Compositional volumetry of non-calcified coronary plaques by multislice computed tomography: an ex vivo feasibility study.
OBJECTIVE
Non-invasive quantitative compositional analysis of coronary plaque would be a major advantage to study coronary artery disease. This study explores the application to use the Hounsfield units (HU) distribution of coronary plaques imaged by multislice computed tomography-coronary angiography (MSCT-CA).


RESULTS
A dedicated computer-assisted method was developed to measure the HU distribution within a coronary plaque by MSCT-CA. To test the feasibility of the method, an ex vivo left anterior descending (LAD) coronary specimen, excised during autopsy, was imaged both by non-enhanced and enhanced MSCT-CA. Quantitative histology was used as a reference. To test the feasibility of the new volumetric analytic method, the MSCT-CA data were compared with volumetric histopathology. The coronary specimen, with a heterogeneously distributed plaque composition without large areas of calcification, was histologically sampled at five different locations, 5 mm apart, where at each location 15 sections were taken at 100 microm intervals, resulting in 75 individual histology sections. Tri-chrome Masson staining was used for histology quantification of three plaque/tissue components: smooth muscle cells (SMC), collagen and calcium. MSCT plaque composition was defined as "lower-HU" or "higher-HU" plaque and "calcium" based on the HU distribution. Comparison of the MSCT defined tissue components against histology showed a good relationship without significant differences.


CONCLUSIONS
This ex vivo study shows the feasibility of using the Hounsfield unit distribution to perform compositional coronary plaque volumetry by MSCT-CA. The results are encouraging.
Bruining
Nico
N
Department of Cardiology, Erasmus MC, Thoraxcenter, Rotterdam, The Netherlands. n.bruining@erasmusmc.nl
Roelandt
Jos R T C
JR
Verheye
Stefan
S
Knaapen
Michiel
M
Onuma
Yoshinobu
Y
Regar
Evelyn
E
Cademartiri
Filippo
F
de Winter
Sebastiaan
S
Van Langenhove
Glenn
G
Serruys
Patrick W
PW
Hamers
Ronald
R
de Feyter
Pim J
PJ
D001344:Autopsy; D001391:Azo Compounds; D002118:Calcium / Q000032:analysis; D003094:Collagen / Q000032:analysis; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000378:metabolism; D003331:Coronary Vessels / Q000737:chemistry / Q000473:pathology*; D004801:Eosine Yellowish-(YS); D005240:Feasibility Studies; D006801:Humans; D008739:Methyl Green; D032389:Myocytes, Smooth Muscle / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D013194:Staining and Labeling / Q000379:methods; D041623:Tomography, Optical Coherence; D014057:Tomography, X-Ray Computed
D001391:Azo Compounds; D003287:Contrast Media; C017768:trichrome stain; D008739:Methyl Green; D003094:Collagen; D002118:Calcium; D004801:Eosine Yellowish-(YS)