Normal Limits of Left Ventricular Volumes and Ejection Fraction Measured by Gated Myocardial Perfusion SPECT: Comparison of Tc-99m MIBI and Tl-201

Hyun, In Young; Seo, Jeong Kee; Kwan, Jun; Park, Keum Soo; Choe, Wonsick; Lee, Woo Hyung

Abstract

PURPOSE
We evaluated radioisotope and sex-specific differences of normal limits for left ventricle volumes (LVVs) and ejection fraction (EF) using myocardial perfusion gated SPECT (g-SPECT). MATERIALS AND METHODS: Rest Tl-201/post-stress Tc-99m MIBI g-SPECT measurements with acquisitions of 8-frame were evaluated for 70 patients (mean age 55 +/- 14, 56% female) who either had < 10% pretest likelihood of CAD (n = 12) or had normal coronary angiography (EF > 50%) (n = 58). LVEF, LVVs were automatically determined by quantitative gated SPECT using QGS program. RESULTS: Similar results were obtained for mean LVEF between Tc-99m MIBI (62% +/- 7%) and Tl-201 (63% +/- 8%) g-SPECT measurements. In Contrast, Tl-201 g-SPECT had significantly lower LVVs values (EDV; 74 +/- 23 mL, ESV; 28 +/- 14 mL) than Tc-99m MIBI g-SPECT (EDV; 82 +/- 25 mL, ESV; 32 +/- 15 mL) (p< 0.05). Women had significantly lower EDV (Tc-99m MIBI; 71 +/- 18 mL, Tl-201; 65 +/- 17 mL), and ESV values (Tc-99m MIBI; 27 +/- 10 mL, Tl-201; 23 +/- 8 mL) compared with EDV (Tc-99m MIBI; 96 +/- 27 mL, Tl-201; 85 +/- 24 mL), and ESV values (Tc-99m MIBI; 40 +/- 17 mL, Tl-201; 36 +/- 16 mL) of men (p< 0.05). Women had significantly higher LV EF values (65% +/- 7%) than men (60% +/- 8%) by Tl-201 gated SPECT (p< 0.05). CONCLUSION: These data suggest significant differeuces in normal limits for LVVs and EF, according to genders and radiopharmaceutical. Therefore, the evaluation of cardiac function in patients should consider radioisotope and sex-matched normal values.