Patient and staff dosimetry during radiographic procedures in an intensive care unit

Scatter Radiation Distribution to Radiographers, Nearby Patients and Caretakers during Portable and Pediatric Radiography Examinations

Scatter radiation from portable and pediatric X-rays could pose a risk to radiographers, nearby patients, and caretakers. We aim to evaluate the spatial scatter radiation distribution to the radiographers, nearby patients, and caretakers during common projections in portable and pediatric X-rays. We evaluated the three-dimensional scatter dose profiles of four and three commonly used portable and pediatric X-ray projections, respectively, by anthropomorphic phantoms and scatter probes. For portable X-ray, the AP abdomen had the highest scatter radiation dose recorded. Radiographer scatter radiation doses were 177 ± 8 nGy (longest cord extension) and 14 ± 0 nGy (hiding behind the portable X-ray machine). Nearby patient scatter radiation doses were 3323 ± 28 nGy (40 cm bed distance), 1785 ± 50 nGy (80 cm bed distance), and 580 ± 42 nGy (160 cm bed distance). The AP chest and abdomen had the highest scatter radiation dose in pediatric X-rays. Caretaker scatter radiation doses were 33 ± 1 nGy (50 cm height) and 659 ± 7 nGy (140 cm height). Although the estimated lens doses were all within safe levels, the use of shielding and caution on dose estimation by inverse square law is suggested to achieve the ALARA principle and dose optimization.

Spatial Scattering Radiation to the Radiological Technologist during Medical Mobile Radiography

Mobile radiography allows for the diagnostic imaging of patients who cannot move to the X-ray examination room. Therefore, mobile X-ray equipment is useful for patients who have difficulty with movement. However, staff are exposed to scattered radiation from the patient, and they can receive potentially harmful radiation doses during radiography. We estimated occupational exposure during mobile radiography using phantom measurements. Scattered radiation distribution during mobile radiography was investigated using a radiation survey meter. The efficacy of radiation-reducing methods for mobile radiography was also evaluated. The dose decreased as the distance from the X-ray center increased. When the distance was more than 150 cm, the dose decreased to less than 1 μSv. It is extremely important for radiological technologists (RTs) to maintain a sufficient distance from the patient to reduce radiation exposure. The spatial dose at eye-lens height increases when the bed height is high, and when the RT is short in stature and abdominal imaging is performed. Maintaining sufficient distance from the patient is also particularly effective in limiting radiation exposure of the eye lens. Our results suggest that the doses of radiation received by staff during mobile radiography are not significant when appropriate radiation protection is used. To reduce exposure, it is important to maintain a sufficient distance from the patient. Therefore, RTs should bear this is mind during mobile radiography.

COVID-19 pandemic and the effect of increased utilisation of mobile X-ray examinations on radiation dose to radiographers

Introduction

The use of ionising radiation results in occupational exposure to medical imaging professionals, requiring routine monitoring. This study aims to assess the effect of increased utilisation of mobile X‐ray units, mobile imaging of non‐routine body regions and radiographer work practice changes for impact on staff radiation dose during the early stages of the COVID‐19 pandemic.

Methods

A retrospective analysis of general radiology departments across two metropolitan hospitals was performed. Personal radiation monitor exposure reports between January 2019 and December 2020 were analysed. Statistical analysis was conducted using a Mann–Whitney U test when comparing each quarter, from 2019 to 2020. Categorical data were compared using a Chi‐squared test.

Results

Mobile X‐ray use during the pandemic increased approximately 1.7‐fold, with the peak usage observed in September 2020. The mobile imaging rate per month of non‐routine body regions increased from approximately 6.0–7.8%. Reported doses marginally increased during Q2, Q3 and Q4 of 2020 (in comparison to 2019 data), though was not statistically significant (Q2: P = 0.13; Q3: P = 0.31 and Q4 P = 0.32). In Q1, doses marginally decreased and were not statistically significant (P = 0.22).

Conclusion

Increased utilisation and work practice changes had no significant effect on reported staff radiation dose. The average reported dose remained significantly lower than the occupational dose limits for radiation workers of 20 mSv.

Exploring the Necessity of Routine Daily Chest X-rays for Mechanically Ventilated Patients in the Pediatric Intensive Care Unit: An Integrative Review

PROBLEM

In the PICU of a university teaching hospital, daily chest X-rays (CXR) are performed on all intubated and non-invasive ventilation-assisted patients, even when the patient is stable with no changes in clinical status. Inconsistent practice was identified with PICUs globally. This review aims to address the risk-benefit balance of clinical value, outcomes, cost, and radiation exposure when performing routine daily CXRs in the PICU.

ELIGIBILITY CRITERIA

CINAHL, Medline, and Embase (Ovid) were searched for relevant articles within the last ten years (2009 to 2019). Articles involving routine daily CXR on adult patients were included due to limited pediatric research.

