Comparison between T1 relaxation time of Gd-EOB-DTPA-enhanced MRI and liver stiffness measurement of ultrasound elastography in the evaluation of cirrhotic liver

Survey of water proton longitudinal relaxation in liver in vivo

Objective

To determine the variability, and preferred values, for normal liver longitudinal water proton relaxation rate R₁ in the published literature.

Methods

Values of mean R₁ and between-subject variance were obtained from literature searching. Weighted means were fitted to a heuristic and to a model.

Results

After exclusions, 116 publications (143 studies) remained, representing apparently normal liver in 3392 humans, 99 mice and 249 rats. Seventeen field strengths were included between 0.04 T and 9.4 T. Older studies tended to report higher between-subject coefficients of variation (CoV), but for studies published since 1992, the median between-subject CoV was 7.4%, and in half of those studies, measured R₁ deviated from model by 8.0% or less.

Discussion

The within-study between-subject CoV incorporates repeatability error and true between-subject variation. Between-study variation also incorporates between-population variation, together with bias from interactions between methodology and physiology. While quantitative relaxometry ultimately requires validation with phantoms and analysis of propagation of errors, this survey allows investigators to compare their own R₁ and variability values with the range of existing literature.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10334-021-00928-x.

Liver Fibrosis Staging with Gadolinium Ethoxybenzyl Diethylenetriamine Penta-Acetic Acid-enhanced: A Systematic Review and Meta-analysis

OBJECTIVE

While liver biopsy is the golden standard for liver-fibrosis diagnosis, it is also invasive and has many limitations. Non-invasive techniques such as Magnetic Resonance Imaging (MRI) need to be further developed for liver fibrosis staging. This study aimed to evaluate the diagnostic accuracy of Gadolinium Ethoxybenzyl Diethylenetriamine Penta-acetic Acid (Gd-EOBDTPA)- enhanced MRI for liver fibrosis through systematic review and meta-analysis.

METHODS

This study comprehensively searched relevant article in PubMed, Embase, and the Cochrane Library published from 2004 to 2018 to find studies analyzing the diagnostic accuracy of Gd-EOB-DTPA-enhanced MRI for liver fibrosis. Two reviewers independently screened the retrieved articles, extracted the required data from the included studies, and evaluated the methodological quality of the studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and Summary Receiver Operating Characteristics (SROC) curve were assessed.

RESULTS

This study finally included 16 studies (n = 1,599) and selected a random-effects model based on the results of the I² statistic to combine them. The areas under the SROC curve for the detection of F1 or greater, F2 or greater, F3 or greater, or F4 liver fibrosis were 0.8669, 0.8399, 0.8481, and 0.8858, respectively.

CONCLUSION

Gd-EOB-DTPA-enhanced MRI showed a good diagnostic performance for staging liver fibrosis, especially for F4 liver fibrosis.

Gadoxetate-disodium-enhanced magnetic resonance imaging for liver fibrosis staging: a systematic review and meta-analysis

AIM

To identify and evaluate the efficiency of the most commonly used parameters applied to gadoxetate disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for liver fibrosis (LF) staging.

MATERIALS AND METHODS

Literature searches of PubMed, Web of Science, Embase, and MEDLINE databases from January 2004 to August 2018 were conducted. The applied parameters during imaging were noted and summarised. Studies using the most commonly used parameter were included. Extractive data were combined as pooled weighted mean difference (WMD) to determine the benefits in LF staging. The pooled sensitivity, specificity, and summary receiver operating characteristics (SROC) curve were calculated.

RESULTS

Among 57 relevant studies, the contrast enhancement index (CEI) was a relatively commonly used parameter. It was calculated as SI_post/SI_pre, where SI_post and SI_pre are the liver-to-muscle signal intensity ratios in the hepatocyte phase and pre-enhanced images, respectively. Six studies were included. F0 was regarded as normal liver, F1 as mild LF, F2 as moderate LF, and F3 and F4 as advanced LF. Comparisons of WMD revealed significant differences between F1-2 and F3-4. For stage ≥F1, the pooled sensitivity, specificity, and areas under SROC curve were 0.58, 0.84, and 0.85, respectively; the corresponding values for ≥F2 were 0.57, 0.68, and 0.76, while those for ≥F3 were 0.61, 0.75, and 0.72.

