Radiation protection of patients in cranial computed tomography (gantry tilt)

CT scanning of the cranium (cranial computed tomography – CCT) is the cross-sectional imaging technique most commonly used for diagnostic purposes in the majority of hospitals and medical practices. It is also the CT scanning technique which results in the highest local doses. For that reason, the German Medical Association (Bundesärztekammer - BÄK) called for particular attention to be paid to the protection of the eye lens by means of gantry tilt and adjustment of the scan range in its 2007 Guidelines on quality assurance for CT scanning.

Due to the development of new multi-detector spiral CT scanners (MDCT) with wide detector arrays, the eye lens increasingly is directly exposed by “overranging” and “overbeaming”. Some new MDCT scanners no longer allow tilting of the gantry. These technical developments as well as new published data on the radiosensitivity of the eye lens, with a much higher risk of cataract formation than previously assumed, have prompted the Commission on Radiological Protection to recommend measures which avoid direct exposure of the eye lens and hence allowing a dose reduction of up to 90 percent. These specific measures to protect the lens of the eye should be integrated into existing standard operating procedures (SOP). Manufacturers of MDCT scanners are called on to provide technical options for a prevention or reduction of overranging. In addition to the scan area, MDCT scanners should display the exposed area, including overranging and overbeaming.

This recommendation complements the BÄK guidelines of 2007 and strengthens the position of the auditing bodies (Ärztlichen Stellen) in the context of their periodic reviews as part of quality assurance in CT scanning.

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URN: urn:nbn:de:101:1-2013111816647
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URN: urn:nbn:de:101:1-2013112510402