Influence of hepatic fibrosis and inflammation: Correlation between histopathological changes and Gd-EOB-DTPA-enhanced MR imaging

Focal fatty sparing areas of the pediatric steatotic liver: pseudolesions on hepatobiliary phase magnetic resonance images

PURPOSE

Focal fatty sparing in liver can be detected as hyperintense pseudolesions on hepatobiliary phase magnetic resonance imaging (MRI). Distinguishing these pseudolesions from liver lesions may make diagnosis challenging. The aim of this study was to evaluate the imaging features of fatty sparing areas on liver MRI in pediatric patients who have been administered gadoxetate disodium.

METHODS

A total of 63 patients between January 2018 and June 2023 underwent gadoxetate disodium-enhanced liver MRI, and 9 (14%) patients with a focal fatty sparing were included in the study. The fat spared areas were evaluated qualitatively and quantitatively including signal intensity measurements and fat fraction calculations.

RESULTS

The liver MRI examinations of 9 patients (5 boys, 4 girls; aged 8-18 years, median age: 14.4) using gadoxetate disodium were evaluated. Based on in-phase and opposed-phase sequences, 13 areas of focal fatty sparing were identified. The mean fat fraction of the liver and fat spared areas were 26.2% (range, 15-47) and 9% (range, 2-17), respectively. All fat spared areas were hyperintense in the hepatobiliary phase images. The mean relative enhancement ratios of the liver and fat spared areas were 0.78 (range, 0.35-1.6) and 1.11 (range, 0.45-1.9), respectively.

CONCLUSION

Focal fatty sparing in liver in children was observed as hyperintense on hepatobiliary phase MRI, and it should not be identified as a focal liver lesion.

Conventional and artificial intelligence-based computed tomography and magnetic resonance imaging quantitative techniques for non-invasive liver fibrosis staging

Chronic liver disease (CLD) ultimately develops into liver fibrosis and cirrhosis and is a major public health problem globally. The assessment of liver fibrosis is important for patients with CLD for prognostication, treatment decisions, and surveillance. Liver biopsies are traditionally performed to determine the stage of liver fibrosis. However, the risks of complications and technical limitations restrict their application to screening and sequential monitoring in clinical practice. CT and MRI are essential for evaluating cirrhosis-associated complications in patients with CLD, and several non-invasive methods based on them have been proposed. Artificial intelligence (AI) techniques have also been applied to stage liver fibrosis. This review aimed to explore the values of conventional and AI-based CT and MRI quantitative techniques for non-invasive liver fibrosis staging and summarized their diagnostic performance, advantages, and limitations.

Combining 99mTc-GSA single-photon emission-computed tomography and Gd-EOB-DTPA-enhanced magnetic resonance imaging for staging liver fibrosis

Preoperative assessment of the degree of liver fibrosis is important to determine treatment strategies. In this study, galactosyl human serum albumin single-photon emission-computed tomography and ethoxybenzyl (EOB) contrast-enhanced magnetic resonance imaging (MRI) were used to assess the changes in hepatocyte function after liver fibrosis, and the standardized uptake value (SUV) was combined with gadolinium EOB-diethylenetriaminepentaacetic acid to evaluate its added value for liver fibrosis staging. A total of 484 patients diagnosed with hepatocellular carcinoma who underwent liver resection between January 2010 and August 2018 were included. Resected liver specimens were classified based on pathological findings into nonfibrotic and fibrotic groups (stratified according to the Ludwig scale). Galactosyl human serum albumin-single-photon emission-computed tomography and EOB contrast-enhanced MRI examinations were performed, and the mean SUVs (SUVmean) and contrast enhancement indices (CEIs) were obtained. The diagnostic value of the acquired SUV and CEIs for fibrosis was assessed by calculating the area under the receiver operating characteristic curve (AUC). In the receiver operating characteristic analysis, SUV + CEI showed the highest AUC in both fibrosis groups. In particular, in the comparison between fibrosis groups, SUV + CEI showed significantly higher AUCs than SUV and CEI alone in discriminating between fibrosis (F3 and 4) and no or mild fibrosis (F0 and 2) (AUC: 0.879, vs SUV [P = 0.008], vs. CEI [P = 0.023]), suggesting that the combination of SUV + CEI has greater diagnostic performance than the individual indices. Combining the SUV and CEI provides high accuracy for grading liver fibrosis, especially in differentiating between grades F0 and 2 and F3-4. SUV and gadolinium EOB-diethylenetriaminepentaacetic acid-enhanced MRI can be noninvasive diagnostic methods to guide the selection of clinical treatment options for patients with liver diseases.

