Effects of postprandial state and mesenteric blood flow on the repeatability of MR elastography in asymptomatic subjects

Abstract

Purpose: To determine the repeatability of stiffness measurements in the liver using MR elastography (MRE) during the fasted and fed states. MRE has gained increased recognition as a noninvasive method to quantify fibrotic changes in the liver. It is well known that eating increases splanchnic blood flow, and fasting status of patients has been recognized as a factor that may affect hepatic stiffness measured with MRE. Materials and Methods:Hepatic MRE stiffness and flow through the superior mesenteric vein (SMV) were measured in 12 healthy subjects in fasted and fed states, and measurements were repeated 5 weeks later. A linear mixed effects model was used to estimate the sources of variability in the data, which included day (exams on different days) and subject. Sources were combined to calculate the overall standard deviation of a single MRE measurement. Results:The total within-subject standard deviation of an MRE exam is 8.5% (standard error [SE] ¼ 1.7%) or 9.0% (SE ¼ 1.8%) for fasted and fed states, respectively. No significant differences between fasted/fed state stiffness and no correlation between hepatic stiffness and SMV flow were observed. Conclusion:As seen in this smaller population, healthy subjects scanned in a known fasted or fed state provide repeatable stiffness estimates with no relationship to SMV flow.

Quantitative Liver MRI Combining Phase Contrast Imaging, Elastography, and DWI: Assessment of Reproducibility and Postprandial Effect at 3.0 T

“…A postprandial decrease of LS has been observed previously by Hines et al [49] (4/12 volunteers had mean decrease of −9.30%±3.35%), and by Berzigotti et al [26] (3/19 patients had mean decrease of −19.47%±15.56%). The observed postprandial decrease in the LS in our study could be partially due to the longer delay between fasting and postprandial exams, which may increase the variability in the measurements.…”

“…Changes in LS in response to a liquid meal have been observed recently using transient elastography and Doppler ultrasound [26] and MRE [40]. This correlation was not significant when only considering healthy volunteers, as observed by Hines et al [49]. Berzigotti et al [26] evaluated 19 patients with cirrhosis and portal hypertension, in whom they measured LS (using transient elastography), PV flow, and hepatic artery blood flow (using Doppler ultrasound) before and 30 minutes after a liquid meal.…”

Ultrasound Elastography and MR Elastography for Assessing Liver Fibrosis: Part 2, Diagnostic Performance, Confounders, and Future Directions

“…However, in one MR elastography study, postprandial status did not significantly alter liver stiffness in healthy subjects [72]. …”

Primary Liver Injury and Delayed Resolution of Liver Stiffness after Alcohol Detoxification in Heavy Drinkers with the PNPLA3 Variant I148M

“…Non-invasive measurement of LS by ultrasoundbased elastographic techniques such as transient elastography (TE) are increasingly used to screen for liver fibrosis [9,[20][21][22][23][24][25] . However, various conditions have been shown to increase LS in the absence of fibrosis including inflammation and liver damage [26][27][28] , congestion [29] , cholestasis [30] , arterial pressure [31] food intake [32,33] or amyloidosis [34,35] . For these reasons, we here study in detail the impact of PNPLA3 I148M substitution on LS and histology in a large population of heavy drinkers primarily admitted to the hospital for alcohol withdrawal.…”