Submillisievert coronary computed tomography angiography using adaptive statistical iterative reconstruction - a new reality.

Coronary computed tomography angiography (CCTA) is becoming an increasingly robust tool in the assessment and exclusion of coronary artery disease. Multiple recent studies have raised concerns regarding the radiation dose exposure of CCTA. A novel approach to dose reduction in CCTA using adaptive statistical iterative reconstruction, resulting in a submillisievert CCTA examination, is described. To the authors' knowledge, the present report describes the first submillisievert study performed in Canada. The ability to perform a diagnostic CCTA with such a low dose challenges the role of coronary calcium scoring and will likely have implications for the future use of this test.