Keywords:
Cardiac, Cardiovascular system, Vascular, CT-Quantitative, CT-Angiography, CT, Computer Applications-General, Arteriosclerosis, Tissue characterisation
Authors:
S. Ilic1, M. Abramovic1, Z. Badnjar2, S. Odalovic3, S. Obradovic2; 1Podgorica, Montenegro/ME, 2Podgorica/ME, 3Belgrade/RS
DOI:
10.26044/ecr2019/C-1481
Methods and materials
Population for our study included patients who underwent MSCT coronary angiography for suspected coronary artery disease (CAD) in time period from September 2017 to June 2018.
Those included 105 patients referred by cardiologists,
without previous history of coronary artery bypass graft (CABG) surgery,
percutaneous coronary intervention or diagnosed CAD.
CT coronary angiographies were performed on Siemens Somatom Sensation 64-slice CT scanner,
using standard protocol.
All patients included in the study were in the sinus rhythm,
heart frequency less than 65/min (those with faster heart rate received b blockers agents).
Before MSCT angiography,
non-contrast CT was acquired for calcium score measurement,
according to Agatston method(5).
Then retrospective electrocardiography triggering cardiac CT was performed,
with use of Omnipaque 350mg iodine/ml contrast agent.
Acquisition started from tracheal bifurcation and ended at the dome of the diaphragm.
The start delay was defined using software equipped bolus tracking,
and ROI was placed within the ascending aorta.
Slice thickness used was 3.0mm,
with reconstruction increment of 0,6mm.
EFV and PCFV were measured three-dimensionally,
using validated semiautomatic software,
with manually traced regions of interest,
on contrast-enhanced data set.
EFV and PCFV were quantified by calculating volume of tissue with CT density ranged from -30 to -250 HU within selected region.
Also,
the degree of stenosis was defined as following: no stenosis was defined as no visible coronary plaque,
mild CAD with <50% of luminal narrowing,
moderate CAD with 50-70% of luminal narrowing,
and severe CAD if plaques were causing >70% of narrowing.
Measurement were performed in the most motionless phase of the cardiac cycle,
most frequently mid-diastolic phase,
with retrospective cardiac gating 65-75% of R-R interval.
The data set were analyzed by two independent radiologists,
on non-enhanced and contrast-enhanced images,
with use of maximum intensity and curved multiplanar reconstruction techniques.
All collected data were then statistically analyzed using the Statistical Package for Social Sciences,
version 25.
According to type of data,
we performed complete descriptive analysis as well as correlation of EFV and PCFV to degree of stenosis on different coronary arteries,
by use of Spearman’s coefficient.
Because of presence of multiple correlations,
we also performed logistic regression.