Quantification Of Hepatic Fat Content Research Articles

The Impact of Administration of Fenofibrate During Suckling on Glucose Homeostasis and Programming of Metabolic Function in Adolescent Sprague Dawley Rats

Fenofibrate, a PPAR α agonist used in the treatment of hyperlipidaemia is known to prevent diabetes and its complications. It is cautiously used during pregnancy and in neonates due to its potential for teratogenesis. The suckling period is a critical window for developmental programming. Drugs with antimetabolic syndrome activities have been used during critical developmental periods to program for protection against metabolic syndrome or its components. We evaluated the long-term metabolic effects of fenofibrate when administered during suckling and whether it would prevent the poor metabolic outcomes associated with high fructose intake in adolescent rats. A total of 119, 6-day-old (male and female) Sprague Dawley pups were randomly allocated to four groups and either orally gavaged with 10ml.kg-1 DMSO (0.5%), 100mg.kg-1 fenofibrate, 20% (w/v) fructose or both fructose and fenofibrate till 21 days after birth (PND) 21. Following weaning onto standard commercial rat cubes, the groups were split up further into two based on their drinking fluid: either fructose (20%, w/v) or tap water till PND 63 when they were subjected to an overnight fast before being terminated. Blood was taken for hormone analysis. The kidneys, pancreas, liver and visceral fat pad were weighed. Hepatic tissue was stored at -20ºC until quantification of hepatic fat content. Although the rats gained weight significantly (p<0.0001) throughout the study period, there were no significant differences in terminal body weights across the groups (p>0.05). The interventions did not significantly (p>0.05) alter concentrations of blood glucose, adiponectin and insulin. In both sexes, the HOMA-IR, liver lipids and visceral masses were similar in the different treatment groups. Fenofibrate administered to suckling rats did not adversely impact health of the study rats. It may therefore be safe for use in neonates.

Detection and quantification of a focal fat deposition in a liver undergoing multiple operations for neuroendocrine tumor disease using attenuation imaging: a case report

BackgroundIn patients with history of malignancy, new-onset liver lesions often present diagnostic challenges. We present the case of a patient with history of neuroendocrine tumor and new-onset echo-rich hepatic lesion, in whom attenuation imaging helped to make the diagnosis. Attenuation imaging is an ultrasound-based technique that allows for the quantification of hepatic fat content on the basis of a measurement of sound attenuation.Case presentationWe present the case of a 62-year-old Caucasian female patient who underwent pylorus-preserving pancreaticoduodenectomy Whipple surgery in 2004 for histologically well-differentiated neuroendocrine tumor with a proliferation rate of 3% of the pancreatic head. During the course, single liver metastases were resected in 2009, 2010, and 2013. In 2019, hemihepatectomy was performed when two liver metastases recurred. The liver metastases each showed a proliferation rate of 10% with vigorous expression of chromogranin A, synaptophysin, and somatostatin. The most recent follow-up examinations showed a normal chromogranin A value and the patient reported a good general condition. However, sonography revealed a blurred, echoic lesion in the liver. On contrast-enhanced sonography, the lesion showed identical behavior to the surrounding liver parenchyma. In the asymptomatic patient, liver biopsy did not seem to be indicated at the current time. Measurement of the attenuation coefficient by attenuation imaging showed a significantly higher measurement in the area of the echo-rich lesion than in the rest of the liver. The overall findings are consistent with focal fat deposition.ConclusionsAttenuation imaging appears to be useful in the evaluation of unclear echo-rich liver lesions. In particular, primary non-malignant-appearing liver lesions that are unremarkable on abdominal contrast-enhanced ultrasound can be more accurately assessed.

Improved Folch Method for Liver-Fat Quantification.

