Noninvasive evaluation of esophageal varices in cirrhotic patients based on spleen hemodynamics: a dual-energy CT study

Predicting High-Risk Esophageal Varices in Cirrhosis: A Multi-Parameter Splenic CT Study

RATIONALE AND OBJECTIVES

To explore the value of splenic hemodynamic parameters from low-dose one-stop dual-energy and perfusion CT (LD-DE&PCT) in non-invasively predicting high-risk esophageal varices (HREV) in cirrhotic patients.

METHODS

We retrospectively analyzed cirrhotic patients diagnosed with esophageal varices (EV) through clinical, laboratory, imaging, and endoscopic examinations from September 2021 to December 2023 in our hospital. All patients underwent LD-DE&PCT to acquire splenic iodine concentration and perfusion parameters. Radiation dose was recorded. Patients were classified into non-HREV and HREV groups based on endoscopy. Univariate and multivariate logistic regression analysis were performed, and the prediction model for HREV was constructed. P < 0.05 was considered statistically significant.

RESULTS

Univariate analysis revealed that significant differences were found in portal iodine concentration (PIC), blood flow (BF), permeability surface (PS), spleen volume (V-S), total iodine concentration (TIC), and total blood volume of the spleen (BV-S) between groups. TIC demonstrated the highest predictive value with an area under the curve (AUC) value of 0.87. Multivariate analysis showed that PIC, PS, and BV-S were independent risk factors for HREV. The logistic regression model for predicting HREV had an AUC of 0.93. The total radiation dose was 20.66 ± 4.07 mSv.

CONCLUSION

Splenic hemodynamic parameters obtained from LD-DE&PCT can non-invasively and accurately assess the hemodynamic status of the spleen in cirrhotic patients with EV and predict the occurrence of HREV. Despite the retrospective study design and limited sample size of this study, these findings deserve further validation through prospective studies with larger cohorts.

Hepatic artery diameter predicts bleeding risk after gastroesophageal varices treatment: a contrast-enhanced CT study

OBJECTIVE

Portal hypertension leads to hepatic artery dilatation and a higher risk of bleeding. We tried to identify the bleeding risk after gastroesophageal varices (GOV) treatment using hepatic artery diameter of contrast-enhanced CT.

METHODS

Retrospective retrieval of 258 patients with cirrhosis who underwent contrast-enhanced CT from January 2022 to May 2023 and endoscopy within one month thereafter at Hainan Affiliated Hospital of Hainan Medical University. Cirrhotic patients before GOV treatment were used as the test cohort (n = 199), and cirrhotic patients after GOV treatment were used as the validation cohort (n = 59). The grading and bleeding risk was classified according to the endoscopic findings. Arterial-phase images of contrast-enhanced CT were used for coronal reconstruction, and the midpoint diameter of the hepatic artery was measured on coronal images. The optimal cutoff value for identifying bleeding risk was analyzed and calculated in the test cohort, and its diagnostic performance was evaluated in the validation cohort.

RESULTS

In the test cohort, hepatic artery diameters were significantly higher in high-risk GOV than in low-risk GOV [4.69 (4.31, 5.56) vs. 3.10 (2.59, 3.77), P < 0.001]. With a hepatic artery diameter cutoff value of 4.06 mm, the optimal area under the operating characteristic curve was 0.940 (95% confidence interval: 0.908-0.972), with a sensitivity of 0.887, a specificity of 0.892, a positive predictive value of 0.904, and a negative predictive value of 0.874 for identifying bleeding risk in the test cohort, while in the validation cohort, the sensitivity was 0.885, specificity was 0.939, positive predictive value was 0.920, and negative predictive value was 0.912.

CONCLUSION

Hepatic artery diameter has high diagnostic performance in identifying bleeding risk after GOV treatment.

Relationship Between Spleen Pathologic Changes and Spleen Stiffness in Portal Hypertension Rat Model

OBJECTIVE

The aim of the study described here was to explore the influence of splenic pathology and hemodynamic parameters on spleen stiffness in portal hypertension (PH).

METHODS

A Sprague‒Dawley rat model of PH (n = 34) induced by CCl4 was established, and 9 normal rats were used as controls. All animals underwent a routine ultrasound examination, spleen stiffness measurement (SSM), liver stiffness measurement (LSM), portal vein pressure (PVP) measurement and histopathologic assessment. The diagnostic performance of SSM and LSM in PH was evaluated. SSMs were compared among the groups at different pathologic and hemodynamic levels. Multiple linear regression was used to analyze the factors affecting SSM.

