title: Characterization of focal liver lesions by ADC measurements using a respiratory triggered diffusion-weighted single-shot echo-planar MR imaging technique.
abstract: The aim of this study was to determine apparent diffusion coefficients (ADCs) of focal liver lesions on the basis of a respiratory triggered diffusion-weighted single-shot echo-planar MR imaging sequence (DW-SS-EPI) and to evaluate whether ADC measurements can be used to characterize lesions. One hundred and two patients with focal liver lesions [11 hepatocellular carcinomas (HCC), 82 metastases, 4 focal nodular hyperplasias (FNH), 56 hemangiomas and 51 cysts; mean size, 16.6 mm; range 5-92 mm] were examined on a 1.5-T system using respiratory triggered DW-SS-EPI (b-values: 50, 300, 600 s/mm2). Results were correlated with histopathologic data and follow-up imaging. The ADCs of different lesion types were compared, and lesion discrimination using optimal thresholds for ADCs was evaluated. Mean ADCs (x10(-3)mm2/s) were 1.24 and 1.04 for normal and cirrhotic liver parenchyma and 1.05, 1.22, 1.40, 1.92 and 3.02 for HCCs, metastases, FNHs, hemangiomas and cysts, respectively. Mean ADCs differed significantly for all lesion types except for comparison of metastases with HCCs and FNHs. Overall, 88% of lesions were correctly classified as benign or malignant using a threshold value of 1.63 x 10(-3)mm2/s. Measurements of the ADCs of focal liver lesions on the basis of a respiratory triggered DW-SS-EPI sequence may constitute a useful supplementary method for lesion characterization.
authors.affiliation: Department of Radiology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 Munich, Germany. mbruegel@roe.med.tum.de
authors.forename: Melanie
authors.initials: M
authors.lastname: Bruegel
authors.forename: Konstantin
authors.initials: K
authors.lastname: Holzapfel
authors.forename: Jochen
authors.initials: J
authors.lastname: Gaa
authors.forename: Klaus
authors.initials: K
authors.lastname: Woertler
authors.forename: Simone
authors.initials: S
authors.lastname: Waldt
authors.forename: Berthold
authors.initials: B
authors.lastname: Kiefer
authors.forename: Alto
authors.initials: A
authors.lastname: Stemmer
authors.forename: Carl
authors.initials: C
authors.lastname: Ganter
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000473:pathology; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000175:diagnosis / Q000473:pathology; D006391:Hemangioma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D008107:Liver Diseases / Q000175:diagnosis* / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D008297:Male; D008875:Middle Aged; D012119:Respiration