Mobile head CT can bring imaging to critically ill neurointensive care patients without transport to a radiology department, but bedside scanning requires careful radiation safety management for staff and nearby people. A 2026 assessment published in the British Journal of Radiology evaluated occupational exposure during use of a mobile head CT system with integrated radiation shielding in a neurointensive care unit. The system includes a foldable lead curtain at the front of the gantry opening and a detachable lead shield at the back. Measurements covered scatter radiation, ambient dose, eye lens dose and personal dose during clinical use. The findings support mobile head CT use when shielding, staff positioning and radiation safety training are applied consistently, particularly when personnel remain behind the operator console or away from the gantry.
Integrated Shielding Reduces Scatter
The mobile head CT system used in the neurointensive care unit supports head imaging at the point of care. Its retractable gantry moves during scanning, while the patient remains on the trolley. Integrated neck and head support are included, and the system provides essential settings for head scans. The gantry is shielded, and the additional shielding consists of a front lead curtain and a back lead cover. Bore lighting and a camera allow patient visibility when the frontal cover is closed.
Scatter radiation was measured around the scanner with an ionisation chamber placed at selected positions. These positions reflected practical neurointensive care scenarios, including staff observing from a distance, attending the patient, operating the scan from the console or managing critical equipment behind the gantry. An anthropomorphic whole-body phantom on a patient trolley simulated scatter from a head CT examination.
The shielding reduced scatter radiation by 91% to 99% in most measured directions. The operator console area already had low exposure because the gantry provided protection in that direction. The least protected areas were beside the patient and behind the gantry, although the top of the gantry reduced dose at eye level behind the system. The pattern of scatter also changed during scanning because the gantry moves along the scan length.
Clinical Exposure Stayed Low
Occupational exposure was assessed in a neurointensive care unit at Karolinska University Hospital in Stockholm. Ambient dose and eye lens dose were monitored over three months. Area dosimeters were mounted on walls, while radiology nurses operating the mobile head CT system wore dosimeters on both sides of their protective glasses. None of the area dosimeters exceeded the minimum detectable level of 0.05 mSv. None of the eye lens dosimeters exceeded the minimum detectable level of 0.1 mSv.
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Active personal dosimeters recorded examination-level exposure during 31 adult patient examinations. The operating radiology nurse and the primary attending clinician wore the devices on the chest pocket of their protective aprons. Average personal dose per examination was 0.07 µSv for the operating nurse and 0.03 µSv for the attending clinician. The maximum recorded dose was approximately 1 µSv and occurred on the only occasion when the integrated shielding was not used.
The attending clinician usually left the room during scanning, which contributed to lower measured exposure than for the operator. The operating nurse could further reduce exposure by staying directly behind the operator console. The attending clinician could reduce exposure by remaining behind the console or keeping a considerable distance from the gantry during scanning.
Training Remains Central to Safe Use
The low exposure recorded when the integrated shielding covered the gantry opening indicates that mobile head CT in a neurointensive care unit can be performed without additional personal protective equipment under defined conditions. That conclusion depends on correct use of the shielding and appropriate positioning of staff. The front lead curtain must be placed correctly on the patient, and the back cover must be secured before scanning.
Radiation safety training remains necessary for clinical staff operating the system. Training should cover correct placement of the frontal lead curtain, use of the back cover and the principles of time, distance and shielding. These measures are relevant because bedside CT takes place outside a conventional radiology suite, where clinical staff, nearby patients and relatives could otherwise be exposed.
Dose projections based on the measurements indicate that staff would need to be involved in more than 1000 shielded mobile head CT examinations to reach a cumulative effective dose of 0.1 mSv, assuming consistent practice and routine exposure minimisation. Without integrated shielding, the same threshold would be reached after about 100 examinations. When clinical circumstances prevent use of integrated shielding, protective aprons and leaded eyewear should be considered to keep exposure low.
Mobile head CT with integrated shielding can substantially reduce occupational radiation exposure in a neurointensive care unit. Scatter radiation fell markedly in most measured directions, and passive and active dosimetry showed low exposure during clinical use. The greatest protection comes from combining built-in shielding with staff positioning behind the operator console or away from the gantry. Radiation safety training remains essential, including correct use of the frontal lead curtain and back cover. Under those conditions, additional personal protective equipment may not be required for routine shielded examinations.
Source: British Journal of Radiology
Image Credit: iStock
References:
Hillergren P, Hulthén M, Vorbau R & Omar A (2026) Mobile head CT with integrated radiation shielding reduces the need for additional personal protective equipment. British Journal of Radiology: tqag079.
