Feasibility of measuring spleen stiffness with MR elastography and splenic volume to predict hepatic fibrosis stage

The impact of hepatic and splenic volumetric assessment in imaging for chronic liver disease: a narrative review

Chronic liver disease is responsible for significant morbidity and mortality worldwide. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) can fully visualise the liver and adjacent structures in the upper abdomen providing a reproducible assessment of the liver and biliary system and can detect features of portal hypertension. Subjective interpretation of CT and MRI in the assessment of liver parenchyma for early and advanced stages of fibrosis (pre-cirrhosis), as well as severity of portal hypertension, is limited. Quantitative and reproducible measurements of hepatic and splenic volumes have been shown to correlate with fibrosis staging, clinical outcomes, and mortality. In this review, we will explore the role of volumetric measurements in relation to diagnosis, assessment of severity and prediction of outcomes in chronic liver disease patients. We conclude that volumetric analysis of the liver and spleen can provide important information in such patients, has the potential to stratify patients' stage of hepatic fibrosis and disease severity, and can provide critical prognostic information. CRITICAL RELEVANCE STATEMENT: This review highlights the role of volumetric measurements of the liver and spleen using CT and MRI in relation to diagnosis, assessment of severity, and prediction of outcomes in chronic liver disease patients. KEY POINTS: Volumetry of the liver and spleen using CT and MRI correlates with hepatic fibrosis stages and cirrhosis. Volumetric measurements correlate with chronic liver disease outcomes. Fully automated methods for volumetry are required for implementation into routine clinical practice.

Interpretation, Reporting, and Clinical Applications of Liver MR Elastography

Chronic liver disease is highly prevalent and often leads to fibrosis or cirrhosis and complications such as liver failure and hepatocellular carcinoma. The diagnosis and staging of liver fibrosis is crucial to determine management and mitigate complications. Liver biopsy for histologic assessment has limitations such as sampling bias and high interreader variability that reduce precision, which is particularly challenging in longitudinal monitoring. MR elastography (MRE) is considered the most accurate noninvasive technique for diagnosing and staging liver fibrosis. In MRE, low-frequency vibrations are applied to the abdomen, and the propagation of shear waves through the liver is analyzed to measure liver stiffness, a biomarker for the detection and staging of liver fibrosis. As MRE has become more widely used in clinical care and research, different contexts of use have emerged. This review focuses on the latest developments in the use of MRE for the assessment of liver fibrosis; provides guidance for image acquisition and interpretation; summarizes diagnostic performance, along with thresholds for diagnosis and staging of liver fibrosis; discusses current and emerging clinical applications; and describes the latest technical developments.

Evaluation of Spleen Stiffness in Young Healthy Volunteers Using Magnetic Resonance Elastography

PURPOSE

Magnetic resonance elastography (MRE) has been established as the most accurate noninvasive technique for diagnosing liver fibrosis. Recent publications have suggested that the measurement of splenic stiffness is useful in setting where portal hypertension may be present. The goal of the current study was to compile normative data for MRE-assessed stiffness measurements of the spleen in young adults.

MATERIALS AND METHODS

A total of 100 healthy young Caucasian volunteers (65 females and 35 males) in the age range of 20 to 32 years were enrolled in this study. The participants reported no history of chronic spleen and liver disease, normal alcohol consumption, and a normal diet. The MRE data were acquired by using a 1.5 T whole-body scanner and a 2D GRE pulse sequence with 60 Hz excitation. Spleen stiffness was calculated as a weighted mean of stiffness values in the regions of interest manually drawn by the radiologist on three to five spleen slices.

RESULTS

Mean spleen stiffness was 5.09 ± 0.65 kPa for the whole group. Male volunteers had slightly higher splenic stiffness compared to females: 5.28 ± 0.78 vs. 4.98 ± 0.51 kPa, however, this difference was not statistically significant (p = 0.12). Spleen stiffness did not correlate with spleen fat content and liver stiffness but a statistically significant correlation with spleen volume was found.

