Hepatic Fat Quantification Research Articles

41. A Comparative Evaluation of MRI and Liver Biopsy for Liver Fat Estimation in Liver Transplant Donors

Background and Aims: Donor hepatic steatosis is associated with a greater risk of complications after living donor liver transplantation (LDLT). MRI IDEAL IQ (Iterative Decomposition of water and fat with Echo Asymmetry and Least squares estimation) has recently been shown to be accurate for hepatic fat quantification in animal and human studies. In this study, we describe the use of MRI IDEAL IQ technique in quantification of hepatic steatosis in live liver donors and compared it with liver biopsy. Methods: Between November 2014 to February 2017 we prospectively evaluated 50 liver donors comparing the MRI IDEAL IQ technique with either preoperative or intraoperative liver biopsy. The accuracy of MRI was assessed by linear regression analysis between MRI liver fat fraction and biopsy fat estimation. Results: Less than 3% fat content was detected in 33 donors (84.6%), 3–6% fat content in 13 (26%), 6–9% fat content in 3 (6%) and more than 9% fat content in 1 donor (2%) on MRI. On linear regression analysis MRI IDEAL IQ fat evaluation correlated well with histopathological fat evaluation for detecting fat content in livers (R2 = 0.757). The accuracy of MRI IDEAL IQ was 88% with sensitivity and specificity rates of 100% and 84.6% respectively for detecting fat content in the liver (P < 0.0001). The average liver fat content evaluated by MRI correlated with BMI but not with age or sex. The groups were comparable in terms of demographic and clinical variables in donors, or development of early graft dysfunction and deranged kidney function in liver transplant recipients. Conclusions: The MRI IDEAL IQ technique is a highly reliable and accurate method, which can replace liver biopsy for the liver fat estimation in live liver donors and hence avoid potential complications of an invasive biopsy. The authors have none to declare.

Free-breathing 3-D quantification of infant body composition and hepatic fat using a stack-of-radial magnetic resonance imaging technique.

Body composition and hepatic fat correlate with future risk for metabolic syndrome. In children, many conventional techniques for quantifying body composition and hepatic fat have limitations. MRI is a noninvasive research tool to study body composition and hepatic fat in infants; however, conventional Cartesian MRI is sensitive to motion, particularly in the abdomen because of respiration. Therefore we developed a free-breathing MRI technique to quantify body composition and hepatic fat in infants. In infants, we aimed to (1) compare the image quality between free-breathing 3-D stack-of-radial MRI (free-breathing radial) and 3-D Cartesian MRI in the liver and (2) determine the feasibility of using free-breathing radial MRI to quantify body composition and hepatic proton-density fat fraction (PDFF). Ten infants ages 2-7months were scanned with free-breathing radial (two abdominal; one head and chest) and Cartesian (one abdominal) MRI sequences. The median preparation and scan times were reported. To assess feasibility for hepatic PDFF quantification, a radiologist masked to the MRI technique scored abdominal scans for motion artifacts in the liver using a 3-point scale (1, or non-diagnostic, to 3, or no artifacts). Median visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and brown adipose tissue (BAT) volume and PDFF, and hepatic PDFF were measured using free-breathing radial MRI. We assessed repeatability of free-breathing radial hepatic PDFF (coefficient of repeatability) between back-to-back scans. We determined differences in the distribution of image-quality scores using McNemar-Bowker tests. P<0.05 was considered significant. Nine infants completed the entire study (90% completion). For ten infants, the median preparation time was 32min and scan time was 24min. Free-breathing radial MRI demonstrated significantly higher image-quality scores compared to Cartesian MRI in the liver (radial scan 1 median = 2 and radial scan 2 median = 3 vs. Cartesian median = 1; P=0.01). Median measurements using free-breathing radial were VAT=52.0cm3, VAT-PDFF=42.2%, SAT=267.7cm3, SAT-PDFF=87.1%, BAT=1.4cm3, BAT-PDFF=26.1% and hepatic PDFF=3.4% (coefficient of repeatability <2.0%). In this study, free-breathing radial MRI in infants achieved significantly improved liver image quality compared to Cartesian MRI. It is feasible to use free-breathing radial MRI to quantify body composition and hepatic fat in infants.

