Article Figures & Data
Figures
- FIGURE 1.
Gated myocardial perfusion SPECT images of 67-y-old woman for whom echocardiographic measurements were 110 mL for ESV, 29 mL for EDV, and 73% for LVEF. (A) Conventional SPECT with QGS: EDV, 60 mL; ESV, 9 mL; and LVEF, 86%. (B) IQ•SPECT with QGS: EDV, 49 mL; ESV, 4 mL; and LVEF, 92%. (C) Conventional SPECT with cardioREPO: EDV, 71 mL; ESV, 12 mL; and LVEF, 84%. (D) IQ•SPECT with cardioREPO: EDV, 70 mL; ESV, 15 mL; and LVEF, 78%. HLA = horizontal long axis; SA = short axis; VLA = vertical long axis.
- FIGURE 2.
Average myocardial counts per pixel as measured from 45° left anterior oblique projection on conventional SPECT (A) and IQ•SPECT (B).
- FIGURE 3.
Bland–Altman analysis of LVEF on conventional SPECT with QGS vs. IQ•SPECT with QGS (A); conventional SPECT with QGS vs. echocardiography (B); IQ•SPECT with QGS vs. echocardiography (C); conventional SPECT with cardioREPO vs. IQ•SPECT with cardioREPO (D); conventional SPECT with cardioREPO vs. echocardiography (E); and IQ•SPECT with cardioREPO vs. echocardiography (F). Gray lines are mean ± 1.96 SD. Black lines are linear regression lines.
- FIGURE 4.
Myocardial perfusion SPECT images showing normal findings in 85-y-old man. (A) Conventional SPECT. (B) IQ•SPECT without attenuation or scatter correction. (C) IQ•SPECT with attenuation and scatter correction. HLA = horizontal long axis; SA = short axis; VLA = vertical long axis.
- FIGURE 5.
Myocardial perfusion SPECT images showing perfusion defect in inferolateral wall of 66-y-old man. (A) Conventional SPECT. (B) IQ•SPECT without attenuation or scatter correction. (C) IQ•SPECT with attenuation and scatter correction. (D) Invasive coronary angiography showing stenosis of left circumflex coronary artery (arrow), supporting the SPECT findings.
Tables
Characteristic Finding Mean age ± SD (y) 72.5 ± 9.4 (range, 28–88) Sex (n) Male 77 (78.6%) Female 21 (21.4%) Mean body mass index ± SD 23.5 ± 3.1 (range, 16.4–32.8) Mean body height ± SD (cm) 161.1 ± 9.4 (range, 134–189) Mean body weight ± SD (kg) 61.7 ± 11.3 (range, 37–93.2) Tracer (n) Sestamibi 2 (2%) Tetrofosmin 96 (98%) Main risk factors (n) Obesity (body mass index > 25) 30 (30.6%) Diabetes mellitus 10 (10.2%) Abdominal aortic aneurysm 37 (37.8%) Thoracic aortic aneurysm 24 (24.5%) Angina pectoris 10 (10.2%) Arteriosclerosis obliterans 9 (9.2%) Previous coronary artery bypass surgery 5 (5.1%) Aortic dissection 5 (5.1%) Common iliac artery aneurysm 3 (3.1%) Abnormal electrocardiographic pattern 2 (2.0%) Renal artery aneurysm 1 (1.0%) Hepatic artery aneurysm 1 (1.0%) Aortic valve stenosis 1 (1.0%) Parameter Conventional SPECT IQ•SPECT Reconstruction algorithm Filtered backprojection OSCGM Collimator LEHR SMARTZOOM Energy window 140 keV ± 7.5% 140 keV ± 7.5% Number of projections 60 views (30 per detector) 34 views (17 per detector) Rotation range 360° 208° Acquisition time (min) 20 (35 s per projection) 5 (9 s per projection) Magnification ×1.45 ×1.00 Rotation radius (cm) 24–25 28 Number of iterations QGS: 30, QPS: 10 Number of subsets QGS: 1, QPS: 3 Updates 30 Gaussian filter (mm) 9.6 Butterworth filter (cycles/cm) QGS: 0.39, QPS: 0.52 Matrix 64 × 64 128 × 128 Pixel size (mm) 6.6 4.8 LEHR = low-energy high-resolution; OSCGM = ordered-subset conjugate gradient minimization.
- TABLE 3
Comparison of EDV, ESV, and LVEF for Conventional SPECT, IQ•SPECT, and Echocardiography
Parameter Conventional IQ Echo Conventional vs. IQ Conventional vs. echo IQ vs. echo QGS EDV (mL) 77.0 ± 39.1 74.2 ± 36.8 110.6 ± 38.3 r = 0.98 r = 0.77 r = 0.77 ESV (mL) 30.0 ± 29.2 27.4 ± 27.3 40.6 ± 26.7 r = 0.97 r = 0.81 r = 0.82 LVEF (%) 65.4 ± 13.8 68.4 ± 15.2 64.8 ± 11.6 r = 0.86 r = 0.63 r = 0.64 CardioREPO EDV (mL) 87.9 ± 35.6 82.8 ± 34.0 110.6 ± 38.3 r = 0.98 r = 0.77 r = 0.75 ESV (mL) 28.1 ± 22.6 27.0 ± 22.4 40.6 ± 26.7 r = 0.98 r = 0.78 r = 0.77 LVEF (%) 69.5 ± 10.6 69.5 ± 11.0 64.8 ± 11.6 r = 0.80 r = 0.60 r = 0.65 QGS (%) All LVEF 65.4 ± 13.8 68.4 ± 15.2 64.8 ± 11.6 P = 0.0002 NS P = 0.019 Small-heart LVEF 75.0 ± 9.6 79.5 ± 8.3 70.1 ± 6.8 P = 0.0005 P = 0.0076 P < 0.0001 CardioREPO (%) All LVEF 69.5 ± 10.6 69.5 ± 11.0 64.8 ± 11.6 NS P < 0.0001 P < 0.0001 Small-heart LVEF 72.3 ± 9.0 74.3 ± 8.3 70.1 ± 6.8 NS NS P = 0.0068 Conventional = conventional SPECT; echo = echocardiography; IQ = IQ•SPECT; NS = not statistically significant.
Data are mean ± SD.
