Effects of patient movement on measurements of myocardial blood flow and viability in resting ¹⁵O-water PET studies.
BACKGROUND
Patient movement has been considered an important source of errors in cardiac PET. This study was aimed at evaluating the effects of such movement on myocardial blood flow (MBF) and perfusable tissue fraction (PTF) measurements in intravenous ¹⁵O-water PET.


METHODS
Nineteen ¹⁵O-water scans were performed on ten healthy volunteers and three patients with severe cardiac dysfunction under resting conditions. Motions of subjects during scans were estimated by monitoring locations of markers on their chests using an optical motion-tracking device. Each sinogram of the dynamic emission frames was corrected for subject motion. Variation of regional MBF and PTF with and without the motion corrections was evaluated.


RESULTS
In nine scans, motions during ¹⁵O-water scan (inter-frame (IF) motion) and misalignments relative to the transmission scan (inter-scan (IS) motion) larger than the spatial resolution of the PET scanner (4.0 mm) were both detected by the optical motion-tracking device. After correction for IF motions, MBF values changed from 0.845 ± 0.366 to 0.780 ± 0.360 mL/minute/g (P < .05). In four scans with only IS motion detected, PTF values changed significantly from 0.465 ± 0.118 to 0.504 ± 0.087 g/mL (P< .05), but no significant change was found in MBF values.


CONCLUSIONS
This study demonstrates that IF motion during ¹⁵O-water scan at rest can be source of error in MBF measurement. Furthermore, estimated MBF is less sensitive than PTF values to misalignment between transmission and ¹⁵O-water emission scans.
Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan. koshino@ri.ncvc.go.jp
Kazuhiro
K
Koshino
Hiroshi
H
Watabe
Junichiro
J
Enmi
Yoshiyuki
Y
Hirano
Tsutomu
T
Zeniya
Shinji
S
Hasegawa
Takuya
T
Hayashi
Shigeru
S
Miyagawa
Yoshiki
Y
Sawa
Jun
J
Hatazawa
Hidehiro
H
Iida
D000328:Adult; D016477:Artifacts; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D006801:Humans; D008297:Male; D009038:Motion; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055414:Myocardial Perfusion Imaging / Q000379:methods; D010104:Oxygen Radioisotopes; D056888:Patient Positioning / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014022:Tissue Survival; D014867:Water; D055815:Young Adult
D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water