Children have higher radiation sensitivity than adults and have a longer life expectancy. Therefore, imaging techniques that do not use ionizing radiation should always be considered as an alternative. Increasing numbers of radiological examinations are being performed in infants and children. Millions of children undergo high dose procedures such as computed tomography and interventional procedures. A paediatric radiological procedure should be individually planned and projections should be limited to what is absolutely necessary for a diagnosis.
CT and interventional procedures are high dose procedures in radiology and yield higher individual patient doses than other radiological procedures do. The patient dose in CT is an important issue for children as reports suggest that in some centres the exposure factors used for scanning children are the same as for adults. This problem is relatively lesser in interventional procedures as the machine, on the basis of the body thickness falling in the X ray beam, automatically adjusts factors in most modern equipment. CT scanning contributes most to collective dose from radiographic exposures due to the increasing use of this modality. It has been reported that 30% of adults and children have three or more CT scans [METTLER, F.A., et al., CT scanning: Patterns, use and dose, J. Radiol. Prot. 20 4 (2000) 353-359].
The short answer is YES. Specific actions include the following:
Further details are available in [EUR 16261].
In general, digital detectors offer the possibility of dose reduction in a similar way as is done in adult radiography. It should be emphasized that while with screen-film combinations overexposure may result in a non-diagnostic image, overexposure using digital detectors may not be as readily recognized as it may result in acceptable quality image. Increased dose in digital imaging can also be caused by re-exposure by technologists not being detected (in most systems currently available), ease and convenience with which images can be taken thus leading to covering a larger area of a patient's body or repeating the examination. Whereas it is possible to have dose reduction, many studies indicate that in actual practice, more so where optimization is lacking, there is increase in patient dose. Further details are available elsewhere on this Website and in [ICRP 93].
The general answer is NO.
An image recorded on film with a high-speed cassette provides a permanent record that can cover the necessary area, e.g. leg, spine. However, when high image detail is not required, for example in follow-up examinations in patients with scoliosis, leg length discrepancy, a stored pulsed fluoroscopic image using last-image-hold may be satisfactory.
Typical values of Entrance Surface Dose (ESD) per radiograph and Dose Area Product (DAP) for common paediatric fluoroscopy examinations are given in Table 1.
Table 1. Typical dose levels in paediatric radiology [NRPB-W14]
|Examination||Entrance surface dose (µGy)|
|Dose area product (mGy.cm2)|
Many actions are similar to those recommended in adult procedures:
The short answer is YES.
When performing radiographs of long bones in children the opposite limb should be imaged if needed by the radiologist and only limited views used. In chest radiographic examination a lateral projection may not be required routinely. When a follow-up examination is justified the number of projections should be restricted to evaluate previous findings [BSS II.16(b).i]. Lumbar spine for follow-up and sometimes for regular examination is an example with too many projections like AP, lateral, obliques, and L5-S1 spot film.
The necessary information on possible pregnancy should be obtained from the patient herself. Further details are available. In female children who are menstruating and are referred for high dose procedures such as CT abdomen or interventional examination, the possibility of pregnancy should be considered.
The recommended actions are:
Strategies should include obtaining only necessary CT examinations. MRI and US should take priority. If possible, the examination should be tailored to answer the specific question asked by the referring clinician, for example pelvic scanning is not always necessary when an abdominal scan is requested and it maybe possible to curtail follow-up CT exams to a specific organ. In addition, imaging parameters such as kVp and mAs need to be adjusted for patient size. Size-based tables for abdominal multidetector CT and body CT angiography in children are available [FRUSH, D.P., Review of radiation issues for computed tomography, Seminars in Ultrasound, CT and MRI, 25 1 (2004) 17-24]. In one study, children were classified by colours based on weight and this was shown to significantly reduce scanning errors in settings for paediatric multi-detector CT [FRUSH, D.P., et al., Improved paediatric multi-detector CT using a size-based color-coded format, Am. J. Roentgenol. 178 3 (2002) 721-726].
Recent technology developments include automatic tube current modulation where the tube current is adjusted according to thickness and density of tissues to maintain a constant level of image noise.
Finally, the use of multiphase scanning should be curtailed as much as possible.
As a general principle, the BSS require that parents or family members rather than staff in the radiology facility, should support the child during any radiological examination. And, when parents or family members support the child during the examination, they should be provided with appropriate shielding [BSSII-3.173].