Clinical Implementation of a Focused MRI Protocol for Hepatic Fat and Iron Quantification.

OBJECTIVE. The purpose of this article is to describe our institutional experience with the clinical implementation of a novel focused rapid chemical shift-encoded MRI protocol specifically intended to detect and quantify hepatic steatosis and iron overload, highlighting usage statistics and issues related to cost. CONCLUSION. Focused MRI examinations for specific clinical indications, such as this protocol for detection and quantification of hepatic steatosis and iron overload, are feasible in a busy clinical practice and add value for patients and referring providers.

State of the art in magnetic resonance imaging of hepatocellular carcinoma.

BackgroundLiver cancer is the sixth most common cancer worldwide and the second leading cause of cancer mortality. Chronic liver disease caused by viral infection, alcohol abuse, or other factors can lead to cirrhosis. Cirrhosis is the most important clinical risk factor for hepatocellular carcinoma (HCC) whereby the normal hepatic architecture is replaced by fibrous septa and a spectrum of nodules ranging from benign regenerative nodules to HCC, each one of them with different imaging features.ConclusionsFurthermore, advanced techniques including the quantification of hepatic and intralesional fat and iron, magnetic resonance elastography, radiomics, radiogenomics, and positron emission tomography (PET)-MRI are highly promising for the extraction of new imaging biomarkers that reflect the tumor microenvironment and, in the future, may add decision-making value in the management of patients with HCC.

Simultaneous quantification of hepatic MRI-PDFF and R2* in a rabbit model with nonalcoholic fatty liver disease

Quantification of hepatic fat and iron content is important for early detection and monitoring of nonalcoholic fatty liver disease (NAFLD) patients. This study evaluated quantification efficiency of hepatic proton density fat fraction (PDFF) by MRI using NAFLD rabbits. R2* was also measured to investigate whether it correlates with fat levels in NAFLD. NAFLD rabbit model was successfully established by high fat and cholesterol diet. Rabbits underwent MRI examination for fat and iron analyses, compared with liver histological findings. MR examinations were performed on a 3.0T MR system using multi-echo 3D gradient recalled echo (GRE) sequence. MRI-PDFF showed significant differences between different steatosis grades with medians of 3.72% (normal), 5.43% (mild), 9.11% (moderate) and 11.17% (severe), whereas this was not observed in R2*. Close correlation between MRI-PDFF and histological steatosis was observed (r=0.78, P=0.000). Hepatic iron deposit was not found in any rabbits. There was no correlation between R2* and either liver MRI-PDFF or histological steatosis. MR measuring MRI-PDFF and R2* simultaneously provides promising quantification of steatosis and iron. Rabbit NAFLD model confirmed accuracy of MRI-PDFF for liver fat quantification. R2* measurement and relationship between fat and iron of NAFLD liver need further experimental investigation.

Free-breathing quantification of hepatic fat in healthy children and children with nonalcoholic fatty liver disease using a multi-echo 3-D stack-of-radial MRI technique

