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Updated: May 23, 2026

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis
Published on: June 2, 2015
Experimental venous thrombi: MRI characteristics with histopathological correlation
1Department of Radiology, Osaka City University Graduate School of Medicine, Abeno-ku, Osaka, Japan. s500820@nifty.com
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 T(1 )weighted images (T(1)WIs) and hyperintensity on both T(2 )weighted images (T(2)WIs) and diffusion-weighted images (DWIs). The mean apparent diffusion coefficient (ADC) value was 1.93 × 10(-3) mm(2) s(-1). The thrombi after Day 1, which consisted of RBCs and migrating neutrophils at the periphery, showed isointensity on T(1)WIs, slight hyperintensity on T(2)WIs and hypointensity on DWIs. The mean ADC value was 1.62 × 10(-3) mm(2) s(-1) [corrected]. The thrombi after Day 3, which consisted of RBCs and peripheral inflammatory cells including macrophages, showed isointensity with peripheral hyperintense regions on T(1)WIs and hypointensity on both T(2)WIs and DWIs. The mean ADC value was 1.67 × 10(-3) mm(2) s(-1). After 2 weeks, the thrombi, which revealed RBC lysis surrounded by granulation tissues, showed isointensity on T(1)WIs and hyperintensity on T(2)WIs and DWIs. The mean ADC value was 2.48 × 10(-3) mm(2) s(-1).
Conclusion:
The temporal MRI characteristics seemed to be related to chemical and physical changes in RBC and organisation of granulation tissues. Free radicals generated by macrophages might also be related to some extent.
Insights
Magnetic resonance imaging (MRI) reveals distinct changes in venous thrombus over time, correlating with histopathology. These temporal MRI characteristics reflect red blood cell (RBC) breakdown and tissue organization, aiding in understanding thrombus evolution.
Area of Science:
- Radiology
- Vascular Imaging
- Histopathology
Background:
- Venous thrombus characterization is crucial for diagnosis and treatment.
- Understanding the temporal evolution of thrombus MRI characteristics is essential.
Purpose of the Study:
- To evaluate the temporal MRI characteristics of venous thrombus.
- To correlate MRI findings with histopathological changes in a porcine model.
Main Methods:
- Inferior vena cava thrombi were induced in 12 pigs.
- MRI was performed at 2 hours, 1 day, 3 days, and 2 weeks post-induction.
- MRI characteristics were analyzed and correlated with histopathology.
Main Results:
- Early thrombi (2 hours) showed isointensity on T1WIs and hyperintensity on T2WIs and DWIs.
- Day 1 thrombi exhibited isointensity on T1WIs, slight T2WIs hyperintensity, and DWI hypointensity.
- Day 3 thrombi displayed isointensity with peripheral T1WIs hyperintensity and T2WIs/DWIs hypointensity.
- 2-week thrombi showed isointensity on T1WIs and hyperintensity on T2WIs and DWIs, with RBC lysis and granulation tissue.
Conclusions:
- Temporal MRI characteristics correlate with red blood cell (RBC) chemical/physical changes and granulation tissue organization.
- Macrophage-derived free radicals may also influence thrombus MRI appearance.
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