Stress Protocol and Myocardial Perfusion Imaging Accuracy

Purpose of Review

To evaluate the most recent evolutions in the field of single photon emission computed tomography (SPECT) nuclear cardiac imaging (NCI), particularly regarding the influence of stress protocol specifics on test accuracy.

Recent Findings

The substantial improvement in both software and hardware SPECT settings may allow a drastic redefinition of the acquisition parameters, with a radical reduction of scanning time. Moreover, recent evidence has identified novel (contra)-indications to the different cardiac stressors, defining the categories of patients in which a specific stressor is most appropriate.

Summary

Whilst exercise stress is favoured in the majority of patients submitted to SPECT NCI, in patients with atrial fibrillation or diabetes mellitus, a vasodilator stress may be preferred because of a significantly higher specificity. Moreover, the use of non-perfusion variables, such as post-stress diastolic left ventricular parameters or eccentricity index, is favoured to increase the accuracy of SPECT imaging. Finally, the quantification of myocardial blood flow through dynamic scans with cadmium-zinc-telluride cameras is gaining its way in clinical practice, possibly further increasing NCI accuracy in the most difficult patients.