In adults, noninvasive chemical shift encoded Cartesian magnetic resonance imaging (MRI) and single-voxel magnetic resonance (MR) spectroscopy (SVS) accurately quantify hepatic steatosis but require breath-holding. In children, especially young and sick children, breath-holding is often limited or not feasible. Sedation can facilitate breath-holding but is highly undesirable. For these reasons, there is a need to develop free-breathing MRI technology that accurately quantifies steatosis in all children. This study aimed to compare non-sedated free-breathing multi-echo 3-D stack-of-radial (radial) MRI versus standard breath-holding MRI and SVS techniques in a group of children for fat quantification with respect to image quality, accuracy and repeatability. Healthy children (n=10, median age [±interquartile range]: 10.9 [±3.3] years) and overweight children with nonalcoholic fatty liver disease (NAFLD) (n=9, median age: 15.2 [±3.2] years) were imaged at 3 Tesla using free-breathing radial MRI, breath-holding Cartesian MRI and breath-holding SVS. Acquisitions were performed twice to assess repeatability (within-subject mean difference, MDwithin). Images and hepatic proton-density fat fraction (PDFF) maps were scored for image quality. Free-breathing and breath-holding PDFF were compared using linear regression (correlation coefficient, r and concordance correlation coefficient, ρc) and Bland-Altman analysis (mean difference). P<0.05 was considered significant. In patients with NAFLD, free-breathing radial MRI demonstrated significantly less motion artifacts compared to breath-holding Cartesian (P<0.05). Free-breathing radial PDFF demonstrated a linear relationship (P<0.001) versus breath-holding SVS PDFF and breath-holding Cartesian PDFF with r=0.996 and ρc=0.994, and r=0.997 and ρc=0.995, respectively. The mean difference in PDFF between free-breathing radial MRI, breath-holding Cartesian MRI and breath-holding SVS was <0.7%. Repeated free-breathing radial MRI had MDwithin=0.25% for PDFF. In this pediatric study, non-sedated free-breathing radial MRI provided accurate and repeatable hepatic PDFF measurements and improved image quality, compared to standard breath-holding MR techniques.

Hepatic fat quantification using automated six-point Dixon: Comparison with conventional chemical shift based sequences and computed tomography

PurposeTo compare automated six-point Dixon (6-p-Dixon) MRI comparing with dual-echo chemical-shift-imaging (CSI) and CT for hepatic fat fraction in phantoms and clinical study. Materials and methodsPhantoms and fifty-nine patients were examined both MRI and CT for quantitative fat measurements. ResultsIn phantom study, linear regression between fat concentration and 6-p-Dixon showed good agreement. In clinical study, linear regression between 6-p-Dixon and dual-echo CSI showed good agreement. CT attenuation value was strongly correlated with 6-p-Dixon (R2=0.852; P<0.001) and dual-echo CSI (R2=0.812; P<0.001). ConclusionAutomated 6-p-Dixon and dual-echo CSI were accurate correlation with CT attenuation value of liver parenchyma. 6-p-Dixon has the potential for automated hepatic fat quantification.

3D Multiecho Dixon for the Evaluation of Hepatic Iron and Fat in a Clinical Setting.

To prospectively evaluate a new 3D-multiecho-Dixon (3D-ME-Dixon) sequence for the quantification of hepatic iron and fat in a clinical setting. In all, 120 patients underwent 1.5T magnetic resonance imaging of the liver between December 2013 and June 2015 including the following three sequences: 3D-ME-Dixon with inline calculation of R2* and proton-density fat-fraction (PDFF) maps, single-voxel-spectroscopy (SVS), 2D multigradient-echo sequence (2D-ME-GRE). SVS and 2D-ME-GRE were used as reference for PDFF and R2*, respectively. R2*- and PDFF-values from 3D-ME-Dixon were compared with those of the reference. Linear regression analysis, Bland-Altman plots, and agreement parameters were calculated. In total, 103 patients were finally included (87 men and 16 women; mean age, 50.51 years); 17/120 were excluded due to fat/water-swaps or R2*-values exceeding the constraint of 400 1/s for 3D-ME-Dixon. A strong correlation (r = 0.992, P < 0.001) between R2* of 3D-ME-Dixon and the reference 2D-ME-GRE was found. Bland-Altman analysis revealed systematically lower values for 3D-ME-Dixon (16.499%). Using an adapted threshold of 57 1/s, 3D-ME-Dixon obtained a positive/negative percentage agreement (PPA/NPA) of 84.4%/91.4% for detecting hepatic iron overload. For hepatic fat the correlation between 3D-ME-Dixon and the reference SVS was strong (r = 0.957, P < 0.001); PPA/NPA was 88.3%/91.4%. The 3D-ME-Dixon sequence is a valuable tool for the evaluation of hepatic iron and fat in a clinical setting. Fat/water-swaps remain a drawback requiring improvements to the implementation and making it necessary to have proven conventional sequences at hand in case of an eventual occurrence. 1. Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:793-800.

