RT Journal Article
SR Electronic
T1 The added value of absolute Tl-201 washout rate in the diagnosis of CAD using a CZT SPECT camera
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1686
OP 1686
VO 57
IS supplement 2
A1 Chi-Lun Ko
A1 Yen-Wen Wu
A1 Mei-Fang Cheng
A1 Ruoh-Fang Yen
YR 2016
UL http://jnm.snmjournals.org/content/57/supplement_2/1686.abstract
AB 1686Objectives Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) is greatly limited by its relative nature, especially in the presence of multi-vessel or diffuse coronary artery disease (CAD). The Tl-201 washout during redistribution may reflect the absolute coronary blood flow reduction from hyperemic state. The aim of this study is to assess the added value of tracer washout rate to MPI in the diagnosis of CAD using a cadmium-zinc-telluride (CZT) SPECT camera.Methods Among 4,258 consecutive patients referred for stress-redistribution Tl-201 MPI, 586 patients (428 men and 158 women) who had no history of myocardial infarction and underwent coronary angiography (CAG) within six months were retrospectively reviewed. A gender-specific normal database was generated from another group of patients with patent coronary arteries documented by CAG. Fully automatic semi-quantification with summed stress score (SSS) from 5-point scale in the 17-segment model was applied. The presence of transient ischemic dilatation (TID) or post-stress ejection fraction (EF) reduction was also recorded. We additionally sampled the whole myocardium without normalization in both post-stress and redistribution images, and the global tracer washout rate (WOR) was calculated with decay correction. The diagnostic performance was assessed by the area under receiver operating characteristics curve (AUC). P-values of less than 0.05 were considered significant.Results In normal database, the WOR was 9.7%±2.9% per hour. In study group, the average WOR was significantly reduced in patients with 1-, 2-, or 3-vessel-disease (WOR=8.3%, 7.7%, and 5.7% per hour, respectively) as compared with patients without significant CAD (WOR=9.4% per hour, all p<0.001). In patients with apparently normal MPI (SSS=0), the WOR significantly identified patients with obstructive CAD (AUC=0.63, p=0.0054) while TID and EF reduction did not (both p>0.1). In this group of patients, the prevalence of obstructive CAD was significantly higher if WOR was reduced (54.7% vs. 30.9%, p=0.0066).Conclusions The quantification of Tl-201 washout rate helps to identify CAD in patients with apparently normal MPI. It may provide additional information in perfusion kinetics and serve as a valuable tool to assist MPI in the diagnosis of CAD.