RESULTS

SSM had excellent diagnostic efficacy for PH (area under the receiver operating characteristic curve [AUC] = 0.900) and was superior to LSM (AUC = 0.794). In a rat model of PH, pathologic changes such as splenic sinus widening, thickening of the splenic capsule and an increase in collagen fibers were observed in the spleen. There were significant differences in SSM at different splenic capsule thicknesses and splenic sinus widths (all p values <0.05), but there were no significant differences in the SSM at different levels of the splenic collagen fiber area and red pulp area (all p values >0.05). In addition, there were significant differences in SSM at different levels of portal vein diameter, blood flow and congestion index (all p values <0.05). Multiple linear regression analysis revealed that PVP, portal vein congestion index and splenic capsule thickness were significantly associated with SSM.

CONCLUSION

SSM is a good non-invasive way to assess PH. PVP, splenic capsule thickness and portal vein congestion index are responsible for spleen stiffness but not the proliferation of splenic fibrous tissue.

Baveno VII algorithm outperformed other models in ruling out high-risk varices in individuals with HBV-related cirrhosis

BACKGROUND & AIMS

The Baveno VII consensus recommends that spleen stiffness measurement (SSM) ≤40 kPa is safe for ruling out high-risk varices (HRVs) and avoiding endoscopic screening in patients who do not meet the Baveno VI criteria. This study aimed to validate the performance of the Baveno VII algorithm in individuals with HBV-related cirrhosis.

METHODS

Consecutive individuals with HBV-related cirrhosis who underwent liver stiffness measurement (LSM) and SSM - using a 50 Hz shear wave frequency, spleen diameter measurement, and esophagogastroduodenoscopy (EGD) were prospectively enrolled from June 2020. A 100 Hz probe has been adopted for additional SSM assessment since July 2021.

RESULTS

From June 2020 to January 2022, 996 patients were screened and 504 were enrolled for analysis. Among the 504 patients in whom SSM was assessed using a 50 Hz probe, the Baveno VII algorithm avoided more EGDs (56.7% vs. 39.1%, p <0.001) than Baveno VI criteria, with a comparable missed HRV rate (3.8% vs. 2.5%). Missed HRV rates were >5% for all other measures: 11.3% for LSM-longitudinal spleen diameter to platelet ratio score, 20.0% for platelet count/longitudinal spleen diameter ratio, and 8.8% for Rete Sicilia Selezione Terapia-hepatitis. SSM@100 Hz was assessed in 232 patients, and the Baveno VII algorithm with SSM@100 Hz spared more EGDs (75.4% vs. 59.5%, p <0.001) than that with SSM@50 Hz, both with a missed HRV rate of 3.0% (1/33).

CONCLUSIONS

We validated the Baveno VII algorithm, demonstrating the excellent performance of SSM@50 Hz and SSM@100 Hz in ruling out HRV in individuals with HBV-related cirrhosis. Furthermore, the Baveno VII algorithm with SSM@100 Hz could safely rule out more EGDs than that with SSM@50 Hz.

CLINICAL TRIAL NUMBER

NCT04890730.

IMPACT AND IMPLICATIONS

The Baveno VII guideline proposed that for patients who do not meet the Baveno VI criteria, SSM ≤40 kPa could avoid further unnecessary endoscopic screening. The current study validated the Baveno VII algorithm using 50 Hz and 100 Hz probes, which both exhibited excellent performance in ruling out HRVs in individuals with HBV-related cirrhosis. Compared with the Baveno VII algorithm with SSM@50 Hz, SSM@100 Hz had a better capability to safely rule out unnecessary EGDs. Baveno VII algorithm will be a practical tool to triage individuals with cirrhosis in future clinical practice.

Pros and Cons of Dual-Energy CT Systems: "One Does Not Fit All"

Dual-energy computed tomography (DECT) uses different energy spectrum x-ray beams for differentiating materials with similar attenuation at a certain energy. Compared with single-energy CT, it provides images with better diagnostic performance and a potential reduction of contrast agent and radiation doses. There are different commercially available DECT technologies, with machines that may display two x-ray sources and two detectors, a single source capable of fast switching between two energy levels, a specialized detector capable of acquiring high- and low-energy data sets, and a filter splitting the beam into high- and low-energy beams at the output. Sequential acquisition at different tube voltages is an alternative approach. This narrative review describes the DECT technique using a Q&A format and visual representations. Physical concepts, parameters influencing image quality, postprocessing methods, applicability in daily routine workflow, and radiation considerations are discussed. Differences between scanners are described, regarding design, image quality variabilities, and their advantages and limitations. Additionally, current clinical applications are listed, and future perspectives for spectral CT imaging are addressed. Acknowledging the strengths and weaknesses of different DECT scanners is important, as these could be adapted to each patient, clinical scenario, and financial capability. This technology is undoubtedly valuable and will certainly keep improving.

