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Biomedical subjects

D P Mueller

Publications and source records attributed to D P Mueller.

23 records · Page 2Linked to original sources
PubMedDate not supplied

MRI spectrum of medulloblastoma.

Medulloblastomas have been characterized as solid, homogeneously enhancing, midline masses of the posterior fossa. To evaluate atypical MRI characteristics, we retrospectively reviewed 13 histologically proven medulloblastomas. MRI examinations were correlated with pathologic specimens and operative reports. Atypical features included cyst formation (77%), irregular enhancement (19%), extension through fourth ventricle foramina (15%), and presentation as a cerebellopontine angle mass (8%). We conclude that "atypical" characteristics are common. In the child or young adult, medulloblastomas must be included in the differential diagnosis of any posterior fissa mass.

Adult↗
PubMedDate not supplied

Gadolinium-enhanced MR of the postoperative internal auditory canal following acoustic neuroma resection via the middle fossa approach.

PURPOSE: To evaluate the ability of gadolinium-enhanced MR in detecting recurrent tumor in patients whose acoustic neuromas were surgically removed via the middle cranial fossa approach. PATIENTS AND METHODS: Postoperative gadolinium-enhanced exams of 13 of 44 patients who underwent excision of acoustic neuromas via the middle cranial fossa approach were reviewed. RESULTS: Postoperative enhancement was seen in 12 of the 13 patients; two patients underwent serial exams without significant change. On the basis of a single exam, we were unable to conclusively differentiate postoperative enhancement from residual or recurrent tumor. CONCLUSIONS: A single exam is of limited value. Serial studies are recommended to identify changes that would indicate tumor growth. A proposed MR follow-up schedule is an initial baseline exam within 2 months of surgery and a repeat exam during the second postoperative year.

Contrast Media↗
PubMedDate not supplied

Arterial enhancement in acute cerebral ischemia: clinical and angiographic correlation.

PURPOSE: To investigate the cause and clinical significance of arterial enhancement (AE) in contrast-enhanced T1-weighted MR examinations after acute cerebral ischemia. METHODS: Contrast MR examinations and conventional angiograms of 17 patients studied following an acute ischemic event or an internal carotid occlusion were retrospectively reviewed. MR and angiographic studies were performed within 1 day of each other. The presence of AE was correlated with both angiographic findings and patient clinical status. RESULTS: AE was not confined to patients with angiographic evidence of complete arterial occlusion. Only 64% of patients demonstrating AE had complete occlusion angiographically. Complete arterial occlusion did not always correlate with AE. In two of nine patients with complete occlusion, no AE was identified. In five of 10 patients with AE, angiographic slow flow was identified. In patients without AE, no angiographic slow flow was identified. In the 64% of patients with AE, significant symptoms were identified. Patients without AE were either asymptomatic or had mild symptoms at the time of the MR study. CONCLUSIONS: Our data support the hypothesis that arterial slowing is the cause of AE, which appears to be an indicator of decreased brain perfusion. Such MR findings may add important supplemental information to those provided by conventional angiography.

Acute Disease↗