Experimental evaluation of a multi-pinhole collimator for a small organ by using a small-field-of-view gamma camera

Jaekeon Bae, Seungbin Bae, Young Jun Jung, Kisung Lee, Yongkwon Kim, Jinhun Joung, Kyeong Min Kim, Hee Joung Kim

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


The aim of this study is to design and evaluate a multi-pinhole (MP) collimator for a gamma imaging system that requires a high sensitivity, organ-specific, and small footprint. To ensure these requirements, we designed an eight-hole collimator that can be integrated into a small field-of-view gamma camera for imaging the thyroid or relatively sized organs. Each pinhole was designed to have a cylindrical shape with a 2-mm diameter. Experiments were performed with both a two-sphere phantom and a four-rod phantom. An image reconstruction based on the maximum likelihood expectation maximization with the distance-driven method was used for obtaining a 3-dimensional image. For improving the uniformity of the reconstruction image, we modeled the sensitivity of the cylindrical pinhole by calculating the area of the overlapped circle. The results show that the full width at half maximum values of the two-sphere phantom and the four-rod phantom were 7.56 mm (5-mm-diameter source) and 6.84 mm (5-mm-diameter rod), respectively. The scanning time can be reduced by up to 20 minutes in small-organ applications by using developed MP collimator. Thus, the results indicate that the proposed MP collimator is suitable for a fast scan time, as well as for organ-specific and small-footprint applications.

Original languageEnglish
Pages (from-to)416-423
Number of pages8
JournalJournal of the Korean Physical Society
Issue number4
Publication statusPublished - 2017 Feb 1


  • Collimator modeling
  • Experimental data
  • Image reconstruction
  • Multi-pinhole collimator
  • Single-photon emission computed tomography

ASJC Scopus subject areas

  • General Physics and Astronomy


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