Noninvasive Diagnosis Of Hepatic Steatosis Research Articles

Clinical research of fibroscan ‒ TE-CAP at noninvasive diagnosis of hepatic steatosis in children

Background & aimsThe authors assess the diagnostic accuracy of the Transient Elastography-Controlled Attenuation Parameter (TE-CAP) in children of Southern China. Methods105 obese or overweight children and adolescents were enrolled in the diagnostic test of TE-CAP assessment of hepatic steatosis using MRI-PDFF. Hepatic steatosis grades S0-S3 were classified. Statistical correlation, agreement and consistency between methods were evaluated. The diagnostic efficiency of TE-CAP was evaluated. The authors used the cutoff value of TE-CAP to detect hepatic steatosis in another 356 children. ResultsThe Area Under Curve (AUC) of TE-CAP for grade ≥ S1, ≥ S2, and ≥ S3 steatosis were 0.975, 0.984, and 0.997, respectively. For detecting ≥ S1 steatosis, TE-CAP had a sensitivity of 96 % and a specificity of 97 %. For detecting ≥ S2 steatosis, TE-CAP had a sensitivity of 97 % and a specificity of 93 %. For detecting ≥ S3 steatosis, TE-CAP had a sensitivity of 1 and a specificity of 94 %. TE-CAP and MRI-PDFF had a linear correlation (r = 0. 0.87, p < 0.001). The hepatic steatosis was identified in 40.2 % (143/356) of children in which the obesity and overweight were 69.8 % (113/162) and 40.0 % (18/45). ConclusionTE-CAP showed excellent diagnostic accuracy in pediatric hepatic steatosis.

Noninvasive diagnosis of hepatic steatosis in patients with severe obesity: a clinically challenging issue.

Noninvasive diagnosis of hepatic steatosis in patients with severe obesity: a clinically challenging issue.

Direct Comparison of Quantitative US versus Controlled Attenuation Parameter for Liver Fat Assessment Using MRI Proton Density Fat Fraction as the Reference Standard in Patients Suspected of Having NAFLD.

Background MRI-derived proton density fat fraction (PDFF) is an accurate, reliable, and safe biologic marker for use in the noninvasive diagnosis of hepatic steatosis in patients with nonalcoholic fatty liver disease (NAFLD). Because of the cost and limited availability of MRI, it is necessary to develop an accurate method to diagnose NAFLD with potential point-of-care access. Purpose To compare the diagnostic accuracy of the quantitative US (QUS) fat fraction (FF) estimator with that of the controlled attenuation parameter (CAP) in the diagnosis of NAFLD using contemporaneous MRI-derived PDFF as the reference standard. Materials and Methods Participants with or suspected of having NAFLD were prospectively recruited at the NAFLD Research Center between July 2015 and July 2019. All participants underwent MRI-derived PDFF measurement, transient elastography with CAP measurement, and QUS. QUS FF was derived using computed QUS parameters from the acquired radiofrequency US data using a calibrated reference phantom. The area under the receiver operating characteristic curve (AUC) was calculated to assess the accuracy of QUS FF and CAP in the diagnosis of hepatic steatosis (defined as MRI-derived PDFF ≥ 5%). AUCs were compared using the DeLong test. Results A total of 123 participants were included (mean age, 52 years ± 13 [SD]; 67 [54%] women). Of these participants, 100 (81%) had MRI-derived PDFF of 5% or more. QUS FF had a significantly higher AUC for diagnosis of NAFLD than did CAP (0.92 [95% CI: 0.87, 0.98] vs 0.79 [95% CI: 0.67, 0.90], P = .03). QUS FF had a sensitivity of 98% (98 of 100) and a specificity of 48% (11 of 23). CAP had a sensitivity of 87% (87 of 100) and a specificity of 57% (13 of 23). Conclusion The quantitative US fat fraction estimator is more accurate than the controlled attenuation parameter in the diagnosis of hepatic steatosis in patients with or suspected of having nonalcoholic fatty liver disease. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Ito in this issue.

Unenhanced computed tomography for non-invasive diagnosis of hepatic steatosis with low tube potential protocol.