Multiparametric MRI combined with liver volume for quantitative evaluation of liver function in patients with cirrhosis

PURPOSE We aimed to establish a liver function evaluation model by combining multiparametric magnetic resonance imaging (MRI) with liver volume (LV) and further verify the effectiveness of the model to evaluate liver function. METHODS This retrospective study included 101 consecutive cirrhosis patients (69 cases for modeling group and 32 cases for validation group) who underwent gadoxetic acid-enhanced MRI. Five signal intensity parameters were obtained by measuring the signal intensities of the liver, spleen, and erector spinae before and 20 minutes after gadoxetic acid disodium enhancement. The dif fusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were obtained from intravoxel incoherent motion diffusion-weighted imaging. The LV parameters (Vliver, Vspleen, and Vliver/Vspleen) were obtained using 3-dimensional image generation software. The most effec tive parameter was selected from each of the 3 methods, and a multivariate regression model for liver function evaluation was established and validated. RESULTS In the modeling group, relative enhancement (RE), D*, and Vliver/Vspleen showed significant dif ferences among the different liver function groups (P < .001). Receiver operating characteristic analysis showed that these parameters had the highest area under the curve (AUC) values for dis tinguishing Child-Pugh A from Child-Pugh B and C groups (0.917, 0.929, and 0.885, respectively). The following liver function model was obtained by multivariate regression analysis: F(x)=3.96 - 1.243 (RE) - 0.034 (D*) - 0.080 (Vliver/Vspleen) (R2=0.811, P < .001). In the patients with cirrhosis, the F(x) of Child-Pugh A, B, and C were 1.16 ± 0.44, 1.95 ± 0.29, and 2.79 ± 0.38, respectively. In the validation group, the AUC for F(x) to distinguish Child-Pugh A from Child-Pugh B and C was 0.973. CONCLUSION Combining multiparametric MRI with LV effectively distinguished patients with different Child Pugh grades. This model could hence be useful as a novel radiological marker to estimate the liver function.

Evaluation of statins as a new therapy to alleviate chronotropic dysfunction in cirrhotic rats

AIMS

Liver cirrhosis defines by regenerative nodules and fibrotic septa, causing a complication called cirrhotic cardiomyopathy (CCM) with chronotropic hypo-responsiveness. In addition to lowering cholesterol levels, statins yield antioxidant and anti-inflammatory effects. In liver diseases animal models, statins have been shown to decrease hepatic inflammation, fibrogenesis, and portal pressure (PP). Therefore, we evaluated the atorvastatin effect on the heart in cirrhotic rats.

MATERIALS AND METHODS

Bile duct ligation (BDL) or sham operation performed on male Wistar rats and grouped as cirrhotic; BDL/Saline, BDL/Ator-7d(days) (Atorvastatin 15 mg/kg/day), and BDL/Ator-14d groups, or control; Sham/Saline, Sham/Ator-7d, and Sham/Ator-14d groups. Corrected QT interval (QTc interval), chronotropic responses, serum brain natriuretic peptides (BNP), heart tumor necrosis factor-α (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2), and malondialdehyde (MDA) levels were studied along with atrial Ras homolog family member A (RhoA) and endothelial nitric oxide synthase (eNOS) gene expression.