Effect of Gd-EOB-DTPA on Hepatic Fat Quantification using Two-point Dixon Technique

Effect of Gd-EOB-DTPA on Hepatic Fat Quantification using Two-point Dixon Technique

T2* Mapping from Multi-Echo Dixon Sequence on Gadoxetic Acid-Enhanced Magnetic Resonance Imaging for the Hepatic Fat Quantification: Can It Be Used for Hepatic Function Assessment?

ObjectiveTo evaluate the diagnostic value of T2* mapping using 3D multi-echo Dixon gradient echo acquisition on gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) as a tool to evaluate hepatic function.Materials and MethodsThis retrospective study was approved by the IRB and the requirement of informed consent was waived. 242 patients who underwent liver MRIs, including 3D multi-echo Dixon fast gradient-recalled echo (GRE) sequence at 3T, before and after administration of gadoxetic acid, were included. Based on clinico-laboratory manifestation, the patients were classified as having normal liver function (NLF, n = 50), mild liver damage (MLD, n = 143), or severe liver damage (SLD, n = 30). The 3D multi-echo Dixon GRE sequence was obtained before, and 10 minutes after, gadoxetic acid administration. Pre- and post-contrast T2* values, as well as T2* reduction rates, were measured from T2* maps, and compared among the three groups.ResultsThere was a significant difference in T2* reduction rates between the NLF and SLD groups (−0.2 ± 4.9% vs. 5.0 ± 6.9%, p = 0.002), and between the MLD and SLD groups (3.2 ± 6.0% vs. 5.0 ± 6.9%, p = 0.003). However, there was no significant difference in both the pre- and post-contrast T2* values among different liver function groups (p = 0.735 and 0.131, respectively). A receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve for using T2* reduction rates to differentiate the SLD group from the NLF group was 0.74 (95% confidence interval: 0.63–0.83).ConclusionIncorporation of T2* mapping using 3D multi-echo Dixon GRE sequence in gadoxetic acid-enhanced liver MRI protocol may provide supplemental information for liver function deterioration in patients with SLD.

Hepatic Steatosis: Etiology, Patterns, and Quantification

Hepatic steatosis can occur because of nonalcoholic fatty liver disease (NAFLD), alcoholism, chemotherapy, and metabolic, toxic, and infectious causes. Pediatric hepatic steatosis is also becoming more frequent and can have distinctive features. The most common pattern is diffuse form; however, it can present in heterogenous, focal, multinodular, perilesional, perivascular, subcapsular, and lobar forms. Focal steatosis and fat sparing can occur because of the presence of veins of Sappey, pancreaticoduodenal vein, and aberrant right and left gastric veins, which drain into the liver as third inflow. Hypersteatosis and multinodular forms can mimic metastasis in patients with cancer. Perilesional fat can be seen in insulinoma. Recent introduction of proton-density fat fraction enabled easy and reproducible quantification of hepatic fat. Follow up of patients with NAFLD can be performed for the assessment of treatment response using proton-density fat fraction as biomarker. Multiecho gradient-echo techniques also simultaneously calculate T2* maps, which is important to rule out coexisting hepatic iron overload. NAFLD can progress to steatohepatitis (nonalcoholic steatohepatitis), which can result in cirrhosis. Magnetic resonance (MR) elastography and functional evaluation with Gd-EOB-DTPA are becoming important for monitoring this process. Hepatocellular carcinoma can develop in patients with NAFLD, which is usually a large tumor with necrotic center. In the future, fatty acid maps obtained by MR imaging may allow more detailed analysis of steatosis. MR imaging is superior to ultrasonography and computed tomography for comprehensive evaluation of steatosis.

Hepatic fat quantification using the two-point Dixon method and fat color maps based on non-alcoholic fatty liver disease activity score.

