A study of T-1 relaxation time as a measure of liver fibrosis and the influence of confounding histological factors

作者：Hoad Caroline L; Palaniyappan Naaventhan; Kaye Philip; Chernova Yulia; James Martin W; Costigan Carolyn; Austin Andrew; Marciani Luca; Gowland Penny A; Guha Indra N; Francis Susan T; Aithal Guruprasad P^*

来源：NMR in Biomedicine, 2015, 28(6): 706-714.

DOI：10.1002/nbm.3299

• relaxometry
• hepatobiliary
• other applications
• fibrosis
• inflammation
• iron

Liver biopsy is the standard test for the assessment of fibrosis in liver tissue of patients with chronic liver disease. Recent studies have used a non-invasive measure of T-1 relaxation time to estimate the degree of fibrosis in a single slice of the liver. Here, we extend this work to measure T-1 of the whole liver and investigate the effects of additional histological factors such as steatosis, inflammation and iron accumulation on the relationship between liver T-1 and fibrosis. We prospectively enrolled patients who had previously undergone liver biopsy to have MR scans. A non-breath-holding, fast scanning protocol was used to acquire MR relaxation time data (T-1 and T-2*), and blood serum was used to determine the enhanced liver fibrosis (ELF) score. Areas under the receiver operator curves (AUROCs) for T-1 to detect advanced fibrosis and cirrhosis were derived in a training cohort and then validated in a second cohort. Combining the cohorts, the influence of various histology factors on liver T-1 relaxation time was investigated. The AUROCs (95% confidence interval (CI)) for detecting advanced fibrosis (F3) and cirrhosis (F=4) for the training cohort were 0.81 (0.65-0.96) and 0.92 (0.81-1.0) respectively (p<0.01). Inflammation and iron accumulation were shown to significantly alter T-1 in opposing directions in the absence of advanced fibrosis; inflammation increasing T-1 and iron decreasing T-1. A decision tree model was developed to allow the assessment of early liver disease based on relaxation times and ELF, and to screen for the need for biopsy. T-1 relaxation time increases with advanced fibrosis in liver patients, but is also influenced by iron accumulation and inflammation. Together with ELF, relaxation time measures provide a marker to stratify patients with suspected liver disease for biopsy.

• 出版日期2015-6