Fatty liver represents a significant metabolic pathology of excess intrahepatic fat in domestic animals and humans. Quantification of hepatic-fat content is therefore essential for diagnosis and investigation of liver and metabolic disease. However, the reproducibility of hepatic steatosis analysis is often low due to subjective and technical factors. We hypothesized that improvement in tissue-lipids extraction efficiency would contribute to the accuracy and precision of liver-fat determination. To test it, we investigated the effect of standardized tissue sonication on liver-fat quantification by the Folch method in sheep. Liver samples from grownup lambs of lean (n = 16) and fatty (n = 15) livers, and from pregnant ewes (n = 6) who died from pregnancy toxemia (PT), were used for hepatic-fat content determination with or without tissue sonication. In the grown lambs, an average hepatic-fat content of 6.6% was determined in sonicated compared to 5.1% in non-sonicated specimens (P = 0.0002). Similarly, in ewes with PT, an average of 12.5% was determined with sonication compared to 10.8% without it (P = 0.0006), and the reproducibility was higher with sonication (CV of 3.1 vs. 6.1%, respectively). Thus, tissue sonication improved the efficiency of liver-lipids extraction and was significant to the accuracy and precision of hepatic-fat determination. Enzymatic quantification of triglycerides was moderately correlated with the results obtained gravimetrically (r = 0.632, P < 0.005). The reported data provide reliable reference values for pregnancy toxemic sheep. The significant improvement in liver-fat quantification observed with the reported revised protocol is likely applicable to most mammals and humans.

Thrombospondin1 as a potential therapeutic target for human nonalcoholic fatty liver disease.

Thrombospondin1 as a potential therapeutic target for human nonalcoholic fatty liver disease.

Prospective, Same-Day, Direct Comparison of Controlled Attenuation Parameter With the M vs the XL Probe in Patients With Nonalcoholic Fatty Liver Disease, Using Magnetic Resonance Imaging–Proton Density Fat Fraction as the Standard

Controlled attenuation parameter (CAP) measurements using M probe have been reported to be lower than those of the XL-probe in detection of hepatic steatosis. However, there has been no direct comparison of CAP with the M vs the XL probe in patients with nonalcoholic fatty liver disease (NAFLD). We compared CAP with the M vs the XL probe for quantification of hepatic fat content, using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the standard. We performed a prospective study of 100 adults (mean body mass index [BMI], 30.6 ± 4.7 kg/m2) with and without NAFLD, assessed by CAP with the M probe and XL probe on the same day, at a single research center, from November 2017 through November 2018. We then measured the MRI-PDFF as the reference standard. Outcomes were presence of hepatic steatosis, defined as MRI-PDFF ≥ 5%, and detection of hepatic fat content ≥ 10%, defined as MRI-PDFF ≥ 10%. We performed area under the receiver operating characteristic curve (AUROC) analyses to assess the diagnostic accuracy of CAP for each probe in detection of hepatic steatosis (MRI-PDFF ≥ 5%) and of hepatic fat content ≥ 10%. Of the study participants, 68% had an MRI-PDFF of 5% or more and 48% had an MRI-PDFF of 10% or more. The mean CAP measured by the M probe (310 ± 62 db/m) was significantly lower than by the X probe (317 ± 63 db/m) (P = .007). When M probe was used in participants with BMIs <30 kg/m2 and XL probe in participants with BMIs ≥30 kg/m2, the CAP measured by the M probe (312 ± 51.4 db/m) remained significantly lower than that of the XL probe (345 ± 47.6 db/m) (P = .0035.), when the MRI-PDFF was above 5%. The optimal threshold of CAP for the detection of MRI-PDFF≥5%, was 294 db/m with the M probe and 307 db/m with the XL probe. The optimal threshold of CAP for the detection of MRI-PDFF ≥ 10%, was 311 db/m with the M probe and 322 db/m with the XL probe. For only the XL probe, CAP measurements with an interquartile range below 30 dB/m detected an MRI-PDFF≥5% with a lower AUROC (0.97; 95% CI, 0.80-1.00) than CAP measurements with an interquartile range above 30 dB/m (AUROC, 0.82; 95% CI, 0.71-0.90) (P = .0129). In an analysis of the same patients using CAP with the M probe and XL probe, with MRI-PDFF as the standard, we found that the M probe under-quantifies CAP values compared with the XL probe, independent of BMI. The type of probe should be considered when interpreting CAP data from patients with NAFLD.

Non-invasive quantification of hepatic fat content in healthy dogs by using proton magnetic resonance spectroscopy and dual gradient echo magnetic resonance imaging.

