To evaluate detectability and quantification of coronary calcifications for CT with a tin filter for spectral shaping.
Phantom inserts with 100 small and 9 large calcifications, and a moving artificial artery with 3 calcifications (speed 0-30 mm/s) were placed in a thorax phantom simulating different patient sizes. The phantom was scanned in high-pitch spiral mode at 100 kVp with tin filter (Sn100 kVp), and at a reference of 120 kVp, with electrocardiographic (ECG) gating. Detectability and quantification of calcifications were analyzed for standard (130 HU) and adapted thresholds.
Sn100 kVp yielded lower detectability of calcifications (9 % versus 12 %, p = 0.027) and lower Agatston scores (p <0.008), irrespective of calcification, patient size and speed. Volume scores of the moving calcifications for Sn100 kVp at speed 10-30 mm/s were lower (p <0.001), while mass scores were similar (p = 0.131). For Sn100 kVp with adapted threshold of 117 HU, detectability (p = 1.000) and Agatston score (p > 0.206) were similar to 120 kVp. Spectral shaping resulted in median dose reduction of 62.3 % (range 59.0-73.4 %).
Coronary calcium scanning with spectral shaping yields lower detectability of calcifications and lower Agatston scores compared to 120 kVp scanning, for which a HU threshold correction should be developed.
aEuro cent Sn100kVp yields lower detectability and lower Agatston scores compared to 120kVp
aEuro cent Adapted HU threshold for Sn100kVp provides Agatston scores comparable to 120kVp
aEuro cent Sn100 kVp considerably reduces dose in calcium scoring versus 120 kVp.
- Computed tomography
- Coronary arteriosclerosis
- Cardiovascular Diseases
- Mass screening
- ELECTRON-BEAM TOMOGRAPHY
- MULTIDETECTOR ROW CT
- DUAL-SOURCE CT
- ARTERY CALCIUM