Diagnostic Reference Levels of Radiographic and CT Examinations in Jordan: A Systematic Review.

ABSTRACT: A comprehensive search was performed to examine the literature on diagnostic reference levels (DRL) for computed tomography (CT) and radiography examinations that are performed routinely in Jordan. EBSCO, Scopus, and Web of Science were used for the search. The acronym "DRL" and the additional phrase "dose reference levels" were used to search for articles in literature. Seven papers that reported DRL values for radiography and CT scans in Jordan were identified. One study reported DRLs for conventional radiography, two studies reported CT DRLs in pediatrics, and the remaining four studies provided DRL values for adult CT scans. The most popular techniques for determining the DRLs were the entrance surface dose, volume CT dose index (CTDIvol), and dose-length product (DLP) values. Variations in Jordanian DRL values were noted across both modalities. Lower radiation doses and less variation in DRL values may be achieved by educating and training radiographers to better understand dose reduction strategies. To limit dose variance and enable dosage comparison, CT DRLs must be standardized in accordance with the guidelines of the International Commission on Radiological Protection (ICRP).

Effects of body part thickness on low-contrast detail detection and radiation dose during adult chest radiography.

INTRODUCTION: Differences in patient size often provide challenges for radiographers, particularly when choosing the optimum acquisition parameters to obtain radiographs with acceptable image quality (IQ) for diagnosis. This study aimed to assess the effect of body part thickness on IQ in terms of low-contrast detail (LCD) detection and radiation dose when undertaking adult chest radiography (CXR). METHODS: This investigation made use of a contrast detail (CD) phantom. Polymethyl methacrylate (PMMA) was utilised to approximate varied body part thicknesses (9, 11, 15 and 17 cm) simulating underweight, standard, overweight and obese patients, respectively. Different tube potentials were tested against a fixed 180 cm source to image distance (SID) and automatic exposure control (AEC). IQ was analysed using bespoke software thus providing an image quality figure inverse (IQFinv ) value which represents LCD detectability. Dose area product (DAP) was utilised to represent the radiation dose. RESULTS: IQFinv values decreased statistically (P = 0.0001) with increasing phantom size across all tube potentials studied. The highest IQFinv values were obtained at 80 kVp for all phantom thicknesses (2.29, 2.02, 1.8 and 1.65, respectively). Radiation dose increased statistically (P = 0.0001) again with increasing phantom thicknesses. CONCLUSION: Our findings demonstrate that lower tube potentials provide the highest IQFinv scores for various body part thicknesses. This is not consistent with professional practice because radiographers frequently raise the tube potential with increased part thickness. Higher tube potentials did result in radiation dose reductions. Establishing a balance between dose and IQ, which must be acceptable for diagnosis, can prevent the patient from receiving unnecessary additional radiation dose.

Effective dose and image quality for different patient sizes during AP upper abdominal radiography: A phantom study.

INTRODUCTION: Undertaking medical imaging examinations on obese patients can present practical challenges. Choosing optimal imaging protocols can be difficult, especially when promoting the ALARA principle. The aim of this study was to assess the effects of increasing body part thickness on image quality (IQ) and effective dose (ED) during upper abdominal radiography. A secondary aim was to determine the optimum exposure settings for larger sized patients. METHODS: Underweight, standard, overweight and obese abdomen sizes were simulated using an anthropomorphic upper abdomen phantom, without and with additional fat layers (6, 10 and 16 cm). Phantoms were imaged using a variety of tube potentials (70-110 kVp), automatic exposure control (AEC) and a source-to-image distance of 120 cm. IQ was assessed visually using a relative visual grading analysis (VGA) method. Radiation dose was evaluated by calculating the ED using the Monte Carlo PCXMC 2.0 computer program. RESULTS: IQ values showed a statistical reduction (p = 0.006) with increasing phantom size across all examined tube potentials. The highest IQ scores (3.3, 2.8, 2.5 and 2.2, respectively) were obtained at 70/75 kVp for all phantom thicknesses. As tube potential increased the IQ was also shown to decrease. ED showed a statistically significant increase (p < 0.001) with increasing phantom thicknesses. CONCLUSION: Higher EDs were evident when applying lower tube potentials. Using an AEC with high tube potentials (105/110 kVp) can lead to a considerable decrease in ED with acceptable IQ when undertaking upper abdomen radiography on patients with large body part thicknesses. IMPLICATION FOR PRACTICE: Applying higher values of tube potentials for patients who have a thicker abdomen can lead to decreased ED.

