title: Using a 3% Proton Density Fat Fraction as a Cut-Off Value Increases Sensitivity of Detection of Hepatic Steatosis, Based on Results From Histopathology Analysis.
abstract: It is possible to estimate hepatic triglyceride content by calculating the proton density fat fraction (PDFF), using proton magnetic resonance spectroscopy (1H-MRS), instead of collecting and analyzing liver biopsy specimens to detect steatosis. However, the current PDFF cut-off value (5%) used to define steatosis by magnetic resonance was derived from studies that did not use histopathology as the reference standard. We performed a prospective study to determine the accuracy of1H-MRS PDFF in the measurement of steatosis using histopathology analysis as the standard. We collected clinical, serologic,1H-MRS PDFF, and liver biopsy data from 94 adult patients with increased levels of liver enzymes (≥6 mo) referred to the Department of Gastroenterology and Hepatology at Linköping University Hospital in Sweden from 2007 through 2014. Steatosis was graded using the conventional histopathology method and fat content was quantified in biopsy samples using stereologic point counts (SPCs). We correlated the1H-MRS PDFF findings with SPCs (r = 0.92; P < .001).1H-MRS PDFF results correlated with histopathology results (ρ = 0.87; P < .001), and SPCs correlated with histopathology results (ρ = 0.88; P < .001). All 25 subjects with PDFF values of 5.0% or more had steatosis based on histopathology findings (100% specificity for PDFF). However, of 69 subjects with PDFF values less than 5.0% (negative result), 22 were determined to have steatosis based on histopathology findings (53% sensitivity for PDFF). Reducing the PDFF cut-off value to 3.0% identified patients with steatosis with 100% specificity and 79% sensitivity; a PDFF cut-off value of 2.0% identified patients with steatosis with 94% specificity and 87% sensitivity. These findings might be used to improve noninvasive detection of steatosis.
authors.affiliation: Department of Medical and Health Sciences, University Hospital, Linköping, Sweden; Department of Gastroenterology and Hepatology, University Hospital, Linköping, Sweden.
authors.forename: Patrik
authors.initials: P
authors.lastname: Nasr
authors.affiliation: Department of Medical and Health Sciences, University Hospital, Linköping, Sweden; Wolfram MathCore AB, University Hospital, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), University Hospital, Linköping, Sweden.
authors.forename: Mikael F
authors.initials: MF
authors.lastname: Forsgren
authors.affiliation: Department of Clinical and Experimental Medicine, University Hospital, Linköping, Sweden; Department of Clinical Pathology and Clinical Genetics, University Hospital, Linköping, Sweden.
authors.forename: Simone
authors.initials: S
authors.lastname: Ignatova
authors.affiliation: Department of Medical and Health Sciences, University Hospital, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), University Hospital, Linköping, Sweden; Department of Radiology, University Hospital, Linköping, Sweden.
authors.forename: Nils
authors.initials: N
authors.lastname: Dahlström
authors.affiliation: Department of Clinical and Experimental Medicine, University Hospital, Linköping, Sweden; Department of Biomedical Engineering, University Hospital, Linköping, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Cedersund
authors.affiliation: Department of Medical and Health Sciences, University Hospital, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), University Hospital, Linköping, Sweden.
authors.forename: Olof Dahlqvist
authors.initials: OD
authors.lastname: Leinhard
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), University Hospital, Linköping, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Norén
authors.affiliation: Department of Medical and Health Sciences, University Hospital, Linköping, Sweden; Department of Gastroenterology and Hepatology, University Hospital, Linköping, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Ekstedt
authors.affiliation: Department of Medical and Health Sciences, University Hospital, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), University Hospital, Linköping, Sweden; Department of Radiation Physics, University Hospital, Linköping, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Lundberg
authors.affiliation: Department of Medical and Health Sciences, University Hospital, Linköping, Sweden; Department of Gastroenterology and Hepatology, University Hospital, Linköping, Sweden. Electronic address: stergios.kechagias@liu.se.
authors.forename: Stergios
authors.initials: S
authors.lastname: Kechagias
mesh_terms: D050154:Adiposity; D000328:Adult; D000368:Aged; D001706:Biopsy; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000175:diagnosis* / Q000473:pathology*; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D014280:Triglycerides / Q000032:analysis*
chemical_list: D014280:Triglycerides
keywords: Diagnostic Tests; NASH; Nonalcoholic Fatty Liver Disease