CT is a valuable technique for prosthetic heart valve (PHV) assessment
CT helps identify the cause of PHV dysfunction including obstructive masses (pannus/thrombus) and endocarditis (vegetations,
mycotic aneurysms).Retrospective ECG-gated CTA is most often used with reconstructions at each 5-10% of R-R interval which are needed to dynamically assess leaflet motion and anatomy.
this results inhigh radiation exposure for the patient.
the ideal scan protocol would include not only acontrast enhanced ECG-gated acquisition with reconstructions at each 5-10% R-R interval but also a non...
Methods and Materials
We retrospectively analyzed the CT scans of patients that were scanned according to the acquistion protocol described below.
The CT acquisition protocol consisted of 3 sequential acquisitions:
Non contrast enhanced prospectively ECG-triggered scan of PHV only at 75% of the R-R interval.
2.Wide pulse window sequential CTA with recons at each 5%,
iterative reconstruction ADMIRE level 4 (Figure 1).For the prospectively ECG-gated sequential scan3 stacks were planned with the middle stack centered on the valve.
The maximum scanlength for 3 stacks in the z-axis...
Scans of 10 patients with 11 prosthetic heart valves were found and analyzed.
Image quality scores were:
Non contrast enhanced scan: 4.0±1.8*
Contrast enhanced scan: 4.8±0.4
Venous phase scan: 4.2±0.4
Values as mean ± SD; 1=non-interpretable; 5= excellent,
Figures 2 and 3 illustrate different scores of image quality.
CTDI values and radiation dose were:
Non contrast enhanced scan: 3.33±1.91 mGy
Contrast enhanced scan: 32.45±15.19 mGy
Venous phase scan: 2.53±1.51mGy
Total dose : 8.4±3.8mSv
Values as mean±SD; total dose for n=9,
dose info not available...
Comprehensive assessment of prosthetic heart valves at moderate radiation dose is possible using dual source CTA an iterative reconstruction.