CONCLUSIONS

The findings of this study provide normative values for 2D MRE-based measurement of spleen stiffness in young adults, a basis for assessing the value of this biomarker in young patients with portal system pathologies.

Magnetic resonance elastography in evaluation of liver fibrosis in children with chronic liver disease

BACKGROUND

Magnetic resonance elastography (MRE) has been used to stage liver fibrosis in adults. We aimed to assess the agreement between the Ishak scoring system and magnetic resonance elastography-measured liver stiffness (MRE-LS) in children. This study included all the children who underwent abdominal MRE and liver biopsies between February 2018 and January 2021. The correlation between MRE-LS and Ishak fibrosis stage, MRE parameters, and clinical and biochemical markers affecting this relationship was investigated.

RESULTS

A total of 52 patients (31 male; a median age of 11.8 years) were included in the study. The MRE-LS values were significantly different between Ishak fibrosis stages (p = 0.036). With a cut-off value of 2.97 kilopascals, MRE-LS had sensitivity, specificity, PPV, NPV and accuracy values of 90.9%, 82.9%, 58.8%, 97.1%, and 84.6%, respectively, for differentiating mild/moderate fibrosis (F0, 1, 2, 3) from severe fibrosis (F ≥ 4). Although MRE-LS was moderately correlated with Ishak fibrosis score and histological activity index and weakly correlated with aspartate aminotransferase, hepatic steatosis, and R2*, only Ishak fibrosis score was a significant predictor of MRE-LS. MRE-measured spleen stiffness was weakly correlated with the Ishak fibrosis score.

CONCLUSIONS

MRE has high sensitivity and specificity for evaluating liver fibrosis in children. MRE may be used to evaluate liver fibrosis in pediatric patients.

Liver and spleen stiffness for the diagnosis of oesophageal varices in adults with chronic liver disease

This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:

To assess the diagnostic accuracy of liver stiffness and spleen stiffness, separately or in combination, as measured by vibration‐controlled transient elastography (VCTE) in detection of any oesophageal varices in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

To compare the diagnostic accuracy of individual tests (liver stiffness and spleen stiffness measured by VCTE) directly and versus the combination of both tests (considering positive when at least one is positive) in detecting any oesophageal varices.

To assess the diagnostic accuracy of liver stiffness and spleen stiffness, separately or in combination, as measured by other elastography techniques (2D‐shear wave elastography (2D‐SWE), point shear wave elastography (pSWE), magnetic resonance elastography (MRE)) in detection of any oesophageal varices in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

To compare the diagnostic accuracy of liver stiffness and spleen stiffness measured by VCTE with other techniques (pSWE, 2D‐SWE, MRE) in detection of any oesophageal varices in adults with chronic liver disease.

Spleen Stiffness on Magnetic Resonance Elastography for the Detection of Portal Hypertension: A Systematic Review and Meta-Analysis

Background

Chronic liver disease, complicated by portal hypertension (PH), may alter the extra-hepatic hemodynamic condition and spleen stiffness (SS). We aimed to evaluate the diagnostic accuracy of MRI-based elastographic methods (MRE) for detecting PH.

Methods

Seven studies were included with reference to SS with regard to the prediction of PH patients. Major outcomes considered for data extraction were diagnostic parameters for MRI for concluding mild PH, clinically significant PH and severe PH. PubMed, Scopus, Google Scholar, Cochrane and Science Direct databases were used to extract the published literature through to May, 2021Using the Rayyan Zotero and R softwares.

