Abstract
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Objectives Data acquisition of IQ-SPECT (IQS) has been optimized for the US population and needs Japanese specific databases (DBs) for supine, prone and CT-based corrections in a Tl-201 study. The aim of this study was to create a common DB for each condition by Japanese Society of Nuclear Medicine (JSNM) working group and to characterize their distributions.
Methods A total of 149 subjects with low-likelihood of cardiac diseases were selected. Projection data, CT data for attenuation correction (AC) and reconstructed short-axis images were collected from multi-center collaborations according to recommended standard acquisition and reconstruction (OSCGM including collimator modeling) parameters. All the data were analyzed with QPS software.
Results Supine images without AC showed relatively increased count in the apex, 98% in female (F) and 92% in male (M), and lower in the inferior wall in M patients (76%/89% for M/F). The prone position significantly increased inferior counts (83%/93% for M/F). With AC, while the apex showed lower counts (75%/78% for M/F) compared with supine and prone images, the inferior counts were increased in M (99%, p<.0001), and uniform increase in all mid anterior, inferior and lateral segments in F (96-104%, p<.0001-.003). M and F DBs did not differ significantly after AC, and all segments became homogeneous distribution except for the apex.
Conclusions Although prone position can be used to compensate for the inferior attenuation, AC showed a more homogeneous pattern for both genders. Tl-201 study could be indicated with a short-time/low-dose protocol.