CONCLUSION

The methodology and parameters used for Gd-EOB-DTPA-enhanced MRI for LF staging are diverse, but the CEI was a relatively common parameter. Overall, there is evidence to support use of CEI, but more evidence from larger studies is needed.

Staging of liver fibrosis using Gd-EOB-DTPA and Gd-BOPTA enhanced magnetic resonance imaging

The severity of cirrhosis is closely related to its clinical treatment. Therefore, it is important to stage liver fibrosis accurately. Although liver biopsy can accurately stage the degree of cirrhosis, it has certain limitations in clinical application because of its invasive nature. Magnetic resonance imaging (MRI) has been used in the diagnosis of liver diseases. In recent years, two new contrast agents, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) and gadobenate dimeglumine (Gd-BOPTA), have been successfully used for noninvasive liver imaging. They can be used for liver fibrosis staging and assessment of liver function. Cirrhotic patients with different liver function levels have a statistical difference in the liver parenchyma enhancement after giving contrast agents. This article briefly summarizes the progress of Gd-EOB-DTPA and Gd-BOPTA enhanced MRI in staging liver fibrosis stage.

Simultaneous acquisition of high-contrast and quantitative liver T1 images using 3D phase-sensitive inversion recovery: a feasibility study

Background Tumor-to-liver contrast is low in images of chronically diseased livers because gadolinium-based hepatocyte-specific contrast agents (Gd-EOB-DTPA) accumulate less to hepatocytes. Purpose To determine whether phase-sensitive inversion recovery (PSIR) could improve the T₁ contrasts of Gd-based contrast agents and liver parenchyma and simultaneously provide accurate T₁ values for abdominal organs. Material and Methods The image contrasts of phantoms with different Gd concentrations that were obtained using PSIR were compared to conventional turbo field echo (TFE) results. T₁ value was estimated using PSIR by performing iterations to investigate the two IR magnetization evolutions. The estimated T₁ values were validated using IR-spin echo (IR-SE) and Look-Locker (L-L) sequences. In an in vivo study, the liver-to-spleen and liver-to-muscle contrasts of the PSIR and TFE images of seven volunteers were compared, as were the T₁ values of liver parenchyma, spleen, and muscle obtained using PSIR and L-L sequences. Results The PSIR images showed T₁ contrasts higher than those in the TFE results. The PSIR and IR-SE T₁ values were linearly correlated. Additionally, the R₁ estimated using PSIR were correlated with those measured using IR-SE and L-L. In the in vivo study, the liver-to-spleen and liver-to-muscle contrasts of PSIR were significantly higher than those obtained using TFE. T₁ values of abdominal organs obtained using PSIR and L-L were clearly correlated. Conclusion PSIR may be capable of improving liver image T₁ contrasts when Gd-based contrast agents are employed and simultaneously yielding accurate T₁ values of abdominal organs.

Evaluation of hepatic fibrosis: a review from the society of abdominal radiology disease focus panel

Hepatic fibrosis is potentially reversible; however early diagnosis is necessary for treatment in order to halt progression to cirrhosis and development of complications including portal hypertension and hepatocellular carcinoma. Morphologic signs of cirrhosis on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) alone are unreliable and are seen with more advanced disease. Newer imaging techniques to diagnose liver fibrosis are reliable and accurate, and include magnetic resonance elastography and US elastography (one-dimensional transient elastography and point shear wave elastography or acoustic radiation force impulse imaging). Research is ongoing with multiple other techniques for the noninvasive diagnosis of hepatic fibrosis, including MRI with diffusion-weighted imaging, hepatobiliary contrast enhancement, and perfusion; CT using perfusion, fractional extracellular space techniques, and dual-energy, contrast-enhanced US, texture analysis in multiple modalities, quantitative mapping, and direct molecular imaging probes. Efforts to advance the noninvasive imaging assessment of hepatic fibrosis will facilitate earlier diagnosis and improve patient monitoring with the goal of preventing the progression to cirrhosis and its complications.

