title: DWI in the Etiologic Diagnosis of Excretory Upper Urinary Tract Lesions: Can It Help in Differentiating Benign From Malignant Tumors? A Retrospective Study of 98 Patients.
abstract: OBJECTIVE
  The objective of this study was to evaluate the diagnostic performance of high-field DWI in distinguishing benign from malignant lesions of the upper urinary tract (UUT).
  
  
  METHODS
  Ninety-eight patients who underwent 3-T DWI (b = 1000 s/mm(2)) for assessment of a UUT lesion were retrospectively included in the study. Data on the size, location, and mean apparent diffusion coefficient (ADC) value of the lesions were collected and correlated with the final diagnosis. ROC curve analysis was used to determine the best threshold value of the mean ADC for characterization of the lesions.
  
  
  RESULTS
  A total of 66 carcinomas and 33 benign lesions were identified. The mean (± SD) ADC value was statistically significantly lower for the malignant lesions than for the benign lesions (0.984 ± 0.048 vs 1.536 ± 0.067 × 10(-3) mm(2)/s; p = 0.000007). For characterization of malignant lesions, the best cutoff ADC value on the ROC curve was found to be less than or equal to 0.996 10(-3) mm(2)/s. On the basis of this value, the sensitivity and specificity of 3-T DWI for the identification of malignant UUT lesions were 78.3% and 95.5%, respectively, with a positive predictive value of 94.7% and a negative predictive value of 80.8% (p = 0.0001). The thickness of the smallest lesion was 3 mm. The mean ADC value of high-grade tumors was not statistically significantly lower than that of low-grade tumors. The best cutoff value for predicting benignancy was greater than or equal to 1.100 × 10(-3) mm(2)/s with sensitivity of 90.9%, specificity of 82.6%, positive predictive value of 83.3%, and negative predictive value of 90.5%.
  
  
  CONCLUSIONS
  The ADC measurement is a useful additional parameter in the differentiation of benign from malignant UUT lesions.
authors.affiliation: 1 Department of Radiology B, University Hospital of Strasbourg-New Civil Hospital, 1, Place de l'Hôpital, BP 426, Strasbourg, 67091 Cedex, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Roy
authors.affiliation: 1 Department of Radiology B, University Hospital of Strasbourg-New Civil Hospital, 1, Place de l'Hôpital, BP 426, Strasbourg, 67091 Cedex, France.
authors.forename: Aïssam
authors.initials: A
authors.lastname: Labani
authors.affiliation: 1 Department of Radiology B, University Hospital of Strasbourg-New Civil Hospital, 1, Place de l'Hôpital, BP 426, Strasbourg, 67091 Cedex, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Alemann
authors.affiliation: 1 Department of Radiology B, University Hospital of Strasbourg-New Civil Hospital, 1, Place de l'Hôpital, BP 426, Strasbourg, 67091 Cedex, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bierry
authors.affiliation: 2 Department of Urology, University Hospital of Strasbourg-New Civil Hospital, Strasbourg, France.
authors.forename: Herve
authors.initials: H
authors.lastname: Lang
authors.affiliation: 1 Department of Radiology B, University Hospital of Strasbourg-New Civil Hospital, 1, Place de l'Hôpital, BP 426, Strasbourg, 67091 Cedex, France.
authors.forename: Mickael
authors.initials: M
authors.lastname: Ohana
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014570:Urologic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: DWI; renal pelvis; ureter; ureteral neoplasms; urothelial carcinoma