KEY FINDINGS

The chronotropic responses decreased in BDL/Saline and increased in BDL/Ator-7d group. The QTc interval, BNP, TNF-α, and MDA levels increased in BDL/Saline and decreased in BDL/Ator-14d group. The Nrf2 level did not change in BDL/Saline and increased in BDL/Ator-14d group. The liver inflammation and fibrosis increased in BDL/Saline and did not affect BDL/Ator-7d and BDL/Ator-14d groups. The RhoA expression was down-regulated in BDL/Saline, BDL/Ator-7d, and BDL/Ator-14d groups. The eNOS expression did not change in BDL/Saline and down-regulated in BDL/Ator-14d group.

SIGNIFICANCE

Atorvastatin alleviates the chronotropic hypo-responsiveness and down-regulates the atrial RhoA and eNOS gene expression along with anti-inflammatory, antioxidant, and anti-stress effects in CCM.

Psoas muscle index predicts time to rehospitalization in liver cirrhosis: An observational study

Sarcopenia is frequent in liver cirrhosis (LC) where it is associated with morbidity and mortality. However, prognostic scores such as model for end-stage liver disease (MELD), MELD-sodium (MELD-Na), or Child-Turcotte-Pugh (CTP) do not contain sarcopenia as a variable. For this study, we utilized psoas muscle index (PMI) to objectively determine sarcopenia in hospitalized LC patients, and evaluated it as a predictor of time between discharge and readmission in LC. Abdominal computed tomography and magnetic resonance imaging scans of 65 consecutive LC patients were retrospectively examined to determine PMI. MELD, MELD-Na, and CTP were calculated from clinical data. PMI was then combined with CTP to form an experimental score: CTP sarcopenia (CTPS). For PMI alone and for each score, correlation with time between discharge and readmission for liver-related complications was calculated. PMI was also tested for correlation with sex, body mass index (BMI), MELD, MELD-Na, and CTP. CTPS was most closely correlated with time to readmission (R = 0.730; P < .001), followed by CTP (R = 0.696; P < .001), MELD-Na (R = 0.405; P = .009), and PMI alone (R = 0.388; P = .01). Correlation with MELD (R = 0.354; P = .05) was lowest. Additionally, there were significant differences in PMI between male and female individuals (5.16 vs 4.54 cm2/m2; P = .04) and in BMI between sarcopenic and nonsarcopenic individuals (29.63 vs 25.88 kg/m2; P = .009). Sarcopenia is an independent short-term prognostic factor in LC. By combining data on sarcopenia with CTP, we created an experimental score that predicts time to readmission better than MELD, MELD-Na, or CTP.

Gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid-enhanced magnetic resonance imaging for evaluating fibrosis regression in chronic hepatitis C patients after direct-acting antiviral

BACKGROUND

Direct acting antiviral (DAA) therapy has enabled hepatitis C virus infection to become curable, while histological changes remain uncontained. Few valid non-invasive methods can be confirmed for use in surveillance. Gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) is a liver-specific magnetic resonance imaging (MRI) contrast, related to liver function in the hepatobiliary phase (HBP). Whether Gd-EOB-DTPA-enhanced MRI can be used in the diagnosis and follow up of hepatic fibrosis in patients with chronic hepatitis C (CHC) has not been investigated.

AIM

To investigate the diagnostic and follow-up values of Gd-EOB-DTPA-enhanced MRI for hepatic histology in patients with CHC.

