Improved detection of left main coronary artery disease with attenuation-corrected SPECT

Background, Myocardial perfusion imaging has demonstrated a limited sensiti vity as a means of accurately identifying left main (LM) coronary disease. Because regional quantitative perfusion biases are eliminated with attenuat ion corrected (AC) single photon emission computed tomography (SPECT), as c ompared with uncorrected (NC) SPECT, we hypothesized that AC SPECT would de monstrate increased diagnostic accuracy for the detection of significant LM coronary stenosis, Methods and Results, We studied 28 patients (23 men, 5 women; mean age, 66 +/- 9 years) with significant LM stenoses (greater than or equal to 50%) an d 34 control patients (27 men, 7 women; mean age, 65 +/- 11 years) with a-v essel coronary disease. Rest thallium-201 and stress technetium 99m sestami bi SPECT imaging with and without AC were performed, as described earlier. Both AC and NC images were analyzed visually and quantitatively in comparis on with corresponding normal databases. A greater sensitivity for detection of an LM defect pattern (64% vs 7%, P =.0009) with equivalent specificity (94% vs 100%, P = not significant) was demonstrated by means of visual anal ysis of AC SPECT images, More disease was demonstrated in a greater number of territories with AC SPECT images than with NC images (2.14 +/- 0.97 for AC images vs 1.43 +/- 0.84 for NC images, P =.0001), Similar improvement in the detection of LM disease was shown by means of automated quantitative a nalysis (57% for AC SPECT vs 14% for NC SPECT, P =.0005), again with no los s in specificity. Conclusions. AC SPECT with the University of Michigan method in consecutive patients with LM stenoses and a select control population with severity ma tched multivessel coronary disease significantly improved the diagnostic ac curacy of myocardial perfusion imaging for the identification of LM coronar y disease, compared with uncorrected SPECT.