You have accessJournal of UrologyImaging/Radiology: Uroradiology II1 Apr 2018MP20-18 SEMI-AUTOMATIC SEGMENTATION ANALYSIS OF DIFFUSION-WEIGHTED MRI AS AN IMAGING BIOMARKER FOR HISTOLOGICAL GRADE OF BLADDER CANCER Kasumi Kaneko, Soichiro Yoshida, Taro Takahara, Shugo Yajima, Tsuyoshi Sakamoto, Thomas Kwee, Yuki Arita, Minato Yokoyama, Junichiro Ishioka, Yoh Matsuoka, Kazutaka Saito, Kazunori Kihara, and Yasuhisa Fujii Kasumi KanekoKasumi Kaneko More articles by this author , Soichiro YoshidaSoichiro Yoshida More articles by this author , Taro TakaharaTaro Takahara More articles by this author , Shugo YajimaShugo Yajima More articles by this author , Tsuyoshi SakamotoTsuyoshi Sakamoto More articles by this author , Thomas KweeThomas Kwee More articles by this author , Yuki AritaYuki Arita More articles by this author , Minato YokoyamaMinato Yokoyama More articles by this author , Junichiro IshiokaJunichiro Ishioka More articles by this author , Yoh MatsuokaYoh Matsuoka More articles by this author , Kazutaka SaitoKazutaka Saito More articles by this author , Kazunori KiharaKazunori Kihara More articles by this author , and Yasuhisa FujiiYasuhisa Fujii More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.688AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The apparent diffusion coefficient (ADC) value is a quantitative parameter for the degree of water diffusion within of tissue, and is calculated from diffusion-weighted MRI (DWI). Previous studies have reported that the ADC value reflects histological characteristics in several malignancies. So far, the ADC value was usually calculated manually, and operator-related errors was induced. To utilize the ADC value as an imaging biomarker, standardization of the objective assessment of the ADC value is needed. Here, we newly developed an objective method for volumetric ADC value analysis using semi-automatic segmentation. The calculated ADC value represents all pixels of the tumor: the global ADC value (gADC). We evaluated the usefulness of gADC as an imaging biomarker for the histological grade of bladder cancer (BC). METHODS A total of 55 consecutive pT1 urothelial cell BC patients who underwent MRI including DWI (b values of 0 and 1000 sec/mm2) before transurethral resection between 2010 and 2015, were retrospectively evaluated. 2 independent readers analyzed the DWI datasets using newly developed medical imaging software, BD score (PixSpace, Japan). The pixels of the tumor in each patient, indicating an ADC from 0.3 x 10-3 to 1.5 x 10-3 mm2/s, were identified from all image slices, and the volume (tVol) and the gADC of the identified pixels were calculated. We compared tVol and gADC with the histological grade of the tumor. RESULTS 11 tumors whose gADC was out-of-measuring range and 2 tumors greater than 5 cm in size were excluded, and the remaining 42 (median tumor size: 2.0 cm (range: 0.5-4.0 cm), dominant grade 3/1-2: n=22/20) were eligible for the analysis. The gADC1 measured by reader 1 and gADC2 measured by reader 2 were significantly lower for grade 3 tumors than for grade 1-2 tumors (median gADC1: 1.05 x 10-3 vs 1.18 x 10-3 mm2/sec, p = 0.023; gADC2 value: 1.05 x10-3 vs 1.18 x 10-3 mm2/sec, p = 0.030). Inter-observer analysis revealed an intraclass correlation coefficient for the gADC and tVol of ρ = 0.96 and 0.98 respectively (p<0.001 for both) CONCLUSIONS The semi-automatic segmentation analysis enables objective evaluations of DWI signals with high concordance between the readers. The gADC reflects the histological grades of BC. The gADC can be an imaging biomarker of BC. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e260 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Kasumi Kaneko More articles by this author Soichiro Yoshida More articles by this author Taro Takahara More articles by this author Shugo Yajima More articles by this author Tsuyoshi Sakamoto More articles by this author Thomas Kwee More articles by this author Yuki Arita More articles by this author Minato Yokoyama More articles by this author Junichiro Ishioka More articles by this author Yoh Matsuoka More articles by this author Kazutaka Saito More articles by this author Kazunori Kihara More articles by this author Yasuhisa Fujii More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...