Pixelized Measurement of 99mTc-HDP Micro Particles Formed in Gamma Correction Phantom Pinhole Scan: a Reference Study

• Published in: Nuclear medicine and molecular imaging Vol. 50; no. 3; pp. 207 - 212
• Main Authors: Jung, Joo-Young, Cheon, Gi Jeong, Lee, Yun-Sang, Ha, Seunggyun, Chae, Mi-Hye, Chung, Yong-An, Yoon, Do Kyun, Bahk, Yong-Whee
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2016; 대한핵의학회
• Subjects: Cardiology; Imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Oncology; Original; Original Article; Orthopedics; Radiology; 방사선과학; Pinhole scan; Pixelized measurement; Micro deposit; Gamma correction; Tc–HDP
• ISSN: 1869-3474; 1869-3482
• DOI: 10.1007/s13139-015-0391-8

Purpose 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.