Lowering kVp affects the image contrast and computed tomography (CT) attenuation values of low kVp CT is different from those of conventional 120-kVp scans. The purpose of this study is to determine the diagnostic performance and to establish the reference range of low-kVp unenhanced CT for the assessment of hepatic steatosis in liver transplantation donors using magnetic resonance (MR) spectroscopy as a reference standard. This retrospective study included 165 potential donors (male:female =114:51, 36.5±12.0 years old) who underwent 100-kVp single-slice unenhanced CT scan and MR spectroscopy. The difference between hepatic and splenic attenuation (CTL-S) and liver-to-spleen attenuation ratio (CTL/S) were calculated. Reference standard was the fat signal fraction measured by MR spectroscopy. Limits of agreement between CT measurements and the reference standard were calculated. Areas under receiver operating characteristic curves (AUROCs) of CTL-S and CTL/S were compared for the diagnosis of moderate to severe steatosis. Cut-off values of CTL-S and CTL/S that provided a balance between sensitivity and specificity and the highest specificity using the lower limit of the reference range were calculated. Eighty-seven subjects had a non-steatotic liver. Sixty-one subjects had mild steatosis and 17 subjects had moderate to severe steatosis based on MR spectroscopy. CTL-S and CTL/S values were negatively correlated with the fat signal fraction (P<0.001) and limits of agreement were -8.4% to 8.4% for CTL-S and -9.6% to 9.6% for CTL/S. AUROCs of CTL-S and CTL/S for diagnosing moderate to severe steatosis were 0.956 and 0.957, respectively. Cut-off values of CTL-S and CTL/S for diagnosis of moderate to severe steatosis by the Youden index were -0.5 HU for CTL-S and 0.99 for CTL/S. Reference ranges of non-steatotic liver were -6.90 to 31.40 HU for CTL-S and 0.89 to 1.77 for CTL/S. Using -6.9 HU for CTL-S and 0.89 for CTL/S as cut-off values, the sensitivity and specificity for diagnosing moderate to severe steatosis were 70.59% and 90.54% (CTL-S) and 76.47% and 90.54% (CTL/S), respectively. Measurements from a low-kVp unenhanced CT scan were negatively correlated with the degree of hepatic steatosis. Low-kVp unenhanced CT is a robust technique with reduced radiation exposure for diagnosing moderate to severe hepatic steatosis.

Association of Hepatic Steatosis Index with Nonalcoholic Fatty Liver Disease Diagnosed by Non-Enhanced CT in a Screening Population.

The noninvasive diagnosis of hepatic steatosis is of increasing concern. This study investigated the association of hepatic steatosis determined by non-enhanced CT criteria with clinical parameters in a screening population. Asymptomatic patients who underwent abdominal CT at our healthcare center were retrospectively analyzed (n = 339). Two radiologists measured the attenuation values of the liver parenchyma and spleen using non-enhanced CT images. CT criteria for hepatic steatosis were (a) absolute liver attenuation value <48 Hounsfield units (HU), (b) liver-to-spleen attenuation ratio <0.8, and (c) attenuation difference between the liver and spleen <−10. Body mass index (BMI) and hepatic steatosis index (HSI) were calculated, and laboratory findings were recorded. The association of hepatic steatosis with clinical parameters was assessed using univariate and logistic regression analyses. The presence of hepatic steatosis was significantly associated with the levels of serum fasting glucose and triglycerides, the alanine aminotransferase to aspartate aminotransferase (ALT/AST) ratio, BMI, and HSI values using any of the CT criteria. Logistic regression analysis revealed that the serum fasting glucose level and HSI were significantly associated with hepatic steatosis using criterion (a), while the ALT/AST ratio and HSI were associated with hepatic steatosis using criteria (b) and (c). The presence of hepatic steatosis on non-enhanced CT should be considered to indicate possible clinical profile abnormalities regarding metabolic syndrome.

Non-invasive diagnosis of hepatic steatosis.

Non-invasive diagnosis and quantification of hepatic steatosis rely on two different but complementary approaches: biomarkers or imaging techniques, either ultrasound-based such as liver ultrasonography and controlled attenuation parameter (CAP), or computed tomography (CT) and magnetic resonance imaging (MRI). Scores for the detection of steatosis have not gained much popularity in clinical practice so far. CAP, using the M probe, is the most promising technique but needs to be implemented with the XL probe and compared to ultrasound that, despite its limitations, remains the most widely used method. CT, owing to its low sensitivity and the fact that it involves a potential radiation hazard, is inappropriate. Finally, proton density fat fraction measurement by MRI is currently the most accurate and sensitive imaging method, simpler and more practical than magnetic resonance spectroscopy, but restricted, up to now, just to research and clinical trials.

Noninvasive Diagnosis of Hepatic Steatosis Using Fat Attenuation Parameter Measured by FibroTouch and a New Algorithm in CHB Patients.