The effect of erect abdomen radiography on absorbed doses to internal organs and tissues: A clinical study.

BACKGROUND: As low as reasonably achievable principles (ALARA) should be applied during all X-ray examinations. In some institutions, an acute abdomen series includes both erect and supine radiography. The purpose of the study was to evaluate the effect of an erect position on absorbed dose to internal abdominal organs when compared with the supine position. MATERIAL AND METHODS: A prospective study was undertaken where 81 patients were imaged in both supine and erect positions. The PCXMC Monte Carlo software was used to estimate individual organ doses using dose area product (DAP). Absorbed doses were calculated for the large intestines, active bone marrow, liver, lungs, small intestine, stomach, gallbladder, breasts, uterus, ovaries, urinary bladder, kidneys, testicles, and prostate. RESULTS: The results showed a significant increase of absorbed dose by 1.4% when moving from a supine to an erect position. The testes were found to be the organs most affected by the erect position and then the urinary bladder. CONCLUSIONS: According to the study's findings, using the erect position during abdominal radiography increases the radiation dose for all of the selected organs compared to using a supine position. Therefore, it is advised that the use of erect abdomen radiography be restricted to certain circumstances.

Supine and erect abdominal radiography: A comparison of radiation dose and image quality.

Abdominal radiographs are often the first diagnostic imaging tool for patients with acute abdominal pain. In most cases, a supine X-ray is sufficient, but in some cases, an erect abdominal radiograph may be warranted and can provide additional benefits. The aim of this study was to compare erect and supine projections in terms of radiation dose and image quality. Body mass index (BMI), sagittal body thickness, dose area product (DAP)and effective dose (ED) data were collected for 81 patients referred for digital abdominal radiography in both the supine and erect positions. The ED was estimated by inserting the dose area product (DAP) for each projection into the dose modelling computer software PCXMC 2.0. Image quality was assessed by both visual and quantitative methods. The mean ± standard deviation (SD) ED was 0.4 ± 0.3 and 0.2 ± 0.1 mSv for erect and supine projections, respectively (p < 0.001). The estimated ED in the erect position was 102% higher compared to the supine position. The mean ± SD visual image quality was reduced (27%) when using an erect position 1.9 ± 0.5 when compared with supine 2.6 ± 0.7. The calculated signal to noise ratio (SNR) was higher in erect position by 14%. Contrast to noise ratio (CNR) was reduced by 16% when using an erect position. Study findings support the continued use of the supine position as the preferred method due to significant reductions in radiation dose when compared to erect imaging. A single projection is likely to be sufficient but in certain situations, for example in case of absence of a computed tomography (CT) scanner or ultrasound, then an additional erect abdominal radiograph may be warranted. The erect abdomen radiograph increases the radiation dose and decreases the image quality. Further research is required to define more holistically evaluation optimisation strategies to reduce the patient dose, such as using an increase source-to-image distance or the development of patient-specific exposure parameters for evaluating different clinical indications and patient sizes.

Comparing the supine and erect pelvis radiographic examinations: an evaluation of anatomy, image quality and radiation dose.

