The effect of breast shielding outside the field of view on breast entrance surface dose in axial X-ray examinations: a phantom study

PURPOSEThe purpose of this study was to evaluate the effect of outside-field-of-view (FOV) lead shielding on the entrance surface dose (ESD) of the breast on an anthropomorphic X-ray phantom for a variety of axial skeleton X-ray examinations.METHODSUsing an anthropomorphic phantom and radiation dosimeter, the ESD of the breast was measured with and without outside-FOV shielding in anterior-posterior (AP) abdomen, AP cervical spine, occipitomental 30° (OM30) facial bones, AP lumbar spine, and lateral lumbar spine radiography. The effect of several exposure parameters, including a low milliampere-seconds technique, grid use, automatic exposure control use, wraparound lead (WAL) use, trolley use, and X-ray table use, on the ESD of the breast with and without outside-FOV shielding was investigated. The mean ESD (μSv) and standard deviation for each radiographic protocol were calculated. A one-tailed Student’s t-test was carried out to evaluate whether ESD to the breast was reduced with the use of outside-FOV shielding.RESULTSA total of 920 breast ESD measurements were recorded across the different protocol parameters. The largest decrease in mean ESD of the breast with outside-FOV shielding was 0.002 μSv (P = 0.084), recorded in the AP abdomen on the table with a grid, OM30 on the table with a grid, OM30 standard protocol on the trolley, and OM30 on the trolley with WAL protocols. This decrease was found to be statistically non-significant.CONCLUSIONThis study found no significant decrease in the ESD of the breast with the use of outside-FOV shielding for the AP abdomen, AP cervical spine, OM30 facial bones, AP lumbar spine, or lateral lumbar spine radiography across a range of protocols

Radiation Dose Assessment for Nuclear Medicine Workers in Riyadh, Saudi Arabia

Nuclear medicine (NM) is an essential radiology department in healthcare facilities. In NM procedures, radioactive isotopes are administered intravenously or orally to assess the molecular, metabolic, physiologic, anatomical and pathologic states of the body for diagnostic therapy and research applications. The personal radiation dose data of 269 NM technologists and 132 nurses, all with annual dose records, from 2016 to 2021 are collected in four major medical centres. Personal radiation doses in NM departments are monitored on a quarterly basis using thermoluminescent dosimeters (TLDs). The TLDs used have an approximate tissue equivalence of 8.14 and a density of around 2.64 g cm3. TLDs are read using WinREMS software and a Harshaw 6600 plus reader. In this study, only Hp (10), which estimates the effective dose, is included in the analysis. The result showed that the NMTs and nurses’ overall mean effective dose during the study period were 1.06±0.60 mSv (0.063.26 mSv) and 0.92±0.70 mSv (0.015.52 mSv), respectively. The result of our study found lower values of annual mean effective doses compared to previous studies conducted in Saudi Arabia. The mean effective dose among both workers were below the permissible dose limits, which suggest a safe work environment in term of radiation protection practices

Estimation of organ and effective doses of CBCT scans of radiotherapy using size-specific field of view (FOV): a Monte Carlo study

The kV cone beam computed tomography (CBCT) is one of the most common imaging modalities used for image-guided radiation therapy (IGRT) procedures. Additional doses are delivered to patients, thus assessment and optimization of the imaging doses should be taken into consideration. This study aimed to investigate the influence of using fixed and patient-specific FOVs on the patient dose. Monte Carlo simulations were performed to simulate kV beams of the imaging system integrated into Truebeam linear accelerator using BEAMnrc code. Organ and size-specific effective doses resulting from chest and pelvis scanning protocols were estimated with DOSXYZnrc code using a phantom library developed by the National Cancer Institute (NCI) of the US. The library contains 193 (100 male and 93 female) mesh-type computational human adult phantoms, and it covers a large ratio of patient sizes with heights and weights ranging from 150 to 190 cm and 40 to 125 kg. The imaging doses were assessed using variable FOV of three sizes, small (S), medium (M), and large (L) for each scan region. The results show that the FOV and the patient size played a major role in the scan dose. The average percentage differences (PDs) for doses of organs that were fully inside the different FOVs were relatively low, all within 11% for both protocols. However, doses to organs that were scanned partially or near the FOVs were affected significantly. For the chest protocol, the inclusion of the thyroid in the scan field could give a dose of 1-7 mGy/100 mAs to the thyroid, compared to 0.4-1 mGy/100 mAs when it was excluded. Similarly, on average, testes doses could be 6 mGy/100 mAs for the male pelvis protocol compared to 3 mGy/100 mAs when it did not lie in the field irradiated. These dose differences resulted in an average increase of up to 27% in the size-specific effective dose of the protocols. Since changing the field size is possible for CBCT scans, the results suggest that patient-specific scanning protocols could be applied for each scan area in a manner similar to that used for CT scans. Adjustment of the FOV size should be subject to the clinical needs, and assist in improving the treatment accuracy. The patient's height and weight might be considered as the main factors upon which, the selection of the appropriate patient-specific protocol is based. This approach should optimize the imaging doses used for IGRT procedures by minimizing doses of a large ratio of patients