BackgroundChronic hepatitis B (CHB) remains a major public health problem worldwide, and the prevalence of CHB patients with hepatic steatosis is gradually increasing. Noninvasive approaches for the assessment of hepatic steatosis have been developed as alternatives to liver biopsy.ObjectivesThis study evaluated the diagnostic performance of the fat attenuation parameter (FAP) measured by transient elastography (FibroTouch) and a new algorithm to assess hepatic steatosis in CHB patients, in comparison to liver biopsy as the gold standard.MethodsTwo hundred fifty-four CHB patients underwent simultaneous liver biopsy, biochemical blood testing, and FibroTouch examination. A new algorithm based on four factors (FAP; body mass index, BMI; high-density lipoprotein, HDL; apolipoprotein B, APOB) was defined as follows: fatty index = 10*ep/ (1+ep), and P = -2.75 + 0.028 ln FAP (dB/m) + 0.409 ln BMI (Kg/m2) - 2.482 ln HDL (mmol/L) + 1.979 ln APOB (g/L). The performances of FAP and fatty index were assessed by area under the ROC curve (AUROC).ResultsThe difference in FAP was significant (P < 0.001) between CHB-only patients and CHB patients with hepatic steatosis. The cytokeratin 18 fragment (CK18-M65) level was significantly higher in CHB patients with non-alcoholic steatohepatitis (NASH) compared with CHB patients without NASH (P < 0.05). The optimal cutoff FAP values for hepatic steatosis of > 0, ≥ 5%, ≥ 10%, ≥ 20%, and ≥ 30% were 224.1, 230.6, 235.5, 246.9, and 261.1 dB/m, and AUROCs were 0.833, 0.801, 0.915, 0.917, and 0.972, respectively. The optimal cutoff value of fatty index for the diagnosis of hepatic steatosis was 1.5 and the AUROC was 0.807.ConclusionsFAP is an accurate, reliable, and noninvasive approach that can also be combined with other metabolic biomarkers to comprehensively detect and quantify hepatic steatosis.

The cheating liver: imaging of focal steatosis and fatty sparing

ABSTRACTFocal steatosis and fatty sparing are a frequent finding in liver imaging, and can mimic solid lesions. Liver regional variations in the degree of fat accumulation can be related to vascular anomalies, metabolic disorders, use of certain drugs or coexistence of hepatic masses. CT and MRI are the modalities of choice for the noninvasive diagnosis of hepatic steatosis. Knowledge of CT and MRI appearance of focal steatosis and fatty sparing is crucial for an accurate diagnosis, and to rule-out other pathologic processes. This paper will review the CT and MRI techniques for the diagnosis of hepatic steatosis and the CT and MRI features of common and uncommon causes of focal steatosis and fatty sparing.

Quantitative Imaging Biomarkers of NAFLD.

Conventional imaging modalities, including ultrasonography (US), computed tomography (CT), and magnetic resonance (MR), play an important role in the diagnosis and management of patients with nonalcoholic fatty liver disease (NAFLD) by allowing noninvasive diagnosis of hepatic steatosis. However, conventional imaging modalities are limited as biomarkers of NAFLD for various reasons. Multi-parametric quantitative MRI techniques overcome many of the shortcomings of conventional imaging and allow comprehensive and objective evaluation of NAFLD. MRI can provide unconfounded biomarkers of hepatic fat, iron, and fibrosis in a single examination-a virtual biopsy has become a clinical reality. In this article, we will review the utility and limitation of conventional US, CT, and MR imaging for the diagnosis NAFLD. Recent advances in imaging biomarkers of NAFLD are also discussed with an emphasis in multi-parametric quantitative MRI.

A new non-invasive method for assessing steatosis in chronic liver diseases

To assess the diagnostic accuracy of the controlled attenuation parameter (CAP) to determine the grade of hepatic steatosis (HS) in patients with chronic liver diseases (CLD) of different etiologies and to compare the obtained results with morphological findings. A total of 45 patients (18 men and 27 women) aged 25 to 73 years with CLD were examined. All the patients underwent liver puncture biopsy for assessing the HS index and fibrosis stage, as well as determination of hepatic elasticity (F, kPa) for estimating the stage of fibrosis and the grade of HS by CAP (S, dB/m) using a FibroScan device. When assessing HS, the CAP values of <229, 230-249, 250-276, and more than 277 dB/m correspond to HS grade 0 (S0), S1, S2, and S3, respectively. This is a pilot study in Russia. CAP is a rather high effective method in determining the absence of steatosis (S0) (the area under the receiver operating characteristics curve (AUROC) was 0.78) and severe steatosis (S3) (AUROC 0.90). AUROC was 0.64 and 0.59 for HS S1 and S2, which is regarded as satisfactory and poor respectively. Only 3 out of the 45 patients had HS, as evidenced by morphological examination; and the results of CAP showed another result; all the other cases had a HS grade corresponding to S1. In the entire cohort of the examinees, the sensitivity, specificity, and accuracy of CAP was 86, 69.5, and 78%, respectively; AUROC was 0.77 (95% CI, 0.6587-0.9006; p=0.40). CAP is a promising method for the rapid and non-invasive diagnosis of HS in patients with CLD. At the same time, our findings show that it is necessary to clarify the quantitative indicators of the compliance of CAP and morphological evaluation of HS.