The objective of the present study was to describe two non-invasive methods for fat quantification in normal canine liver by using magnetic resonance imaging (MRI) and spectroscopy. Eleven adult beagle dogs were anesthetized and underwent magnetic resonance examination of the cranial abdomen by performing morphologic, modified Dixon (mDixon) dual gradient echo sequence, and proton magnetic resonance spectroscopy (1H MRS) imaging. In addition, ultrasonographic liver examination was performed, fine-needle liver aspirates and liver biopsies were obtained, and hepatic triglyceride content was assayed. Ultrasonographic, cytologic, and histologic examination results were unremarkable in all cases. The median hepatic fat fraction calculated was 2.1% (range, 1.3%–5.5%) using mDixon, 0.3% (range, 0.1%–1.0%) using 1H MRS, and 1.6% (range 1.0%–2.5%) based on triglyceride content. The hepatic fat fractions calculated using mDixon and 1H MRS imaging were highly correlated to that based on triglyceride content. A weak correlation between mDixon and 1H MRS imaging was detected. The results show that hepatic fat content can be estimated using non-invasive techniques (mDixon or 1H MRS) in healthy dogs. Further studies are warranted to evaluate the use of these techniques in dogs with varying hepatic fat content and different hepatic disorders.

Simultaneous MR quantification of hepatic fat content, fatty acid composition, transverse relaxation time and magnetic susceptibility for the diagnosis of non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is characterized at histology by steatosis, hepatocyte ballooning and inflammatory infiltrates, with or without fibrosis. Although diamagnetic material in fibrosis and inflammation can be detected with quantitative susceptibility imaging, fatty acid composition changes in NASH relative to simple steatosis have also been reported. Therefore, our aim was to develop a single magnetic resonance (MR) acquisition and post-processing scheme for the diagnosis of steatohepatitis by the simultaneous quantification of hepatic fat content, fatty acid composition, T2 * transverse relaxation time and magnetic susceptibility in patients with non-alcoholic fatty liver disease. MR acquisition was performed at 3.0T using a three-dimensional, multi-echo, spoiled gradient echo sequence. Phase images were unwrapped to compute the B0 field inhomogeneity (ΔB0 ) map. The ΔB0 -demodulated real part images were used for fat-water separation, T2 * and fatty acid composition quantification. The external and internal fields were separated with the projection onto dipole field method. Susceptibility maps were obtained after dipole inversion from the internal field map with single-orientation Bayesian regularization including spatial priors. Method validation was performed in 32 patients with biopsy-proven, non-alcoholic fatty liver disease from which 12 had simple steatosis and 20 NASH. Liver fat fraction and T2 * did not change significantly between patients with simple steatosis and NASH. In contrast, the saturated fatty acid fraction increased in patients with NASH relative to patients with simple steatosis (48±2% versus 44±4%; p<0.05) and the magnetic susceptibility decreased (-0.30±0.27ppm versus 0.10±0.14ppm; p<0.001). The area under the receiver operating characteristic curve for magnetic susceptibility as NASH marker was 0.91 (95% CI: 0.79-1.0). Simultaneous MR quantification of fat content, fatty acid composition, T2 * and magnetic susceptibility is feasible in the liver. Our preliminary results suggest that quantitative susceptibility imaging has a high diagnostic performance for the diagnosis of NASH.

Feasibility and reproducibility of echo planar spectroscopic imaging on the quantification of hepatic fat.

Objectives1H-MRS is widely regarded as the most accurate noninvasive method to quantify hepatic fat content (HFC). When practical period of breath holding, and acquisition of HFC over multiple liver areas is considered, a fast MR spectroscopic imaging technique is desired. The aim of this study is to examine the feasibility and reproducibility of echo planar spectroscopic imaging (EPSI) on the quantification of HFC in subject with various HFCs.MethodsTwenty two volunteers were examined in a 3T MR system. The acquisition time of proposed EPSI protocol was 18 seconds. The EPSI scans were repeated 8 times for each subject to test reproducibility. The peak of water and individual peaks of fat including methyl, methylene, and allylic peaks at 0.9, 1.3, and 2.0 ppm were fitted. Calculated amount of water and fat content were corrected for T2 relaxation. The total HFC was defined as the combination of individual peaks. Standard deviation (SD), coefficient of variance (COV) and fitting reliability of HFC quantified by LCModel were calculated.ResultsOur results show that the SDs of total HFC for all subjects are less than 2.5%. Fitting reliability is mostly under 10% and positively correlates with COV. Subjects separated into three subgroups according to quantified total HFC show that improved fitting reliability and reproducibility can be achieved on subjects with higher total HFC.ConclusionsWe have demonstrated feasibility of the proposed EPSI protocols on the quantification of HFC over a whole slice of liver with scan time in a single breath hold.

