Impact of intravascular enhancement, heart rate, and calcium score on diagnostic accuracy in multislice computed tomography coronary angiography.
OBJECTIVE
To assess the effect of intravascular enhancement, heart rate, and calcium score on diagnostic accuracy in the detection of significant coronary artery stenosis using 16-row multislice computed tomography (MSCT).


METHODS
One hundred patients (88 males; 59+/-11 years) with suspected coronary artery disease who had undergone conventional coronary angiography (CA) and MSCT-CA were retrospectively enrolled for the study. Patients underwent a MSCT-CA, with the following protocol: collimation 16x0.75 mm, gantry rotation time 420 ms, feed/rotation 2.8 mm, kV 120, mAs 400-500. The protocol for contrast material administration was 100 ml of Iodixanol 320 mgI/ml at 4 ml/s and the scan delay was defined with a bolus tracking technique. In all patients vascular enhancement was measured in the aortic root, and in the left and right coronary arteries. The average vascular enhancement was used to divide the population in two groups of 50 patients each, one with lower enhancement (Low), and one with higher enhancement (High). In the two groups diagnostic accuracy (per coronary segment) for the detection of significant stenosis (= or >50% lumen reduction) was evaluated in vessels = or >2 mm in diameter using quantitative CA as the reference standard. The differences in diagnostic accuracy were compared with a Chi-square test and a p<0.05 was considered significant.


RESULTS
Of the total 1116 segments (= or >2 mm lumen diameter), 173 presented significant stenosis. The sensitivity and specificity for the assessment of significant stenosis were 89.4% and 93.3% vs 94.3% and 97.4% in the presence of increasing intravascular enhancement, 92.8% and 96.7% vs 91.1% and 93.9% in the presence of increasing heart rate, and 89.7% and 97.6% vs 93.3% and 92,8% in the presence of an increasing calcium score.


CONCLUSIONS
Increasing intravascular enhancement significantly improves diagnostic accuracy in MSCT-CA. A higher heart rate lowers the specificity in the detection of significant obstructing lesions of the coronary artery. An increasing calcium score determines a lower specificity and a higher sensitivity.
Cademartiri
Filippo
F
Dipartimento di Radiologia, Erasmus Medical Center, Rotterdam, The Netherlands. filippocademartiri@hotmail.com
Runza
Giuseppe
G
Mollet
Nico R
NR
Luccichenti
Giacomo
G
Belgrano
Manuel
M
Bartolotta
Tommaso Vicenzo
TV
Galia
Massimo
M
Midiri
Massimo
M
Pozzi Mucelli
Roberto
R
Krestin
Gabriel P
GP
D000368:Aged; D016477:Artifacts; D001835:Body Weight; D002114:Calcinosis / Q000000981:diagnostic imaging*; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging; D003627:Data Interpretation, Statistical; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014283:Triiodobenzoic Acids / Q000008:administration & dosage
D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol