Effects of pacemaker, implantable cardioverter-defibrillator, and left ventricular leads on CT-based attenuation correction.
CT-based attenuation correction (CTAC) of myocardial SPECT images has been becoming more popular--and the application of SPECT/CT increasing--because it prevents attenuation-induced image degradation. However, CTAC can be affected by overestimation of counts caused by metals. It is possible that pacemaker, left ventricle (LV), and implantable cardioverter-defibrillator (ICD) leads have an influence on myocardial SPECT findings. The present study investigated the impact of these leads on SPECT with CTAC.


METHODS
Pacemaker, LV, and ICD leads were examined using a simple phantom and a cardiac phantom. The effects of metal artifacts from leads in high-resolution mode and ultra-high-resolution mode were assessed using a simple phantom. Images and polar maps were generated from the cardiac phantom.


RESULTS
The pacemaker and LV leads essentially had no influence, whereas the ICD lead resulted in maximal (6%) overestimation in a study investigating which metals cause artifacts that affect CTAC. None of the leads seriously influenced CTAC when the cardiac phantom was used.


CONCLUSIONS
Small pacemaker or ICD and LV leads will cause a slight overestimation, but CTAC should be used because it can correct attenuation of the inferior and anteroseptal walls on SPECT images.
Diagnostic Imaging Center, Japanese Red Cross Sendai Hospital, Miyagi, Japan.
Akira
A
Suzuki
Kichiro
K
Koshida
Kosuke
K
Matsubara
D016477:Artifacts; D017147:Defibrillators, Implantable; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D010138:Pacemaker, Artificial; D019047:Phantoms, Imaging; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed
CTAC; SPECT/CT; myocardial perfusion; pacemaker