Reduced stress dose with rapid acquisition CZT SPECT MPI in a non-obese clinical population: comparison to coronary angiography.

BACKGROUND

Cadmium Zinc Telluride (CZT) SPECT camera technology has the potential to reduce patient's radiation exposure and shorten imaging time. This study evaluated the correlation of low stress tracer dose, rapid CZT SPECT myocardial perfusion imaging (MPI) to coronary angiography in a <200-lbs population to further validate its ability to achieve both goals while preserving diagnostic accuracy.

METHODS

All patients who had a low-dose stress (≤15 mCi) Tc-99m sestamibi SPECT MPI study using a CZT camera (GE Discovery NM 530c) with 3- to 5-minute image acquisition over a 2-year period followed by a coronary angiogram within 2 months were included. Patients with a history of coronary revascularization, left ventricular dysfunction, and LBBB or paced rhythms were excluded. Both MPI studies and coronary angiograms were interpreted by blinded readers and coronary artery disease (CAD) was defined as ≥70% stenosis.

RESULTS

A total of 71 patients were included with a mean age of 64 years, 55% male, and a BMI of 25.4 kg/m(2) with an average stress dose of 13.3 mCi. Exercise stress was performed in 54% of patients and vasodilator pharmacologic stress in 46%. Sensitivity was 89%, specificity was 66%, and accuracy was 78% for detecting obstructive CAD.

CONCLUSIONS

In this group of non-obese patients undergoing low stress dose imaging, high-efficiency CZT SPECT imaging demonstrated a high sensitivity, specificity, and accuracy for detecting obstructive epicardial CAD with a greatly reduced imaging time.