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PURPOSE: To determine the factors that correspond to adenoidal hypertrophy, often prominent in human immunodeficiency virus (HIV)-positive patients. METHODS: The sagittal T1-weighted MR images of 21 HIV-positive patients (age range, 25 to 50 years; mean, 37 years) and 21 healthy control subjects (age range, 24 to 55 years; mean, 35 years) were reviewed blindly and independently by two radiologists who measured the maximal dimension of the nasopharyngeal lymphoid tissue. Twenty-six additional HIV-positive patients were combined with the original 21 HIV-positive patients, and the hematologic studies of these 47 patients were compared with the adenoidal measurements to assess whether a relationship existed between nasopharyngeal prominence and hematocrit, white blood cell count, and CD4 count. RESULTS: Mean adenoidal width was 6.76 mm (SD, 5.82) in the HIV-positive population, but was only 3.36 mm (SD, 2.48) in the age-matched control group. Age and HIV status correlated with nasopharyngeal width measurements. No relationship between adenoidal width and hematocrit, CD4 count, or white blood cell count was evident. CONCLUSION: After correcting for age, we found that adenoidal lymphoid tissue is more abundant in HIV-positive persons than in control subjects. The hematologic ramifications of this finding remain uncertain.

Heterotopic brain outside the cranial vault is uncommon. It occurs most frequently in the nasal region, although rests elsewhere in the aerodigestive tract have been reported. We describe a case of heterotopic brain in the pterygopalatine fossa.

Granular cell myoblastomas are uncommon, typically benign tumors. Involvement of the esophagus is rare, and frequently they are asymptomatic. We report a granular cell myoblastoma involving the cervical esophagus in a patient who had paralysis of the true vocal cord and progressive dysphagia. At MR imaging, the circumscribed mass was hypointense on T1-weighted images and mildly hyperintense on T2-weighted images, with homogeneous contrast enhancement.

PURPOSE: To evaluate the sites of injury in patients with posttraumatic olfactory deficits and to compare damage with findings on clinical olfactory tests. METHODS: Twenty-five patients with posttraumatic olfactory dysfunction were examined by means of olfactory testing, endoscopy, and MR imaging. MR surface-coil scans through the olfactory bulbs and tracts and head-coil scans of the temporal lobes were evaluated. Quantitative and qualitative gradings of damage to the olfactory bulbs, tracts, subfrontal region, hippocampus, and temporal lobes were compared with results on tests of odor identification, detection, memory, and discrimination. RESULTS: Twelve patients were anosmic, eight had severe impairment, and five were mildly impaired. Injuries to the olfactory bulbs and tracts (88% of patients), subfrontal region (60%), and temporal lobes (32%) were found, but these did not correlate well with individual olfactory test scores. Volumetric analysis showed that patients without smell function had greater volume loss in olfactory bulbs and tracts than did those posttraumatic patients who retained some sense of smell. Qualitative and quantitative assessments of damage showed few significant correlations with olfactory tests, probably because of multifocal injuries, primary olfactory nerve damage, and the constraints of a small sample size on the detection of clinically significant differences. CONCLUSION: MR imaging shows abnormalities in patients with posttraumatic olfactory dysfunction at a very high rate (88%), predominantly in the olfactory bulbs and tracts and the inferior frontal lobes.