The Impact of the COVID-19 Pandemic on Medical Imaging Case Volumes in Aseer Region: A Retrospective Study

COVID-19 has had a significant impact on global health systems. The aim of this study was to evaluate how imaging volumes and imaging types in radiology departments have been affected by the COVID-19 pandemic across different locations. Methods: Imaging volumes in the Aseer region (in the south of Saudi Arabia) across main hospitals were reviewed retrospectively including all cases referred from different locations (outpatient, inpatient and emergency departments). Data for years 2019 and 2020 were compared. The mean monthly cases were compared using a t-test. Results: The total imaging volumes in 2019 were 205,805 compared to 159,107 in 2020 with a 22.7% overall reduction. A substantial decline was observed in both the April to June and the July to September periods of approximately 42.9% and 44.4%, respectively. With respect to location, between April and June, the greatest decline was observed in outpatient departments (76% decline), followed by emergency departments (25% decline), and the least impact was observed in inpatient departments, with only 6.8% decline over the same period. According to modality type, the greatest decreases were reported in nuclear medicine, ultrasound, MRI, and mammography, by 100%, 76%, 74%, and 66%, respectively. Our results show a statistically significant (p-value ≤ 0.05) decrease of cases in 2020 compared to 2019, except for mammography procedures. Conclusion: There has been a significant decline in radiology volumes due to COVID-19. The overall reduction in radiology volumes was dependent on the stage/period of lockdown, location, and imaging modality

Evaluation of Ultrasound Accuracy in Acute Appendicitis Diagnosis

Acute appendicitis it a quite common abdominal disorder and considered as a difficult diagnosis. An accurate diagnosis is essential to prevent any complication from delayed surgical intervention. Aim: To evaluate the diagnostic accuracy of ultrasound in acute appendicitis cases in Saudi Arabia compared with histopathology. Moreover, to determine whether there is a correlation between the accuracy of ultrasound in acute appendicitis and the sonographers’ expertise. Methods: A retrospective study was conducted, including patients who admitted to the emergency room with clinical symptoms of suspected acute appendicitis and underwent ultrasound examinations. Diagnostic features, including diameter of the appendix ≥7 mm, free fluid, lack of compressibility, no appendix seen, normal appearance, and thick wall, were recorded for each patient. Results: Only 61 of the 132 patients in the study were accurately diagnosed with the use of ultrasound. Just 44 of them were diagnosed with appendicitis (true positives) and 17 without appendicitis (true negatives). However, 69 patients who had positive histopathologic results received a negative ultrasound diagnosis (false negatives), and 2 patients with negative histopathologic findings had a positive ultrasound diagnosis (false positives). There was no significant association between the accuracy of the ultrasound diagnosis and the years of experience of the sonographers. Conclusion: a low level of diagnostic accuracy was demonstrated when utilizing ultrasound to diagnose cases of acute appendicitis. In addition, no association was found between the years of experience of the sonographer conducting the examination and the diagnosis of acute appendicitis

Assessment of Pregnant Women’s Knowledge and Perceptions of Antenatal Ultrasound in Saudi Arabia