Results

Out of 587 studies extracted, 7 were selected based on inclusion and exclusion criteria. A QUADAS-2 assessment showed that all studies were clear in terms of patient selection and reference standard. A funnel plot showed that all the selected studies were outliers, indicating a low level of accuracy for the studies included. Subgroup analysis, with reference to SS as a predictor of PH, revealed raw mean difference (RMD) of 7.78% (95% CI 5.23-10.34, P<0.01). The corresponding RMD observed for <60 years and >60 yr were 34.26% (95% CI 9.33- 59.20, I²=100%, τ²=646.7688, P=0), and 46.92% (95% CI 20-59.33, I²=97%, τ²=1003.023, P=0) respectively. The specificity and sensitivity noted for MRI in determining SS were 0.721 and 0.747, respectively with an area-under the curve of 0.788. The estimated random effect models for specificity and sensitivity were 0.938 and 0.842, respectively.

Conclusion

The real-time MRE has acceptable specificity and sensitivity for diagnosing SS.

Liver and Spleen Stiffness Surveillance Through Elastography During and After Direct-Acting Antiviral Therapy in Patients With Chronic Hepatitis C

OBJECTIVES

Direct-acting antiviral agents achieve a high cure rate, resulting in early hepatic necroinflammatory resolution and sustained fibrosis regression. This study aimed to obtain longitudinal, concurrent within-subject measurements of liver stiffness (LS) and spleen stiffness (SS) and their correlates over time.

METHODS

Participants with hepatitis C (n = 592) receiving direct-acting antiviral-based therapy were monitored through point shear-wave elastography from the treatment baseline (TW0) across follow-up visits in terms of LS and SS.

RESULTS

Generalized linear mixed modeling indicated that all LS values (2301 visits) were negatively correlated with the follow-up times (all P < .05) from TW0 to 24 weeks (PW24) after the end of treatment (EOT) and positively correlated with baseline LS values (P < .001). The slopes of declines (preceding minus next) differed significantly (P < .001) between TW0-TW4 (treatment week 4) (0.060 [-0.050 to 0.225] meter/second/month [m/s/mo]) and TW4-EOT (0.010 [-0.030 to 0.075] m/s/mo). All SS values (1704 visits) were negatively correlated with time only at PW24 (P < .001) and positively correlated with baseline SS values (P < .001). The slopes of the SS values differed significantly (P < .001) only between EOT-PW12 (-0.010 [-0.110 to 0.083] m/s/mo) and PW12-PW24 (0.043 [-0.063 to 0.160] m/s/mo).

CONCLUSIONS

The biphasic fast-to-slow decline in LS occurred early in the on-treatment phase, which is consistent with the resolution of hepatic necroinflammation. The slow-to-fast decline in SS occurred off treatment. Future studies should investigate the association with regressions in liver fibrosis and portal hypertension.

Noninvasive assessment of clinically significant portal hypertension using ΔT1 of the liver and spleen and ECV of the spleen on routine Gd-EOB-DTPA liver MRI

PURPOSE

To analyze the predictive value of ΔT1 of the liver and spleen as well as the extracellular volume fraction (ECV) of the spleen as noninvasive biomarkers for the determination of clinically significant portal hypertension (CSPH) on routine Gd-EOB-DTPA liver MRI.

METHOD

195 consecutive patients with known or suspected chronic liver disease from 9/2018 to 7/2019 with Gd-EOB-DTPA liver MRI and abdominal T1 mapping were retrospectively included. Based on the presence of splenomegaly with thrombocytopenia, ascites and portosystemic collaterals, the patients were divided into noCSPH (n = 113), compensated CSPH (cCSPH, ≥1 finding without ascites; n = 55) and decompensated CSPH (dCSPH, ascites ± other findings; n = 27). T1 times were measured in the liver, spleen and abdominal aorta in the unenhanced and contrast-enhanced T1 maps. Native T1 times and ΔT1 of the liver and spleen as well as ECV of the spleen were compared between groups using the Kruskal-Wallis test with Dunn's post hoc test. Furthermore, cutoff values for group differentiation were calculated using ROC analysis with Youden's index.

