Native <i>T</i>₁ Mapping and Magnetization Transfer Imaging in Grading Bowel Fibrosis in Crohn’s Disease: A Comparative Animal Study

Abstract

In this study, we investigated the utility of native T1 mapping in differentiating between various grades of fibrosis and compared its diagnostic accuracy to magnetization transfer imaging (MTI) in a rat model of CD. Bowel specimens (64) from 46 CD model rats undergoing native T1 mapping and MTI were enrolled. The longitudinal relaxation time (T1 value) and normalized magnetization transfer ratio (MTR) were compared between none-to-mild and moderate-to-severe fibrotic bowel walls confirmed by pathological assessments. The results showed that the correlation between the T1 value and fibrosis (r = 0.438, p r = 0.623, p T1 values (t = −3.066, p = 0.004) and normalized MTRs (z = 0.081, p T1 value (AUC = 0.716, p = 0.004) was significantly lower than that of the normalized MTR (AUC = 0.881, p z = −2.037, p = 0.042). Our results support the view that the T1 value could be a promising imaging biomarker in grading the fibrosis severity of CD. However, the diagnostic performance of native T1 mapping was not superior to MTI.

Keywords

• Crohn’s disease
• fibrosis
• <i>T</i>₁ mapping
• magnetization transfer imaging