The two-point Dixon method for magnetic resonance imaging (MRI) is commonly used to non-invasively measure fat deposition in the liver. The aim of the present study was to assess the usefulness of MRI-fat fraction (MRI-FF) using the two-point Dixon method based on the non-alcoholic fatty liver disease activity score. This retrospective study included 106 patients who underwent liver MRI and MR spectroscopy, and 201 patients who underwent liver MRI and histological assessment. The relationship between MRI-FF and MR spectroscopy-fat fraction was used to estimate the corrected MRI-FF for hepatic multi-peaks of fat. Then, a color FF map was generated with the corrected MRI-FF based on the non-alcoholic fatty liver disease activity score. We defined FF variability as the standard deviation of FF in regions of interest. Uniformity of hepatic fat was visually graded on a three-point scale using both gray-scale and color FF maps. Confounding effects of histology (iron, inflammation and fibrosis) on corrected MRI-FF were assessed by multiple linear regression. The linear correlations between MRI-FF and MR spectroscopy-fat fraction, and between corrected MRI-FF and histological steatosis were strong (R2 = 0.90 and R2 = 0.88, respectively). Liver fat variability significantly increased with visual fat uniformity grade using both of the maps (ρ = 0.67-0.69, both P <0.001). Hepatic iron, inflammation and fibrosis had no significant confounding effects on the corrected MRI-FF (all P >0.05). The two-point Dixon method and the gray-scale or color FF maps based on the non-alcoholic fatty liver disease activity score were useful for fat quantification in the liver of patients without severe iron deposition.

Quantification of hepatic and visceral fat by CT and MR imaging: relevance to the obesity epidemic, metabolic syndrome and NAFLD.

Trends in obesity have continued to increase in the developed world over the past few decades, along with related conditions such as metabolic syndrome, which is strongly associated with this epidemic. Novel and innovative methods to assess relevant obesity-related biomarkers are needed to determine the clinical significance, allow for surveillance and intervene if appropriate. Aggregations of specific types of fat, specifically hepatic and visceral adiposity, are now known to be correlated with these conditions, and there are a variety of imaging techniques to identify and quantify their distributions and provide diagnostic information. These methods are particularly salient for metabolic syndrome, which is related to both hepatic and visceral adiposity but currently not defined by it. Simpler non-specific fat measurements, such as body weight, abdominal circumference and body mass index are more frequently used but lack the ability to characterize fat location. In addition, non-alcoholic fatty liver disease (NAFLD) is a related condition that carries relevance not only for obesity-related diseases but also for the progression of the liver-specific disease, including non-alcoholic steatohepatitis and cirrhosis, albeit at a much lower frequency. Recent CT and MRI techniques have emerged to potentially optimize diagnosing metabolic syndrome and NAFLD through non-invasive quantification of visceral fat and hepatic steatosis with high accuracy. These imaging modalities should aid us in further understanding the relationship of hepatic and visceral fat to the obesity-related conditions such as metabolic syndrome, NAFLD and cardiovascular disease.

Effect of gadolinium on hepatic fat quantification using multi-echo reconstruction technique with T2* correction and estimation.

To determine whether hepatic fat quantification is affected by administration of gadolinium using a multiecho reconstruction technique with T2* correction and estimation. Forty-eight patients underwent the investigational sequence for hepatic fat quantification at 3.0T MRI once before and twice after administration of gadopentetate dimeglumine (0.1mmol/kg). A one-way repeated-measures analysis of variance with pairwise comparisons was conducted to evaluate the systematic bias of fat fraction (FF) and R2* measurements between three acquisitions. Bland-Altman plots were used to assess the agreements between pre- and post-contrast FF measurements in the liver. A P value <0.05 indicated statistically significant difference. FF measurements of liver, spleen and spine revealed no significant systematic bias between the three measurements (P > 0.05 for all). Good agreements (95% confidence interval) of FF measurements were demonstrated between pre-contrast and post-contrast1 (-0.49%, 0.52%) and post-contrast2 (-0.83%, 0.77%). R2* increased in liver and spleen (P = 0.039, P = 0.01) after administration of gadolinium. Although under the impact of an increased R2* in liver and spleen post-contrast, the investigational sequence can still obtain stable fat quantification. Therefore, it could be applied post-contrast to substantially increase the efficiency of MR examination and also provide a backup for the occasional failure of FF measurements pre-contrast. • Fat quantification with IDEAL-based investigational sequence remains stable after gadolinium administration. • It can be integrated into tri-phase liver MRI without adding scan time. • This helps optimize MR protocols and provides more useful information for clinicians.

