Segmental distributions of calcifications and non-assessable lesions on coronary computed tomographic angiography: evaluation in symptomatic patients.

Purpose: To clarify the frequency and distribution pattern of calcifications in all and in only non-assessable coronary arterial segments in symptomatic patients with coronary heart disease. Materials and methods: Among 2355 consecutive coronary CT angiographies performed using a 320-row ADCT, 1129 studies performed by prospective one-beat scanning without metallic and motion artifacts were evaluated. Frequency and degree of calcification were assessed for each coronary segment. Evaluations were performed in all and in only non-assessable segments, and the results were compared. Results: Calcified segments were observed in 15.6 % of patients and 2.4 % of segments. The most extensively calcified segments were those in the proximal left anterior descending branch. 1.1 % of all of the segments were not assessable due to calcification, and 90 % of those non-assessable segments had high-grade calcifications. When the calcium score value was 1000 or 2000, the expected frequency of non-assessable segments was 27.5 or 53.5 %, respectively. Conclusion: There were specific features of the distribution of coronary arterial calcifications. It is important to be familiar with these features when deciding whether or not to perform subtraction CCTA. [ABSTRACT FROM AUTHOR]