PURPOSE: To investigate the MR findings in patients who have had osteoplastic frontal sinus flaps placed for inflammatory sinonasal disease. METHODS: The MR images of 13 patients who had improvement of symptoms after osteoplastic frontal sinus flap placement with fat autograft were prospectively evaluated for the presence of high intensity on T2-weighted scans, contrast enhancement, and replacement of frontal sinus fat by lower-signal soft tissue. All studies were performed on a 1.5-T unit using a 5-in round surface coil placed over the nasion. Sagittal T1-weighted, axial and coronal fast spin-echo T2-weighted, and precontrast and postcontrast axial and coronal T1-weighted images were obtained through the operative bed. The T2-weighted and postgadolinium sequences were done with a fat-suppression technique. RESULTS: Hyperintensity within the frontal sinuses on T2-weighted images and enhancement (peripherally and/or centrally where fat was replaced with soft tissue) were found to some degree in all patients. The degree of replacement of frontal sinus fat with soft tissue ranged from 4% to 85% (mean, 43%). Five patients with persistent symptoms had no distinguishing MR features when compared with asymptomatic patients. CONCLUSIONS: Although increased T2-weighted intensity, fat replacement, and enhancement are findings compatible with inflammation, these changes may be seen in patients who are asymptomatic after placement of osteoplastic frontal sinus flaps; they may represent the normal granulation process. MR findings after flap placement are nonspecific and have limited utility in distinguishing symptomatic patients with recurrent inflammatory disease from asymptomatic patients whose imaging findings are related to postoperative scar tissue.

PURPOSE: To investigate whether MR imaging is an accurate means of assessing mandibular invasion in patients with carcinoma. METHODS: We retrospectively studied the MR scans of 22 patients with pathologic or surgical confirmation of mandibular invasion from oral and oropharyngeal cancers. The MR images were blindly analyzed using primary criteria of: (a) cortical breakdown, (b) replacement of bone marrow fat, or (c) gadopentetate dimeglumine enhancement of a mass at the bone marrow defect. Secondary criteria of: (a) contiguous soft-tissue mass, and (b) mass on both sides of the mandibular cortex were also examined. Mandibular invasion was graded as periosteal/cortical, medullary, or no invasion. RESULTS: Primary positive findings of cortical breakdown and abnormal bone marrow signal were highly sensitive (100%) for periosteal/cortical invasion and medullary involvement, respectively. However, a high rate of false-positive studies hampered the MR accuracy, which fell into the 73% to 77% range. A negative MR study was highly predictive, but a positive study was less valuable. Gadolinium enhancement added little to the MR study's accuracy. False-positive studies mainly occurred in the setting of prior irradiation, osteoradionecrosis, and odontogenic infections. CONCLUSIONS: MR imaging is a sensitive method for detecting mandibular invasion but has a low positive predictive value. A negative study virtually excludes cortical/periosteal or bone marrow invasion.

PURPOSE: To examine the hypothesis that lumbar puncture alone may cause meningeal enhancement in the brain. METHODS: We prospectively reviewed the brain MR examinations of all patients from a 6-month period who were studied within 1 month after lumbar puncture. We also retrospectively reviewed all cases of dural-arachnoidal enhancement in the brain from the preceding 18-month period. RESULTS: In the prospective group, only one case out of 97 enhanced brain MR examinations after lumbar puncture did not have a clear cause for dural-arachnoidal enhancement. In the retrospective group, only one case out of 11 with enhancement was not clearly explained. CONCLUSIONS: Dural-arachnoidal enhancement in the brain after lumbar puncture is uncommon, if it occurs at all, and lumbar puncture as a cause of enhancement should be considered a rare diagnosis of exclusion.

PURPOSE: To describe the MR appearance of the olfactory bulbs and tracts and temporal lobes in patients with Kallmann syndrome, a disorder characterized by hypogonadotropic hypogonadism and anosmia. METHODS: High-resolution MR scans with a surface coil placed over the nasion were performed in two patients with Kallmann syndrome. Coronal 3-mm thick contiguous sections were obtained through the olfactory bulbs and tracts. MR scans included volumetric analysis of the bulbs, tracts, temporal lobes, and hippocampi. RESULTS: No olfactory bulbs or tracts could be identified in patients with Kallmann syndrome. In comparison, the olfactory bulbs and tracts were identifiable in seven healthy volunteers. The temporal lobe and hippocampal volumes were comparable between control subjects and Kallmann patients. CONCLUSIONS: High-resolution surface-coil MR can identify the absence of olfactory bulbs and tracts in patients with Kallmann syndrome. Normal olfactory bulbs and tracts are easily discerned with surface-coil imaging.