Quantitative dual-energy CT techniques in the abdomen

Advances in dual-energy CT (DECT) technology and spectral techniques are catalyzing the widespread implementation of this technology across multiple radiology subspecialties. The inclusion of energy- and material-specific datasets has ushered overall improvements in CT image contrast and noise as well as artifacts reduction, leading to considerable progress in radiologists' ability to detect and characterize pathologies in the abdomen. The scope of this article is to provide an overview of various quantitative clinical DECT applications in the abdomen and pelvis. Several of the reviewed applications have not reached mainstream clinical use and are considered investigational. Nonetheless awareness of such applications is critical to having a fully comprehensive knowledge base to DECT and fostering future clinical implementation.

A novel machine learning-based radiomic model for diagnosing high bleeding risk esophageal varices in cirrhotic patients

BACKGROUND AND AIM

To develop and validate a novel machine learning-based radiomic model (RM) for diagnosing high bleeding risk esophageal varices (HREV) in patients with cirrhosis.

METHODS

A total of 796 qualified participants were enrolled. In training cohort, 218 cirrhotic patients with mild esophageal varices (EV) and 240 with HREV RM were included to training and internal validation groups. Additionally, 159 and 340 cirrhotic patients with mild EV and HREV RM, respectively, were used for external validation. Interesting regions of liver, spleen, and esophagus were labeled on the portal venous-phase enhanced CT images. RM was assessed by area under the receiver operating characteristic curves (AUROC), sensitivity, specificity, calibration and decision curve analysis (DCA).

RESULTS

The AUROCs for mild EV RM in training and internal validation were 0.943 and 0.732, sensitivity and specificity were 0.863, 0.773 and 0.763, 0.763, respectively. The AUROC, sensitivity, and specificity were 0.654, 0.773 and 0.632, respectively, in external validation. Interestingly, the AUROCs for HREV RM in training and internal validation were 0.983 and 0.834, sensitivity and specificity were 0.948, 0.916 and 0.977, 0.969, respectively. The related AUROC, sensitivity and specificity were 0.736, 0.690 and 0.762 in external validation. Calibration and DCA indicated RM had good performance. Compared with Baveno VI and its expanded criteria, HREV RM had a higher accuracy and net reclassification improvements that were as high as 49.0% and 32.8%.

CONCLUSION

The present study developed a novel non-invasive RM for diagnosing HREV in cirrhotic patients with high accuracy. However, this RM still needs to be validated by a large multi-center cohort.

Establishment of a non-invasive prediction model for the risk of oesophageal variceal bleeding using radiomics based on CT

AIM

To establish a non-invasive prediction model for the risk of oesophageal variceal bleeding (OVB) using radiomics based on computed tomography (CT).

MATERIALS AND METHODS

The study included 317 patients, 69 of whom were OVB-positive and 248 were OVB-negative. The OVB was caused by cirrhosis associated with hepatitis B. All patients underwent both oesophagogastroduodenoscopy (OGD) and triple-phase contrast-enhanced CT with spectral imaging mode within 14 days before OGD. The patients were divided chronologically into training (n=222) and validation (n=95) cohorts at a ratio of 7:3. The clinical and CT features were collected from a picture archiving and communication system, and radiomics features were extracted from the portal venous phase CT. Spearman's correlation, least absolute shrinkage, and selection operator regression analyses were used to select the most correlated features. Models were built using the selected features. The predictive performance of the models was evaluated using the area under the receiver operating characteristic curve (AUC).

RESULTS

One clinical feature, five CT features, and three radiomics features were selected, and three non-invasive models were built. Integration of the radiomics, CT, and clinical features model showed a better performance in predicting the risk of OVB, with an AUC of 0.89 (95% confidence interval [CI], 0.84-0.94) in the training dataset and 0.78 (95% CI, 0.68-0.87) in the validation dataset.

CONCLUSION

The combination of radiomics, CT, and clinical features may have added value in the non-invasive prediction of OVB, enabling early prevention and treatment.

