Third generation dual source CT with ultra-high pitch protocol for TAVI planning and coronary tree assessment: feasibility, image quality and diagnostic performance

Purpose: To evaluate the feasibility, image quality (IQ) and diagnostic performance of third generation 192 × 2 dual source computer tomography (DSCT) with ultra-high pitch acquisition for trans-catheter aortic valve implantation (TAVI) planning and coronary tree assessment. Method: In this prospective study, 223 patients underwent to DSCT for TAVI. Coronary calcium scoring (CCS) was calculated. Attenuation values were measured at aortic levels, femoral and coronary arteries. IQ was evaluate with a 4-point scale. The CT performance, in the assessment of coronary stenosis ≥50 % and ≥70 %, was compared with invasive coronary angiography (ICA), served as reference standard. Aortic annulus (AoA) CT derived area and implanted prosthesis size were correlate with Spearman's test. Results: Attenuation values >400HU were obtain in all segments. IQ median value was ≥ 3. In the assessment of stenosis ≥50 %, on a segment-based analysis, CT sensitivity, specificity, positive and negative predictive values and diagnostic accuracy were 97.6 %, 87.6 %, 64.2 %, 99.0 % and 89.6 %, on patient-based analysis were 97.8 %, 88.8 %, 68.8 %, 99.4 % and 90.6 %, respectively. In the assessment of stenosis ≥70 %, on segment-based analysis, were 88.5 %, 83.8 %, 54.7 %, 96.8 % and 84.8 %, and on patient-based analysis were 92.5 %, 85.8 %, 58.7 %, 98.1 % and 87.0 %, respectively. The CT performed better in the group with lower CCS. A direct correlation was found between AoA CT derived area and prosthesis size. Conclusion: DSCT, using a single prospective ECG-triggered ultra-high pitch acquisition, is feasible for TAVI planning and in the assessment of coronary stenosis. CT performed worse in patients with severe coronary calcifications.