METHODS

Patients with CHC were invited to undergo Gd-EOB-DTPA-enhanced MRI and liver biopsy before treatment, and those with paired qualified MRI and liver biopsy specimens were included. Transient elastography (TE) and blood tests were also arranged. Patients treated with DAAs who achieved 24-wk sustained virological response (SVR) underwent Gd-EOB-DTPA-enhanced MRI and liver biopsy again. The signal intensity (SI) of the liver and muscle were measured in the unenhanced phase (UEP) (SI_UEP-liver, SI_UEP-muscle) and HBP (SI_HBP-liver, SI_HBP-muscle) via MRI. The contrast enhancement index (CEI) was calculated as [(SI_HBP-liver/SI_HBP-muscle)]/[(SI_UEP-liver/SI_UEP-muscle)]. Liver stiffness measurement (LSM) was confirmed with TE. Serologic markers, aspartate aminotransferase-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4), were also calculated according to blood tests. The grade of inflammation and stage of fibrosis were evaluated with the modified histology activity index (mHAI) and Ishak fibrosis score, respectively. Fibrosis regression was defined as a ≥ 1-point decrease in the Ishak fibrosis score. The correlation between the CEI and liver pathology was evaluated. The diagnostic and follow-up values of the CEI, LSM, and serologic markers were compared.

RESULTS

Thirty-nine patients with CHC were enrolled [average age, 42.3 ± 14.4 years; 20/39 (51.3%) male]. Twenty-one enrolled patients had eligible paired Gd-EOB-DTPA-enhanced MRI and liver tissues after achieving SVR. The mHAI median significantly decreased after SVR [baseline 6.0 (4.5-13.5) vs SVR 2.0 (1.5-5.5), Z = 3.322, P = 0.017], but the median stage of fibrosis did not notably change (P > 0.05). Sixty pairs of qualified MRI and liver tissue samples were available for use to analyze the relationship between the CEI and hepatic pathology. The CEI was negatively correlated with the mHAI (r = -0.56, P < 0.001) and Ishak score (r = -0.69, P < 0.001). Further stratified analysis showed that the value of the CEI decreased with the progression of the stage of fibrosis rather than with the grade of necroinflammation. For patients with Ishak score ≥ 5, the areas under receiver operating characteristics curve of the CEI, LSM, APRI, and FIB-4 were approximately at baseline, 0.87–0.93, and after achieving SVR, 0.83–0.91. The CEI cut-off value was stable (baseline 1.58 and SVR 1.59), but those of the APRI (from 1.05 to 0.24), FIB-4 (from 1.78 to 1.28), and LSM (from 10.8 kpa to 7.1 kpa) decreased dramatically. The APRI and FIB-4 cannot be used as diagnostic means for SVR in patients with Ishak score ≥ 3 (P > 0.05). Seven patients achieved fibrosis regression after achieving SVR. In these patients, the CEI median increased (from 1.71 to 1.83, Z = -1.981, P = 0.048) and those of the APRI (from 1.71 to 1.83, Z = -2.878, P = 0.004) and LSM (from 6.6 to 4.8, Z = -2.366, P = 0.018) decreased. However, in patients without fibrosis regression, the medians of the APRI, FIB-4, and LSM also changed significantly (P < 0.05).

CONCLUSION

Gd-EOB-DTPA-enhanced MRI has good diagnostic value for staging fibrosis in patients with CHC. It can be used for fibrotic-change monitoring post SVR in patients with CHC treated with DAAs.

Assessment of Liver Function With MRI: Where Do We Stand?

Liver disease and hepatocellular carcinoma (HCC) have become a global health burden. For this reason, the determination of liver function plays a central role in the monitoring of patients with chronic liver disease or HCC. Furthermore, assessment of liver function is important, e.g., before surgery to prevent liver failure after hepatectomy or to monitor the course of treatment. Liver function and disease severity are usually assessed clinically based on clinical symptoms, biopsy, and blood parameters. These are rather static tests that reflect the current state of the liver without considering changes in liver function. With the development of liver-specific contrast agents for MRI, noninvasive dynamic determination of liver function based on signal intensity or using T1 relaxometry has become possible. The advantage of this imaging modality is that it provides additional information about the vascular structure, anatomy, and heterogeneous distribution of liver function. In this review, we summarized and discussed the results published in recent years on this technique. Indeed, recent data show that the T1 reduction rate seems to be the most appropriate value for determining liver function by MRI. Furthermore, attention has been paid to the development of automated tools for image analysis in order to uncover the steps necessary to obtain a complete process flow from image segmentation to image registration to image analysis. In conclusion, the published data show that liver function values obtained from contrast-enhanced MRI images correlate significantly with the global liver function parameters, making it possible to obtain both functional and anatomic information with a single modality.

