Adenosine Stress Dual-Energy CT for the Diagnosis of Coronary Heart Disease: Do We Need Rest Images?
To prospectively compare the diagnostic accuracy of stress-only dual-energy CT (DECT) combined with delayed enhancement imaging with a stress-rest DECT protocol for detection of myocardial perfusion defects seen on SPECT.
Method and materials
57 patients underwent three-phase contrast (Isovue, Bracco) enhanced ECG-gated DECT (Definition, Siemens) with adenosine-stress, rest, and delayed enhancement imaging. DECT datasets were used to map the myocardial iodine distribution within the left ventricular myocardium. Myocardial segments were classified, in a blinded fashion, as normal, showing reversible ischemia, or fixed perfusion defects. This segmental analysis was done based on a combination of stress-, rest-, and delayed enhancement DECT series as well as using a combination of stress-only and delayed-enhancement DECT. Results were compared with stress-rest SPECT.
214 of all analyzed 969 myocardial segments showed perfusion defects on rest DECT and 227/969 on adenosine stress DECT studies. Delayed enhancement was positive in 175/969 myocardial segments. Rest DECT confirmed rest SPECT findings with 92.1% sensitivity, 96.4% specificity, and 96.5% accuracy. Stress DECT confirmed stress SPECT findings with 94.6% sensitivity, 97.5% specificity, and 96.8% accuracy. The overall sensitivity, specificity, and accuracy of combined stress-, rest-, and delayed-enhancement DECT for diagnosing normal, ischemic, and infarcted myocardial segments were 93%, 97.1%, and 96.0%, respectively. Stress-only combined with delayed enhancement DECT confirmed SPECT findings with 89% sensitivity, 97.5% specificity, and 95.5% accuracy.
Stress-, rest-, and delayed enhancement DECT shows excellent agreement with SPECT for characterizing myocardial perfusion patterns. However, similar to recent findings in nuclear myocardial perfusion imaging, almost identical accuracies can be achieved without rest imaging.
Obviating the need for an additional image acquisition during rest holds promise to substantially reduce radiation doses involved with CT-based myocardial perfusion imaging.
Submission Type: Scientific Presentations RSNA 2010
Authors: T Henzler, MD; U J Schoepf, MD; D Kang, MD, ; C Fink, MD; S O Schoenberg, MD, PhD; M Weininger, MD