Noninvasive Staging of Liver Fibrosis Using 5-Minute Delayed Dual-Energy CT: Comparison with US Elastography and Correlation with Histologic Findings

Background Normalized iodine concentration (NIC) (ratio of iodine concentration of liver to that of aorta) of liver at delayed dual-energy CT (DECT) may reflect the amount of fibrosis based on the extent of iodine uptake. Purpose To stage liver fibrosis by using 5-minute delayed DECT and compare findings with those of transient elastography (TE), shear-wave elastography (SWE), and histologic examination. Materials and Methods This prospective study included patients with chronic liver disease who were scheduled to undergo multiphase abdominal CT and liver biopsy from January 2017 to September 2018. Fifty individuals being screened as renal donors comprised the control group. Study participants underwent TE, SWE, multiphasic DECT (including 5-minute delayed dual-energy scanning), and liver biopsy. Multiphasic DECT and SWE were performed in the control group. The NIC of the right lobe of the liver (RNIC) was compared with liver stiffness (LS) as measured with TE and SWE and with the METAVIR fibrosis stage (ranging from F0 to F4). Diagnostic performance was assessed by using areas under the receiver operating characteristic curve (AUCs). Results A total of 107 participants (mean age, 35 years ± 12 [standard deviation]; 57 men) and 50 control subjects (mean age, 47 years ± 11; 29 women) were evaluated. The RNIC showed strong correlation with METAVIR stage (Spearman ρ = 0.81, P < .001). The AUC for RNIC with each METAVIR stage ranged between 0.86 (95% CI: 0.76, 0.97) and 0.96 (95% CI: 0.92, 0.99). The cut-off value of RNIC was 0.24 (sensitivity: 85% [86 of 101 participants; 95% CI: 77%, 91%]; specificity: 83% [84 of 101 participants; 95% CI: 42%, 98%]) for stage F1 fibrosis and 0.29 (sensitivity: 84% [67 of 80 participants; 95% CI: 74%, 90%]; specificity: 81% [65 of 80 participants; 95% CI: 63%, 92%]) for stage F2 fibrosis. RNIC correlated well with LS as measured with TE and SWE (Spearman ρ = 0.60 and 0.64, respectively; P < .001). Conclusion Normalized iodine concentration of liver at 5-minute delayed dual-energy CT showed strong correlation with the histologic stages of liver fibrosis and good diagnostic performance in estimating liver fibrosis. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Chandarana and Shanbhogue in this issue.

Safety and Efficacy of Transjugular Intrahepatic Portosystemic Shunt for Non-tumoral Cirrhotic Portal Vein Thrombosis Not Responding to Anticoagulation Therapy

OBJECTIVES

To evaluate the feasibility, safety, and efficacy of add-on transjugular-intrahepatic-portosystemic shunt (TIPS) for portal vein recanalization (PVR) in cirrhotic patients with non-tumoral chronic portal vein thrombosis (PVT) after 6 months of monitored anticoagulation therapy (ACT).

METHODS

We conducted a retrospective search of the hospital database for patients who underwent TIPS for persistent PVT despite 6 months of ACT (January 2011 to August 2021). These patients were compared to control group (ACT group; no TIPS but continued on ACT). Post-TIPS periodic assessment was done to look for clinical outcome, PVR (using contrast-enhanced CT scan), and complications.

RESULTS

A total of 90 patients were analyzed. Thirty-six patients in TIPS group and 54 patients in ACT group. TIPS was successfully performed in all patients. TIPS group showed complete recanalization of portal vein in 77.8%, partial recanalization in 16.7%, and stable thrombus in 5.5% of the patients. TIPS thrombosis was seen in 3 patients, all underwent successful endovascular thrombolysis. Seven patients developed post-TIPS hepatic encephalopathy and were managed conservatively. In contrast, no patient in ACT group achieved PVR on 12-month follow-up. After propensity score matching, patients in TIPS group showed significantly lower incidence of variceal re-bleeding (22.2% vs. 77.8%, p = 0.03) and refractory ascites (11.1% vs. 51.9%, p < 0.01) with significantly better 12-month survival as compared to ACT group (88.9% vs. 69.4%, p = 0.04).

CONCLUSION

TIPS in cirrhotic patients with PVT result in superior recanalization rates, better control of ascites, and variceal re-bleeding resulting in better survival. TIPS may be considered a preferred therapy after anticoagulation failure.

CLINICAL IMPACT

TIPS is associated with good technical and clinical success in patients of cirrhosis with PVT and should be considered in patients not responding to ACT.