Background: This study aims to evaluate pregnant women’s knowledge of antenatal ultrasound in Saudi Arabia and its correlation with demographic factors like age and education to enhance prenatal care. Methods: A cross-sectional study was conducted in six Saudi Arabian hospitals, involving 22 questions split between sociodemographic information and knowledge of antenatal ultrasound. Descriptive statistics were used to characterize the participants’ demographics and responses. Additionally, inferential statistics were employed to analyze the relationships and differences among the study variables. Results: Among the 531 pregnant women in the study, most demonstrated a good understanding of antenatal ultrasound, identifying its various uses. Specifically, they recognized its roles in evaluating fetal growth (82.5%), placental location (81.7%), amniotic fluid volume (67%), and fetal morphology (65%), predicting the delivery date (79%), and determining the baby’s sex (89%). A majority viewed ultrasound as important (89.3%), safe (82.3%), and tolerable (76.3%) for prenatal care. Additionally, 66.7% felt adequately informed, mainly through clinical staff and doctors. Younger age, lower education, lack of prior ultrasound experience, and first pregnancy were linked to lower knowledge. Approximately 65% were uncertain about the nonionizing radiation properties of ultrasound. Conclusions: The study found that while most pregnant women in Saudi Arabia understand the objectives of antenatal ultrasonography, there are gaps in their knowledge about its nonionizing properties. Younger age, lower education, lack of prior ultrasound experience, and first pregnancy contribute to lower knowledge

Provision of Safe Anesthesia in Magnetic Resonance Environments: Degree of Compliance with International Guidelines in Saudi Arabia

Background: The lack of local guidelines and regulations for the administration of anesthesia in magnetic resonance imaging (MRI) units presents a potential risk to patient safety in Saudi Arabia. Hence, this study aimed to evaluate the extent to which hospitals in Saudi Arabia follow international guidelines and recommendations for the safe and effective administration of anesthesia in an MRI environment. Methods: This study used a questionnaire that was distributed to 31 medical facilities in Saudi Arabia that provided anesthesia in MRI units. Results: The findings of the study revealed that the mean compliance with the 17 guidelines across the 31 sites was 77%; 5 of the 31 sites (16.1%) had a compliance rate of less than 50% with the recommended guidelines. Only 19.4% of the institutes provided general safety education. Communication breakdowns between anesthesia providers and MRI teams were reported. Conclusions: To conclude, this survey highlights the status of anesthesia standards in Saudi Arabian MRI units and emphasizes areas that require better adherence to international guidelines. The results call for targeted interventions, including the formulation of specific national anesthesia guidelines for MRI settings. Communication breakdowns between anesthesia providers and MRI teams were reported at a rate of 83.9% during the administration of a gadolinium contrast agent. There were additional breakdowns, particularly for high-risk patients with implants, such as impaired respirators (74.2%), thus requiring further investigation due to potential safety incidents during MRI procedures. While considering the limitations of this study, such as potential biases and the low response rate, it provides a valuable foundation for refining protocols and promoting standardized practices in Saudi Arabian healthcare

Proposing Multiregional Diagnostic Reference Levels for Common CT Angiography Examinations in Saudi Arabia

Objectives: Diagnostic reference levels (DRLs) are crucial tools for optimizing radiation exposure during different radiological examinations. This study aimed to establish preliminary DRLs for commonly performed computed tomographic angiography (CTA) examinations in Saudi Arabia. Methods: Data for three types of CTA examinations (cerebral, pulmonary, and lower-extremity) were collected from six medical cities across Saudi Arabia. Data sets related to 723 CTAs with a mean patient weight of 75 kg were analysed in detail. The DRL values were determined based on the 75th, median, and 25th CT dose index volume (CTDIvol) and dose length product (DLP) values. Results: The established DRLs were 1221 mGy cm for cerebral CTAs, 475 mGy cm for pulmonary CTAs, and 1040 mGy cm for lower-extremity CTAs. These values were comparable to those reported in other studies. Conclusions: This study provides preliminary DRLs for three common CTA procedures in Saudi Arabia. The widespread implementation of a low kVp and a high level of image reconstruction (IR) presents an opportunity for further dose reduction. These findings can serve as a foundation for future nationwide DRL surveys and the optimization of CTA imaging protocols in Saudi Arabia