| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3982118 | Clinical Radiology | 2014 | 9 Pages |
•We derive aortic and coronary calcium scores from DECT scans.•The associated radiation exposure was examined.•Coronary and aortic valve calcium scores can be accurately determined from DECT scans.•This incurs an increased radiation burden.•DECT should not be routinely used for this purpose.
AimTo assess the validity of virtual non-contrast (VNC) reconstructions for coronary artery calcium (CACS) and aortic valve calcium scoring (AVCS) in patients undergoing trans-catheter aortic valve implantation (TAVI).Materials and methodsTwenty-three consecutive TAVI patients underwent a three-step computed tomography (CCT) acquisition: (1) traditional CACS; (2) dual-energy (DE) CT coronary angiogram (CTCA); and (3) DE whole-body angiogram. Linear regression was used to model calcium scores generated from VNC images with traditional scores to derive a conversion factor [2.2 (95% CI: 1.97–2.58)]. The effective radiation dose for the TAVI protocol was compared to a standard control group. Bland–Altman analysis and weighted k-statistic were used to assess inter-method agreement for absolute score and risk centiles.ResultsCACS and AVCS from VNC reconstructions correlated well with traditional scores (r = 0.94 and r = 0.86; both p < 0.0001). There was excellent agreement between VNC and non-contrast coronary calcium scores [mean difference −71.8 (95% limits of agreement −588.7 to 445.1)], with excellent risk stratification into risk centiles (k = 0.99). However, the agreement was weaker for the aortic valve [mean difference −210.6 (95% limits of agreement −1233.2 to 812)]. Interobserver variability was excellent for VNC CACS [mean difference of 6 (95% limits of agreement 134.1–122.1)], and AVCS [mean difference of −16.4 (95% limits of agreement 576 to −608.7)]. The effective doses for the DE TAVI protocol was 16.4% higher than standard TAVI protocol (22.7 versus 19.5 mSv, respectively) accounted for by the DE CTCA dose being 47.8% higher than that for a standard CTCA [9.9 (5.6–14.35) versus 6.7 (1.17–13.72) mSv; p < 0.01).ConclusionsCACS and AVCS can be accurately quantified, and patients can be risk stratified using DECT VNC reconstructions. However, the dose from DE CTCA is significantly greater than the standard single-energy CTCA precluding the use of this technology in routine clinical practice.
