The effect of breast shielding outside the field of view on breast entrance surface dose in axial X-ray examinations: a phantom study

• Published in: Diagnostic and interventional radiology (Ankara, Turkey) Turkey), 2023-05, Vol.29 (3), p.555-560
• Main Authors: Hurley, Lauren, Alashban, Yazeed, Albeshan, Salman, England, Andrew, McEntee, Mark F
• Format: Article
• Language: English
• Subjects: anthropomorphic phantom; Breast; entrance surface dose; field of view; Health aspects; Humans; Lumbar Vertebrae; Methods; Phantoms, Imaging; Physiological aspects; Radiation Dosage; Radiation dosimetry; Radiography; Radiology Physics - Original; shielding; Thorax; wraparound lead; X-Rays
• ISSN: 1305-3825; 1305-3612
• DOI: 10.4274/dir.2023.232126

The purpose of this study was to evaluate the effect of outside-field-of-view (FOV) lead shielding on the entrance surface dose (ESD) of the breast on an anthropomorphic X-ray phantom for a variety of axial skeleton X-ray examinations. Using an anthropomorphic phantom and radiation dosimeter, the ESD of the breast was measured with and without outside-FOV shielding in anterior-posterior (AP) abdomen, AP cervical spine, occipitomental 30° (OM30) facial bones, AP lumbar spine, and lateral lumbar spine radiography. The effect of several exposure parameters, including a low milliampere-seconds technique, grid use, automatic exposure control use, wraparound lead (WAL) use, trolley use, and X-ray table use, on the ESD of the breast with and without outside-FOV shielding was investigated. The mean ESD (μSv) and standard deviation for each radiographic protocol were calculated. A one-tailed Student's t-test was carried out to evaluate whether ESD to the breast was reduced with the use of outside-FOV shielding. A total of 920 breast ESD measurements were recorded across the different protocol parameters. The largest decrease in mean ESD of the breast with outside-FOV shielding was 0.002 μSv ( = 0.084), recorded in the AP abdomen on the table with a grid, OM30 on the table with a grid, OM30 standard protocol on the trolley, and OM30 on the trolley with WAL protocols. This decrease was found to be statistically non-significant. This study found no significant decrease in the ESD of the breast with the use of outside-FOV shielding for the AP abdomen, AP cervical spine, OM30 facial bones, AP lumbar spine, or lateral lumbar spine radiography across a range of protocols.