Coronary CT angiography (CCTA) is being used increasingly as a screening tool for coronary artery disease (CAD) in those with an intermediate or low risk for CAD. Acquisition of good quality images is an important factor in the success of coronary CT angiography. But in some individuals, this may not be possible due to various reasons. Vanhecke TE and associates  have developed an uninterpretable risk score using clinical and patient variables. They identified variables which were independently associated with the occurrence of at least one uninterpretable major coronary segment, using data from over eight thousand five hundred patients. This was then prospectively validated among nine hundred odd patients. The scores ranged from zero to twelve. The risk score was predictive of uninterpretable results in both the development and validation cohorts used in the study. The seven factors which constitute the uninterpretable risk score are diabetes mellitus, hypertension, chronic obstructive pulmonary disease (COPD), sedentary lifestyle, body mass index, age, and history of atrial fibrillation. The authors conclude that the scoring system may help in predicting those in whom the unnecessary radiation exposure due to the study may be avoided if the risk score suggests uninterpretable results.
- Vanhecke TE et al. Development and Validation of a Predictive Screening Tool for Uninterpretable Coronary CT Angiography Results. Circ Cardiovasc Imaging. 2011 Sep;4(5):490-7.