Appropriate collimators in a small animal SPECT scanner with CZT detector
- 359 Downloads
Almost all small animal SPECT is performed with pinhole collimators (PH), including single-PH (SPH) and multi-PH (MPH). In the clinical study, not only PH but also parallel-hole collimator (PAH) is often used in planar and SPECT imaging. However, there have been no comparative studies on image quality with various collimators on the small animal imaging. This study compared the basic characteristics of PH and PAH in small animal imaging.
Performance of planar and SPECT images was evaluated using 99mTcO4 − and SPH, MPH and PAH with low energy and high resolution on the SPECT/CT scanner FX3200. We measured sensitivity, resolution, concentration linearity and uniformity. Planar imaging of mice with 99mTc-labeled mercaptoacetyltriglycine (99mTc-MAG3) was performed using SPH and PAH. SPECT imaging with 99mTc-methylene diphosphonate (99mTc-MDP) was performed using all collimators.
With SPH, MPH and PAH, sensitivity was 43.5, 211.2 and 926.5 cps/MBq, respectively, and spatial resolution was 0.60/0.56, non/0.96, 5.20/5.34 mm full-width half maximum (planar/SPECT), respectively. There were marked correlations between the radioactivity counts on images and radioactivity with all collimators. Values of % standard deviation on planar imaging showed small differences between the SPH and PAH, while the values were the smallest on SPECT imaging with MPH. On imaging of mice, SPH yielded high-quality 99mTc-MAG3-planar images when compared with PAH. MPH yielded sharper 99mTc-MDP-SPECT images than SPH and PAH.
The characteristics of PH and PAH differed on small animal imaging. Although sensitivity was higher with PAH, PH showed higher resolution. Among the PH collimators, SPH was more appropriate for planar imaging, and MPH was more suitable for SPECT imaging in a small animal imaging scanner with CZT detector.
KeywordsSmall animal imaging Planar imaging SPECT imaging Pinhole collimator Parallel-hole collimator
The author would like to thank the staff of Chiba University for their technical assistance. This study was partly funded by a Grant-in-Aid for Scientific Research from Japan Society for the Promotion of Science (23659578, 23659579, 24601008, and 24659558).
- 5.Funk T, Parnham KB, Patt BE, Li J, Iwanczyk JS, Iwata K. A new CdZnTe-based gamma camera for high resolution pinhole SPECT. Conf Record IEEE Nucl Sci Symp Med Imag. 2003;4:2320–4.Google Scholar
- 14.Song TY, Choi Y, Chung YH, Jung JH, Min BJ, Hong KJ, et al. Performance amelioration for small animal SPECT using optimized pinhole collimator and image correction technique. IEEE Trans Nucl Sci. 2004;6:3458–62.Google Scholar
- 17.Figueroa SD, Winkelmann CT, Volkert WA, Hoffman TJ. Performance characteristics of an integrated small animal SPECT/CT unit. Conf Record IEEE Nucl Sci Symp Med Imag. 2005;1752–6.Google Scholar
- 20.Arveschoug AK, Bertelsen H, Vammen B. Presurgical localization of abnormal parathyroid glands using a single injection of Tc-99m sestamibi: comparison of high-resolution parallel-hole and pinhole collimators, and interobserver and intraobserver variation. Clin Nucl Med. 2002;27:249–54.PubMedCrossRefGoogle Scholar