Keywords:
Cardiac, CT-Angiography, Stents, Arteriosclerosis
Authors:
J. Hoe, R. K. Kwok; Singapore/SG
Results
There were 38 coronary stents in 19 patients.Image quality was visually assessed to be adequate to good in 23 (60 %) stents and was excellent in 7 (18 %) Image quality was considered to be in the poor or unevaluable in 8 (21%) of stents .The average heart rate in all patients was 57 bpm.In those with multiple stents ,sometimes one stent was unevaluable.
Average breathing difference was measured from position of distal RCA between pre-contrast scan (calcium score equivalent) and CCTA scan ,
was 3.6 mm.Breathing differences ranged from 0.4mm to 6.6mm and did not affect the subtraction.
Software compensates for breathing <1cm Manual registration possible for breathing >1cm –not needed in this patient group.
As precontrast scans and post contrast CCTA scans need to be performed at same kVp,
should try to avoid using 120kVp and use 100kVp when possible to reduce radiation dose.Using 100kVp for stents does not seem to affect image quality of subtracted images