Encircling reperfusion pattern on the stress-minus-delay bull's-eye map improves sensitivity of myocardial perfusion scans.

Background: Myocardial perfusion imaging is subject to considerable noise due to re-registration and attenuation artifact.

Methods: On a retrospective review, we identified 51 studies that showed encircling reperfusion pattern on a stress-minus-delay bull's-eye map with concurrent cardiac catheterization within 4 months. Encircling reperfusion was defined as a band of reversibility > or =2.5 standard deviations above that of the gender-matched and age-matched normal studies. This had to surround the delay defect for at least two-thirds of its circumference on the stress-minus-delay bull's-eye map. Three expert readers, blinded to cardiac catheterization results, individually interpreted myocardial perfusion imaging without and with a stress-minus-delay bull's-eye map. A certainty index of 1-100 (100 being the highest certainty for the presence of perfusion defects) was recorded for image interpretation.

Results: The intra-class correlation coefficient between readers indicated a strong agreement. Using encircling reperfusion pattern on a stress-minus-delay bull's-eye map, the mean increase in certainty index scores was 8.0+/-7.30 (P<0.0001). This increase in certainty index scores was associated with a significant increase in sensitivity from 67 to 83% (P=0.01) without any significant decrease in specificity (P=0.16).

Conclusions: The pattern of encircling reperfusion on the stress-minus-delay bull's-eye map can improve the interpreter's confidence and sensitivity without significantly compromising specificity for identifying true myocardial perfusion defects.