Clinical relevance and scope of accidental extracoronary findings in coronary computed tomography angiography: A cardiac versus thoracic FOV study

Abstract

Objective To assess the spectrum and clinical relevance of extracoronary findings in coronary CT angiography (CCTA), and to compare a small (cardiac) field of view (FOV) to a large (thoracic) FOV setting. Material and methods 1084 consecutive patients (mean 57 years) with low-to-intermediate risk of coronary artery disease were enrolled. 542 CCTA scans were interpreted with small FOV (160–190 mm 2) encompassing the cardiac region. In another 542 CCTA (patients matched for age and gender), read-out of an additional full FOV (>320 mm 2) covering the thorax was performed. Clinical relevance of extracoronary findings was considered as either “ significant” or “ non- significant”. “ Significant” findings were subclassified as either score 1: findings necessitating immediate therapeutic actions, or score 2: findings with undoubted clinical or prognostic relevance, requiring clinical awareness, follow-up or further investigations (non-urgent). “ Non- significant” findings were assigned to either score 3: findings not requiring follow-up or further tests, or as score 4: irrelevant incidental findings. Results Significantly more patients with extracoronary findings were identified by using a full FOV with 43.2% (234/542) compared to a small FOV with 33.6% (182/542) ( p = 0.001). Similarly, a higher total number of extracoronary findings ( n = 394) was found on full FOV compared to small FOV ( n = 250) ( p < 0.001). The detection rate of clinically significant findings was higher by using full FOV compared to small FOV (25.6% versus 15.4%) ( p < 0.001), out of those 2.2% versus 1.8% of findings required immediate actions (score 1), and 23.4% versus 13.6% ( p = 0.0001), respectively were of clinical relevance (non-urgent, score 2). The rate of malign findings was 0.2%, and of acute pulmonary embolism 0.1%. More lung pathologies were observed by using full FOV compared to small FOV (22% versus 7%) ( p < 0.0001), and the detection rate of intrapulmonary nodules increased by 2.1%. Prevalence of aortic valve calcification ( n = 72) was 13.3%, out of those 7% had less than 2 cm 2 aortic valve orifice area. Conclusions The interpretation of extracoronary findings on CCTA scans is mandatory given high prevalence of clinically significant findings by using a full “thoracic” FOV.