SAMPLE

18 articles were included in this review which evaluated the necessity of routine daily CXR protocol in the ICU setting and the risks of radiation exposure (pediatric n = 5, adult n = 10, both n = 3).

RESULTS

When comparing the routine daily to on-demand CXR ordering protocols, there was no difference noted in clinical outcomes including mortality, complications, length of stay in hospital or ICU, and number of ventilator days. The on-demand CXR protocol decreased the number of CXRs per patient, which thereby decreased radiation exposure for patients, decreasing their risk of potential toxicity and malignancy.

CONCLUSION

Routine daily CXR protocols are no longer recommended due to lack of clinical value, similar outcomes, increased cost, and since it places patients at risk for undue radiation exposure.

IMPLICATIONS

Further studies should evaluate clinical and physical exam findings that would trigger ordering a CXR in order to optimize their diagnostic value in the pediatric setting.

Patient X-ray exposure and ALARA in the neonatal intensive care unit: Global patterns

A literature review was conducted to determine norms for practice in neonatal intensive care units (NICU) around the world, given the harmful risks associated with radiation exposure at a very young age; risk of radiation-induced harm later in life increases with every X-ray image taken, more so for younger premature babies. Empirical studies including a measurement of radiation dose in a NICU, published after the year 2000 in a peer-reviewed journal, were collected. Measured doses to patients or X-ray phantoms, number of X-rays per stay and conclusions with recommendations made in response to these values were compared for 25 studies from around the world. The number of X-rays a patient underwent during a NICU stay ranged from 0 to 159. Younger, lower birth weight patients consistently had the greatest number of X-rays per stay. Recommended action based on measured dose ranged from extensive (to minimize risk to neonates) to minimal (to reduce risk) to none (because imaging benefits outweigh patient risk), with no consistent pattern linking recommended action with dose quantity. This demonstrates a broad range of interpretations of the As Low As Reasonably Achievable (ALARA) concept. These findings indicate a disparity in the response to neonatal X-ray dose concerns on a global scale, posing a public health risk to this particular neonatal population. More up-to-date imaging protocols and dose limits specifically for the NICU environment with standardized dose monitoring would help minimize this risk to achieve the public health goals of prevention and harm reduction.

Simple preoperative radiation safety interventions significantly lower radiation doses during central venous line placement in children

PURPOSE

The purpose of this study was to reduce radiation exposure during pediatric central venous line (CVL) placement by implementing a radiation safety process including a radiation safety briefing and a job-instruction model with a preradiation time-out.

METHODS

We reviewed records of all patients under 21 who underwent CVL placement in the operating room covering 22 months before the intervention through 10 months after 2013-2016. The intervention consisted of a radiation safety briefing by the surgeon to the intraoperative staff before each case and a radiation safety time-out. We measured and analyzed the dose area product (DAP), total radiation time pre- and postintervention, and the use of postprocedural chest radiograph.

RESULTS

100 patients with valid DAP measurements were identified for analysis (59 preintervention, 41 postintervention). Following implementation of the radiation safety process, there was a 79% decrease in median DAP (61.4 vs 13.1 rad*cm², P < 0.001) and a 73% decrease in the median radiation time (28 vs 7.6 s, P < 0.001). Additionally, there was a significant reduction in use of confirmatory CXR (95% vs 15%, P < 0.01).

CONCLUSION

A preoperative radiation safety briefing and a radiation safety time-out supported by a job-instruction model were effective in significantly lowering the absorbed doses of radiation in children undergoing CVL insertion.

TYPE OF STUDY

Case-control study.

LEVEL OF EVIDENCE

Level III.

Quantification of scatter radiation from radiographic procedures in a neonatal intensive care unit

BACKGROUND

In a neonatal intensive care unit (NICU), preterm infants are often exposed to a large number of radiographic examinations, which could cause adjacent neonates, family caregivers and staff members to be exposed to a dose amount due to scatter radiation.

OBJECTIVE

To provide information on scatter radiation exposure levels in a NICU, to compare these values with the effective dose limits established by the European Union and to evaluate the effectiveness of radiation protection devices in this setting.

MATERIALS AND METHODS

Radiation exposure levels due to scatter radiation were estimated by passive detectors (thermoluminescent dosimeters) and direct dosimetric measurements (with a dose rate meter); in the latter case, an angular map of the scatter dose distribution was achieved.

RESULTS

The dose due to scatter radiation to staff in our setting is approximately 160 μSv/year, which is markedly lower than the effective dose limit for workers established by the European Union (20 mSv/year). The doses range between 0.012 and 0.095 μSv/radiograph. Considering a mean hospitalization period of 3 months and our NICU workload, the corresponding scatter radiation dose to an adjacent patient and/or his/her caregiver is at most 40 μSv.

CONCLUSION

For distances greater than 1 m from the irradiation field, both scatter dose absorbed by a staff member during a year and that by an adjacent patient and/or his/her caregiver during hospitalization is less than 1 mSv, which is the exposure limit for public members in a year.