Biomedical subjects
Publications and source records attributed to D W Williams.
The authors present the MR appearance of an intracanalicular eighth nerve lipoma in a 30-year-old woman, describe the clinical manifestations, and discuss the possible etiology; biopsy findings were conclusive. Precontrast T1-weighted images should be obtained.
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Two cases of neurosarcoidosis studied by Gd-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging are reported. Both patients demonstrated multifocal white matter abnormalities that were clustered near regions of intense meningeal enhancement. Presumed spread of neurosarcoidosis along Virchow-Robin spaces was demonstrated, as evidenced by contrast enhancement along the course of vessels supplying some of the white matter abnormalities.
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Two cases of Madelung disease (benign symmetrical lipomatosis) are presented. The MR findings in this striking condition are demonstrated. Short-repetition-time/short-echo time sequences nicely show the relationship of the cervical lipomatous accumulations to the airway and major neurovascular structures in the carotid spaces. Fat-suppression techniques add no additional information in the radiologic evaluation of these patients.
The authors report three cases of penetrating craniocervical injury by wooden foreign bodies, which were initially hypodense on CT and thought to be air. When these structures were scrutinized with higher window settings, they had a higher attenuation and a unique striated internal architecture which the authors propose may be specific to wood.
We reviewed MR and CT myelographic studies in patients with the Klippel-Feil syndrome (KFS) to determine the patterns of associated congenital and acquired abnormalities of the spine and spinal cord and to correlate these radiologic findings with the manner of clinical presentation. Twenty-four consecutive patients with radiologically definite KFS were evaluated by a cross-sectional imaging technique (CT or MR) over a 6 year period. Radiologic images were blindly interpreted by a panel of three experienced neuroradiologists and then correlated with clinical history. Cervical spondylosis or disk herniations were the most common radiologic abnormalities encountered, seen in 10 (42%) of the 24 patients. While some clustering of these secondary degenerative changes occurred at levels immediately adjacent to the fused vertebrae, in most patients spondylotic changes were seen widely distributed throughout the lower cervical region. Coexisting congenital defects of the spinal cord or brain were encountered in seven patients, six of whom were female, consisting of cervical cord dysraphism or diastematomyelia (n = 5) and Chiari I malformations (n = 2). In only eight patients (33%) had the diagnosis of KFS been suspected clinically prior to imaging by the presence of short neck, limited cervical mobility, or low occipital hairline. In the remaining 16 patients, mostly adolescents or adults being evaluated for cervical sensory or motor syndromes, the diagnosis of KFS was made radiologically at the time of the imaging referral.
PURPOSE: Distinguishing persistent or recurrent tumor from post-radiation edema or soft-tissue/cartilage necrosis in patients treated for carcinoma of the larynx can be difficult. Because recurrent tumor is often submucosal, multiple deep biopsies may be necessary before a diagnosis can be established. Positron emission tomography with F-18 fluorodeoxyglucose was studied for its ability to aid in this problem. PATIENTS AND METHODS: FDG PET scans were performed on 31 patients who were suspected of having persistent or recurrent tumor after radiation treatment for carcinoma of the larynx. Patients underwent thorough history and physical examinations, scans with computed tomography (23 patients), and pathological evaluation when indicated. PET scans were interpreted by each of the two radiologists, who were blinded to patient outcome and the other's report. RESULTS: The time between completion of radiation treatment and positron emission tomography examination ranged from 2 to 61 months with a median of 6 months. Fifteen patients had pathological evidence of tumor in the larynx, while 16 have remained without evidence of disease. The overall sensitivity and specificity of the positron emission tomography interpretations were 80% and 81%, respectively. The sensitivity and specificity of the computed tomography scan interpretations were 58% and 100%, respectively. Of the 23 patients with computed tomography scans, eight patients acquired useful information from the positron emission tomography, three patients had incorrect positron emission tomography interpretations and correct computed tomography interpretations, and one patient had positive tumor despite a negative positron emission tomography and computed tomography. DISCUSSION: Positron emission tomography is useful in distinguishing benign from malignant changes in the larynx after radiation treatment. This noninvasive technique can supplement information provided by computed tomography scans. It is reasonable to delay biopsy, which could traumatize radiation-damaged tissues and precipitate necrosis, for those patients with negative positron emission tomography scans who have clinical signs and symptoms associated with recurrence.