title: Pixelized Measurement of (99m)Tc-HDP Micro Particles Formed in Gamma Correction Phantom Pinhole Scan: a Reference Study.
abstract: OBJECTIVE
  Currently, traumatic bone diseases are diagnosed by assessing the micro (99m)Tc-hydroxymethylene diphosphonate (HDP) uptake in injured trabeculae with ongoing osteoneogenesis demonstrated by gamma correction pinhole scan (GCPS). However, the mathematic size quantification of micro-uptake is not yet available. We designed and performed this phantom-based study to set up an in-vitro model of the mathematical calculation of micro-uptake by the pixelized measurement.
  
  
  METHODS
  The micro (99m)Tc-HDP deposits used in this study were spontaneously formed both in a large standard flood and small house-made dish phantoms. The processing was as follows: first, phantoms were flooded with distilled water and (99m)Tc-HDP was therein injected to induce micro (99m)Tc-HDP deposition; second, the deposits were scanned using parallel-hole and pinhole collimator to generally survey (99m)Tc-HDP deposition pattern; and third, the scans underwent gamma correction (GC) to discern individual deposits for size measurement.
  
  
  RESULTS
  In original naïve scans, tracer distribution was simply nebulous in appearance and, hence, could not be measured. Impressively, however, GCPS could discern individual micro deposits so that they were calculated by pixelized measurement. Phantoms naturally formed micro (99m)Tc-HDP deposits that are analogous to (99m)Tc-HDP uptake on in-vivo bone scan. The smallest one we measured was 0.414 mm. Flooded phantoms and therein injected (99m)Tc-HDP form nebulous micro (99m)Tc-HDP deposits that are rendered discernible by GCPB and precisely calculable using pixelized measurement.
  
  
  CONCLUSIONS
  This method can be used for precise quantitative and qualitative diagnosis of bone and joint diseases at the trabecular level.
authors.affiliation: Biomedical Engineering and Research Institute, Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Joo-Young
authors.initials: JY
authors.lastname: Jung
authors.affiliation: Radiopharmaceutical Science Laboratory, Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Gi Jeong
authors.initials: GJ
authors.lastname: Cheon
authors.affiliation: Radiopharmaceutical Science Laboratory, Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yun-Sang
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Radiopharmaceutical Science Laboratory, Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seunggyun
authors.initials: S
authors.lastname: Ha
authors.affiliation: Department of Nuclear Medicine, Sung Ae General Hospital, 22, Yeouidaebang-ro 53-gil, Yeongdeungpo-gu, Seoul, 07354 Korea.
authors.forename: Mi-Hye
authors.initials: MH
authors.lastname: Chae
authors.affiliation: Department of Nuclear Medicine, Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Chung
authors.affiliation: Biomedical Engineering and Research Institute, Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Do Kyun
authors.initials: do K
authors.lastname: Yoon
authors.affiliation: Department of Nuclear Medicine, Sung Ae General Hospital, 22, Yeouidaebang-ro 53-gil, Yeongdeungpo-gu, Seoul, 07354 Korea.
authors.forename: Yong-Whee
authors.initials: YW
authors.lastname: Bahk
keywords: 99mTc–HDP; Gamma correction; Micro deposit; Pinhole scan; Pixelized measurement