Morphometric analysis of the maxillary sinus in patients with nasal septum deviation.

The aim of this study was to evaluate the relationship between nasal septum deviation, which is common in the general population, and maxillary sinus volume. A retrospective assessment was made for 96 patients with nasal septum deviation without coexisting sinonasal morbidity and compared to 60 healthy individuals. A three-dimensional reconstruction of computed tomography images was used to assess a total of 312 maxillary sinus volumes. Septal deviation angles and volumes were also measured to standardize and determine the severity of the septal deviations. Septal deviations were right-sided in 36.5% of the cases (n = 35) and left-sided in 63.5% (n = 61). Deviation angles varied between 5° and 24.4°, with a mean value of 12.9 ± 5.0. The mean value for the deviation volume was 4.6 ± 1.5 cm(3) (range 1.7-9.4). The right and left maxillary sinus volumes were 11.8 ± 4.7 cm(3) and 11.5 ± 4.4 cm(3), respectively, in control group. Statistically significant discrepancy was observed between the ipsilateral and contralateral maxillary sinus volumes, in regard to the side of the septal deviation in study group. Maxillary sinus volumes were found to be significantly smaller on the ipsilateral side of septal deviation compared with the contralateral side.

Influence of analysis technique on measurement of diffusion tensor imaging parameters.

OBJECTIVE: We compared results from various methods of analysis of diffusion tensor imaging (DTI) data from a single dataset consisting of 10 healthy adolescents. SUBJECTS AND METHODS: All subjects were imaged on a single 3-T MRI system (single-shot echo-planar imaging pulse sequence; b value, 1000 s/mm(2)). We measured fractional anisotropy (FA), apparent diffusion coefficient (ADC), and axial and radial diffusivity values using 64-pixel rectangular regions of interest (ROIs) in the right side, midline, and left side of the central portion of the splenium of the corpus callosum for fixed (i.e., at same sites in all subjects) and targeted (i.e., at sites of highest FA values) locations. We compared results with those obtained using 64-pixel oval ROIs and 100-pixel rectangular ROIs in the same locations. Finally, we compared results from ROI-based methods and from tractography. All comparisons used the Wilcoxon signed rank test and the intraclass correlation of individual values. RESULTS: Compared to tractography, the average of mean ROI-based values was significantly higher for fixed (approximately 14%) and targeted (approximately 39%) FA values and was significantly lower for ADC (approximately 16%) and radial diffusivity (approximately 38%) values. For solely ROI-based comparisons, statistically significant differences were found in the following comparisons: 64- versus 100-pixel ROI, oval versus rectangular ROI, targeted FA left of midline versus mean targeted FA value, and targeted ROI right of midline versus mean targeted FA value. CONCLUSION: Markedly different values were obtained when using either ROI- or tractography-based techniques or ROI analysis techniques that differ only relatively slightly.

Isolated bone marrow natural killer cell lymphoma with central nervous system involvement mimicking a cerebral infarct.

BACKGROUND: We describe the case of an isolated bone marrow natural killer (NK) cell lymphoma with central nervous system (CNS) involvement mimicking a cerebral infarct. CNS involvement in isolated bone marrow lymphoma has not been reported previously. CASE REPORT: A 49-year-old man with complaints of fever, confusion, and agitation was presented. A bone marrow biopsy was performed to investigate the etiology of bicytopenia which was consistent with NK-cell lymphoma. Brain MRI findings were suggestive of a subacute infarct. CONCLUSION: Even if pathological signal changes of the brain without contrast enhancement resembling infarct are detected in patients with lymphoma on the magnetic resonance imaging, CNS involvement of the lymphoma should be kept in mind in the differential diagnosis.

MR Imaging of pial melanosis secondary to a posterior fossa melanotic ependymoma.

A 36-year-old man presented with trouble speaking and bilateral progressive hearing loss. MR imaging and histopathologic results revealed a posterior fossa melanotic ependymoma. Pial surfaces appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. Histopathologic examination revealed that tumor cells and interstitial spaces had abundant melanin accumulation. There was no evidence of hemosiderin in tumor cells and in interstitial spaces. Pial melanin accumulation secondary to a posterior fossa melanotic ependymoma explained our MR findings.