Experimental venous thrombi: MRI characteristics with histopathological correlation

Objectives: The purpose of this study was to evaluate the MRI characteristics of venous thrombus over set time thresholds with histopathological correlation in a porcine model. Methods: Inferior vena cava thrombi were induced in 12 pigs. MRI was performed in three pigs 2 h, 1 day, 3 days and 2 weeks after thrombus induction. Results: The MRI characteristics were analysed in correlation with histopathological findings. The thrombi after 2 hours, which consisted of red blood cells (RBCs), showed isointensity on T1 weighted images (T1WIs) and hyperintensity on both T2 weighted images (T2WIs) and diffusion-weighted images (DWIs). The mean apparent diffusion coefficient (ADC) value was 1.93×10−3 mm2 s−1. The thrombi after Day 1, which consisted of RBCs and migrating neutrophils at the periphery, showed isointensity on T1WIs, slight hyperintensity on T2WIs and hypointensity on DWIs. The mean ADC value was 1.62×10−3 mm/s−2. The thrombi after Day 3, which consisted of RBCs and peripheral inflammatory cells includ...