Radiosurgery for cerebral arteriovenous malformations: assessment of early phase magnetic resonance imaging and significance of gadolinium-DTPA enhancement.

Purpose: To evaluate the initial changes within the nidus of arteriovenous malformations (AVMs) and to assess the reaction to the brain tissue surrounding AVMs after radiosurgery by serial magnetic resonance (MR) imaging.

Methods And Materials: Twenty-one patients, treated using 60Co gamma knife unit with cerebral AVMs, were retrospectively evaluated. Forty-seven follow-up MR images of the 21 patients were performed including 10 patients with two or more serial gadolinium enhanced studies (Gd-MR).

Detection of intracranial internal carotid artery and middle cerebral artery vasospasm following subarachnoid hemorrhage.

Little is known about the accuracy of transcranial Doppler (TCD) sonography in detecting intracranial internal carotid artery (IICA) and middle cerebral artery (MCA) vasospasm. TCD was performed in 49 patients with subarachnoid hemorrhage to evaluate 90 IICAs and 87 MCAs during the vasospasm period. When a mean velocity of at least 90 cm/sec was used to indicate IICA vasospasm, there were 11 positive, 42 negative, 4 false-positive, and 33 false-negative results.

Stroke in Williams syndrome.

Background: Williams syndrome is a genetic disorder characterized by a high incidence of heart disease, arterial stenosis, and hypertension. Despite these features, cerebrovascular accidents have been described only recently and only in association with stenoses of the cerebral vasculature.

Case Description: A 19-year-old girl with Williams syndrome developed an acute-onset hemiparesis.

Histopathology and CT analysis of partially resected middle turbinates.

Thirty-eight partial middle turbinate resections from 20 patients undergoing endoscopic sinus surgery were evaluated by histopathology of mucosa and bone and by computed tomography (CT) appearance prior to resection. Histopathologic analysis revealed not only mucosal inflammation but also chronic osteitis of the bone in all patients with sinus disease. The preoperative CT was accurate in predicting turbinate osteitis when the scans displayed advanced grades III and IV disease.

A new decision model for cost-utility comparisons of chemotherapy in recurrent metastatic breast cancer.

In the absence of comparative clinical and pharmacoeconomic trial data for docetaxel versus paclitaxel as second-line therapy for patients with anthracycline-resistant metastatic breast cancer, a computer-based decision-analysis model was designed to evaluate the comparative utility to patients of these two taxoids. The model used the Markov process to analyse disease states (response, stable disease, progressive disease) and toxicities (acute, cumulative) for each treatment during the period from commencement of up to six 3-weekly cycles of chemotherapy, to death. A cost-utility analysis was carried out using the model, with a probability, a cost and a utility determined for each health state.

Hemangioma of the small intestine: case report and literature review.

One case of small bowel polypoid hemangioma of the jejunum presenting as recurrent gastrointestinal blood loss is reported. The presenting symptoms and diagnostic methods are discussed. The importance of intraoperative enteroscopy in diagnosing and treating this condition is emphasized.

Radiologic appearance of the dysembryoplastic neuroepithelial tumor.

Purpose: To evaluate the computed tomographic (CT) and magnetic resonance (MR) imaging features of dysembryoplastic neuroepithelial tumor (DNT).

Materials And Methods: Six CT studies (four with contrast material enhancement) and 10 MR imaging studies (seven with gadolinium enhancement) obtained in 10 patients with a history of seizures and pathologically proved DNT were retrospectively reviewed.

Results: All tumors were intracortical or subcortical.

Structural model of the phospholamban ion channel complex in phospholipid membranes.

Phospholamban is a 52 amino acid residue membrane protein involved with the regulation of calcium levels across sarcoplasmic reticulum membranes in cardiac muscle cells. The N-terminal 30 amino acid residues of the protein are largely hydrophilic and include two sites whose phosphorylation is thought to dissociate an inhibitory complex between phospholamban and Ca2+ ATPase. The C-terminal 22 amino acid residues are largely hydrophobic, anchor the protein in the membrane and are responsible for Ca2+ selective ion conductance.

MRI of silicone vitreous ocular implants with phantom correlation.

We imaged two patients who had silicone oil injected their vitreous cavities. The images demonstrated an increased chemical shift artifact. We developed and tested an in vitro silicone oil model in an attempt to explain this.

Including deaths when measuring health status over time.