Noninvasive Quantification of Hepatic Fat Content Using Three-Echo Dixon Magnetic Resonance Imaging With Correction for T2* Relaxation Effects

To investigate three-echo T2*-corrected Dixon magnetic resonance imaging (MRI) for noninvasively estimating hepatic fat content (HFC) compared with biopsy. One hundred patients (50 men, 50 women; mean age, 57.7±14.2 years) underwent clinically indicated liver core biopsy (102 valid tissue samples) and liver MRI 24 to 72 hours later. MRI was performed at 1.5T (Magnetom Avanto, Siemens Healthcare, Erlangen, Germany) using Dixon imaging with T2* correction (work in progress, WIP-432.rev.1, Siemens Healthcare). An ultrafast breath-hold three-echo 3D-gradient echo sequence with TR/TE1/TE2/TE3 of 11/2.4/4.8/9.6 milliseconds, and online calculation of T2*-corrected water images (signal intensities of water [SIW]), fat images (SIF), and fat content map (SIFAT=10×SIF/(SIW+SIF)) was used. SIs of the calculated fat content map (SIFAT) were verified using the histologically quantified HFC (HFC(path)). Spearman correlation for HFC(path) and SIFAT was calculated. Stage of fibrosis, hepatic iron content, and patterns of liver fat (macrovesicular, microvesicular, mixed) and their influence on predicting HFC by MRI were determined. Correlation between SIFAT and HFC(path) was rspearman=0.89. Agreement between HFC predicted by MRI and HFC(path) calculated by nonlinear saturation-growth regression was rspearman=0.89. Kruskal-Wallis analysis revealed no significant difference for SIFAT across fibrosis grades (P=0.90) and liver iron content (P=0.76). Regarding the cellular architecture of liver fat, the microvesicular pattern showed lower mean ranks in SI than macrovesicular and mixed patterns (P=0.01). T2*-corrected Dixon MRI is a noninvasive tool for estimating HFC, showing excellent correlation with liver biopsy without being limited by liver iron content and fibrosis/cirrhosis.

Detection of a Fatty Liver After Binge Drinking: Correlation of MR-spectroscopy, DECT, Biochemistry and Histology in a Rat Model

The purpose of this study was to evaluate the possibility of detecting a fatty liver after binge drinking in an animal model using (1)H magnetic resonance spectroscopy ((1)H-MRS), dual-energy computed tomography (DECT), biochemistry, and the gold standard of histology. In 20 inbred female Lewis rats, an alcoholic fatty liver was induced; 20 rats served as controls. To simulate binge drinking, each rat was given a dose of 9.3 g/kg body weight 50% ethanol twice, with 24 hours between applications. Forty-eight hours after the first injection, DECT and (1)H-MRS were performed. Fat content as well as triglycerides were also determined histologically and biochemically, respectively. To assess specific liver enzymes, blood was drawn from the orbital venous plexus. In all 20 animals in the experimental group, fatty livers were detected using (1)H-MRS, DECT, and biochemical and histologic analysis. The spectroscopic fat/water ratio and the biochemical determination were highly correlated (r = 0.892, P < .05). A significant correlation was found between (1)H-MRS and histologic analysis (r = 0.941, P < .001). Also, a positive linear correlation was found between the dual-energy computed tomographic density of ΔHU and the biochemical (r = 0.751, P < .05) and histologic (r = 0.786, P < .001) analyses. Quantification of hepatic fat content on (1)H-MRS showed high correlation with histologic and biochemical steatosis determination. In comparison to DECT, it is more suitable to reflect the severity of acute fatty liver.

On the performance of T2* correction methods for quantification of hepatic fat content

Nonalcoholic fatty liver disease is the most prevalent chronic liver disease in Western societies. MRI can quantify liver fat, the hallmark feature of nonalcoholic fatty liver disease, so long as multiple confounding factors including T(2)* decay are addressed. Recently developed MRI methods that correct for T(2)* to improve the accuracy of fat quantification either assume a common T(2)* (single-T(2)*) for better stability and noise performance or independently estimate the T(2)* for water and fat (dual-T(2)*) for reduced bias, but with noise performance penalty. In this study, the tradeoff between bias and variance for different T(2)* correction methods is analyzed using the Cramér-Rao bound analysis for biased estimators and is validated using Monte Carlo experiments. A noise performance metric for estimation of fat fraction is proposed. Cramér-Rao bound analysis for biased estimators was used to compute the metric at different echo combinations. Optimization was performed for six echoes and typical T(2)* values. This analysis showed that all methods have better noise performance with very short first echo times and echo spacing of ∼π/2 for single-T(2)* correction, and ∼2π/3 for dual-T(2)* correction. Interestingly, when an echo spacing and first echo shift of ∼π/2 are used, methods without T(2)* correction have less than 5% bias in the estimates of fat fraction.

