title: Diffusion Weighted Magnetic Resonance Imaging for the Classification of Focal Liver Lesions as Benign or Malignant.
abstract: OBJECTIVE
  To assess the role of diffusion weighted imaging sequence (DWI), routinely used in hepatic magnetic resonance imaging (MRI) for the differentiation of focal liver lesions (FLLs) as benign or malignant.
  
  
  METHODS
  99 FLLs assessed by liver MRI in 80 patients were included in the present study. All lesions were retrospectively analyzed by two experienced radiologists, independent from each other, who were not aware of the previous results obtained by using different imaging techniques. All included FLLs had a final histological diagnosis or a final diagnosis based on consensus reading by two experienced radiologists and follow-up at 6 months. The FLLs signal was qualitatively appreciated on the b-800 sequences and on the apparent diffusion coefficient (ADC) map. The ADC value of each FLL was measured and the ADC ratio between the ADC value of the assessed FLL and that of the surrounding liver parenchyma were calculated.
  
  
  RESULTS
  The mean ADC value for benign FLLs as assessed by the two independent readers was 1.78 x 10¯³ and 1.72 x 10¯³, respectively. The mean ADC value for malignant FLLs was 0.92 x 10¯³ for the first reader and 0.95 x 10¯³ for the second reader. The mean ADC ratio for benign FLLs was 1.91 and 1.85 for the two readers and for malignant FLLs was 0.91 and 0.94, respectively. Using an ADC value lower than 1.024 x 10¯³ offers a specificity of 100% and a sensitivity of 62.5% for the diagnosis of malignant FLLs. The ADC value is an indicator which is less prone to interobserver variability (correlation of 0.919→1). The ADC ratio has, as the analysis of the ROC curve shows, the best predictive value for differentiation between benign and malignant FLLs. Analysis of the signal intensity on the DWI b-800 image alone is of no significance in differentiating benign from malignant FLLs (p>0.05).
  
  
  CONCLUSIONS
  The ADC value and the ADC ratio assessed on liver DWI are useful diagnostic tools in the differential diagnosis of benign vs. malignant FLLs. Quantitative methods such as calculating the ADC value or ADC ratio have better diagnostic value than the qualitative techniques.
authors.affiliation: Department of Radiology and Computed Tomography, Prof. Dr. Octavian Fodor Institute of Gastroenterology and Hepatology; "Iuliu Hatieganu" University of Medicine and Pharmacy, Cluj-Napoca, Romania. ccaraiani@yahoo.com.
authors.forename: Cosmin
authors.initials: C
authors.lastname: Caraiani
authors.affiliation: Med. Klinik 2, Caritas Krankenhaus Bad Mergentheim, Bad Mergentheim, Germany; Département d'imagerie médicale, Clinique des Cévennes, 07100 Annonay, France.
authors.forename: Liliana
authors.initials: L
authors.lastname: Chiorean
authors.affiliation: Department of Radiology and Computed Tomography, Prof. Dr. Octavian Fodor Institute of Gastroenterology and Hepatology, Cluj-Napoca, Romania.
authors.forename: Diana Ioana
authors.initials: DI
authors.lastname: Fenesan
authors.affiliation: Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Andrei
authors.initials: A
authors.lastname: Lebovici
authors.affiliation: Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Diana
authors.initials: D
authors.lastname: Feier
authors.affiliation: Department of Radiology and Computed Tomography, Prof. Dr. Octavian Fodor Institute of Gastroenterology and Hepatology, Cluj-Napoca, Romania.
authors.forename: Mirela
authors.initials: M
authors.lastname: Gersak
authors.affiliation: Department of Radiology and Computed Tomography, Prof. Dr. Octavian Fodor Institute of Gastroenterology and Hepatology, Cluj-Napoca, Romania.
authors.forename: Adriana Mirela
authors.initials: AM
authors.lastname: Calin
authors.affiliation: Department of Radiology and Computed Tomography, Prof. Dr. Octavian Fodor Institute of Gastroenterology and Hepatology, Cluj-Napoca, Romania.
authors.forename: Marian
authors.initials: M
authors.lastname: Dan
authors.affiliation: Medisprof Oncology Clinic, Cluj-Napoca, Romania.
authors.forename: Claudia
authors.initials: C
authors.lastname: Militaru
authors.affiliation: Faculty of Economy and Business Administration, Cluj-Napoca, Romania.
authors.forename: Codruta
authors.initials: C
authors.lastname: Mare
authors.affiliation: Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Lidia
authors.initials: L
authors.lastname: Ciobanu
authors.affiliation: Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Radu
authors.initials: R
authors.lastname: Badea
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055815:Young Adult