbar extradural juxtaarticular cysts were examined by magnetic resonance (MR) imaging. The highly variable MR signal patterns are presented.

Post-traumatic spinal synovial cyst with spondylolysis: CT features.

A spinal synovial cyst at L2-L3 produced obstruction at myelography and simulated an intraspinal tumor on CT. The CT recognition of bilateral spondylolysis of L3 suggested the possibility of a mobile posterior arch of L3 and associated synovial herniation. This was verified at surgery.

MRI of marked dural sac compression by surgicel in the immediately postoperative period after uncomplicated lumbar laminectomy.

PURPOSE Our purpose was to determine what represents normal findings on MR examinations of the lumbar spine in the immediately postoperative period following lumbar laminectomy with retained Surgicel. METHOD MR examinations were performed immediately following lumbar laminectomy in 10 patients referred for symptoms of spinal stenosis. All had Surgicel retained against the dura and were doing well postoperatively without suggestion of adverse symptoms. Images were obtained within 4 days of surgery, most within 24 h. RESULTS In 9 of 10 patients, severe dural tube compression was present, greater than that evident on preoperative studies. CONCLUSION Marked spinal canal compression can be a normal finding in the immediately postlaminectomy period in patients with retained Surgicel. There is a lack of correlation between apparent mass effect on the thecal sac and adverse effect. The MR appearance in such instances is not significant in the absence of compressive clinical symptomatology.

The imaging of an intraspinal cervical dermoid tumor by MR, CT, and sonography

Epidermoid and dermoid tumors are uncommon lesions and within the spinal cord are rare. Magnetic resonance imaging has proved sensitive to their detection in the intracranial cavity but the pattern of signal intensities on T1 and T2 weighted images has not been uniform. Utilizing a 0.6 T superconductive magnet an intramedullary cervical dermoid tumor was examined. The correlation between CT demonstrated regions of fat density and the MRI appearance of comparable regions of high intensity signal on T1 weighted images has only rarely been demonstrated in such tumors that have no histologic evidence of adipose tissue. MRI provided all of the information needed pre-operatively.

Unusual hemorrhage with use of synthetic dural substitute : MR findings

Delayed hemorrhage is an unusual complication of silastic dural substitute that can have a prolonged latent period. Two such patients that presented 6 and 12 years following surgery and that were evaluated by MR imaging are reported.

Parathyroid adenomas: computed tomographic imaging and the importance of preoperative localization

Contrary to what is frequently stated in the literature, preoperative localization of parathyroid adenomas is important. Surgery limited to removal of the adenoma is associated with significantly less morbidity than when bilateral exploration is undertaken. In fact, a 2 to 12 fold decrease in post-operative hypocalcemia has been reported when the surgical exploration is unilateral. Pre-operative CT scans localized 10 of 13 surgically proven adenomas for an overall detection rate of 77%. Only one adenoma in our series had an average axial diameter of greater than 1 cm, the smallest measuring 5 mm X 3 mm. This paper outlines our CT technique and results and summarizes the pertinent recent surgical literature in reference to the importance of preoperative localization.