Accurate and simple method for quantification of hepatic fat content using magnetic resonance imaging: a prospective study in biopsy-proven nonalcoholic fatty liver disease

To assess the degree of hepatic fat content, simple and noninvasive methods with high objectivity and reproducibility are required. Magnetic resonance imaging (MRI) is one such candidate, although its accuracy remains unclear. We aimed to validate an MRI method for quantifying hepatic fat content by calibrating MRI reading with a phantom and comparing MRI measurements in human subjects with estimates of liver fat content in liver biopsy specimens. The MRI method was performed by a combination of MRI calibration using a phantom and double-echo chemical shift gradient-echo sequence (double-echo fast low-angle shot sequence) that has been widely used on a 1.5-T scanner. Liver fat content in patients with nonalcoholic fatty liver disease (NAFLD, n = 26) was derived from a calibration curve generated by scanning the phantom. Liver fat was also estimated by optical image analysis. The correlation between the MRI measurements and liver histology findings was examined prospectively. Magnetic resonance imaging measurements showed a strong correlation with liver fat content estimated from the results of light microscopic examination (correlation coefficient 0.91, P < 0.001) regardless of the degree of hepatic steatosis. Moreover, the severity of lobular inflammation or fibrosis did not influence the MRI measurements. This MRI method is simple and noninvasive, has excellent ability to quantify hepatic fat content even in NAFLD patients with mild steatosis or advanced fibrosis, and can be performed easily without special devices.

Noninvasive quantification of hepatic steatosis inrats using 3.0 T 1H‐magnetic resonance spectroscopy

To assess the accuracy of noninvasive 3.0 T (1)H-magnetic resonance spectroscopy ((1)H-MRS) in an experimental steatosis model for the discrimination of clinically relevant macrovesicular steatosis degrees and to evaluate three different (1)H-MR spectrum-based fat quantification methods. Steatosis was induced in rats by a methionine/choline-deficient diet for 0-5 weeks. (1)H-MRS measurements of hepatic fat content were compared with histopathological and biochemical steatosis degree. In (1)H-MR spectra, areas under the curve (AUC) of fat (1.3 ppm), water (4.7 ppm), total fat (0.5-5.3 ppm), and total spectrum peaks (0.5-5.3 ppm) were determined and hepatic fat content calculated as follows: [AUC(total fat peaks)/AUC(total peaks)], [AUC(fat)/AUC(fat) + (AUC(water)/0.7)], and [AUC(fat)/AUC(water)]. A significant correlation was found between (1)H-MRS and macrovesicular steatosis (r = 0.932, P < 0.0001) and between (1)H-MRS and total fatty acids (r = 0.935, P < 0.0001). (1)H-MRS accurately distinguished mild from moderate and moderate from severe steatosis. Calculations using [AUC(fat)/AUC(water)] ratio in severe steatotic livers resulted in higher hepatic fat percentages as compared to the other methods due to a decrease in hepatic water content. (1)H-MRS quantification of hepatic fat content showed high correlations with histological and biochemical steatosis determination in an experimental steatosis rat model and accurately discriminated between clinically relevant steatosis degrees. These results encourage further application of (1)H-MRS in patients for accurate steatosis assessment.

Proton magnetic resonance spectroscopy and ultrasound for hepatic fat quantification