Heterogeneous Iron Oxide/Dysprosium Oxide Nanoparticles Target Liver for Precise Magnetic Resonance Imaging of Liver Fibrosis

Challenges remain in precisely diagnosing the progress of liver fibrosis in a noninvasive way. We here synthesized small (4 nm) heterogeneous iron oxide/dysprosium oxide nanoparticles (IO-DyO NPs) as a contrast agent (CA) for magnetic resonance imaging (MRI) to precisely diagnose liver fibrosis in vivo at both 7.0 and 9.4 T field strength. Our IO-DyO NPs can target the liver and show an increased T₂ relaxivity along with an increase of magnetic field strength. At a ultrahigh magnetic field, IO-DyO NPs can significantly improve spatial/temporal image resolution and signal-to-noise ratio of the liver and precisely distinguish the early and moderate liver fibrosis stages. Our IO-DyO NP-based MRI diagnosis can exactly match biopsy (a gold standard for liver fibrosis diagnosis in the clinic) but avoid the invasiveness of biopsy. Moreover, our IO-DyO NPs show satisfactory biosafety in vitro and in vivo. This work illustrates an advanced T₂ CA used in ultrahigh-field MRI (UHFMRI) for the precise diagnosis of liver fibrosis via a noninvasive means.

Gd-EOB-DTPA-enhanced MRI-a noninvasive and short-term assessment method for liver necroinflammation after direct-acting antiviral (DAA) therapy in patients with chronic hepatitis C

PURPOSE

To assess liver necroinflammation in HCV patients undergone antiviral therapy by Gd-EOB-DTPA-enhanced MRI with histopathologic analyses as reference.

METHODS

HCV patients were enrolled in this prospective study before antiviral treatment between 09-2016 and 07-2017. Unenhanced MR, Gd-EOB-DTPA-enhanced MR, and liver biopsy were performed before and 24 weeks after treatment of daclatasvir with asunaprevir (DAA). DWI was obtained using a breath-hold single-shot echo planar spin-echo sequence. Twenty minutes after administration of Gd-EOB-DTPA, the relative enhancement (RE) and the contrast enhancement index (CEI) were recorded. Liver necroinflammatory activity grades (G0-18) were categorized on the Ishak Scoring systems. CEI, RE, and DWI of baseline and 24 weeks after treatment were compared by paired t test. Relationship between MR parameters and histologic scores was evaluated by Pearson's correlation. Receiver operating characteristic analysis evaluated the measurements' diagnostic performance. MRI variability between two readers was assessed using the intraclass correlation coefficient.Results RESULTS: A decrease of liver necroinflammatory activity grade (p < 0.0001) was detected in final cohort (n = 21; mean age 44 years; 23 to 67 years; 11 F, 10 M). Statistical results of 42 person-times in 21 patients at baseline and follow-up showed CEI and ADC were significantly different (p = 0.006 and 0.036) across histologic grades of liver necroinflammation. Significant increase of CEI, RE, and ADC (p = 0.0004, 0.0032, 0.0110) 24 weeks after DAA treatment was seen. Additionally, CEI was correlated to necroinflammatory grade (r =  - 0.596, p = 0.006). AUROC for CEI, ADC, and CEI combined with ADC to differentiate patients with none and mild (G0-6) from patients with moderate and severe necroinflammation (G7-18) was 0.834 (95% CI 0.712-0.956, 0.724(95% CI 0.565-0.884) and 0.837(95% CI 0.717-0.956).

CONCLUSION

Gd-EOB-DTPA-enhanced MRI by CEI could be used as a noninvasive imaging biomarker to distinguish grades of necroinflammatory activity in patients with HCV after DAAs therapy at early stage and CEI combined with ADC could get a better diagnostic accuracy.

