Multislice computed tomography coronary angiography for triaging patients with positive radionuclide myocardial perfusion imaging

Sir, Myocardial perfusion imaging using single-photon emission computedtomography (SPECT) is the most commonly applied diagnostic imagingmodality in patients with suspected coronary artery diseasein the US, with more than 9 million procedures performed annually.¹The positive predictive value of SPECT is limited, and in aconsiderable number of patients with suspected perfusion deficitsconventional coronary angiography shows no significant coronarystenoses. Multislice computed tomography (MSCT) coronary angiographyallows the non-invasive assessment of coronary artery stenoses,and has a high negative predictive value.^2–4 Thus, MSCTmight be applied as a secondary gate-keeper in patients withpositive SPECT, prior to deciding whether to perform conventionalcoronary