Stratification of Patients With Liver Fibrosis Using Dual-Energy CT

Abstract

Assessing the severity of liver fibrosis has direct clinical implications for patient diagnosis and treatment. Liver biopsy, typically considered the gold standard, has limited clinical utility due to its invasiveness. Therefore, several imaging-based techniques for staging liver fibrosis have emerged, such as magnetic resonance elastography (MRE) and ultrasound elastography (USE), but they face challenges that include limited availability, high cost, poor patient compliance, low repeatability, and inaccuracy. Computed tomography (CT) can address many of these limitations, but is still hampered by inaccuracy in the presence of confounding factors, such as liver fat. Dual-energy CT (DECT), with its ability to discriminate between different tissue types, may offer a viable alternative to these methods. By combining the "multi-material decomposition" (MMD) algorithm with a biologically driven hypothesis we developed a method for assessing liver fibrosis from DECT images. On a twelve-patient cohort the method produced quantitative maps showing the spatial distribution of liver fibrosis, as well as a fibrosis score for each patient with statistically significant correlation with the severity of fibrosis across a wide range of disease severities. A preliminary comparison of the proposed algorithm against MRE showed good agreement between the two methods. Finally, the application of the algorithm to longitudinal DECT scans of the cohort produced highly repeatable results. We conclude that our algorithm can successfully stratify patients with liver fibrosis and can serve to supplement and augment current clinical practice and the role of DECT imaging in staging liver fibrosis.

Current status of imaging in nonalcoholic fatty liver disease

“…Dual-energy CT: Recent advances in dual-energy CT (DECT) have introduced the ability to perform material decomposition, which has been shown to more accurately quantify hepatic steatosis and potentially permit fibrosis staging[70]. In DECT, the liver is imaged at two different energy levels (typically 80 kVp and 140 kVp).…”

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

“…It utilizes high and low x-ray energy datasets to generate qualitative and quantitative material-specific (“material density”) imaging information [163]. As research suggests a correlation between iodine concentration on delayed phase images with higher stages of fibrosis [164], a normalized iodine concentration (liver/aorta) can be used to estimate the degree of disease. In a study using dual energy or spectral CT, the combination of normalized iodine concentration and iodine concentration ratio showed high sensitivity and specificity for differentiating healthy liver from cirrhotic liver, especially in Class C cirrhotic liver [165].…”

Multiorgan, Multimodality Imaging in Cardiometabolic Disease

“…Preliminary data suggest high reproducibility and good correlation to histological measures using dual energy CT acquisition and multi-material decomposition to quantify liver fibrosis 27 ; further validation of this technique in prospective trials are warranted. Magnetic resonance elastography is an emerging method involving external placement of a pneumatic driver to generate low-frequency waves.…”