Quantification of experimental venous thrombus resolution by longitudinal nanogold-enhanced micro-computed tomography.
BACKGROUND
The assessment of thrombus size following treatments directed at preventing thrombosis or enhancing its resolution has generally relied on physical or histological methods. This cross-sectional design imposes the need for increased numbers of animals for experiments. Micro-computed tomography (microCT) has been used to detect the presence of venous thrombus in experimental models but has yet to be used in a quantitative manner. In this study, we investigate the use of contrast-enhanced microCT for the longitudinal assessment of experimental venous thrombus resolution.


METHODS
Thrombi induced by stenosis of the inferior vena cava in mice were imaged by contrast-enhanced microCT at 1, 7 and 14 days post-induction (n=18). Thrombus volumes were determined longitudinally by segmentation and 3D volume reconstruction of microCT scans and by standard end-point histological analysis at day 14. An additional group of thrombi were analysed solely by histology at 1, 7 and 14 days post-induction (n=15).


RESULTS
IVC resident thrombus was readily detectable by contrast-enhanced microCT. MicroCT-derived measurements of thrombus volume correlated well with time-matched histological analyses (ICC=0.75, P<0.01). Thrombus volumes measured by microCT were significantly greater than those derived from histological analysis (P<0.001). Intra- and inter-observer analyses were highly correlated (ICC=0.99 and 0.91 respectively, P<0.0001). Further histological analysis revealed noticeable levels of contrast agent extravasation into the thrombus that was associated with the presence of neovascular channels, macrophages and intracellular iron deposits.


CONCLUSIONS
Contrast-enhanced microCT represents a reliable and reproducible method for the longitudinal assessment of venous thrombus resolution providing powerful paired data.
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK.
Steven P
SP
Grover
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK.
Prakash
P
Saha
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK.
Julia
J
Jenkins
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK.
Arun
A
Mukkavilli
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK.
Oliver T
OT
Lyons
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK.
Ashish S
AS
Patel
Division of Imaging Sciences and Biomedical Engineering, King's College London, Wellcome Trust - EPSRC Medical Engineering Centre & NIHR Biomedical Research Centre at King's Health Partners, St. Thomas' Hospital, London, UK.
Kavitha
K
Sunassee
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK.
Bijan
B
Modarai
Academic Department of Vascular Surgery, Cardiovascular Division, King's College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King's Health Partners, St Thomas' Hospital, London, UK. Electronic address: alberto.smith@kcl.ac.uk.
Alberto
A
Smith
D000818:Animals; D003287:Contrast Media / Q000737:chemistry; D003430:Cross-Sectional Studies; D006046:Gold / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007501:Iron / Q000737:chemistry; D008264:Macrophages / Q000378:metabolism; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D018919:Neovascularization, Physiologic; D015588:Observer Variation; D015203:Reproducibility of Results; D013927:Thrombosis / Q000276:immunology; D014682:Vena Cava, Inferior / Q000473:pathology; D020246:Venous Thrombosis / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000379:methods*
D003287:Contrast Media; D006046:Gold; D007501:Iron
Animal models; MicroCT; Nanogold; Venous thrombosis