The increasing prevalence of fatty liver disease requires routine assessment methods. Proton magnetic resonance spectroscopy ((1)H MRS) is increasingly used for steatosis measurement, but due to cost, is unlikely to become a widely-used screening tool. Ultrasound is cheaper and more widely available, although subject to observer variability. Our aim was to determine the sensitivity and specificity of ultrasound against (1)H MRS, using MRS as a gold standard, for the detection and quantification of hepatic fat content. Fifty adults participated (43 men, seven women) in this study. Hepatic steatosis was assessed by ultrasound and (1)H MRS. Images were graded by two independent radiologists to classify severity and distribution of liver fat. Ultrasound detected liver fat infiltration in 82% of cases measurable by (1)H MRS, while liver fat was detectable in 44% of cases graded absent by ultrasound. Ultrasound grading was subjective, with the radiologists in agreement in 53% of cases (kappa = 0.39, P = 0.002). Considerable overlap in intrahepatocellular lipid content was observed between different grades: absent (0.0-1.58%), mild (2.2-16.2%), moderate (4.9-26.7%) and severe (8.1-76.8%) steatosis. Ultrasound could not detect liver fat levels below 2% as measured by (1)H MRS Conclusion: Ultrasound is less sensitive than (1)H MRS in detecting very low levels of liver fat content, but is sensitive to fatty infiltration greater than 2%. There is a tendency of higher ultrasound grades to correlate with higher degrees of fatty infiltration, although some overlap exists. Our findings are still consistent with ultrasound being useful as a low cost screening tool.

Non-invasive quantification of hepatic fat fraction by fast 1.0, 1.5 and 3.0 T MR imaging

Introduction Even mild hepatic steatosis in a split liver donor may cause general liver failure and death in the donor. So far, CT density measurements or percutaneous biopsy is used to determine the presence of hepatic steatosis. Magnetic resonance imaging (MRI) may be an elegant method of non-invasive and non-radiation quantification of hepatic fat content. Methods Fast gradient echo (GRE) technique was used to discriminate between fat and water spins. Echo time (TE) was adjusted for field strength dependent in-phase and out-of-phase states at 1.0, 1.5 and 3.0 T. Continuous MR signal transition from 100% water to 100% fat was investigated using a wedge water–oil phantom, which was positioned in such a way, that no spatial resolution occurred, thereby combining water and fat in one slice. Results Using the phantom, a significant difference for a 5% difference in fat content was demonstrated in the range from 20 to 80% fat content ( p < 0.05) for all tested field strengths. In 25 patients MRI data were correlated with the percentage of fat determined by histologic evaluation of a CT-guided liver biopsy. Using the linear correlation calculated from the MRI phantom data at 1.0 T, we determined the liver fat from each patient's MRI measurements. Comparison of these data with the histologic quantified fat fraction of liver tissue showed a strong correlation ( r 2 = 0.93 for TE 6 ms and r 2 = 0.91 for TE 10 ms). Conclusion The described method can be used to determine the presence of hepatic steatosis of >10% with p < 0.05.

Fatty infiltration of the liver: quantification with phase-contrast MR imaging at 1.5 T vs biopsy.

Quantification of hepatic fat content by application of MR phase-contrast imaging (Dixon method) at 1.5 T was compared with results of biopsy in 16 patients with a variety of liver abnormalities. Motion artifact was suppressed by employing six or eight averages of short TR in-phase (echo offset, 0 msec), out-of-phase (echo offset, 1.1 msec), and in-phase (echo offset, 2.2 msec) spin-echo pulse sequences. The 360 degree out-of-phase sequence was used to assess the impact of T2* decay on this method of estimating fat fraction. A standard two-echo long TR sequence also was obtained in all patients. Histologic preparations from the biopsy specimens were examined by a pathologist who had no knowledge of the MR results and were graded according to overall visual assessment as belonging to one of four categories of fat fraction. Results of the MR-calculated apparent fat fraction were compared directly with biopsy category and were also placed in MR fat fraction categories, allowing estimation of the statistical correlation between the biopsy and MR grading systems. Eight of eight patients with biopsy categories indicating a fat fraction of less than 0.25 were computed by MR to have a fat fraction of less than 0.1. Seven of eight patients with biopsy categories indicating a fat fraction of greater than 0.25 were computed by MR to have a fat fraction of at least 0.24. The MR-calculated apparent fat fraction category correlated significantly with the histologic biopsy category (r = .86, p less than .01). When compared with the in-phase image, decreased signal from liver was visually apparent on the 180 degree out-of-phase images in all cases in which the fat fraction was at least 0.24, but there was no indication of fatty liver on the standard T1- or T2-weighted images. Calculated T2 also showed no correlation with degree of fatty deposition. Correction for T2* decay by using the 360 degree out-of-phase acquisition in addition to the standard 0 degree and 180 degree out-of-phase images had little effect on fat fraction computation. Phase-contrast MR is a promising noninvasive method for quantitative assessment of fatty deposition in the liver.