Malaysia's mammography QA practice was surveyed based on the Malaysian Ministry of Health and the American College of Radiology (ACR) requirements. Data on mammography unit, processor, image receptor, exposure factors, mean glandular dose (MGD), sensitometry, image quality and viewbox luminance were obtained. Mean developer temperature and cycle time were 34.1 +/- 1.8degreesC and 107.7 +/- 33.2 seconds. Mean base+fog level, speed index and contrast index were 0.20+/-0.01, 1.20+/-0.01 and 1.33+/-0.26 respectively. Eighty-six percent of the fifty centres passed the image quality test while 12.5% complied with ACR recommended viewbox luminance. Average MGD was 1.0+/-0.4 mGy. Malaysia is on the right track for QA but with room for total quality improvement.
The systematic monitoring of image quality and radiation dose is an ultimate solution to ensuring the continuously high quality of mammography examination. At present several protocols exist around the world, and different test objects are used for quality control (QC) of the physical and technical aspects of screen-film mammography. This situation may lead to differences in radiation image quality and dose reported. This article reviews the global QC perspective for the physical and technical aspects of screen-film mammography with regard to image quality and radiation dose. It points out issues that must be resolved in terms of radiation dose and that also affect the comparison.
Rationale and objectives: Target recall rates are often used as a performance indicator in mammography screening programs with the intention of reducing false positive decisions, over diagnosis and anxiety for participants. However, the relationship between target recall rates and cancer detection is unclear, especially when readers are directed to adhere to a predetermined rate. The purpose of this study was to explore the effect of setting different recall rates on radiologist’s performance. Materials and Methods: Institutional ethics approval was granted and informed consent was obtained from each participating radiologist. Five experienced breast imaging radiologists read a single test set of 200 mammographic cases (20 abnormal and 180 normal). The radiologists were asked to identify each case that they required to be recalled in three different recall conditions; free recall, 15% and 10% and mark the location of any suspicious lesions. Results: Wide variability in recall rates was observed when reading at free recall, ranging from 18.5% to 34.0%. Readers demonstrated significantly reduced performance when reading at prescribed recall rates, with lower sensitivity (H=12.891, P=0.002), case location sensitivity (H=12.512, P=0.002) and ROC AUC (H=11.601, P=0.003) albeit with an increased specificity (H=12.704, P=0.002). However, no significant changes were evident in lesion location sensitivity (H=1.982, P=0.371) and JAFROC FOM (H=1.820, P=0.403). Conclusion: In this laboratory study, reducing the number of recalled cases to 10% significantly reduced radiologists’ performance with lower detection sensitivity, although a significant improvement in specificity was observed.