Non-Invasive Assessment of Hepatic Steatosis in Patients with NAFLD Using Controlled Attenuation Parameter and 1H-MR Spectroscopy

Abstract

IntroductionNon-invasive assessment of steatosis and fibrosis is of growing relevance in non-alcoholic fatty liver disease (NAFLD). 1H-Magnetic resonance spectroscopy (1H-MRS) and the ultrasound-based controlled attenuation parameter (CAP) correlate with biopsy proven steatosis, but have not been correlated with each other so far. We therefore performed a head-to-head comparison between both methods.MethodsFifty patients with biopsy-proven NAFLD and 15 healthy volunteers were evaluated with 1H-MRS and transient elastography (TE) including CAP. Steatosis was defined according to the percentage of affected hepatocytes: S1 5-33%, S2 34–66%, S3 ≥67%.ResultsSteatosis grade in patients with NAFLD was S1 36%, S2 40% and S3 24%. CAP and 1H-MRS significantly correlated with histopathology and showed comparable accuracy for the detection of hepatic steatosis: areas under the receiver-operating characteristics curves were 0.93 vs. 0.88 for steatosis ≥S1 and 0.94 vs. 0.88 for ≥S2, respectively. Boot-strapping analysis revealed a CAP cut-off of 300 dB/m for detection of S2-3 steatosis, while retaining the lower cut-off of 215 dB/m for the definition of healthy individuals. Direct comparison between CAP and 1H-MRS revealed only modest correlation (total cohort: r = 0.63 [0.44, 0.76]; NAFLD cases: r = 0.56 [0.32, 0.74]). For detection of F2–4 fibrosis TE had sensitivity and specificity of 100% and 98.1% at a cut-off value of 8.85 kPa.ConclusionOur data suggest a comparable diagnostic value of CAP and 1H-MRS for hepatic steatosis quantification. Combined with the simultaneous TE fibrosis assessment, CAP represents an efficient method for non-invasive characterization of NAFLD. Limited correlation between CAP and 1H-MRS may be explained by different technical aspects, anthropometry, and presence of advanced liver fibrosis.

Diagnostic Accuracy of Controlled Attenuation Parameter Measured by Transient Elastography for the Non-invasive Assessment of Liver Steatosis: a Prospective Study

“…Despite some overlap in adjacent steatosis grades, the overall differences between any two steatosis grades were statistically significant, except S2 vs S3, finding which is also confirmed by other authors [23-25, 40, 41]. Moreover, this situation is also encountered when quantifying steatosis using 1 H-magnetic resonance spectroscopy [41], which raises the suspicion of bias on steatosis quantification on LB for those grades.…”

“…24 No 1: [35][36][37][38][39][40][41][42] The current "gold standard" for evaluating steatosis is liver biopsy (LB), but it is invasive and may result in severe complications [8]. Furthermore, LB has potential sampling errors and cannot be readily repeated for adequate patient follow-up [9].…”

A case of insulinoma with non-alcoholic fatty liver disease: Roles of hyperphagia and hyperinsulinemia in pathogenesis of the disease

“…Liver biopsy was done during the operation and the patient was diagnosed as NAFLD type 1 according to Matteoni's criteria [6] based on 1) the findings of hepatic steatosis diagnosed by ultrasonography and histological examination and 2) no significant alcohol consumption [1]. The high level of liver enzymes and controlled attenuation parameter (CAP), which is a measurement of ultrasound attenuation analyzed by ultrasonic transient elastography using the M probe according to the manufacturer's recommendation (FibroScan; Echosens, Paris, France) [7], supported this diagnosis (Fig. 1A).…”

The relationship between hepatic steatosis and skeletal muscle mass index in men with type 2 diabetes

“…We defined fatty liver as steatosis categories over S1 stage [25]. In addition, we defined nonalcoholic steatohepatitis as FIB4 index ≥ 2.67 [26].…”