title: Comparison between computed tomography multislice and high-field magnetic resonance in the diagnostic evaluation of patients with renal masses.
abstract: BACKGROUND
  Renal masses are a common finding in diagnostic imaging; these lesions usually are solid or cystic, benign or malignant, and the correct diagnosis may be difficult. The aim of our study was the comparison of multi-slice computed tomography (MSCT) and high-field magnetic resonance (MR) in the diagnostic evaluation of renal masses.
  
  
  METHODS
  We studied 29 patients, 16 men and 13 women aged 8-85 years (mean 61±17 years) with histo-cytological diagnosis of renal masses (n=31), of which the majority (74%; n=23) was represented by malignant lesions [renal cell carcinoma (Ca) =16, chromophobe renal cell Ca =2, squamous cell Ca =1, urothelial Ca =2, lymphoma =1, Wilms tumor =1]; the remaining 8 masses (26%) were benign (pyelonephritis =2, simple cyst =1, hematic cyst =1, lipoma =1 and oncocytoma =3). All patients underwent MSCT and MR (3.0 Tesla) before and after contrast injection; the images were evaluated in double-blind by two expert radiologists. The results of the images were then compared with the histo-cytological data to calculate the values of diagnostic accuracy for both methods in the identification and characterization of renal masses. The benign or malignant nature of the lesions was established according to the regularity of the margins, presence or absence of significant contrast enhancement, infiltration of perirenal fat and vascular invasion. The concordance of the results of the two imaging techniques was then calculated using the coefficient Kappa Cohen.
  
  
  RESULTS
  For both identification and characterization of renal masses, MSCT and MR showed comparable values of diagnostic accuracy with a significant concordance (k=1); in particular, the diagnostic accuracy of MSCT/MR was 100%/100% for lesion identification, 90%/90% for lesion characterization in terms of benign or malignant nature, 97%/97% for the evaluation of lesion edges, 90%/90% for the assessment of lesion contrast enhancement, 93%/93% for the evaluation of peri-renal fat infiltration and 96%/96% for the evaluation of vascular infiltration. Only in three cases of oncocytoma the two imaging methods were both inaccurate for diagnosis of benignity classifying the lesions as probably malignant on the basis of the absence of central scar and of dynamic contrast enhancement pattern.
  
  
  CONCLUSIONS
  The results of our study show comparable diagnostic accuracy of computed tomography (CT) and MR for the identification and characterization of expansive renal lesions. High-field MR is, therefore, a valid alternative to MSCT in the evaluation of renal masses avoiding exposure to ionizing radiation.
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Baldari
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Capece
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Mainenti
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Anna Giacoma
authors.initials: AG
authors.lastname: Tucci
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Klain
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Immacolata
authors.initials: I
authors.lastname: Cozzolino
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Salvatore
authors.affiliation: 1 Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy ; 2 Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Naples, Italy ; 3 IRCCS SDN, Naples, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Maurea
keywords: Multi-slice computed tomography (MSCT); characterization; identification; magnetic resonance (MR); renal masses