Optimisation of scoliosis examinations in children.
OBJECTIVE
To present results of optimising scoliosis examination by changing from a conventional film/grid (F/G) to air-gap technique using computed radiography (CR), and to evaluate different methods for estimating effective radiation doses.


METHODS
Forty-nine children and adolescents were examined with an F/G technique, and 21 with air-gap and CR techniques. Entrance surface doses (ESD) were determined with lithium fluoride thermoluminescence dosimeters. For all patients, the effective radiation doses were determined using a hermaphrodite PCXMC computer program. For all F/G radiographs, the effective doses were also determined according to the NRPB-R279 report, and for 22 children (>9 years and/or >40 kg) also with the ODS-60 program, which allows separate gender calculations. Accumulated doses for 37 children examined more than once with F/G examinations were assessed.


RESULTS
For F/G techniques, the ESDs for both frontal and lateral views varied with age and were significantly correlated to the patients' thickness. The calculated effective doses using the PCXMC program and the NRPB-R279 did not differ significantly for all frontal and lateral radiographs, respectively, but ODS-60 gave significantly higher values in female subjects. With air-gap and CR techniques, the mean effective doses were reduced by a factor over 10. The mean accumulated effective dose for 37 children with a mean of seven F/G examinations was 6.1 mSv, implying a risk of death of about 1:2,000 for boys and at least 1:1,000 for girls.


CONCLUSIONS
Paediatric scoliosis radiography should be considered a specialised procedure, which has to be optimised using a non-grid technique.
Hansen
Jolanta
J
Department of Medical Physics, Aarhus University Hospital, Aarhus Kommunehospital, Aarhus, Denmark.
Jurik
Anne Grethe
AG
Fiirgaard
Bente
B
Egund
Niels
N
D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection; D011859:Radiography / Q000379:methods; D012600:Scoliosis / Q000000981:diagnostic imaging*; D013131:Spine / Q000000981:diagnostic imaging; D013819:Thermoluminescent Dosimetry; D014057:Tomography, X-Ray Computed / Q000379:methods