Non-gated chest CT reliable for measuring coronary calcifications

Non-gated chest CT with 256-detector row is more reliable for detecting and measuring coronary artery calcification (CAC) compared to dedicated calcium scoring CT (CSCT), reported authors of a Jan. 23 study published in Academic Radiology.

“Vascular calcification is a common pathological feature of many diseases such as atherosclerosis, diabetes, and chronic kidney disease, and one of the important reasons for the high morbidity and mortality of cardiovascular and cerebrovascular diseases,” wrote first author Yuhuan Chen, MD with Shaanxi University of Chinese Medicine in Xianyang, Shaanxi, China, and colleagues.

Somewhat recently, CAC scoring with ECG-gated CT has become the non-invasive reference standard for detecting calcifications, but nongated chest CT has also demonstrated promise in this arena, they added.

In the study, Chen et al. enrolled more than 1,300 patients scheduled for chest exams to undergo non-gated chest CT and dedicated CSCT on a 256-detector row CT scanner from December 2016-2017. The team compared CAC scores, which included the Agatston scores, mass and volume.

For determining positive CAC, non-gated chest CT achieved a sensitivity and specificity of 95 percent and 100 percent, respectively. Unlike prior studies which have included specific patient populations, this study, according to the authors, was for routine chest CT exams and thus more representative of a real clinical situation.

Agreement in assessing quantitative Agatston, volume and mass scores between both modalities was nearly “perfect,” the authors wrote. There was also good agreement (95 percent) in quantifying the severity of CAC between the two methods, “suggesting that information provided by non-gated chest CT has high clinical value for diagnosing CAC and stratifying patients according to the severity categories of CAC for the prognosis prediction in CAD,” the authors wrote.

“In conclusion, non-gated chest CT on a 256-detector row CT is a reliable imaging mode for detecting and quantifying calcifications in coronary arteries compared to dedicated calcium-scoring CT,” the group concluded. “By adding the coronary artery calcification evaluation to the routine non-gated chest CT which is becoming more popular, we can improve the clinical usage of CT, reduce cost and overall radiation to patients and providing positive social benefits.”