Feasibility of a three-step magnetic resonance imaging approach for the assessment of hepatic steatosis in an asymptomatic study population.

To determine the feasibility of a multi-step magnetic resonance imaging (MRI) approach for comprehensive assessment of hepatic steatosis defined as liver fat content of ≥5% in an asymptomatic population. The study was approved by the institutional review board and written informed consent of all participants was obtained. Participants of a population-based study cohort underwent a three-step 3-T MRI-based assessment of liver fat. A dual-echo Dixon sequence was performed to identify subjects with hepatic steatosis, followed by a multi-echo Dixon sequence with proton density fat fraction estimation. Finally, single-voxel T2-corrected multi-echo spectroscopy was performed. A total of 215 participants completed the MRI protocol (56.3% male, average age 57.2 ± 9.4years). The prevalence of hepatic steatosis was 55%. Mean liver proton density fat fraction was 9.2 ± 8.5% by multi-echo Dixon and 9.3 ± 8.6% by multi-echo spectroscopy (p = 0.51). Dual-echo Dixon overestimated liver fat fraction by 1.4 ± 2.0% (p < 0.0001). All measurements showed excellent correlations (r ≥ 0.9, p < 0.001). Dual-echo Dixon was highly sensitive for the detection of hepatic steatosis (sensitivity 0.97, NPV 0.96) with good specificity and PPV (0.75 and 0.81, respectively). A multi-step MRI approach may enable rapid and accurate identification of subjects with hepatic steatosis in an asymptomatic population. • Dual-echo Dixon can rapidly and reliably exclude hepatic steatosis without complex post-processing. • Multi-echo Dixon and multi-echo spectroscopy yield similar results regarding hepatic fat quantification. • Each sequence can be performed in one breath-hold. • These sequences can be implemented in routine abdominal MRI protocols. • Thus hepatic fat can be evaluated without relevant increase in scan time.

NAFLD. Accurate quantification of hepatic fat--is it important?

New ultrasonography and MRI techniques offer the promise of accessible and accurate quantification of hepatic steatosis. Application of these techniques to help define the natural history and severity of NAFLD is required before we can determine their clinical utility.

Hepatic fat quantification magnetic resonance for monitoring treatment response in pediatric nonalcoholic steatohepatitis

To evaluate the possibility of treatment effect monitoring using hepatic fat quantification magnetic resonance (MR) in pediatric nonalcoholic steatohepatitis (NASH). We retrospectively reviewed the medical records of patients who received educational recommendations and vitamin E for NASH and underwent hepatic fat quantification MR from 2011 to 2013. Hepatic fat fraction (%) was measured using dual- and triple-echo gradient-recalled-echo sequences at 3T. The compliant and non-compliant groups were compared clinically, biochemically, and radiologically. Twenty seven patients (M:F = 24:3; mean age: 12 ± 2.3 years) were included (compliant group = 22, non-compliant = 5). None of the baseline findings differed between the 2 groups, except for triglyceride level (compliant vs non-compliant, 167.7 mg/dL vs 74.2 mg/dL, P = 0.001). In the compliant group, high-density lipoprotein increased and all other parameters decreased after 1-year follow-up. However, there were various changes in the non-compliant group. Dual-echo fat fraction (-19.2% vs 4.6, P < 0.001), triple-echo fat fraction (-13.4% vs 3.5, P < 0.001), alanine aminotransferase (-110.7 IU/L vs -10.6 IU/L, P = 0.047), total cholesterol (-18.1 mg/dL vs 3.8 mg/dL, P = 0.016), and triglyceride levels (-61.3 mg/dL vs 11.2 mg/dL, P = 0.013) were significantly decreased only in the compliant group. The change in body mass index and dual-echo fat fraction showed a positive correlation (ρ = 0.418, P = 0.030). Hepatic fat quantification MR can be a non-invasive, quantitative and useful tool for monitoring treatment effects in pediatric 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.

