Type:
Poster Presentation
Keywords:
Radioprotection / Radiation dose, Cardiac, CT-Angiography, Diagnostic procedure, Radiation effects, Transplantation
Authors:
D. Beitzke1, V. Berger-Kulemann2, V. Schoepf1, S. Unterhumer2, R. Schernthaner1, R. Nolz1, C. Loewe1, F. Wolf1; 1Vienna/AT, 2Wien/AT
Purpose
Coronary transplant vasculopathie (CTV) represents the main reasons for vascular complication in the long term course of cardiac transplant,
resulting in graft failure.
CTV is believed to be based on endothelial damage due to infection,
immunmodulated graft rejection,
ischemic events and pre-existing risk factors like diabetes mellitus,
hypertension and hyperlipidaemia.
Over the time this process of endothelial dysfunction results in a diffuse form of arteriosclerotic vascular damage based on intimal proliferation.
The risk of developing CVT is approximately 10 % per year.
Due to denervation of the graft CTV is usually clinically silent and patient often present in a progressive stage of disease with cardiac failure,
arrhythmias,
or even witness sudden cardiac death.
Therefore imaging of CVT,
including detection of coronary artery stenosis and plaque characterization is of main importance for long term surveillance in cardiac transplant patients.
Non-invasive imaging in CVT includes imaging modalities like echocardiography,
PET and SPECT,
mainly focused on function and viability [1].
Coronary computed tomography angiography (CCTA) recently approached as a useful tool in CVT as it depicts the coronary arteries and the perivascular tissue [2,3] (Fig.
1).
However,
cumulative radiation exposure is one of the limitations in CCTA.
In cardiac transplant patients,
dose reduction is challenging as patients often present with elevated heart rates and do not respond to beta blockers due to denervation of the heart.
Most of the dose reduction algorithms in CCTA on the other hand are based on scanning at a low heart rate below 65 beat per minutes.
However,
prospective scanning in the systolic phase (35-45 % RR interval) proved feasibility at higher heart with the advantage of lowered radiation dose [4].
The aim of this study was to prospectively evaluate image quality and radiation dose using three different CT scan protocols for dual source-CCTA in heart transplant recipients.