[Doses to adult patients from computed tomography examinations]

The observed increasing number of computed tomography (CT) examinations and the fact that the doses absorbed in tissues from CT are among the highest in diagnostic radiology show that special attention has to be paid to the optimization of patient protection. The first step in that direction is the assessment of doses delivered to the patients, therefore, this issue was the aim of the presented study. MATERIALS AD METHODS: The study was conducted in one of the major hospitals in Lodz on one CT scanner. The effective doses and the organ doses to eye lens, thyroid and gonads were assessed for the most common examinations of head, chest and abdomen in adult patients.

The highest effective doses were received from abdomen (9.7-75.6 mSv) and the lowest from sinuses (0.6-1.1 mSv) examinations. For the head, neck and chest examinations the doses ranged from 0.9 to 3.1 mSv from 4.6 to 11.8 mSv and from 3.7 to 27.2 mSv, respecvtively. As regards organ doses the highest (10.6-25.5 mGy) doses to the eye lens were received from CT head examination, to thyroid (8.7-41.8 mGy) from chest and to gonads (1.5-36.5 mGy) from abdomen examinations.

The doses vary significantly even for the same type of examination. Although in some examinations the average effective dose is relatively low, e.g., about 2 mSv (for the head) the absorbed dose to the eye lens can be higher (26 mGy), which might be relevant in repeated or pediatric examinations.