title: Appropriate collimators in a small animal SPECT scanner with CZT detector.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Performance of planar and SPECT images was evaluated using (99m)TcO4(-) 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 (99m)Tc-labeled mercaptoacetyltriglycine ((99m)Tc-MAG3) was performed using SPH and PAH. SPECT imaging with (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) was performed using all collimators.
  
  
  RESULTS
  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 (99m)Tc-MAG3-planar images when compared with PAH. MPH yielded sharper (99m)Tc-MDP-SPECT images than SPH and PAH.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Graduate School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa 920-0942, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Higaki
authors.forename: Masato
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Tomoya
authors.initials: T
authors.lastname: Uehara
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hanaoka
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Arano
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawai
mesh_terms: D000818:Animals; D002104:Cadmium; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D051379:Mice; D019047:Phantoms, Imaging; D013669:Technetium Tc 99m Medronate; D017263:Technetium Tc 99m Mertiatide; D013691:Tellurium; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation*; D015032:Zinc
chemical_list: C474490:CdZnTe; D002104:Cadmium; D017263:Technetium Tc 99m Mertiatide; D015032:Zinc; D013691:Tellurium; D013669:Technetium Tc 99m Medronate