RESULTS

ΔT1 of the liver was significantly lower in patients with cCSPH and dCSPH (p < 0.001) compared to patients with noCSPH. In the ROC analyses for differentiation between noCSPH and CSPH (cCSPH + dCSPH), a cutoff of < 0.67 for ΔT1 of the liver (AUC = 0.79) performed better than ΔT1 (AUC = 0.69) and ECV (AUC = 0.63) of the spleen with cutoffs of > 0.29 and > 41.9, respectively.

CONCLUSION

ΔT1 of the liver and spleen in addition to ECV of the spleen allow for determination of CSPH on routine Gd-EOB-DTPA liver MRI.

Diagnostic value of spleen stiffness by magnetic resonance elastography for prediction of esophageal varices in cirrhotic patients

PURPOSE

To evaluate the diagnostic value of spleen stiffness (SS) via magnetic resonance elastography (MRE) in predicting esophageal varices.

METHODS

From January 2016 to September 2018, we retrospectively reviewed 263 patients with esophagogastroduodenoscopy (EGD) records and available spleen and liver stiffness (LS) values from MRE. Clinical information including the underlying diseases, endoscopic grade of esophageal varices (EV) and laboratory data were collected from electronic medical records.

RESULTS

In cirrhotic patients, MRE-SS was higher in those with EV than in those without. MRE-SS also showed significant association with EV in the multivariate analysis, whereas MRE-LS did not. The diagnostic performance of MRE-SS for EV in cirrhotic patients was demonstrated by the area under curve of 0.853 (cut-off value: 9.53 kPa, P < 0.001), 84.4% sensitivity and 73.7% specificity.

CONCLUSION

For prediction of EV in cirrhotic patients, MRE-SS is a useful non-invasive tool and it demonstrates better diagnostic performance than MRE-LS does.

T1 mapping of the liver and the spleen in patients with liver fibrosis-does normalization to the blood pool increase the predictive value?

Purpose

To analyze whether the T1 relaxation time of the liver is a good predictor of significant liver fibrosis and whether normalization to the blood pool improves the predictive value.

Methods

This prospective study was conducted between 03/2016 and 02/2018. One hundred seventy-three patients underwent multiparametric liver MRI at 3 T. The T1 relaxation time was measured in the liver and the spleen, in the aorta, the portal vein, and the inferior vena cava (IVC). T1 relaxation times with and without normalization to the blood pool were compared between patients with (n = 26) and without (n = 141) significant liver fibrosis, based on a cutoff value of 3.5 kPa in MRE as the noninvasive reference standard. For statistics, Student’s t test, receiver operating characteristic (ROC) curve analysis, and Pearson’s correlation were used.

Results

The T1 relaxation time of the liver was significantly longer in patients with liver fibrosis, both with and without blood pool normalization (p < 0.001). T1 relaxation time of the liver allowed prediction of significant liver fibrosis (AUC = 0.88), while normalization to the IVC resulted in a slightly lower performance (AUC = 0.82). The lowest performance was achieved when the T1 relaxation times of the liver were normalized to the aorta (AUC = 0.66) and to the portal vein (AUC = 0.62). The T1 relaxation time of the spleen detected significant liver fibrosis with an AUC of 0.68, and 0.51–0.64 with normalization to the blood pool.

Conclusion

The T1 relaxation time of the liver is a good predictor of significant liver fibrosis. However, normalization of the blood pool did not improve the predictive value.

Key Points

• The T1 relaxation time of the liver is a good predictor of significant liver fibrosis.

• Normalization to the blood pool did not improve the predictive value of T1 mapping.

• If the blood pool normalization was weighted 30% to the aorta and 70% to the portal vein, the performance was better than normalization to the aorta alone but still lower than normalization to the IVC.

A study of spleen shear-wave elastography in indirect prediction of liver fibrosis in patients with chronic hepatitis B

PURPOSE

To evaluate the value of spleen shear-wave elastography (sound touch elastography [STE], sound touch quantification [STQ]) in indirect prediction of liver fibrosis in patients with chronic hepatitis B (CHB).