Specificity of unenhanced CT for non-invasive diagnosis of hepatic steatosis: implications for the investigation of the natural history of incidental steatosis

To determine a highly specific liver attenuation threshold at unenhanced CT for biopsy-proven moderate to severe hepatic steatosis (≥30% at histology). 315 asymptomatic adults (mean age ± SD, 31.5 ± 10.1 years; 207 men, 108 women) underwent same-day unenhanced liver CT and ultrasound-guided liver biopsy. Blinded to biopsy results, CT liver attenuation was measured using standard region-of-interest methodology. Multiple linear regression analysis was used to assess the relationship of CT liver attenuation with patient age, gender, BMI, CT system, and hepatic fat and iron content. Thirty-nine subjects had moderate to severe steatosis and 276 had mild or no steatosis. A liver attenuation threshold of 48 HU was 100% specific (276/276) for moderate to severe steatosis, with no false-positives. Sensitivity, PPV and NPV at this HU threshold was 53.8%, 100% and 93.9%. Hepatic fat content was the overwhelming determinant of liver attenuation values, but CT system (P < 0.001), and hepatic iron (P = 0.035) also had a statistically significant independent association. Unenhanced CT liver attenuation alone is highly specific for moderate to severe hepatic steatosis, allowing for confident non-invasive identification of large retrospective/prospective cohorts for natural history evaluation of incidental non-alcoholic fatty liver disease. Low sensitivity, however, precludes effective population screening at this threshold. • Unenhanced CT liver attenuation is highly specific for diagnosing moderate/severe hepatic steatosis. • Unenhanced CT can identify large cohorts for epidemiological studies of incidental steatosis. • Unenhanced CT is not, however, effective for population screening for hepatic steatosis.

Imaging of hepatic steatosis and fatty sparing: a review

Radiology has gained importance in the noninvasive diagnosis of hepatic steatosis. Ultrasonography is usually the first imaging modality for the evaluation of hepatic steatosis. Unenhanced computed tomography (CT) with or without dual kVp measurement and magnetic resonance imaging (MRI) with in- and out-of-phase sequence can allow objective evaluation of hepatic steatosis. However, none of the imaging modalities can differentiate nonalcoholic steatohepatitis/fatty liver disease from simple steatosis. Evaluation of hepatic steatosis is important in donor evaluation before orthotopic liver transplantation and hepatic surgery. Recently, one-stop-shop evaluation of potential liver donors has become possible by CT and MRI, integrating vascular, parenchymal, volume, and steatosis evaluation. Moreover, hepatic steatosis (diffuse, multinodular, focal, subcortical, perilesional, intralesional, periportal, and perivenular), hypersteatosis and sparing (geographic, nodular, and perilesional or peritumoral) can cause diagnostic problems as a pseudotumor, particularly in the evaluation of oncology patients. Liver MRI is used as a problem-solving tool in these patients. In this review, we discuss the current role of radiology in diagnosing and quantifying hepatic steatosis and solutions for diagnostic problems associated with fatty infiltration and sparing. Radiology has gained importance in the noninvasive diagnosis of hepatic steatosis. Ultrasonography is usually the first imaging modality for the evaluation of hepatic steatosis. Unenhanced computed tomography (CT) with or without dual kVp measurement and magnetic resonance imaging (MRI) with in- and out-of-phase sequence can allow objective evaluation of hepatic steatosis. However, none of the imaging modalities can differentiate nonalcoholic steatohepatitis/fatty liver disease from simple steatosis. Evaluation of hepatic steatosis is important in donor evaluation before orthotopic liver transplantation and hepatic surgery. Recently, one-stop-shop evaluation of potential liver donors has become possible by CT and MRI, integrating vascular, parenchymal, volume, and steatosis evaluation. Moreover, hepatic steatosis (diffuse, multinodular, focal, subcortical, perilesional, intralesional, periportal, and perivenular), hypersteatosis and sparing (geographic, nodular, and perilesional or peritumoral) can cause diagnostic problems as a pseudotumor, particularly in the evaluation of oncology patients. Liver MRI is used as a problem-solving tool in these patients. In this review, we discuss the current role of radiology in diagnosing and quantifying hepatic steatosis and solutions for diagnostic problems associated with fatty infiltration and sparing.