Radiation dose optimisation for conventional imaging in infants and newborns using automatic dose management software: an application of the new 2013/59 EURATOM directive

Effect of varying X-ray tube voltage and additional filtration on image quality and patient dose in digital radiography system

This study investigated the effect of varying x-ray tube voltage and additional filtration thicknesses on radiation dose and image quality in digital radiography system. The polymethylmethacrylate (PMMA) phantoms of different thicknesses simulating both the adult chest and abdomen and the pediatric patient's chest examinations were used. X-ray tube voltage range of 70-125 kVp was used for adult patient chest radiography, 70-100 kVp for adult patient abdominal radiography, and 50-70 kVp for pediatric 1-year-old chest examination. 0.1-0.3 mm Cu and 1.0 mm Al filters were used as additional filters. Patient doses were measured with an ionization chamber, considering the irradiation parameters recommended for radiographic examinations performed in radiology clinics in the EUR 16260 protocol. The Entrance Skin Dose (ESD) was calculated from the air kerma value measured at the entrance surface of the PMMA phantoms. Effective dose values were calculated by employing PCXMC 2.0 program. For image quality evaluations, CDRAD, LCD-4, Beam stop and Huttner test object used together with PMMA phantoms and Alderson RS-330 Lung/Chest phantom were used. Figure of Merit (FOM), which allows quantitative assessment in terms of image quality and patient dose, has been calculated. Based on the calculated FOM values were evaluated at the tube voltages and additional filter thicknesses recommended in the EUR 16260 protocol. Entrance Skin Dose and Inverse Image Quality Figure (IQF_inv) value obtained from contrast detail analysis decreased with increasing filter thickness and tube voltage. Decrease in ESD and IQF_inv with increasing tube voltage without additional filter was 56% and 21% for adult chest radiography, 69% and 39% for adult abdominal radiography and 34% and 6% for 1-year-old pediatric chest radiography. When calculated FOM values are examined, it can be recommended to use a 0.1 mm Cu filter at 90 kVp and a 0.1 mm Cu + 1.0 mm Al filter at 125 kVp for adult chest radiography. For adult abdominal radiography, 0.2 mm Cu filter at 70 and 80 kVp and 0.1 mm Cu filter at 90 and 100 kVp were found to be appropriate. It was determined that the appropriate additional filter at 70 kVp for 1-year-old chest radiography was 1.0 mm Al+0.1 mm Cu.

Prevalence of Enthesopathies in Adults With X-linked Hypophosphatemia: Analysis of Risk Factors

CONTEXT

Enthesopathies are the determinant of a poor quality of life in adults with X-linked hypophosphatemia (XLH).

OBJECTIVE

To describe the prevalence of patients with enthesopathies and to identify the risk factors of having enthesopathies.

METHODS

Retrospective study in the French Reference Center for Rare Diseases of the Calcium and Phosphate Metabolism between June 2011 and December 2020. Adult XLH patients with full body X-rays performed using the EOS® low-dose radiation system and clinical data collected from medical records. The main outcome measures were demographics, PHEX mutation, conventional treatment, and dental disease with the presence of enthesopathies.

RESULTS

Of the 114 patients included (68% women, mean age 42.2 ± 14.3 years), PHEX mutation was found in 105 patients (94.6%), 86 (77.5%) had been treated during childhood. Enthesopathies (spine and/or pelvis) were present in 67% of the patients (n = 76). Patients with enthesopathies were significantly older (P = .001) and more frequently reported dental disease collected from medical records (P = .03). There was no correlation between the PHEX mutations and the presence of enthesopathies. Sixty-two patients had a radiographic dental examination in a reference center. Severe dental disease (number of missing teeth, number of teeth endodontically treated, alveolar bone loss, and proportion of patients with 5 abscesses or more) was significantly higher in patients with enthesopathies.

CONCLUSION

Adult XLH patients have a high prevalence of enthesopathies in symptomatic adults patients with XLH seen in a reference center. Age and severe dental disease were significantly associated with the presence of enthesopathies.