METHODS

The Young's modulus (kPa) of spleen STE, STQ and liver FibroScan were measured in 112 patients with CHB. The final diagnosis was according to histological results from liver biopsy based on Scheure G/S scoring system and liver FibroScan was considered as a reference index of prediction efficiency. Grouped by the stage of liver fibrosis, data were analyzed by Spearman correlation analysis, Mann-Whitney test and receiver operating characteristic curve (ROC).

RESULTS

Spleen STE was positively correlated with the degree of liver fibrosis, but spleen STQ was not. STEmean and STEmax of spleen were statistically different between the groups categorized by S = 2, S = 3 and S = 4 (all p < 0.05), respectively. Spleen STEmean had the best predicting performance on staging liver fibrosis. The areas under the ROC (AUC) for spleen STEmean were 0.66 (95% confidence interval [CI], 0.56-0.76) for stage S = 2 or higher, 0.72 (95% CI, 0.60-0.83) for S = 3 or higher, 0.83 (95% CI, 0.74-0.92) for S = 4 (all P < 0.01). The differences between the AUC for spleen STEmean and liver FibroScan in liver fibrosis staging were not statistically significant when the groups categorized by S = 2 and S = 4 (P = 0.146 and P = 0.052). But when categorized by S = 3, the evaluating performance of liver FibroScan was better (P = 0.004).

CONCLUSION

STEmean of spleen is applicable in indirect predicting fibrosis stage in patients with CHB.

Assessment of liver fibrosis with liver and spleen magnetic resonance elastography, serum markers in chronic liver disease

Background

The accurate assessment of liver fibrosis is essential for patients with chronic liver disease. A liver biopsy is an invasive procedure that has many potential defects and complications. Therefore, noninvasive assessment techniques are of considerable value for clinical diagnosis. Liver and spleen magnetic resonance elastography (MRE) and serum markers have been proposed for quantitative and noninvasive assessment of liver fibrosis. This study aims to compare the diagnostic performance of liver and spleen stiffness measured by MRE, fibrosis index based on the 4 factors (FIB-4), aspartate aminotransferase-to-platelet ratio index (APRI), and their combined models for staging hepatic fibrosis.

Methods

One hundred and twenty patients with chronic liver disease underwent MRE scans. Liver and spleen stiffness were measured by the MRE stiffness maps. Serum markers were collected to calculate FIB-4 and APRI. Liver biopsies were used to identify pathologic grading. Spearman's rank correlation analysis evaluated the correlation between the parameters and fibrosis stages. Receiver operating characteristic (ROC) analysis evaluated the performance of the four individual parameters, a liver and spleen stiffness combined model, and an all-parameters combined model in assessing liver fibrosis.

Results

Liver stiffness, spleen stiffness, FIB-4, and APRI were all correlated with fibrosis stage (r=0.87, 0.64, 0.65, and 0.51, respectively, all P<0.001). Among the 4 individual diagnostic markers, liver stiffness showed the highest values in staging F1-4, F2-4, F3-4 and F4 (AUC =0.89, 0. 97, 0.95, and 0.95, all P<0.001). The AUCs of the liver and spleen stiffness combined model in the F1-4, F2-4, F3-4, and F4 staging groups were 0.89, 0.97, 0.95, and 0.96, respectively (all P<0.001). The corresponding AUCs of the all-parameters combined model were 0.90, 0.97, 0.95, and 0.96 (all P<0.001). The AUCs of the liver and spleen stiffness combined model were significantly higher than those of APRI, FIB-4 in the F2-4, F3-4, and F4 staging groups (all P<0.05). Both combined models were not significantly different from liver stiffness in staging liver fibrosis (all P>0.05).

Conclusions

Liver stiffness measured with MRE had better diagnostic performance than spleen stiffness, APRI, and FIB-4 for fibrosis staging. The combined models did not significantly improve the diagnostic value compared with liver stiffness in staging fibrosis.