Department of Otolaryngology, Xiamen Branch, Zhongshan Hospital, Fudan University, No. 668 JinHu Road, Xiamen, China.
Radiol Med. 2021 Jan;126(1):47-54. doi: 10.1007/s11547-020-01227-6. Epub 2020 May 26.
Cone beam CT dacryocystography (CBCT-DCG) is a new imaging technique for assessing the lacrimal drainage system (LDS). The purpose of this pilot study is to compare the diagnostic capability and radiation dose of CBCT-DCG in different scanning fields of view (FOV) to evaluate the possibilities of the reduction of radiation dose.
Fifteen healthy volunteers underwent CBCT-DCG in an upright position. The first five subjects were scanned using the scanning FOV of 11 × 10 cm (Group A), then 8 × 8 cm (Group B), and the last five subjects 5 × 5.5 cm (Group C). The image quality and diagnostic validity of different groups were evaluated by two experienced otolaryngologists. The effective dose of each group was calculated and compared.
All images showed good delineation of the LDS and its surrounding structures. With regard to the image quality and diagnostic validity, no differences were found among different groups. Compared with Group A, the effective radiation dose for Group B (38.40 μSv) was 38.54% lower and that for Group C (17.12 μSv) was 72.60% lower.
A substantial reduction of the effective dose for CBCT-DCG in healthy volunteer by decreasing FOV is possible without compromising the diagnostic capability. CBCT-DCG is a potential valid first-line imaging test for the evaluation of LDS, and it permits functional assessment of lacrimal drainage.
锥形束 CT 泪道造影术（CBCT-DCG）是一种用于评估泪液排出系统（LDS）的新型成像技术。本研究旨在比较不同视野（FOV）下 CBCT-DCG 的诊断能力和辐射剂量，以评估降低辐射剂量的可能性。
15 名健康志愿者采用直立位进行 CBCT-DCG。前 5 例采用 11×10cm 的扫描 FOV（A 组），然后是 8×8cm（B 组），最后 5 例是 5×5.5cm（C 组）。两位经验丰富的耳鼻喉科医生评估不同组的图像质量和诊断有效性。计算并比较各组的有效剂量。
所有图像均清晰显示 LDS 及其周围结构。关于图像质量和诊断有效性，各组之间无差异。与 A 组相比，B 组（38.40μSv）的有效辐射剂量降低了 38.54%，C 组（17.12μSv）降低了 72.60%。
通过降低 FOV 可显著降低健康志愿者 CBCT-DCG 的有效剂量，而不影响诊断能力。CBCT-DCG 是评估 LDS 的一种有潜力的有效一线成像检查方法，可对泪液引流进行功能评估。