Multiparametric or practical quantitative liver MRI: towards millisecond, fat fraction, kilopascal and function era

New advances in liver magnetic resonance imaging (MRI) may enable diagnosis of unseen pathologies by conventional techniques. Normal T1 (550-620 ms for 1.5 T and 700-850 ms for 3 T), T2, T2* (>20 ms), T1rho (40-50 ms) mapping, proton density fat fraction (PDFF) (≤5%) and stiffness (2-3kPa) values can enable differentiation of a normal liver from chronic liver and diffuse diseases. Gd-EOB-DTPA can enable assessment of liver function by using postcontrast hepatobiliary phase or T1 reduction rate (normally above 60%). T1 mapping can be important for the assessment of fibrosis, amyloidosis and copper overload. T1rho mapping is promising for the assessment of liver collagen deposition. PDFF can allow objective treatment assessment in NAFLD and NASH patients. T2 and T2* are used for iron overload determination. MR fingerprinting may enable single slice acquisition and easy implementation of multiparametric MRI and follow-up of patients. Areas covered: T1, T2, T2*, PDFF and stiffness, diffusion weighted imaging, intravoxel incoherent motion imaging (ADC, D, D* and f values) and function analysis are reviewed. Expert commentary: Multiparametric MRI can enable biopsyless diagnosis and more objective staging of diffuse liver disease, cirrhosis and predisposing diseases. A comprehensive approach is needed to understand and overcome the effects of iron, fat, fibrosis, edema, inflammation and copper on MR relaxometry values in diffuse liver disease.

Staging liver fibrosis in chronic hepatitis B with T1 relaxation time index on gadoxetic acid-enhanced MRI: Comparison with aspartate aminotransferase-to-platelet ratio index and FIB-4

PURPOSE

To assess the accuracy of the T₁ relaxation time index on gadoxetic acid-enhanced magnetic resonance imaging (MRI) for staging liver fibrosis in chronic hepatitis B (CHB), in comparison and combination with the aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 (FIB-4).

MATERIALS AND METHODS

A retrospective study of gadoxetic acid-enhanced T₁ mapping and serum biochemical tests was performed on 126 CHB patients who underwent gadoxetic acid-enhanced 1.5T MRI, and the histological score used as the gold standard. The reduction rate of T₁ relaxation time before and 20 minutes after gadoxetic acid injection (ΔT₁ , ΔR1%), the contrast uptake rate (K_Hep ), APRI, and FIB-4 were calculated. The diagnostic efficacy of ΔT₁ , ΔR1%, K_Hep , APRI, and FIB-4 for predicting stage 2 or greater (≥S2), stage 3 or greater (≥S3), and stage 4 (S4) was compared.

RESULTS

ΔT₁ (r = -0.513, P < 0.001), ΔR1% (r = -0.626, P < 0.001), K_Hep (r = -0.527, P < 0.001), APRI (r = 0.519, P < 0.001), and FIB-4 (r = 0.476, P < 0.001) correlated significantly with fibrosis stages. Areas under the curves (AUCs) of ΔR1% for detecting ≥S2, ≥S3, and S4 were 0.849, 0.827, and 0.809, which were greater than that of APRI (0.763, 0.745, 0.787) and FIB-4 (0.727, 0.738, 0.772), but significant difference was found only in discriminating ≥S2 between ΔR1% and FIB-4 (P = 0.027). The combination of all five indices performed best, with AUC, sensitivity, and specificity of 0.860, 87.21%, and 72.50% for diagnosing ≥S2, 0.878, 82.81%, and 85.48% for ≥S3, and 0.867, 80.00%, and 83.95% for S4.

CONCLUSION

The gadoxetic acid-enhanced T₁ relaxation time index appears to be superior to APRI and FIB-4 for predicting hepatic fibrosis. The combined use of gadoxetic acid-enhanced T₁ mapping, APRI, and FIB-4 may be more reliable for staging liver fibrosis in CHB.

LEVEL OF EVIDENCE

4 J. Magn. Reson. Imaging 2017;45:1186-1194.

Novel Imaging Diagnosis for Hepatocellular Carcinoma: Consensus from the 5th Asia-Pacific Primary Liver Cancer Expert Meeting (APPLE 2014)

Current novel imaging techniques in the diagnosis of hepatocellular carcinoma (HCC), with the latest evidence in this field, was discussed at the Asia-Pacific Primary Liver Cancer Expert (APPLE) meeting held in Taipei, Taiwan, in July 2014. Based on their expertise in a specific area of research, the novel imaging group comprised 12 participants from Japan, South Korea, Taiwan, and China and it included 10 abdominal radiologists, one hepatologist, and one pathologist. The expert participants discussed topics related to HCC imaging that were divided into four categories: (i) detection method, (ii) diagnostic method, (iii) evaluation method, and (iv) functional method. Consensus was reached on 10 statements; specific comments on each statement were provided to explain the rationale for the voting results and to suggest future research directions.