Prediction of high-risk esophageal varices in patients with chronic liver disease with point and 2D shear wave elastography: a systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic performance of liver stiffness (LS) and spleen stiffness (SS) measured by point shear wave elastography (pSWE) and 2D shear wave elastography (2D-SWE) in the detection of high-risk esophageal varices (HREV) and to compare their diagnostic accuracy.

METHODS

Through systematic search of PubMed, Embase, and Web of Science databases, we included 17 articles reporting the diagnostic performance of LS or SS measured by pSWE or 2D-SWE for HREV. We used a bivariate random-effects model to estimate pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), area under summary receiver operator characteristic curve (AUSROC), and diagnostic odds ratio (DOR).

RESULTS

For LS, there was no significant difference between the pooled sensitivity, 0.89 (95% confidence interval CI, 0.81-0.94) vs. 0.8 (95% CI, 0.72-0.86) (p = 0.13), and specificity, 0.81 (95% CI, 0.73-0.87) vs. 0.73 (95% CI, 0.65-0.79) (p = 0.07) of pSWE and 2D-SWE. The AUSROC and DOR of pSWE were higher than those of 2D-SWE: 0.92 (95% CI, 0.89-0.94) vs. 0.84 (95% CI, 0.80-0.87), p = 0.03, 33 (95% CI, 25-61) vs. 11 (95% CI, 5-22), (p < 0.01). For SS, there was no significant difference between the pooled sensitivity 0.91 (95% CI, 0.78-0.96) vs. 0.89 (95% CI, 0.80-0.94) (p = 0.43); specificity, 0.79 (95% CI, 0.72-0.84) vs. 0.72 (95% CI, 0.63-0.79) (p = 0.06); and DOR, 35 (95% CI, 13-100) vs. 20 (95% CI, 8-50) (p = 0.16) of pSWE and 2D-SWE.

CONCLUSION

LS and SS measured by pSWE and 2D-SWE have good accuracy in predicting HREV.

KEY POINTS

• There is modest difference between the diagnostic performance of LS and SS measured by pSWE and 2D-SWE. • LS and SS measured by pSWE and 2D-SWE both have high sensitivity, specificity, and AUSROC for the evaluation of HREV in patients with CLD. • pSWE and 2D-SWE are promising tools for noninvasive monitoring risk of esophageal varices bleeding of CLD patients.

Magnetic resonance parametric mapping of the spleen for non-invasive assessment of portal hypertension

OBJECTIVES

In patients with advanced liver disease, portal hypertension is an important risk factor, leading to complications such as esophageal variceal bleeding, ascites, and hepatic encephalopathy. This study aimed to determine the diagnostic value of T1 and T2 mapping and extracellular volume fraction (ECV) for the non-invasive assessment of portal hypertension.

METHODS

In this prospective study, 50 participants (33 patients with indication for trans-jugular intrahepatic portosystemic shunt (TIPS) and 17 healthy volunteers) underwent MRI. The derivation and validation cohorts included 40 and 10 participants, respectively. T1 and T2 relaxation times and ECV of the liver and the spleen were assessed using quantitative mapping techniques. Direct hepatic venous pressure gradient (HVPG) and portal pressure measurements were performed during TIPS procedure. ROC analysis was performed to compare diagnostic performance.

RESULTS

Splenic ECV correlated with portal pressure (r = 0.72; p < 0.001) and direct HVPG (r = 0.50; p = 0.003). No significant correlations were found between native splenic T1 and T2 relaxation times with portal pressure measurements (p > 0.05, respectively). In the derivation cohort, splenic ECV revealed a perfect diagnostic performance with an AUC of 1.000 for the identification of clinically significant portal hypertension (direct HVPG ≥ 10 mmHg) and outperformed other parameters: hepatic T2 (AUC, 0.731), splenic T2 (AUC, 0.736), and splenic native T1 (AUC, 0.806) (p < 0.05, respectively). The diagnostic performance of mapping parameters was comparable in the validation cohort.

CONCLUSION

Splenic ECV was associated with portal pressure measurements in patients with advanced liver disease. Future studies should explore the diagnostic value of parametric mapping accross a broader range of pressure values.

KEY POINTS

• Non-invasive assessment and monitoring of portal hypertension is an area of unmet interest. • Splenic extracellular volume fraction is strongly associated with portal pressure in patients with end-stage liver disease. • Quantitative splenic and hepatic MRI-derived parameters have a potential to become a new non-invasive diagnostic parameter to assess and monitor portal pressure.