Application of upper limbs-raised position in CT examination of airway foreign body in children / 中华放射医学与防护杂志

ABSTRACT

Objective To confirm the effect of the relative position between upper limbs and cervicothoracic vertebrae on image quality and radiation dose while performing airway CT examination of children with airway foreign bodies. Methods One hundred and three children, aged from 1 to 48 months were enrolled prospectively and divided into 3 groups according to the position of upper limbs. In group A, the upper limbs were raised beside the cervical vertebra, in group B, the upper limbs were placed beside the thoracic vertebra, and in group C, the upper limbs were raised about 45 degrees with sponge pads and placed beside the chest. Data were acquired by Philips 128iCT, and CT dose index (CTDIvol ) and dose-length product ( DLP ) were recorded and compared among three groups. The image qualities were evaluated subjectively and objectively. Results Subjective score of cervical image quality in group B (4. 33±0. 72) and group C (4. 19± 0. 63) were higher than that in group A (3. 71 ± 0. 66), and the difference was statistically significant (Z = -3. 19、 -2. 61, P<0. 05) . Subjective score of chest image quality in group A (4. 21±0. 47) was higher than that in group B (3. 71± 0. 39) and group C (3. 92± 0. 42), and group C was higher than that in group B, the difference was statistically significant ( Z =-1. 71, -2. 08, P<0. 05). The difference of DLP in group B (57. 7±6. 8) mGy·cm was higher than that in group A (51. 6±7. 6) mGy·cm and group C (51. 3±6. 3) mGy·cm, the difference was statistically significant (P<0. 05), and there was no significant difference between group A and group C (P>0. 05). Conclusions Raising upper limbs 45 degrees and placing them beside the chest will improve the CT image quality of airway and reduce the radiation dose.