title: Investigation of renal lesions by diffusion-weighted magnetic resonance imaging applying intravoxel incoherent motion-derived parameters--initial experience.
abstract: OBJECTIVE
  Usefulness of biexponentially fitted signal attenuation at different b-values for differentiating the histological characteristics of renal tumors.
  
  
  METHODS
  A total of 26 patients with 28 renal masses (histologically proven: 20 clear cell renal cell carcinomas [ccRCC], three transitional cell carcinomas, two oncocytomas, and one papillary RCC) and 30 volunteers with healthy kidneys were examined at 1.5 Tesla using an echo-planar DWI sequence. Using the IVIM model, we calculated the perfusion fraction f and the diffusion coefficient D. Furthermore, the ADC was obtained. These tumor parameters were compared to healthy renal tissue nonparametrically, and a receiver operating characteristic (ROC) analysis was performed.
  
  
  RESULTS
  Healthy renal parenchyma showed higher ADC and D values (p<0.001) than ccRCC (ADC 1.95±0.10 [SD] μm2/ms, f 18.32±2.52%, and D 1.88±0.11 μm2/ms versus ADC 1.45±0.38 μm2/ms, f 18.59±6.16%, and D 1.34±0.38 μm2/ms). When detecting malignancies the area under the curve for D was higher than for ADC. The f values for ccRCC were higher (p<0.001) than for non-ccRCC (ADC 1.52±0.47 μm2/ms, f 8.44±1.24%, and D 1.30±0.18 μm2/ms). Both f and D correlated with ccRCC grading.
  
  
  CONCLUSIONS
  IVIM imaging is able to provide reliable diffusion values in the human kidney and may enhance the accuracy of tumor diagnosis. The D value was the best parameter to distinguish renal tumors from healthy renal tissue. The f value is promising for determining the histological subgroups.
authors: Diagnostic and Interventional Radiology, University of Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany. Rheinheimer@stud.uni-heidelberg.de
authors: S
authors: S
authors: Rheinheimer
authors: B
authors: B
authors: Stieltjes
authors: F
authors: F
authors: Schneider
authors: D
authors: D
authors: Simon
authors: S
authors: S
authors: Pahernik
authors: H U
authors: HU
authors: Kauczor
authors: P
authors: P
authors: Hallscheidt
mesh_terms: D018249:Adenoma, Oxyphilic / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D002291:Carcinoma, Papillary / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000473:pathology; D002295:Carcinoma, Transitional Cell / Q000473:pathology; D016022:Case-Control Studies; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D016018:Least-Squares Analysis; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol