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Kisung Lee,Miyaoka, R.S.,Lewellen, T.K.,Alessio, A.M.,Kinahan, P.E. IEEE 2009 IEEE transactions on nuclear science Vol.56 No.5
<P>We study the noise characteristics of an image reconstruction algorithm that incorporates a model of the non-stationary detector blurring (DB) for a mouse-imaging positron emission tomography (PET) scanner. The algorithm uses ordered subsets expectation maximization (OSEM) image reconstruction, which is used to suppress statistical noise. Including the non-stationary detector blurring in the reconstruction process [OSEM(DB)] has been shown to increase contrast in images reconstructed from measured data acquired on the fully-3D MiCES PET scanner developed at the University of Washington. As an extension, this study uses simulation studies with a fully-3D acquisition mode and our proposed FORE+ OSEM(DB) reconstruction process to evaluate the volumetric contrast versus noise trade-offs of this approach. Multiple realizations were simulated to estimate the true noise properties of the algorithm. The results show that incorporation of detector blurring FORE+OSEM(DB) into the reconstruction process improves the contrast/noise trade-offs compared to FORE +OSEM in a radially dependent manner. Adding post reconstruction 3D Gaussian smoothing to FORE +OSEM and FORE +OSEM(DB) reduces the contrast versus noise advantages of FORE+ OSEM(DB).</P>
Rino Hasegawa,Kenshi Yao,Shoutomi Ihara,Masaki Miyaoka,Takao Kanemitsu,Kenta Chuman,Go Ikezono,Akikazu Hirano,Toshiharu Ueki,Hiroshi Tanabe,Atsuko Ota,Seiji Haraoka,Akinori Iwashita 대한소화기내시경학회 2018 Clinical Endoscopy Vol.51 No.6
Background/Aims: While the occurrence of multiple whitish flat elevated lesions (MWFL) was first reported in 2007, no studieson MWFL have been published to date. The present retrospective observational study aimed to clarify the endoscopic findings andclinicopathological features of MWFL. Methods: Subjects were consecutive patients who underwent upper gastrointestinal endoscopy as part of routine screening betweenApril 2014 and March 2015. The conventional white-light, non-magnifying and magnifying narrow-band images were reviewed. Clinical features were compared between patients with and without MWFL. Results: The conventional endoscopic findings of MWFL include multiple whitish, flat, and slightly elevated lesions of various sizes,mainly located in the gastric body and fundus. Narrow-band imaging enhanced the contrast of MWFL and background mucosa,and magnifying narrow-band imaging depicted a uniformly long, narrow, and elliptical marginal crypt epithelium with an unclearmicrovascular pattern. Histopathological findings revealed hyperplastic changes of the foveolar epithelium, and parietal cell protrusionsand oxyntic gland dilatations were observed in the fundic glands, without any intestinal metaplasia. The rate of acid-reducing drug usewas significantly higher in patients with MWFL than in those without (100% [13/13] vs. 53.7% [88/164], p<0.001). Conclusions: The present study indicated a relationship between the presence and endoscopic features of MWFL and history of acidreducingdrug use.
Kenta Chuman,Kenshi Yao,Takao Kanemitsu,Takashi Nagahama,Masaki Miyaoka,Haruhiko Takahashi,Kentaro Imamura,Rino Hasegawa,Toshiharu Ueki,Hiroshi Tanabe,Seiji Haraoka,Akinori Iwashita 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.2
Background/Aims: The objective of this study was to elucidate the histological structure of the absent microsurface patterns (MSPs)that were visualized by magnifying endoscopy with narrow-band imaging (M-NBI). Methods: The study included consecutive gastric epithelial neoplasias for which M-NBI findings and histological findings couldbe compared on a one-to-one basis. The lesions were classified as absent MSPs and present MSPs based on the findings obtainedusing M-NBI. Of the histopathological findings for each lesion that corresponded to M-NBI findings, crypt opening densities, cryptlengths, crypt opening diameters, intercrypt distances, and crypt angles were measured and compared. Results: Thirty-six lesions were included in the analysis; of these, 17 lesions exhibited absent MSP and 19 lesions exhibited presentMSP. Comparing the histological measurements for absent MSPs vs. present MSPs, median crypt opening density was 0.9 cryptopenings/mm vs. 4.8 crypt openings/mm (p<0.001), respectively. The median crypt length, median crypt opening diameter, medianintercrypt distance, and median crypt angle were 80.0 μm vs. 160 μm (p<0.001), 40.0 μm vs. 44.2 μm (p=0.09), 572.5 μm vs. 166.7μm (p<0.001), and 21.6 degrees vs. 15.5 degrees (p<0.001), respectively. Conclusions: Histological findings showed that lesions exhibiting absent MSPs had lower crypt opening density, shorter crypt length,greater intercrypt distance, and larger crypt angle.