Comprehensive Assessment of Ankle Syndesmosis Injury Using 3D Isotropic Turbo Spin-Echo Sequences: Diagnostic Performance Compared With That of Conventional and Oblique 3-T MRI.

OBJECTIVE: The objective of this study is to evaluate the diagnostic performance of 3D sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) sequences in the evaluation of ankle syndesmosis injuries, compared with that of conventional orthogonal MRI and oblique proton density-weighted turbo spin-echo (TSE) sequences performed with 3-T MRI. MATERIALS AND METHODS: This retrospective study included 98 patients with suspected ankle syndesmosis injuries who underwent both MRI and surgery. Fifty patients (mean [± SD] age, 34.5 ± 15.3 years) had acute injuries, and 48 patients (mean age, 28.5 ± 9.6 years) had chronic injuries. For both groups, the diagnostic performance of each MRI sequence with regard to syndesmosis injuries was evaluated. Arthroscopy findings were used as a reference standard to confirm diagnosis. RESULTS: No statistically significant differences in the sensitivity, specificity, accuracy, and AUC values were noted between images of the syndesmosis obtained using proton density-weighted TSE sequences and images of the syndesmosis obtained using 3D SPACE sequences (p > 0.05). Interobserver agreement regarding the diagnosis of both acute and chronic syndesmosis injuries was almost perfect for proton density-weighted TSE images (κ > 0.80) and was substantial for 3D SPACE images (κ > 0.75). Both methods of obtaining images of the syndesmosis had a diagnostic performance superior to that of conventional orthogonal MRI. CONCLUSION: The performance of 3D SPACE sequences is comparable to that of 2D proton density-weighted MR images for the diagnosis of acute and chronic syndesmosis injuries.

Novel disposable transnasal endoscopy for assessment of esophageal motor function.

BACKGROUND: A novel disposable transnasal endoscopy (DTE) with a portable system has been developed to provide unsedated esophagoscopy by modifying capsule endoscopy. The aim of this study was to assess the feasibility of DTE to evaluate esophageal motor function. MATERIALS AND METHODS: Patients with or suspected esophageal motility disorders and healthy volunteers were enrolled. Participants underwent esophageal high-resolution manometry and DTE in random order on different days. Motility was observed with DTE at 1, 8, and 16 cm above the gastroesophageal junction. RESULTS: Twenty healthy volunteers and 20 symptomatic subjects participated (8 achalasia, 5 scleroderma, 3 diffuse esophageal spasm, 1 hypertensive peristalsis, 1 peristaltic dysfunction, and 22 normal esophageal function). The normal findings on DTE were as follows. As the subject swallowed water, swallow-induced relaxation with elevation of the lower esophageal sphincter caused the endoscope to cross the Z-line into the gastric lumen. After the passage of water and air, complete closure of the lower esophageal sphincter occurred, with the return of the endoscope to its previous position. During the resting stage of the esophageal body, an air bubble could be seen in the center of the radially wrinkled and occluded lumen. The endoscopic diagnosis was in agreement with the clinical diagnosis in all but 2. Most of the participants reported acceptable discomfort during DTE and 62.5% of the subjects preferred DTE to manometry. CONCLUSIONS: DTE can accurately characterize normal esophageal motor function, allowing the diagnosis of esophageal motility disorders. DTE has potential widespread applications, especially in outpatient clinics.

Assessment of cerebral glucose metabolism in cat deafness model: strategies for improving the voxel-based statistical analysis for animal PET studies.

PURPOSE: The aim of this study was to establish the procedures for 3D voxel-based statistical analysis of 2-deoxy-2-[(18)F]fluoro-D-glucose-positron emission tomography (FDG-PET) images of a cat's brain obtained using a small animal-dedicated PET system and to assess the utility of this approach in investigating the cerebral glucose metabolism in an animal model of cortical deafness. PROCEDURES: This study compared several different strategies for the spatial processing of PET data acquired twice from eight cats before and after inducing deafness in terms of the comparability of the statistical analysis results to the established pattern of the cerebral glucose metabolic changes in the deaf animals. RESULTS: The accuracy of the spatial preprocessing procedures and the statistical significance of the comparison were improved by removing the background activities outside the brain regions. The use of the spatial normalization parameters obtained from the mean image of the realigned data set for individual data also helped improve the statistical significance of the paired t testing. It was also found that an adjustment of the registration options was also important for increasing the precision of the realignment. CONCLUSIONS: A method for voxel-based analysis of the PET data of a cat's brain was optimized. The results demonstrated the high localization accuracy and specificity of this method, which is expected to be useful for examining the brain PET data of medium-sized animals such as cats.