OBJECTIVES: Pelvis radiographs are usually acquired supine despite standing imaging reflecting functional anatomy. We compared supine and erect radiographic examinations for anatomical features, radiation dose and image quality. METHODS: 60 patients underwent pelvis radiography in both supine and erect positions at the same examination appointment. Measures of body mass index and sagittal diameter were obtained. Images were evaluated using visual grading analysis and pelvic tilt was compared. Dose-area product values were recorded and inputted into the CalDose_X software to estimate effective dose (ED). The CalDose_X software allowed comparisons using data from the erect and supine sex-specific phantoms (MAX06 & FAX06). RESULTS: Patient sagittal diameter was greater on standing with an average 20.6% increase at the iliac crest (median 30.0, interquartile range [26.0 to 34.0] cm), in comparison to the supine position [24.0 (22.3 to 28.0) cm; p < 0.001]. 57 (95%) patients had posterior pelvic tilt on weight-bearing. Erect image quality was significantly decreased with median image quality scores of 78% (69 to 85) compared to 87% for the supine position [81 to 91] (p < 0.001). In the erect position, the ED was 47% higher [0.17 (0.13 to 0.33) mSv vs 0.12 (0.08 to 0.18) mSv (p < 0.001)], influenced by the increased sagittal diameter. 42 (70%) patients preferred the standing examination. CONCLUSION: Patient diameter and pelvic tilt were altered on weightbearing. Erect images demonstrated an overall decrease in image quality with a higher radiation dose. Optimal acquisition parameters are required for erect pelvis radiography as the supine technique is not directly transferable.

Optimum Positioning for Anteroposterior Pelvis Radiography: A Literature Review.

AIM: Pelvic radiography is used for the identification of hip joint changes, including pathologies such as osteoarthritis. Several studies have recommended that the position for this radiological procedure should be standing, not supine, to reflect the functional appearances of the hip joint. The aim of this review was to evaluate pelvis radiography positioning with respect to the image appearances and information provided for clinical decision-making. Aside from this, potential recommendations to the radiographic technique for an erect pelvis projection will be considered. METHOD: A literature search was performed using databases/abstract systems (ScienceDirect, Web of Science, PubMed, and MEDLINE). Only articles written in English were included. RESULTS: Twenty-five articles were identified. Findings from the review describe the effect of repositioning from supine to erect on a series of specific hip measurements. These include pelvic tilt, joint space width, and the acetabular component. CONCLUSION: Evidence within the literature illustrates that in several studies, there were differences when repositioning from supine to standing for a number of pelvic metrics. Standing positioning is promoted by some authors since this may facilitate the early diagnosis of hip joint pathology and assist in the planning of surgical interventions. Literature is very limited on how to optimally perform erect pelvis radiography, and this should be an area for future research.

Response Detection of Castrate-Resistant Prostate Cancer to Clinically Utilised and Novel Treatments by Monitoring Phospholipid Metabolism.

Androgen receptor (AR) activation is the primary driving factor in prostate cancer which is initially responsive to castration but then becomes resistant (castration-resistant prostate cancer (CRPC)). CRPC cells still retain the functioning AR which can be targeted by other therapies. A recent promising development is the use of inhibitors (Epi-1) of protein-protein interaction to inhibit AR-activated signalling. Translating novel therapies into the clinic requires sensitive early response indicators. Here potential response markers are explored. Growth inhibition of prostate cancer cells with flutamide, paclitaxel, and Epi-1 was measured using the MTT assay. To simulate choline-PET scans, pulse-chase experiments were carried out with [3H-methyl]choline and proportion of phosphorylated activity was determined after treatment with growth inhibitory concentrations of each drug. Extracts from treated cells were also subject to 31P-NMR spectroscopy. Cells treated with flutamide demonstrated decreased [3H-methyl]choline phosphorylation, whilst the proportion of phosphorylated [3H-methyl]choline that was present in the lipid fraction was increased in Epi-1-treated cells. Phospholipid breakdown products, glycerophosphorylcholine and glycerophosphoethanolamine levels, were shown by 31P-NMR spectroscopy to be decreased to undetectable levels in cells treated with Epi-1. LNCaP cells responding to treatment with novel protein-protein interaction inhibitors suggest that 31P-NMR spectroscopy may be useful in detecting response to this promising therapy.