Avtor/Urednik		Rep, Sebastijan
Naslov		Analiza testov enakomernosti na SPECT/CT gama kamerah
Prevedeni naslov		Analysis of uniformity tests on SPECT/CT gamma cameras
Tip		članek
Vol. in št.		Letnik 36, št. št 1
Leto izdaje		2019
Obseg		str. 24-30
ISSN		1855-5136 - Bilten: Newsletter of the Society of Radiological Engineers in Slovenia & the Chamber of Radiological Engineers of Slovenia
Jezik		slv
Abstrakt		Introduction: The purpose of quality control is to determine the changes in the functioning of the gamma camera's detector system, which may have a negative impact on the interpretation of nuclear-medical examinations. Many factors contribute to the final quality of the image, including the uniformity of the detector system, the spatial resolution, the energy resolution, collimation, and the sensitivity of the detector system. When using tomography, it is necessary to evaluate additional parameters that may influence the interpretation of nuclear medicine examinations: the centre of rotation, collimator alignment, the stability of the rotation of the detector head, and the integrity of reconstruction algorithms. The time available for the day-to-day implementation of QC tests is limited and needs to be reasonably adjusted to working time. Therefore, the main objective of the programme should be the implementation of QC tests that are most sensitive to changes in the functioning of the imaging system and will most likely affect the nuclearmedicine examination. Purpose: The purpose of the study is to analyse the intrinsic and extrinsic uniformity of gamma cameras and their impact on the image quality. Methods: We performed daily and monthly uniformity tests on Symbia T2 and SPECT/CT Intevo T2 single-photon emission computed tomography/computed tomography (SPECT/CT) systems. On both systems, system daily extrinsic tests were performed automatically with the 153Gd line source. A monthly intrinsic test was performed with 99mTc, with an activity concentration of 0.8 % 20% MBq. We calculated the integral and differential uniformity in the central field of view (CFOV) and the useful field of view (UFOV) for extrinsic and intrinsic uniformity. Results: The results of the extrinsic uniformity tests on SPECT/ CT Symbia T2 showed a statistically significant difference between Detectors 1 and 2 in the integral uniformity of CFOV and UFOV and in the differential uniformity of CFOV (<0.05). The differential uniformity between UFOVs was not statistically significant. In uniformity tests for SPECT/CT Symbia T2, there was no statistically significant difference between integral and differential uniformity in CFOV and UFOV. For SPECT/ CT Intevo T2, extrinsic uniformity tests showed a statistically significant difference between Detectors 1 and 2 in the integral and differential uniformity of CFOV and UFOV (<0.05). Intrinsic uniformity tests at SPECT/CT Intevo T2 showed a statistically significant difference between Detectors 1 and 2 at the differential uniformity of UFOV (<0.05). In other intrinsic uniformity tests, there were no statistically significant diff erences. Conclusion: Uniform tests are essential for ensuring quality and radiation protection for patients. Based on the analysis, we can conclude that the SPECT/CT gamma cameras were in good working condition and could be safely used for diagnostic purposes.
Proste vsebinske oznake		test enakomernosti notranja enakomernost sistemska enakomernost uniformity test internal equilibrium systemic uniformity