title: Diffusion-weighted imaging using 3.0 T MRI as a possible biomarker of renal tumors.
abstract: OBJECTIVE
  Diffusion-weighted imaging (DWI) allows for differentiation of benign from malignant tumors, histological tumor types and their grade. The aim of the study was to evaluate the capabilities of DWI using 3 Tesla Magnetic resonance imaging (3T MRI) in the preoperative assessment of renal tumors.
  
  
  METHODS
  This retrospective study included 143 tumors in 139 patients (130 malignant tumors and 13 benign tumors) that were examined using DWI with b values of 50, 400 and 800 s/mm(2). In all tumors, the lowest value of apparent diffusion coefficient (ADC) in the solid tissue was measured and correlated with the histological finding.
  
  
  RESULTS
  A significant difference between ADCs of malignant and benign tumors was found (p<0.001). Comparison of the most common malignant and benign tumors clear-cell renal carcinoma (CCRCC) grade I and oncocytoma resulted in a difference of borderline significance with a marked overlap (p=0.046). By assessing the histological types of malignant tumors, we detected a significant difference between CCRCC and all other histological types (p=0.048 for chromophobe (CH) RCC, p=0.002 for papillary (P) RCC and p=0.002 for urothelial carcinoma (UC)). Mutual differentiation of other types of carcinomas was not feasible (p=1.0 in all cases). The differences between low-grade (grade I+II) and high-grade (grade III+IV) CCRCC was significant (p<0.001). A significant difference was found even between CCRCC grade I and others (p=0.01 for grade II, p<0.001 for grade III+IV, respectively).
  
  
  CONCLUSIONS
  DWI may contribute in distinguishing CCRCC from other histological types and to determinits grade. The method has certain potential for distinguishing benign from malignant tumors; however, differentiation of the most frequently represented types, CCRCC grade I and oncocytoma, remains difficult.
authors: Department of Radiology, Medical School and Teaching Hospital Pilsen, Charles University in Prague, Pilsen, Czech Republic Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic mirka@fnplzen.cz.
authors: Hynek
authors: H
authors: Mirka
authors: Department of Radiology, Medical School and Teaching Hospital Pilsen, Charles University in Prague, Pilsen, Czech Republic.
authors: Eva
authors: E
authors: Korcakova
authors: Department of Radiology, Medical School and Teaching Hospital Pilsen, Charles University in Prague, Pilsen, Czech Republic.
authors: Jan
authors: J
authors: Kastner
authors: Department of Urology, Medical School and Teaching Hospital Pilsen, Charles University in Prague, Pilsen, Czech Republic.
authors: Milan
authors: M
authors: Hora
authors: Sikl's Department of Pathology, Medical School and Teaching Hospital Pilsen, Charles University in Prague, Pilsen, Czech Republic Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic.
authors: Ondrej
authors: O
authors: Hes
authors: Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic.
authors: Petr
authors: P
authors: Hosek
authors: Department of Radiology, Medical School and Teaching Hospital Pilsen, Charles University in Prague, Pilsen, Czech Republic Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic.
authors: Jiri
authors: J
authors: Ferda
mesh_terms: D018249:Adenoma, Oxyphilic / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000737:chemistry; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media / Q000737:chemistry; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011859:Radiography; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media
keywords: Renal tumor; apparent diffusion coefficient; biomarker; diffusion weighted MRI; magnetic resonance imaging