To evaluate the performance of a new generation multi-detector CT scanner (Brilliance 40, Philips) for segmental assessment of coronary artery disease.
METHOD AND MATERIALS
22 patients (19 male, 2 female), mean age 56 years (range 36-72), with suspected coronary artery disease underwent retrospectively gated spiral scans in the run-in phase of a 40-slice CT scanner (40x0.625mm collimation, 420msec rotation, 0.2-0.3 pitch, 120kV, 500-700mAs depending on patient’s girth). The total volume of contrast (350 mg%I, 4-5ml/sec) was 80-100ml. The heart rate (HR) varied between 50-80 bpm and premedication (50mg Atenolol) was given when HR was above 60bpm. All coronary artery segments (American Heart Association classification) with a diameter above 1mm were assessed for the presence of stenosis exceeding 50% diameter reduction. Invasive angiography was performed in 15/22 (68%) of patients.
All studies were completed successfully. Scanning time was 7.5-13sec (about 10-12 cm). Nearly all coronary segments (93%) could be evaluated by CT. In comparison to invasive angiography the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 78%, 99%, 87%, 98% and 97% respectively.
The new 40-slice CT scanner enables: 1. Very short scan time (7.5-13sec). 2. Assessment of over 90% of coronary segments above 1mm diameter. 3. The very short breath hold time and full coronary coverage make this scanner a promising tool for screening a much wider patient population than previous scanners. Clinical stratification of patient subsets will be performed as soon as a larger patient database is compiled.