Correlation of liver enhancement in gadoxetic acid-enhanced MRI with liver functions: a multicenter-multivendor analysis of hepatocellular carcinoma patients from SORAMIC trial

OBJECTIVES

To evaluate the correlation between liver enhancement on hepatobiliary phase and liver function parameters in a multicenter, multivendor study.

METHODS

A total of 359 patients who underwent gadoxetic acid-enhanced MRI using a standardized protocol with various scanners within a prospective multicenter phase II trial (SORAMIC) were evaluated. The correlation between liver enhancement on hepatobiliary phase normalized to the spleen (liver-to-spleen ratio, LSR) and biochemical laboratory parameters, clinical findings related to liver functions, liver function grading systems (Child-Pugh and Albumin-Bilirubin [ALBI]), and scanner characteristics were analyzed using uni- and multivariate analyses.

RESULTS

There was a significant positive correlation between LSR and albumin (rho = 0.193; p < 0.001), platelet counts (rho = 0.148; p = 0.004), and sodium (rho = 0.161; p = 0.002); and a negative correlation between LSR and total bilirubin (rho = -0.215; p < 0.001) and AST (rho = -0.191; p < 0.001). Multivariate analysis confirmed independent significance for each of albumin (p = 0.022), total bilirubin (p = 0.045), AST (p = 0.031), platelet counts (p = 0.012), and sodium (p = 0.006). The presence of ascites (1.47 vs. 1.69, p < 0.001) and varices (1.55 vs. 1.69, p = 0.006) was related to significantly lower LSR. Similarly, patients with ALBI grade 1 had significantly higher LSR than patients with grade 2 (1.74 ± 0.447 vs. 1.56 ± 0.408, p < 0.001); and Child-Pugh A patients had a significantly higher LSR than Child-Pugh B (1.67 ± 0.44 vs. 1.49 ± 0.33, p = 0.021). Also, LSR was negatively correlated with MELD-Na scores (rho = -0.137; p = 0.013). However, one scanner brand was significantly associated with lower LSR (p < 0.001).

CONCLUSIONS

The liver enhancement on the hepatobiliary phase of gadoxetic acid-enhanced MRI is correlated with biomarkers of liver functions in a multicenter cohort. However, this correlation shows variations between scanner brands.

KEY POINTS

• The correlation between liver enhancement on the hepatobiliary phase of gadoxetic acid-enhanced MRI and liver function is consistent in a multicenter-multivendor cohort. • Signal intensity-based indices (liver-to-spleen ratio) can be used as an imaging biomarker of liver function. • However, absolute values might change between vendors.

Imaging-Based Staging of Hepatic Fibrosis in Patients with Hepatitis B: A Dynamic Radiomics Model Based on Gd-EOB-DTPA-Enhanced MRI

Accurate grading of liver fibrosis can effectively assess the severity of liver disease and help doctors make an appropriate diagnosis. This study aimed to perform the automatic staging of hepatic fibrosis on patients with hepatitis B, who underwent gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging with dynamic radiomics analysis. The proposed dynamic radiomics model combined imaging features from multi-phase dynamic contrast-enhanced (DCE) images and time-domain information. Imaging features were extracted from the deep learning-based segmented liver volume, and time-domain features were further explored to analyze the variation in features during contrast enhancement. Model construction and evaluation were based on a 132-case data set. The proposed model achieved remarkable performance in significant fibrosis (fibrosis stage S1 vs. S2–S4; accuracy (ACC) = 0.875, area under the curve (AUC) = 0.867), advanced fibrosis (S1–S2 vs. S3–S4; ACC = 0.825, AUC = 0.874), and cirrhosis (S1–S3 vs. S4; ACC = 0.850, AUC = 0.900) classifications in the test set. It was more dominant compared with the conventional single-phase or multi-phase DCE-based radiomics models, normalized liver enhancement, and some serological indicators. Time-domain features were found to play an important role in the classification models. The dynamic radiomics model can be applied for highly accurate automatic hepatic fibrosis staging.