Effect of Gd-EOB-DTPA on hepatic fat quantification using high-speed T2-corrected multi-echo acquisition in 1H MR spectroscopy

PurposeTo determine whether gadolinium ethoxybenzyldiethylenetriaminepentaacetic acid (Gd-EOB-DTPA) administration affects hepatic fat quantification by magnetic resonance spectroscopy (MRS) using the fast breath-hold high-speed T2-corrected multiecho (HISTO) technique. Materials and MethodsSeventy-six patients underwent Gd-EOB-DTPA-enhanced liver MR and 15sec breath-hold HISTO MRS (4 times), twice before and twice after Gd-EOB-DTPA administration. Two consecutive MRSs were performed immediately before the dynamic study. Post-contrast MRS was performed twice continuously, approximately 15min after contrast injection, prior to obtaining 20-min hepatobiliary phase images. We used paired t-test and intraclass correlation coefficient (ICC) to evaluate the variability of the mean fat fraction (FF) on pre-contrast MRS and post-contrast MRS and the effect of the contrast agent on the mean FF. ResultsThe mean FFs were not significantly different between pre-contrast MRS and post-contrast MRS (6.50%±6.54 versus 6.70%±6.61, P=0.15). The ICC of FF calculation between pre- and post-contrast MRS was 0.984. The ICCs for the FF magnitude between pre- and post-contrast MRS were 0.452, 0.771, and 0.995 for FF <5%, FF 5–10%, and FF ≥10%, respectively. ConclusionGd-EOB-DTPA does not appear to influence hepatic fat quantification, especially for patients with hepatic steatosis.

Effect of Progressive Resistance Exercise Training on Hepatic Fat in Asian Indians with Non-Alcoholic Fatty Liver Disease

Introduction: Nonalcoholic fatty liver disease (NAFLD) is closely associated with obesity and insulin resistance and lifestyle measures form the cornerstone of therapy. Objective: To study the effect of progressive resistance training (PRT) on hepatic fat Research Article British Journal of Medicine & Medical Research, 4(1): 114-124, 2014 115 content, body composition and insulin sensitivity in patients with NAFLD. Methods: This study included 24 adult patients with NAFLD diagnosed on ultrasonography. Subjects with alcohol intake >140 gm/week and any secondary cause of fatty liver were excluded. Patients underwent thrice weekly sessions (40 minutes each) of resistance exercises including flexion at biceps, triceps, and hip flexion, knee extension and heel rise for 12 weeks. Preand post-intervention evaluation included anthropometry, BIA analysis, short insulin tolerance test (SITT), lipid profile and hepatic fat quantification by MRI. Results: Twenty four patients (17 males, 7 females, mean age 39.8±10.5 yrs) completed the study protocol with 78.7% compliance to PRT protocol. There was significant decrease in waist, hip and mid-thigh circumferences and skinfold thicknesses at biceps, triceps, subscapular and suprailiac regions (p<0.05), with no significant change in BMI and WHR. Insulin sensitivity improved significantly at 12 weeks as indicated by increase in k-value (rate of change of glucose) on SITT (0.84 vs 1.3, p=0.002). A decrease in total cholesterol and LDL-c with increase in HDL-c was noted after 12 weeks (p<0.05). Hepatic fat content also decreased at 12 weeks (22.3±3.9 vs 21.4±4.0 %, p=0.01). Conclusion: Moderate intensity PRT is associated with significant improvement in hepatic fat, truncal subcutaneous fat and insulin sensitivity in patients with NAFLD.