Measuring health status over time is problematic when some subjects die, because death does not have a defined value on most health status measures. This situation is different from the usual missing data problem because the health status of the dead is, in a sense, known. We examined eight strategies for incorporating deaths into such analyses using three health status measures taken from two data sets, after which we used computer simulation to explore more fully the effect of deaths.

Posterior fossa glioblastoma multiforme: MR findings.

Purpose: To characterize the MR findings of glioblastoma multiforme in the posterior fossa.

Methods: MR studies of nine patients with surgically proved posterior fossa glioblastoma multiforme were retrospectively evaluated. MR characteristics studied included tumor location, signal intensity, enhancement pattern, and presence of intratumoral hemorrhage, as well as presence of secondary hydrocephalus or metastatic spread.

Localization of a misplaced coronary artery stent by magnetic resonance imaging.

Coronary artery stents have been developed to overcome arterial abrupt closure and restenosis following balloon angioplasty. Complications of stent insertion include loss of the device from its delivery system into the peripheral circulation. Certain types of stents are almost radiolucent, making localization of the lost devices difficult.

Cost effectiveness of the multichannel cochlear implant.

Although most third-party payors presently fund cochlear implantation, some do not, and many cite the current lack of cost-effectiveness data as a major concern. Cost-utility analysis is a widely used method of medical technology assessment that permits cost-effectiveness comparisons between medical interventions by determining the cost per quality-adjusted life-year (QALY) they provide. The cost per QALY for the cochlear implant was determined using clinical cost data and a health-utility outcome model based on the established communication gains attained with the device.

MR imaging of adult supratentorial astrocytomas: an attempt of semi-automatic grading.

Using multiple regression analysis, six MR parameters were correlated with three histological grades among 43 proven adult supratentorial astrocytic gliomas to ascertain important MR parameters and their optimal contributions. Analysis revealed that two parameters, border definition and tumor hemorrhage, were unreliable. Using the remaining four parameters an equation was derived: Tumor grade = 0.

Non-enhancing supratentorial malignant astrocytomas: MR features and possible mechanisms.

To clarify the MR features of supratentorial malignant astrocytic gliomas that did not exhibit contrast enhancement of MR imaging, six MR parameters were evaluated in two glioblastomas and six anaplastic astrocytomas. Moderate to marked edema, mass effect, and moderate tumor heterogeneity were noted in all cases. Hemorrhage was absent in all cases.

Accuracy of clinical examination versus computed tomography in detecting occult lymph node involvement in patients with oral epidermoid carcinoma.

Purpose: To determine the accuracy of clinical examination versus computed tomography (CT) scanning in detecting positive cervical lymph nodes (N) in patients with epidermoid carcinomas of the oral cavity, 27 patients with epidermoid carcinomas were reviewed.

Patients And Methods: The patients underwent 40 neck dissections, 20 with N- and 20 with N+ necks histologically. All patients were examined by the same clinician, and all CT scans were read by the same radiologist.

Cerebral mucormycosis associated with intravenous drug use: three case reports and review.

We describe three cases of cerebral mucormycosis in intravenous drug users and review 22 previously reported cases. Involvement of the basal ganglia was demonstrated in all but two cases. Seven of the 10 patients tested for antibodies to the human immunodeficiency virus (HIV) were seronegative.

Transcranial Doppler detection of vertebrobasilar vasospasm following subarachnoid hemorrhage.

Background And Purpose: Transcranial Doppler sonography is of established value in the detection and monitoring of middle cerebral artery vasospasm. Little information exists on the utility of transcranial Doppler for detection of posterior circulation vasospasm.

Methods: Cerebral angiography and conventional hand-held transcranial Doppler sonography were compared to determine sensitivity and specificity of transcranial Doppler for detection of vertebral and basilar artery vasospasm.

Emergency surgical revascularisation for coronary angioplasty complications.

Objectives: To evaluate trends in referrals for emergency operations after percutaneous transluminal coronary angioplasty (PTCA) complications; to analyse morbidity and mortality and assess the influence of PTCA backup on elective surgery.

Design: A retrospective analysis of patients requiring emergency surgical revascularisation within 24 hours of percutaneous transluminal coronary angioplasty.

Patients: Between January 1980 and December 1990, 75 patients requiring emergency surgery within 24 hours of percutaneous transluminal coronary angioplasty.