Combining 18F-FDG PET and Gd-EOB-DTPA-enhanced MRI for staging liver fibrosis

AIM

To evaluate the diagnostic performance of combining ¹⁸F-2-fluoro-2-D-deoxyglucose-positron emission tomography (¹⁸F-FDG PET) and gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for liver fibrosis staging.

MATERIALS AND METHODS

Male New Zealand white rabbits (n = 48) were treated with carbon tetrachloride (CCl4) to induce liver fibrosis, while control group rabbits (n = 8) received normal saline. The liver tissues of rabbits were histopathologically examined (classified according to the METAVIR classification system) for liver fibrosis staging and real-time polymerase chain reaction (RT-PCR) was used to ensure diagnostic accuracy. Integrated PET/MRI was performed. The mean standardised uptake value (SUV_mean) and relative enhancement (RE) were evaluated for different liver fibrosis stages using a Mann-Whitney U test. The performance of PET/MRI was evaluated by using the receiver operating characteristic curve (ROC) and the area under the ROC curve (AUC).

KEY FINDINGS

In total, 10, 16, and 8 rabbits classified into no fibrosis (F0), mild fibrosis (F1-2), and severe fibrosis (F3-4) categories, respectively. There were significant differences in SUV_mean and RE between F0 and F3-4 and between F1-2 and F3-4 (p < 0.01), but no significance between F0 and F1-2 (p > 0.5). Combined SUV_mean and RE performed well in staging liver fibrosis, with AUC of 0.8 for F0 or greater, 0.744 for F0 or F1-2, 0.945 for F1-2 or F3-4, and 0.962 for F3-4.

SIGNIFICANCE

Combining SUV_mean and RE provides high accuracy for grading liver fibrosis, especially in the differentiation between F1-2 and F3-4. ¹⁸F-FDG and Gd-EOB-DTPA-enhanced PET/MRI could be a non-invasive diagnostic method to guide the selection of clinical treatment options.

Noninvasive diagnosis of portal hypertension using gadoxetate DCE-MRI of the liver and spleen

OBJECTIVES

To assess the performance of gadoxetate dynamic contrast-enhanced (DCE) MRI of the liver and spleen for noninvasive diagnosis of portal hypertension (PH).

METHODS

Thirty-five patients (M/F 22/13, mean age 55 years) with chronic liver disease who underwent hepatic venous pressure gradient (HVPG) measurements were prospectively enrolled in this IRB-approved study. All patients underwent multiparametric MRI including gadoxetate DCE-MRI acquisition. Model-based and model-free DCE-MRI analyses were performed. The correlation between DCE-MRI parameters and HVPG was assessed. ROC analysis was employed to determine the diagnostic performance of DCE-MRI parameters alone and in combination for prediction of PH and clinically significant (CS)PH (HVPG > 5 and ≥ 10 mmHg, respectively).

RESULTS

Mean HVPG was 7.0 ± 5.0 mmHg (range 0-18 mmHg). Twenty-one (60%) patients had PH, of whom 9 had CSPH. Modeled liver uptake fraction f_i and uptake rate k_i and model-free parameters liver upslope and uptake were all significantly negatively correlated with HVPG (r range - 0.490 to - 0.398, p value range 0.003-0.018), while spleen interstitial fraction v_e was significantly positively correlated with HVPG (r = 0.336, p = 0.048). For PH diagnosis, liver k_i showed the best diagnostic performance with an AUC, sensitivity, and specificity of 0.74 (confidence interval (CI) 0.57-0.91), 71.4%, and 78.6%. The combination of liver k_i and spleen v_e was selected as the best classifier for diagnosis of CSPH with an AUC, sensitivity, and specificity of 0.87 (CI 0.75-0.99), 100%, and 73.1%.

CONCLUSIONS

Our results demonstrate the potential utility of hepatocyte uptake parameters and spleen interstitial fraction obtained with gadoxetate DCE-MRI for the diagnosis of PH and CSPH.

