OBJECTIVE: Many studies have reported pre-processing effects for brain volumetry; however, no study has investigated whether non-parametric non-uniform intensity normalization (N3) correction processing results in reduced system dependency when using an atlas-based method. To address this shortcoming, the present study assessed whether N3 correction processing provides reduced system dependency in atlas-based volumetry. MATERIALS AND METHODS: Contiguous sagittal T1-weighted images of the brain were obtained from 21 healthy participants, by using five magnetic resonance protocols. After image preprocessing using the Statistical Parametric Mapping 5 software, we measured the structural volume of the segmented images with the WFU-PickAtlas software. We applied six different bias-correction levels (Regularization 10, Regularization 0.0001, Regularization 0, Regularization 10 with N3, Regularization 0.0001 with N3, and Regularization 0 with N3) to each set of images. The structural volume change ratio (%) was defined as the change ratio (%) = (100 x [measured volume - mean volume of five magnetic resonance protocols] / mean volume of five magnetic resonance protocols) for each bias-correction level. RESULTS: A low change ratio was synonymous with lower system dependency. The results showed that the images with the N3 correction had a lower change ratio compared with those without the N3 correction. CONCLUSION: The present study is the first atlas-based volumetry study to show that the precision of atlas-based volumetry improves when using N3-corrected images. Therefore, correction for signal intensity non-uniformity is strongly advised for multi-scanner or multi-site imaging trials.
Adult ; Atlases as Topic ; Brain Mapping/*methods ; Female ; Humans ; Image Enhancement/methods ; Image Processing, Computer-Assisted/*methods ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Software ; Statistics, Nonparametric

Objectives: Duodenal perforation as a complication of endoscopic ultrasound-guided fine needle aspiration may progress to acute peritonitis and septic shock. Open surgery, the standard treatment, can be avoided by performing closure during endoscopy using endoscopic clips.Patient: A 77-year-old woman was referred to our hospital with salivary gland swelling. She had elevated hepatobiliary enzymes and jaundice. Computed tomography (CT) revealed pancreatic head swelling and bile duct dilation. Endoscopic ultrasonography revealed a hypoechoic mass in the pancreatic head. The pancreatic head mass was punctured twice using a 22-gauge Franchine-type puncture needle at the duodenal bulb. The endoscope was advanced to the descending part of the duodenum, and part of the superior duodenal angle was perforated (diameter approximately 15 mm) with the endoscope. The duodenal mucosa around the perforation was immediately closed using endoscopic clips.Results: Abdominal CT showed gas in the peritoneal and retroperitoneal spaces. The patient experienced abdominal pain and fever and was treated with fasting and antibiotics. The gas gradually decreased, symptoms improved, and she was discharged 18 days after the perforation. Histopathologically, the pancreatic tissue was consistent as autoimmune pancreatitis.Conclusion: Endoscopic closure using endoscopic clips may be a better therapeutic option for duodenal perforation caused by endoscopy.