Left-sided portal hypertension: what an interventional radiologist can offer?

Left-sided portal hypertension (LPH) refers to increased splenic venous pressure caused by splenic vein stenosis or occlusion. Pancreatitis is the leading cause of LPH. Typically, LPH remains asymptomatic, but it can lead to life-threatening hemorrhage from ruptured fundal varices in about 10% of patients. Further, it may be complicated by hypersplenism. Interventional radiology plays an essential role in LPH patients with failed endoscopic treatment. Variceal embolization is an effective salvage measure in bleeding gastric varices, but it carries a risk of recurrence and worsening of hypersplenism. Considering the pathophysiology, splenic vein recanalization (SVR) appears to be the best treatment; nevertheless, its lower technical success rate limits its utility only to a subgroup of LPH patients. Partial splenic embolization (PSE), a non-surgical alternative to splenectomy, reduces the splenic volume and venous outflow, thereby lowering variceal pressure. PSE is technically easier, which may explain its widespread use. Nonetheless, PSE can be complicated by life-threatening sepsis and portal vein thrombosis. Despite all attempts, some LPH patients eventually require a splenectomy. Importantly, the choice of therapy requires multidisciplinary discussion and is often influenced by availability, expertise, and clinical context. This article discusses various interventional strategies for managing LPH with the available evidence. KEY POINTS: Question Pressure within the main portal vein is normal in left-sided portal hypertension; thus, transjugular intrahepatic portosystemic shunt is ineffective. Findings Splenic vein stent placement can restore hepatopetal splenic blood flow and decompress splenic venous pressure. Clinical relevance Partial splenic embolization (PSE) is the most widely used interventional approach to manage left-sided portal hypertension-related complications.

Dual-Energy Computed Tomography in Diffuse Liver Diseases

Dual-energy computed tomography (DECT) is an advancement in the field of CT, where images are acquired at two energies. Materials are identified and quantified based on their attenuation pattern at two different energy beams using various material decomposition algorithms. With its ability to identify and quantify materials such as fat, calcium, iron, and iodine, DECT adds great value to conventional CT and has innumerable applications in body imaging. Continuous technological advances in CT scanner hardware, material decomposition algorithms, and image reconstruction software have led to considerable growth of these applications. Among all organs, the liver is the most widely investigated by DECT, and DECT has shown promising results in most liver applications. In this article, we aim to provide an overview of the role of DECT in the assessment of diffuse liver diseases, mainly the deposition of fat, fibrosis, and iron and review the most relevant literature.

Leveraging existing mid-end ultrasound machine for point-of-care intestinal ultrasound in low-resource settings: Prospective, real-world impact on clinical decision-making

BACKGROUND

Point-of-care ultrasound (POCUS) has transformed inflammatory bowel disease (IBD) management, but the cost to purchase high-end equipment can be prohibitive.

AIM

To assess prospectively the feasibility of POCUS using pre-existing mid-end ultrasound equipment without incurring additional cost.

METHODS

Consecutive IBD patients underwent POCUS with or without faecal calprotectin (FCP) using a mid-end ultrasound machine. If POCUS with or without FCP could not guide management, we performed additional ileocolonoscopy or cross-sectional imaging. We evaluated the impact of POCUS on IBD management and its correlation with ileocolonoscopy or cross-sectional imaging. We analysed pregnant, paediatric and post-operative patients separately.

RESULTS

Among 508 patients with IBD, we analysed 419 (60.4% Crohn's disease [CD]; 61.3% male, age [years]: 36 [18-78]) undergoing 556 POCUS sessions. POCUS with or without FCP independently influenced clinical management in 42.8% of patients with CD and 49.7% with ulcerative colitis (UC). POCUS helped avoid colonoscopy in 51.4% of patients with CD and 51.8% with UC, and cross-sectional imaging in 38.1% of suspected active small bowel CD. In patients with additional diagnostics, POCUS-based decisions remained unchanged in 81.2% with CD and 85% with UC. Sensitivity and specificity of POCUS compared to ileocolonoscopy were 80% and 94.4% for CD and 80.8% and 92.8% for UC, respectively. Sensitivity and specificity compared to cross-sectional imaging were 87.2% and 87.5%, respectively.

CONCLUSION

POCUS using existing mid-end ultrasound equipment in low-resource settings influenced IBD clinical decision-making with excellent accuracy, often avoiding colonoscopy and cross-sectional imaging.