Cardiac, Arteries / Aorta, Computer applications, CT-Angiography, CT, Experimental investigations, Computer Applications-Detection, diagnosis, Computer Applications-General, Artifacts, Arteriosclerosis, Image verification
D. D. DELACOUR, E. Elie, J.-N. Dacher, B. Dubourg; Rouen/FR
Aims and objectives
Since the years 2000 and the use of 64-slice multidetector computed tomography,
cardiac computed tomographic angiography (CCTA) has been widely utilized as a noninvasive diagnostic modality for visualizing the coronary arteries to detect coronary artery disease (CAD).
Although the diagnostic accuracy of CCTA for detection of obstructive CAD has been validated by numerous retrospective and prospective trials,
most of the available study samples consisted of selecting patients with low heart rate (HR) in order to be optimal for CCTA with a high sensitivity and an excellent negative predictive value (1).
the positive predictive value of CTCA has yielded considerably lower results,
particularly in patients with intermediate-to-high probability of CAD,
driven by a larger prevalence of false-positive findings in such populations (2).
The main challenge in imaging the coronary arteries remains their fast motion during the cardiac cycle,
which reaches up to 70 mm-per-second in the right coronary artery (3).
The diagnostic accuracy of CCTA is known to be diminished by elevations in the HR due to motion artifact.
There are a variety of methods for improving image quality of coronary arteries including hardware solution (faster gantry rotation,
use of dual sources scanners) or software solution (half scan reconstruction,
multisegment reconstruction methods).
It improves the temporal resolution of modern CT systems with approximately 66-150 ms but motion artifact remains important.
In deed 12% of coronary artery segments are judged as “noninterpretable” because of motion artifacts alone in using 64-slice CCTA (4).
to achieve excellent CCTA image quality,
we need to use rate-control medications to make heart rate lower (3).
But a low heart rate is not achieved in all patients.
In patients with persistently high heart rates,
novel intracycle motion correction reconstruction algorithm (MCA) can improve image quality.
MCA adjusts the motion of coronary arteries and defines the actual vessel location by using the adjacent cardiac phase information (5),
improving the effective temporal resolution at 29 ms (4).
Some studies have evaluated the beneficial effects of MCA,
and how it might improve image quality and interpretability (6–17),
but there is only one multicenter study compare to the gold standard in order to definite the accuracy (18).
one experimental study have been made to evaluate the impact of MCA by the vendor (19),
but there is no independent study.
In this experimental study using a coronary motion phantom model,
we systematically investigated image quality,
diagnostic accuracy and robustness to high HR of CCTA provided by a novel intracycle MCA (SnapShot Freeze®) in comparison with conventional reconstruction algorithm.