Quantitative X-ray imaging of intraplaque hemorrhage in aortas of apoE(-/-)/LDL(-/-) double knockout mice.
OBJECTIVE
To determine if hemorrhage into an arterial wall can be detected in CT images by virtue of the iron content.


METHODS
Aortas from male apoE(-/-)/LDL(-/-) mice (n = 31) were infused in situ with contrast agent, for micro-CT scanning and histology. Roentgen-opacities within the aortic walls were identified by histology and micro-x-ray fluorescence to be iron or calcium. Dual-energy scanning was performed at 2 energy levels using synchrotron-based micro-CT [(2 microm)(3) voxels, 16 and 20 keV] and 64-slice CT (0.4 x 0.4 x 0.6 mm voxels, 80 and 120 kVp).


RESULTS
Opacities were identified as hemorrhage-related clusters of multiple punctate deposits, containing both Fe (0.48 x 10(-12) g/voxel) and Ca (3.18 x 10(-2) g/voxel), or as isolated confluent accumulations of exclusively calcium. Subtraction of the dual-energy CT scans discriminated iron from calcium deposits.


CONCLUSIONS
Detection and quantification of iron deposits in hemorrhaged atherosclerotic lesions is feasible by dual-energy CT imaging.
Langheinrich
Alexander C
AC
Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
Michniewicz
Agata
A
Sedding
Daniel G
DG
Lai
Barry
B
Jorgensen
Steven M
SM
Bohle
Rainer M
RM
Ritman
Erik L
EL
D000818:Animals; D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D001057:Apolipoproteins E / Q000235:genetics*; D050197:Atherosclerosis / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology; D002118:Calcium / Q000032:analysis; D004195:Disease Models, Animal; D006470:Hemorrhage / Q000000981:diagnostic imaging* / Q000473:pathology; D007501:Iron / Q000032:analysis; D008077:Lipoproteins, LDL / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*
D001057:Apolipoproteins E; D008077:Lipoproteins, LDL; D007501:Iron; D002118:Calcium