Abstract 673: Adenosine Stress Dual-Energy CT of the Heart for Diagnosing Myocardial Ischemia and Viability Compared With Cardiac MRI and SPECT
PURPOSE Evaluate the feasibility and accuracy of dual-energy CT (DECT) including rest-, stress-, and delayed enhancement imaging for diagnosing fixed/reversible myocardial ischemia and viability compared with cardiac MRI (cMRI) and SPECT-myocardial perfusion imaging (MPI).
METHODS 29 patients with known or suspected coronary artery disease underwent
Adenosine stress/rest SPECT-MPI
Contrast enhanced adenosine stress/rest perfusion and delayed enhancement cMRI (1.5T Avanto, Siemens)
Contrast (Ultravist) enhanced, retrospectively ECG-gated adenosine stress/rest and delayed enhancement DECT.
DECT was performed by independently operating the two tubes of a dual-source CT system (Definition, Siemens) at 140kV and 100kV. In each patient all three DECT data sets were analyzed for blood volume deficits and for delayed enhancement by mapping the iodine content within the myocardium based on the different x-ray spectra. Two independent, blinded observers evaluated SPECT-MPI, cMRI and DECT for fixed/reversible ischemia, and cMRI and DECT for delayed enhancement based.
RESULTS All patients (7 female, mean age 61 years) were successfully imaged with all three modalities. 493 myocardial segments were analyzed, 91 were abnormal at cMRI. Inter-reader agreement for detection of fixed/reversible ischemia and delayed enhancement at DECT was moderate to excellent (k=0.8/0.8-k=0.8). Compared with cMRI, DECT and SPECT-MPI had 92% (92%) sensitivity, 96% (97%) specificity, and 95% (95%) accuracy for detecting myocardial segments with fixed ischemia, respectively. Reversible ischemia was detected with 100% (100%) sensitivity, 100% (90%) specificity, and 100% (92%) accuracy by DECT and SPECT-MPI. Compared with cMRI, DECT detected myocardial segments showing delayed enhancement with 82% sensitivity, 97% specificity, and 95% accuracy.
CONCLUSION Adenosine stress and delayed enhancement DECT is feasible. Compared to cMRI, standard DECT showed good agreement for delayed enhancement and equal or better performance than SPECT-MPI for detection of myocardial ischemia. DECT enables assessment of both myocardial perfusion and viability and may promise to be a single imaging modality for the evaluation of ischemic heart disease.