Abstract:
The study was conducted with the aim to evaluate the performance of three CT scanners in Khartoum Sudan through extensive quality control measurements. Image quality was assessed using a CATPHAN 412 CT image quality Phantom. Image quality parameters evaluated were: CT Image noise, uniformity, CT number linearity, Low Contrast Resolution, High Contrast Resolution. Measurements were performed in accordance with guidelines set out by the Institute of Physical Sciences and Engineering in Medicine (IPEM 91). Image quality parameters tested were within the acceptable limit specified in the relevant CT guidelines. Measured slice thickness 9.9 mm for large slice and 5.2 mm for medium slice. The correlation coefficient (R) between the measured and the reference CT number was better than 0.99 for all CT scanners. High resolution for large slice was 7 LP/ cm and 7 LP/ cm for small slice. The measured noise was 3.2 HU for large slice and 3.9 HU for small slice. Uniformity was -2.4 HU. The results indicate that routine maintenance, service and calibration, as well as the frequent quality control of CT scanners play a key role in achieving the best performance of the system. Since computed tomography (CT) contributes the most to the collective dose compared to other radiological examinations, it is a necessity for quality control and quality assurance programs to be established in each radiology department
