Common Artifacts in PET Myocardial Perfusion Images Due to Attenuation–Emission Misregistration: Clinical Significance, Causes, and Solutions
Catalin Loghin, MD1,
Stefano Sdringola, MD2,3 and
K. Lance Gould, MD2
1 Division of Cardiology, Department of Medicine, University of Texas Medical School, Memorial Hermann Hospital, Houston, Texas
2 Weatherhead PET Center for Preventing and Reversing Atherosclerosis, University of Texas Medical School, Memorial Hermann Hospital, Houston, Texas
3 Department of Medicine, Division of Cardiology, University of Texas Medical School, Memorial Hermann Hospital, Houston, Texas
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FIGURE 1. Severe rest perfusion defect. (A) Topographic display. Top panel shows topographic display of unshifted images with artifactual defect due to misregistration of emission and attenuation data. Middle panel shows topographic display of same patient after shifting emission images for optimal coregistration with attenuation image. Bottom panel shows our myocardial perfusion map relating 3D quadrant views of PET images to arterographic anatomy from (4). RI = ramus intermedius; OM1 = first obtuse marginal branch; OM2 = second obtuse marginal branch; LCx = left circumflex artery; D1 = first diagonal branch; D2 = second diagonal branch; RCA = right coronary artery; LAD = left anterior descending (artery). (B) Quantitative analysis of misregistration. Top panel shows rotated transmission images in scanner horizontal longitudinal section before shifting (left) and after shifting emission data (right) with superimposed outline of emission image in same tomographic slice using same rotation angles. Middle panel shows rotated transmission images in scanner vertical longitudinal section before shifting (left) and after shifting emission data (right) with superimposed outline of emission image in same tomographic slice using same rotation angles. Bottom panel shows transmission images (red color) in in-plane acquisition tomographic view using shift software with emission image superimposed (yellow color) before (left) and after shifting emission images (right) showing misregistration area (green) between emission and transmission images.
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FIGURE 2. Severe stress perfusion defect. Legend is the same as Figure 1.
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FIGURE 3. Moderate rest perfusion defect. Legend is the same as Figure 1.
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FIGURE 4. Mild stress perfusion defect. Legend is the same as Figure 1.
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FIGURE 5. Normal cardiac and diaphragmatic motion. Black lines show left heart border during diastole and mediastinal outline during expiration. Red lines show changes in left heart border during systole and mediastinal outline during inspiration.
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FIGURE 6. Mechanisms for attenuation artifacts using resting attenuation scan. Red lines show positions of heart, mediastinum, and diaphragm during data acquisition; dashed red lines indicate mediastinum and diaphragm during standing and on first assuming supine position (left red dashed lines) and later in supine position after abdominal content shift cephalad (right red dashed lines). Black lines show positions of those structures not being imaged during attenuation or emission data acquisition of structures in red. Attn = attenuation; Dipy = dipyridamole.
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FIGURE 7. Mechanisms for attenuation artifacts using postdipyridamole scan. Legend is the same as Figure 6.
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Copyright © 2004 by the Society of Nuclear Medicine.