KEY POINTS

• Liver uptake and spleen interstitial fraction estimates from gadoxetate DCE-MRI are significantly correlated with portal pressure measurements. • Liver uptake rate shows good diagnostic performance for the diagnosis of portal hypertension. • The combination of liver uptake rate with spleen interstitial fraction exhibits excellent diagnostic performance for the diagnosis of clinically significant portal hypertension.

Quantification of liver function using gadoxetic acid-enhanced MRI

The introduction of hepatobiliary contrast agents, most notably gadoxetic acid (GA), has expanded the role of MRI, allowing not only a morphologic but also a functional evaluation of the hepatobiliary system. The mechanism of uptake and excretion of gadoxetic acid via transporters, such as organic anion transporting polypeptides (OATP1,3), multidrug resistance-associated protein 2 (MRP2) and MRP3, has been elucidated in the literature. Furthermore, GA uptake can be estimated on either static images or on dynamic imaging, for example, the hepatic extraction fraction (HEF) and liver perfusion. GA-enhanced MRI has achieved an important role in evaluating morphology and function in chronic liver diseases (CLD), allowing to distinguish between the two subgroups of nonalcoholic fatty liver diseases (NAFLD), simple steatosis and nonalcoholic steatohepatitis (NASH), and help to stage fibrosis and cirrhosis, predict liver transplant graft survival, and preoperatively evaluate the risk of liver failure if major resection is planned. Finally, because of its noninvasive nature, GA-enhanced MRI can be used for long-term follow-up and post-treatment monitoring. This review article aims to describe the current role of GA-enhanced MRI in quantifying liver function in a variety of hepatobiliary disorders.

FN1 mRNA expression of fibronectin 1 and distribution of fibronectin-associated leukocytes in humans with chronic diffuse liver diseases

Chronic diffuse liver diseases are characterized by continuous progression of fibrosis, ultimately leading to cirrhosis with the following loss of the normal functioning of this organ due to excessive accumulation of the components of extracellular matrix. To find new, more available diagnostic markers of detecting disorders in the liver, we used methods of antifungal cytofluorometry and quantitative real-time polymerase chain reaction. Intensity of exposure of fibronectin and plasmatic membrane of lymphocytes in the group of patients with chronic diffuse diseases compared with the control group of practically healthy donors decreased both inside and on the surface of the cells respectively by 45.3% and 16.2%. Similar tendency towards decrease was observed during the assays of the level of the exposure of fibronectin on the surface and inside the blood granulocytes: by 25.0% and 36.5%, respectively. In the blood of the patients suffering from chronic diffuse diseases, compared with the control group, there was determined reliable increase in percentage of lymphocytes and granulocytes which contain topical fibronectin, by 32.3% and 2.78 times, correspondingly. The level of monocytes (as a percentage) with cell-associated fibronectin and fibronectin localized inside, by contrast, reliably decreased in 2.07 and 4.50 times, respectively. Analysis of the expression of FN1 in lymphocytes of blood of the studied groups using quantitative real-time polymerase chain reaction revealed decrease in the level of FN1 mRNA expression by 34.0% in the group of ill patients compared with the control group. We determined excellent diagnostic informativeness of the parameters of the level of exposure of fibronectin inside and on the surface of granulocytes and prognostic accuracy of the classifier from these parameters at the level of 100% using the method of support vector machine, SVM. High levels of diagnostic informativeness were recorded for the tests of all types of analyzed leukocytes with cell-associated fibronectin, and the classifiers based on the pair combinations of the tests with cell-associated fibronectin and fibronectin localized within the cells provide high diagnostic accuracy of the prognosis. Because the mentioned indicators are highly-sensitive tests, they can be proposed for early diagnostics and evaluation of the effectiveness of the conducted therapy of chronic diffuse liver diseases, which would allow reducing the use of paracentetic trepanobiopsy, a painful and risky procedure, which still remains the main type of diagnostic.