Changes in measured size of atherosclerotic plaque calcifications in dual-energy CT of ex vivo carotid endarterectomy specimens: effect of monochromatic keV image reconstructions.
OBJECTIVE
The aim of this study was to compare the size of the calcifications measured on the different keV images to a histological standard.


METHODS
Five ex vivo carotid endarterectomy (CEA) specimens were imaged with a dual-energy CT. CT images were reconstructed at different monochromatic spectral energies (40, 60, 77, 80, 100, 120, 140 keV). Cross-sectional area of the plaque calcifications present on each CT image was measured. The histological calcium areas on each corresponding CEA specimen were traced manually on digitised images of Toluidine Blue/Basic Fuchsin stained plastic sections. The CT images and corresponding histology sections were matched. The CT-derived calcium areas on each keV image were compared to the calcified area measurements by histology.


RESULTS
A total of 107 histology sections were matched to corresponding CT images. The average calcified area per section by histology was 7.6 ± 7 mm(2) (range 0-26.4 mm(2)). There was no significant difference between the calcified areas measured by histology and those measured on CT-virtual monochromatic spectral (VMS) reconstructed images at 77 keV (P = 0.08), 80 keV (P = 0.20) and 100 keV (P = 0.14).


CONCLUSIONS
Calcium area measured on the 80 keV image set was most comparable to the amount of calcium measured by histology.
Departments of Radiology, University of Washington, Seattle, WA, USA. mannellilorenzo@yahoo.it
Lorenzo
L
Mannelli
Lee M
LM
Mitsumori
Marina
M
Ferguson
Dongxiang
D
Xu
Baocheng
B
Chu
Kelley R
KR
Branch
William P
WP
Shuman
Chun
C
Yuan
D001707:Biopsy, Needle; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D016001:Confidence Intervals; D016894:Endarterectomy, Carotid / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007150:Immunohistochemistry; D008297:Male; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D014057:Tomography, X-Ray Computed / Q000379:methods*