[Radiation Dose of Body Surface at Sensitive Organs and Its Protective Precaution in Head CT Scanning:Initial Experience.]

OBJECTIVES: To investigate the radiation dose of body surface at sensitive organs using different protective precaution in head CT scanning.

METHODS: The standard phantom received head routine sequence scanning with dual-source computed tomography.The phantoms were scanned with three different protective precaution:group A (without protective clothing),group B (wearing lead collar and cover lead clothes),group C (wearing lead collar and clothes without cuffs).The thermoluminescence dosimeters (TLD) was placed on the body surface corresponding to sensitive organs to measure radiation dose.

RESULTS: The volume of CT dose index (CTDIvol ) and dose length product (DLP) in group A,B and C were same,44.06 mGy and 634 mGy×cm,respectively.There was no statistic significant difference between group A,B and C of radiation dose in non-protective region ( P =0.712).The radiation dose in the neck region under the cover of lead collar in group A,B and C were (2.57 ± 0.65) mGy,(2.30 ± 1.10) mGy and (2.48 ± 0.90) mGy,respectively,without statistic significant difference between groups ( P =0.816).However,the radiation dose in abdominal region of group A was (0.66±0.37) mGy,which was significantly higher than that of group B [(0.18 ± 0.18) mGy] and group C [(0.18±0.16) mGy],The radiation dose in dorsal region of group A was (0.55±0.43) mGy,which was significantly higher than that of group B [(0.28±0.22) mGy],while that of group C [(0.14±0.12) mGy] was significantly lower than group B.

CONCLUSIONS: Compared to traditional lead coverage,lead collar and cloth can decrease the radiation dose of body surface and sensitive organs in head scan with dual source CT.