title: The value of adding diffusion-weighted images for tumor detection and preoperative staging in renal pelvic carcinoma for the reader's experience.
abstract: This retrospective study aimed to assess the value of adding diffusion-weighted magnetic resonance imaging (DWI) or gadolinium-enhanced fat-suppressed T1WI (CEI) to T2-weighted imaging (T2WI) for preoperative T categorization in renal pelvic carcinoma by the reader's experience using surgical specimens as the reference standard.
  
  
  
  Two radiologists (Reader 1; 3 years, 2; 13 years) reviewed 49 cases with urothelial carcinoma who underwent magnetic resonance imaging examination before surgery, independently, using three image sets: T2WI alone, T2WI plus DWI, and T2WI plus CEI for tumor detection and T categorization. The differences in the apparent diffusion coefficient values between tumors and renal parenchyma, histopathologic grade were analyzed.
  
  
  
  T2WI plus CEI or DWI had high detection rates (93.4%) compared to T2WI alone. When discriminating T3a/T3b, for Reader 1, the use of T2WI plus DWI (88.0%) and T2WI plus CEI (92.0%) was significantly more accurate than T2WI alone (73%), with AUCs of 0.86, 0.86 and 0.77, respectively. For Reader 2, the accuracies were high on all image sets, with AUCs of 0.87-0.95, and the mean ADC of the tumors was significantly lower than that of the normal renal parenchyma. In addition, the mean ADC values of high-grade tumors were significantly lower than that of low-grade tumors.
  
  
  
  DWI and CEI could be more helpful than T2WI alone for preoperative T categorization by less-experienced reader and DWI could be used for preoperative T categorization and for predicting the histopathologic grade of renal pelvic carcinoma.
authors.affiliation: Department of Radiology, Faculty of Medicine, Shimane University, 89-1, Enya-cho, Izumo, Shimane, 693-8501, Japan. ryoshida0917@yahoo.co.jp.
authors.forename: Rika
authors.identifier: 0000-0002-9157-643X
authors.initials: R
authors.lastname: Yoshida
authors.affiliation: Department of Radiology, Faculty of Medicine, Shimane University, 89-1, Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshizako
authors.affiliation: Department of Radiology, Faculty of Medicine, Shimane University, 89-1, Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Maruyama
authors.affiliation: Department of Radiology, Faculty of Medicine, Shimane University, 89-1, Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mori
authors.affiliation: Department of Organ Pathology, Faculty of Medicine, Shimane University, 89-1, Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Ishikawa
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Shimane University, 89-1, Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Tamaki
authors.affiliation: Department of Radiology, Faculty of Medicine, Shimane University, 89-1, Enya-cho, Izumo, Shimane, 693-8501, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kitagaki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D007682:Kidney Pelvis / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011300:Preoperative Care; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media
keywords: 1.5T MRI; ADC value; Contrast-enhanced imaging; DWI; Renal pelvic carcinoma; Urothelial carcinoma