The achievement of a temporal resolution of less than 100 ms is the requirement for coronary CT imaging without artificial motion artifacts where there is no need for heart rate lowering medications. Amongst the currently available CT devices the Dual Source-CT (DSCT) has the greatest temporal (83 ms) and spatial (0.33 mm) resolution, therefore making coronary artery examinations possible without compromise and without pre-treatment with ß-blockers. Clinical tests have proven that these latter technical parameters further improve the sensitivity and specificity values of the non-invasive CT coronary angiography (Table II).
Table II: Sensitivity and specificity values for coronary CT angiographies based on 36 clinical tests.
Number of CT slices | Sens.(%) | Spec. (%) | Proportion of coronary segments that can be evaluated | Average heart rate |
4 | 78 | 94 | 79% (4368/5521) | 64.5 min-1 |
16 | 87 | 93 | 95% (10538/11136) | 62.0 min-1 |
64 | 89 | 94 | 98% (6472/6602) | 62.6 min-1 |
Dual Source | 96 | 98 | 100% (420/420) |
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