Estimation of dose and cancer risk to newborn from chest X-ray in South-South Nigeria: a call for protocol optimization

Background

The use of X-ray as a diagnostic tool for complication and anomaly in the neonatal patient has been helpful, but the effect of radiation on newborn stands to increase their cancer risk. This study aims to determine the mean, 50th percentile (quartile 2 (Q2)), and 75th percentile (quartile 3 (Q3)) entrance surface dose (ESD) from anteroposterior (AP) chest X-ray and to compare our findings with other relevant studies. The study used calibrated thermoluminescent dosimeters (TLDs), which was positioned on the central axis of the patient. The encapsulated TLD chips were held to the patients’ body using paper tape. The mean kilovoltage peak (kVp) and milliampere seconds (mAs) used was 56.63(52–60) and 5.7 (5–6.3). The mean background TLD counts were subtracted from the exposed TLD counts and a calibration factor was applied to determine ESD.

Results

The mean ESDs of the newborn between 1 and 7, 8 and 14, 15 and 21, and 22 and 28 days were 1.09 ± 0.43, 1.15 ± 0.50, 1.19 ± 0.45, and 1.32 ± 0.47 mGy respectively. A one-way ANOVA test shows that there were no differences in the mean doses for the 4 age groups (P = 0.597). The 50th percentile for the 4 age groups was 1.07, 1.26, 1.09, and 1.29 mGy respectively, and 75th percentile were 1.41, 1.55, 1.55, and 1.69 mGy respectively. The mean effective dose (ED) in this study was 0.74 mSv, and the estimated cancer risk was 20.7 × 10−6.

Conclusion

ESD was primarily affected by the film-focus distance (FFD) and the patient field size. The ESD at 75th percentile and ED in this study was higher compared to other national and international studies. The estimated cancer risk to a newborn was below the International Commission on Radiological Protection (ICRP) limit for fatal childhood cancer (2.8 × 10−2Sv−1).

REDUCING PELVIS RADIOGRAPH EXPOSURE IN CHILDREN USING A DOSE SIMULATION X-RAY RESEARCH SOFTWARE

Pelvis radiography is a frequent X-ray examination. The objective of our study was to determine the minimum dose to be delivered without reducing the quality. We included 60 children having a pelvis X-ray in four groups that were equally represented by weight ranges. A software simulated, for each radiograph, six additional simulated photonic noise images corresponding to 100, 80, 64, 50, 40 and 32% of the initial dose. The 360 radiographs were blindly scored by two radiologists using a semi-quantitative Likert scale. There was no significant difference in scoring between the reference radiograph and simulated radiographs at 80% of the dose in children between 0 and 15 kg and over 35 kg. Inter-observer reproducibility was moderate to very good. Pelvis X-ray doses might be reduced by 20% in children in our institution. Software that produces simulated X-ray with decreasing dose might be a useful tool for an optimization process.

A Dose Simulation X-Ray Software: An Innovating Tool to Reduce Chest Radiograph Exposure in Children

PURPOSE

Chest radiography is one of the most frequent x-ray examinations performed on children. Reducing the delivered dose is always a major task. The objective of our study was to determine the minimum dose to be delivered while maintaining the image quality of chest radiographs, using dose reduction simulation software.

MATERIALS AND METHODS

We included 60 children who had had a chest radiography in 5 groups established according to the diagnostic reference levels equitably represented by weight ranges. The software simulated for each radiograph 6 additional simulated photonic noise images corresponding to 100%, 80%, 64%, 50%, 40%, and 32% of the initial dose. The 360 radiographs were blindly scored by 2 radiologists, according to the 7 European quality criteria and a subjective criterion of interpretability, using a semiquantitative visual Lickert scale.

RESULTS

There was no significant difference in scoring between the reference radiograph (100%) and simulated radiographs at 80% of the dose in children between 5 and 20 kg, 50% of the dose in children between 20 and 30 kg, and between simulated radiographs at 40% of the dose in children over 30 kg. Interobserver reproducibility was moderate to excellent.

CONCLUSION

Chest radiography dose might be reduced by 20% in children between 5 and 20 kg, 50% in children between 20 and 30 kg, and 60% in children over 30 kg, without any difference in the image quality appreciation. Software that produced simulated x-ray with decreasing delivered dose is an innovating tool for an optimization process.