title: Magnetic resonance with diffusion-weighted imaging in the evaluation of transplanted kidneys: preliminary findings.
abstract: BACKGROUND
  The aim of this study was to compare values of apparent diffusion coefficient (ADC) and diffusion (D) with renal function indexes, in a population of kidney transplant recipients who underwent magnetic resonance with diffusion-weighted imaging (DWI) of the transplanted graft.
  
  
  METHODS
  We studied 21 patients using a 1.5-Tesla magnetic resonance; DWI sequences were acquired with several b-values. Patients were divided into 3 groups by their creatinine clearance values: group A, clearance >60 mL/min; group B, clearance >30 and ≤60 mL/min; and group C, clearance ≤30 mL/min. ADCs values between groups were compared using the Mann-Whitney U test. Receiver operating characteristic (ROC) curves were created for prediction of normal renal function (group A) and renal failure (group C).
  
  
  RESULTS
  Comparing mean values of ADC between groups A and C, we observed a difference (P=0.0012), with higher values in group A. Regarding mean values of D, we observed a difference between groups A and C (P=0.022). In the comparison between contiguous groups, we observed no difference for ADC and D values. In the prediction of normal clearance values (group A), ROC curve showed an area under curve (AUC) of 0.861, with a sensitivity of 88.89% and specificity of 75% using a threshold ADC value ≥2.1 × 10(-3) mm(2)/sec. For prediction of normal clearance values (group A), ROC curve showed an AUC of 0.787, with a sensitivity of 77.8% and specificity of 83.3% using a threshold D value ≥2.3 × 10(-3) mm(2)/sec.
  
  
  CONCLUSIONS
  Although studies with a larger number of patients are needed, DWI represents a promising tool for noninvasive assessment of renal function. An ADC ≥ 2.1 × 10(-3) mm(2)/sec and a D ≥ 2.3 × 10(-3) mm(2)/sec may be used as a threshold for predicting normal clearance.
authors.affiliation: Section of Radiological Sciences, Maternal-Child and Radiological Sciences Department, 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: P
authors.initials: P
authors.lastname: Veroux
authors.forename: G
authors.initials: G
authors.lastname: Failla
authors.forename: P
authors.initials: P
authors.lastname: Milone
authors.forename: G C
authors.initials: GC
authors.lastname: Ettorre
authors.forename: N
authors.initials: N
authors.lastname: Sinagra
authors.forename: G
authors.initials: G
authors.lastname: Giuffrida
authors.forename: D
authors.initials: D
authors.lastname: Zerbo
authors.forename: M
authors.initials: M
authors.lastname: Veroux
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007558:Italy; D007668:Kidney / Q000503:physiopathology / Q000601:surgery*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D012372:ROC Curve; D051437:Renal Insufficiency / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D003404:Creatinine