title: Magnetic resonance with diffusion-weighted imaging in the evaluation of transplanted kidneys: updating results in 35 patients.
abstract: BACKGROUND
  We compared values of apparent diffusion coefficient (ADC) with renal function indices among a population of kidney transplant recipients who underwent magnetic resonance with diffusion-weighted imaging (DWI) of their grafts.
  
  
  METHODS
  Thirty-five patients with right iliac transplanted kidneys were studied using 1.5-T magnetic resonance. Diffusion echo-planar sequences with several b-values were acquired to investigate transplanted grafts. Patients were divided into 3 groups according to their creatinine clearances; Group A, clearance >60 mL/min; Group B, clearance >30 and ≤60 mL/min; and Group C, clearance ≤30 mL/min. ADC values between groups were compared using Mann-Whitney U test. Receiver operating characteristic (ROC) curves were used to predict the normal function (Group A) versus renal failure cohorts (Group C).
  
  
  RESULTS
  Comparing mean values of ADC between Group A and Group C patients, we observed a significant difference (P = .0003) with higher ADC values among patients with a normal creatinine clearance (>60 mL/min). Comparing Groups B and C did not show a significant difference (P = .05); nor did Group A and Group B reveal a significant difference (P = .38). To predict normal clearance values, the Group A ROC curve showed an area under curve (AUC) of 0.780 with a sensitivity of 92.3% and a specificity of 68.2% at a threshold ADC value of ≥2.08 × 10(-3) mm(2)/sec. In the prediction of low clearance values, the Group C ROC curve showed an AUC of 0.846 with a sensitivity of 83.3% and a specificity of 82.6% using a threshold ADC value of ≤2.07 × 10(-3) mm(2)/sec.
  
  
  CONCLUSIONS
  Updating our experience among 35 patients, DWI was confirmed to be a promising noninvasive tool to assess renal function; an ADC ≥2.08 × 10(-3) mm(2)/sec may be used as a threshold to predict a normal clearance. However, an overlap of ADC values between groups is a limit.
authors.affiliation: Radiodiagnostic and Oncological Radiotherapy Unit, University Hospital Policlinico-Vittorio Emanuele, Catania, Italy. spalmucci@sirm.org
authors.forename: S
authors.initials: S
authors.lastname: Palmucci
authors.forename: L A
authors.initials: LA
authors.lastname: Mauro
authors.forename: G
authors.initials: G
authors.lastname: Failla
authors.forename: P V
authors.initials: PV
authors.lastname: Foti
authors.forename: P
authors.initials: P
authors.lastname: Milone
authors.forename: N
authors.initials: N
authors.lastname: Sinagra
authors.forename: D
authors.initials: D
authors.lastname: Zerbo
authors.forename: P
authors.initials: P
authors.lastname: Veroux
authors.forename: G C
authors.initials: GC
authors.lastname: Ettorre
authors.forename: M
authors.initials: M
authors.lastname: Veroux
mesh_terms: D000328:Adult; D000368:Aged; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged