Reliability of Ultrasound Measurements of the Median Nerve in Asymptomatic Subjects Using a Handheld Device.

This study investigated the reliability of measuring the median nerve cross-sectional area (CSA) at the carpal tunnel inlet using a handheld ultrasound device (HUD) compared to a standard ultrasound system, focusing on intra- and inter-operator reproducibility among novice and expert operators. Employing a prospective cross-sectional design, 37 asymptomatic adults were assessed using both devices, with measurements taken by an expert with over five years of experience and a novice with less than six months. The CSA was determined using manual tracing and ellipse methods, with reproducibility evaluated through intraclass correlation coefficients (ICCs) and agreement assessed via Bland-Altman plots. Results showed a high degree of agreement between the devices, with excellent intra-operator reproducibility (ICC > 0.80) for the expert, and moderate reproducibility for the novice (ICCs ranging from 0.539 to 0.841). Inter-operator reliability was generally moderate, indicating acceptable consistency across different experience levels. The study concludes that HUDs are comparable to standard ultrasound systems for assessing median nerve CSA in asymptomatic subjects, with both devices providing reliable measurements. This supports the use of HUDs in diverse clinical environments, particularly where access to traditional ultrasound is limited. Further research with a larger sample and symptomatic patients is recommended to validate these findings.

Semi-quantitative scoring of imaging modalities in detecting soft tissue foreign bodies: an in vitro study.

BACKGROUND: Accurate identification of foreign bodies (FB) using medical imaging is essential for diagnosis and determining the suitable retrieval technique. PURPOSE: To compare the sensitivity of different imaging modalities for detecting various FB materials in soft tissue and assess the reproducibility of a scoring system for grading the conspicuity of FBs. MATERIAL AND METHODS: Five FB materials (plastic, wood, glass, aluminum, and copper) were embedded in a tissue-mimicking phantom. Computed radiography (CR), ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) were compared using a semi-quantitative 5-point Likert scale scoring system. The intra- and inter-reader reproducibility of four independent readers was analyzed using Kendall's coefficient of concordance (W). RESULTS: Glass was visible on all imaging modalities. Plastic was only visible in excellent detail using ultrasound. Wood was detected in excellent resolution using ultrasound and CT using the default window while plain X-ray failed to detect it. Ultrasound was the only modality that showed aluminum in excellent quality while CT showed it with good demarcation from the surroundings. Copper was detectable in excellent detail using CR, ultrasound, and CT. MRI performance was suboptimal, especially with the plastic FB. The scoring system showed excellent intra-reader (W = 0.91, P = 0.001) and inter-reader (W = 0.88, P < 0.001) reproducibility. CONCLUSION: Ultrasound can be used as the first line of investigation for wood, plastic, glass, and metallic FBs impacted at superficial depths in soft tissue. The semi-quantitative FB scoring system showed excellent within- and between-reader reliability, which can be used to score and compare the detection performance of new imaging techniques.

The Association between Tensiomyography and Elastography Stiffness Measurements in Lower Limb Skeletal Muscles.

The objective was to test the measurements association between tensiomyography (TMG) and shear wave elastography (SWE) when evaluating the skeletal muscle stiffness of healthy subjects. The secondary objective was to evaluate the effect of superficial non-muscular tissues thickness on the measurements. A cross-sectional study was conducted with adults who are asymptomatic and had no previous history of musculoskeletal conditions. The vastus lateralis (VL) and biceps femoris (BF) muscle contraction was tested using TMG and SWE. The TMG parameters included time of contraction (Tc), sustain time (Ts), relaxation time (Tr), delay time (Td), and maximal displacement (Dm). The skin, subcutaneous fat, and fascia thicknesses were investigated using ultrasound imaging. A total of 25 participants were enrolled in the study. Six participants were females (24%). The mean age (SD) was 26.5 years (4.7). There was a statistically significant difference (p < 0.001) in SWE between VL (8.1 kPa) compared with the BF (10.8 kPa). As for Dm, which reflects stiffness in TMG, no difference was detected (p = 0.90), as both muscles had a maximum displacement of 3.7 mm. The correlation coefficients failed to detect any significant correlation (r ≤ 0.300, p ≥ 0.1) between SWE and TMG variables. There was no significant difference between male and female participants across all TMG and SWE variables (p > 0.10). Overall, there was no association between TMG parameters and SWE measurements, indicating that each technique might be evaluating a different biomechanical property of skeletal muscle.

The diagnostic performance of lung ultrasound for detecting COVID-19 in emergency departments: A systematic review and meta-analysis.

PURPOSE: To perform a systematic review and meta-analysis of published literature investigating the use of lung ultrasound (LUS) on COVID-19 patients, in emergency point of care settings, and to determine its diagnostic value compared with lung computed tomography (LCT) diagnostic performance. Whilst using the real-time polymerase chain reaction test as the 'gold standard'. METHODS: Literature searches were performed on MEDLINE, Embase, Web of Science, and PubMed databases for eligible studies. The LUS and LCT pooled diagnostic performance were measured using DerSimonian-Laird random effect method. RESULT: Out of a total of 158 studies, 16 met the eligibility criteria and were included in this review. The pooled sensitivity, specificity, positive and negative likelihood ratios were 86.9%, 62.4%, 2.4 and 0.19, respectively for LUS and 93.5%, 72.6%, 3.3 and 0.05, respectively for LCT. CONCLUSION: The lung ultrasound (LUS) demonstrated acceptable sensitivity but poor specificity when used independently to diagnose COVID-19 pneumonia patients in emergency departments, while the lung computed tomography showed higher performance. Thus, LUS can be used to supplement existing diagnostic tools and possibly for the triage of patients.

Inter- and intra-reader reproducibility of shear wave elastography measurements for musculoskeletal soft tissue masses.

OBJECTIVE: To determine inter- and intra-reader reproducibility of shear wave elastography measurements for musculoskeletal soft tissue masses. MATERIALS AND METHODS: In all, 64 patients with musculoskeletal soft tissue masses were scanned by two readers prior to biopsy; each taking five measurements of shear wave velocity (m/s) and stiffness (kPa). A single lesion per patient was scanned in transverse and cranio-caudal planes. Depth measurements (cm) and volume (cm3) were recorded for each lesion, for each reader. Linear mixed modelling was performed to assess limits of agreement (LOA), inter- and intra-reader repeatability, including analyses for measured depth and volume. RESULTS: Of the 64 lesions scanned, 24 (38%) were malignant. Bland-Altman plots demonstrated negligible bias with wide LOA for all measurements. Transverse velocity was the most reliable measure-intraclass correlation (95% CI) = 0.917 (0.886, 1)-though reader 1 measures could be between 38% lower and 57% higher than reader 2 [ratio-scale bias (95% LOA) = 0.99 (0.64, 1.55)]. Repeatability coefficients indicated most disagreement resulted from poor within-reader reproducibility. LOA between readers calculated from means of five repeated measurements were narrower-transverse velocity ratio-scale bias (95% LOA) = 1.00 (0.74, 1.35). Depth affected both estimated velocity and repeatability; volume also affected repeatability. CONCLUSION: This study found poor repeatability of measurements with wide LOA due mostly to intra-reader variability. Transverse velocity was the most reliable measure; variability may be affected by lesion depth. At least five measurements should be reported with LOA to assist future comparability between shear wave elastography systems in evaluating soft tissue masses.

Muscle stiffness in rheumatoid arthritis is not altered or associated with muscle weakness: A shear wave elastography study.

Objectives: To investigate muscle stiffness and strength in rheumatoid arthritis patients compared to healthy controls.Methods: A sample of 80 RA patients from three discrete groups: 1 - newly diagnosed treatment-naïve RA (n = 29), 2 - active RA for at least 1 year (n = 18) and 3 - in remission RA for at least 1 year (n = 33), was compared to 40 healthy controls. Shear wave velocity (SWV) was measured using shear wave elastography as a surrogate for tissue stiffness in multiple muscles. All participants performed isometric grip strength, timed get-up-and-go test, 30-s chair stand test and isokinetic knee extension/flexion (60°/s). The difference in SWV amongst the groups was tested using one-way ANOVA, and the correlation between SWV and muscle strength results were calculated using Pearson's coefficients.Results: The mean age ± SD was 61.2 ± 12.8 for RA patients and 61.5 ± 10.5 years for controls. SWV was not significantly different amongst the groups on all muscles (p > .05). In comparison to controls, the new and active RA groups showed a significantly lower isokinetic strength by -29% (p = .013) and -28% (p = .040), fewer chair stands by -28% (p = .001) and -44% (p < .001), longer walking times by -25% (p = .025) and -30% (p = .001), respectively, and weaker grip strength by -45% for both (p < .001). The muscle strength in the remission RA groups was not significantly lower, except in the isokinetic knee strength (-21%; p = .027). The correlations between SWE and the muscle assessment results were weak and insignificant (r < 0.30; p > .05).Conclusion: Significant muscle weakness was demonstrated in patients with RA disease. However, muscle stiffness was normal and not associated with muscle strength.

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI.

Purpose To examine if shear-wave elastography (SWE) improves the accuracy of diagnosing soft-tissue masses as benign or malignant compared with US alone or in combination with MRI. Materials and Methods Two hundred six consecutive adult participants (mean age, 57.7 years; range, 18-91 years), including 89 men (median age, 56.0 years; range, 21-91 years) and 117 women (median age, 59.1 years; range, 18-88 years), who were referred for biopsy of a soft-tissue mass were prospectively recruited from December 2015 through March 2017. Participants underwent B-mode US, MRI, and SWE prior to biopsy. Three musculoskeletal radiologists independently reviewed US images alone, followed by US and MRI images together, and classified lesions as benign, probably benign, probably malignant, or malignant. For SWE, the area under the receiver operating characteristic (ROC) curve (AUC) was calculated for transverse shear-wave velocity (SWV). Multivariable logistic regression was used to investigate the association between SWE and malignancy alongside individual demographic and imaging variables. Results At histologic examination, 79 of 206 (38%) participants had malignant lesions. SWV showed good diagnostic accuracy for lesions classified as benign or probably benign by US alone (AUC = 0.87 [95% confidence interval {CI}: 0.79, 0.95]). SWV did not provide substantive diagnostic information for lesions classified as probably malignant or malignant, whether the classification was made with or without MRI. However, multivariable modeling indicated that diagnostic accuracy may vary by lesion position (interaction P = .02; superficial, odds ratio [OR] = 17.7 [95% CI: 1.50, 207], P = .02; deep/mixed, OR = 0.24 [95% CI: 0.07, 0.86], P = .03) and participant age (interaction P = .01; eg, age 43 years, OR = 0.72 [95% CI: 0.15, 3.5], P = .69; age 72 years, OR = 0.08 [95% CI: 0.02, 0.37], P = .001). Conclusion Shear-wave elastography can increase accuracy of soft-tissue lesion diagnosis in conjunction with US. However, a single cut-off may not be universally applicable with diagnostic accuracy that is affected by lesion position and patient age. © RSNA, 2018 Online supplemental material is available for this article.

The effect of ageing on shear wave elastography muscle stiffness in adults.

BACKGROUND: Skeletal muscle undergoes structural changes with ageing which may alter its biomechanical properties. Shear wave elastography (SWE) may detect these changes by measuring muscle stiffness. AIMS: To investigate muscle stiffness in healthy young, middle-aged and elderly cohorts using SWE and correlate it with muscle strength and mass. METHODS: Shear wave velocity (SWV) was measured in the quadriceps, hamstrings and biceps brachii of 26 young (range 20-35 years), 21 middle-aged (40-55) and 30 elderly (77-94) volunteers. The participants performed several muscle tests to evaluate their strength. The One-way ANOVA was used to test the muscle stiffness differences between the groups and the Pearson's correlation coefficient to evaluate the relationship between SWV and muscle strength. RESULTS: The overall resting muscle SWV gradually decreased with age but was only significantly reduced in the elderly group (p < 0.001); with the exception of the vastus lateralis SWV where a significant difference was noted (p < 0.05) between young (1.77 m/s), middle-aged (1.64 m/s) and elderly (1.48 m/s). The elderly group had on average 16.5% lower muscle stiffness compared to the young. SWV significantly correlated with muscle mass (r = 0.316), walking time (r = - 0.560), number of chair stands (r = 0.522), handgrip strength (r = 0.436) and isokinetic knee strength (r = 0.640). Sex and BMI did not explain any significant variation in SWV. CONCLUSIONS: Ageing was associated with a decline in skeletal muscle stiffness which positively correlates with muscle weakness. Further research is needed to evaluate the promising role of SWE as a biomarker for sarcopenia assessment and potential falls risk prediction in elderly individuals.

Muscle shear wave elastography in idiopathic inflammatory myopathies: a case-control study with MRI correlation.

OBJECTIVE: To investigate muscle stiffness in patients with idiopathic inflammatory myopathies (IIM) using shear wave elastography (SWE) and to correlate the results with muscle strength and MRI features of myositis. MATERIALS AND METHODS: Muscle shear wave velocity (SWV) was measured in 23 active IIM patients (13 females, mean age 50.4 ± 16.1 years) and 23 matched healthy controls (13 females, mean age 50.7 ± 16.2 years). The investigated muscles included the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM) vastus intermedius (VI), biceps femoris (BF), semitendinosus (ST), semimembranosus (SM) and the biceps brachii (BB) scanned during relaxed resting and passive stretching positions. Participants performed multiple tests to evaluate their muscle strength. IIM patients had a thigh MRI to assess degrees of oedema, fatty infiltration and atrophy. RESULTS: In the resting position, IIM patients had a 12.9-22.2% significantly lower SWV (p < 0.05) for the quadriceps and hamstrings, but not BB. There was no difference during passive stretching. The SWV for VL, VI and BF showed moderate correlations with the muscle strength tests ranging from r = 0.47 to r = 0.70 (all p < 0.05). Lower SWV was associated with greater MRI scores of oedema (p = 0.001) and atrophy (p = 0.006). However, SWV did not correlate with fatty infiltration (r < 0.3; p = 0.28), creatine kinase (r = 0.28; p = 0.19) or disease duration (r = 0.26; p = 0.24). CONCLUSION: Shear wave elastography may detect abnormal reduced thigh stiffness in IIM patients. SWE measurements were significantly associated with muscle weakness and MRI signs of oedema and atrophy. Future research should investigate this new technology for monitoring disease activity.

The effect of unit, depth, and probe load on the reliability of muscle shear wave elastography: Variables affecting reliability of SWE.

PURPOSE: There is currently no standardized method for muscle shear wave elastography (SWE). The objective of this study was to investigate the effect of unit of measurement, depth, and probe load on the reliability of muscle SWE. METHODS: The vastus lateralis, biceps femoris, biceps brachii, and abductor digiti minimi muscles were scanned on 20 healthy participants. The SWE readings were measured in shear wave velocity (m/s) and Young's modulus (kPa). Three acquisitions of varying depths were acquired from vastus lateralis. Minimal probe load was compared with the use of a standoff gel layer. Three repeated measurements were acquired to assess reliability using intraclass correlations (ICC). RESULTS: The mean elasticity varied across muscle groups and ranged from 1.54 m/s for biceps femoris to 2.55 m/s for abductor digiti minimi (difference = 1.01 m/s [95% confidence interval, CI = 0.92, 1.10]). Reporting readings in meters per second resulted in higher ICC of 0.83 (0.65, 0.93) in comparison to 0.77 (0.52, 0.90) for kilopascal for the vastus lateralis muscle only. Variance increased proportionally with depth reaching 0.17 (equivalent to ±0.82 m/s) at 6 cm. Using a standoff gel decreased ICC to 0.63 (0.20, 0.84) despite similar mean elasticity readings to minimal probe load. CONCLUSIONS: Different acquisition and technical factors may significantly affect the reliability of SWE in skeletal muscles. Readings acquired in the unit of shear wave velocity (m/s) from depths less than 4 cm using a minimal probe load without a standoff gel yielded the best reliability.

The Predictive Accuracy of Anogenital Distance and Genital Tubercle Angle for First-Trimester Fetal Sex Determination.

BACKGROUND: Early identification of fetal gender is crucial for managing gender-linked genetic disorders. This study aimed to evaluate the predictive performance of anogenital distance (AGD) and genital tubercle angle (GTA) for fetal sex determination during the first trimester. METHODS: A multicenter retrospective cohort study was conducted on 312 fetal cases between 11 and 13 + 6 weeks of gestation from two tertiary hospitals. AGD and GTA measurements were taken from midsagittal plane images using ultrasound, with intra- and inter-reader reproducibility assessed. Binomial logistic regression and ROC curve analysis were employed to determine the diagnostic performance and optimal cutoff points. RESULTS: AGD had a mean of 7.16 mm in male fetuses and 4.42 mm in female fetuses, with a sensitivity of 88.8%, specificity of 94.4%, and an area under the ROC curve (AUC) of 0.931 (95% CI: 0.899-0.962) using 5.74 mm as a cutoff point. For GTA, the mean was 35.90 degrees in males and 21.57 degrees in females, with a sensitivity of 92%, specificity of 84.7%, and an AUC of 0.932 (95% CI: 0.904-0.961) using 28.32 degrees as a cutoff point. The reproducibility results were excellent for AGD (intra-operator ICC = 0.938, inter-operator ICC = 0.871) and moderate for GTA (intra-operator ICC = 0.895, inter-operator ICC = 0.695). CONCLUSIONS: The findings suggest that AGD and GTA are reliable markers for early fetal sex determination, with AGD showing higher reproducibility. The findings highlight the feasibility and accuracy of these non-invasive sonographic markers and their potential usefulness in guiding timely interventions and enhancing the management of gender-linked genetic conditions.

Evaluating diagnostic accuracy and agreement of TI-RADS scoring in thyroid nodules: A comparative analysis between sonographers and radiologists.

OBJECTIVE: The Thyroid Imaging Reporting and Data System (TI-RADS) is an essential tool for assessing thyroid nodules, primarily used by radiologists. This study aimed to compare the agreement of TI-RADS scores between sonographers and radiologists and to assess the diagnostic performance of these scores against histological findings in suspicious thyroid nodules. METHODS: In a retrospective analysis, 168 patients with suspicious thyroid nodules classified as TR3 and above by the radiologists were included. Both sonographers and radiologists independently assigned the American College of Radiologists (ACR) TI-RADS scores, which were then compared for inter-reader agreement using Cohen's Kappa statistic. The scores were also evaluated for diagnostic performance against histological results based on the Bethesda system. RESULTS: The study revealed a moderate overall agreement between sonographers and radiologists in TI-RADS scoring (κ = 0.504; 95% CI: 0.409-0.599), with poor agreement noted specifically for nodule margin scores (κ = 0.102; 95% CI: -1.430-0.301). In terms of diagnostic performance against histological outcomes, sonographers' TI-RADS scores showed a sensitivity of 100% and a specificity of 44.6%, while radiologists' scores showed a sensitivity of 100% but a lower specificity of 29.3%. CONCLUSION: The findings indicate moderate agreement in TI-RADS scoring between sonographers and radiologists, with reproducibility challenges especially in scoring nodule margins. The marginally superior diagnostic performance of sonographers' scores suggests potential efficiency benefits in involving sonographers in preliminary assessments. Future research should aim to encompass a wider range of TI-RADS categories and focus on minimizing scoring variability to enhance the system's clinical utility.

Reproducibility and feasibility of a handheld ultrasound device compared to a standard ultrasound machine in muscle thickness measurements.

Objective: To test the feasibility and reproducibility of a handheld ultrasound device (HUD) compared to a standard ultrasound machine for muscle thickness measurements in healthy participants. Methods: A prospective cross-sectional study was designed where two novice operators tested the thickness of the vastus lateralis, rectus femoris, and vastus intermedius muscles on recruited asymptomatic participants with no history of muscle diseases. The anterior-posterior thickness of each muscle was measured three times per operator to evaluate intra-operator reproducibility and using two machines to evaluate inter-system reproducibility. Scanning started using the HUD followed by the standard system. Intraclass correlation coefficients (ICC) and simple linear regression were used to test for reproducibility and proportional bias respectively. Results: A total of 33 male participants volunteered to take part in this study with a mean age of 22.7 years (6.8). Intra-operator reproducibility was almost perfect for both operators on both machines (ICC > 0.80). The measurements difference percentage between the machines ranged from 1.8% to 6.6% and inter-system reproducibility ICC ranged from 0.815 to 0.927 showing excellent reproducibility. Inter-operator reproducibility was poor to moderate on both machines (ICC: 0.522-0.849). Regression analysis showed no proportional bias in the measurements. All measurements were completed successfully using the HUD. Conclusion: The HUD demonstrated excellent accuracy compared to the standard ultrasound machine for measuring thigh muscle thickness.

Simulation of Gamma-Ray Transmission Buildup Factors for Stratified Spherical Layers.

Deterministic particle transport codes usually take into account scattered photons with correct attenuation laws and application of buildup factor to incident beam. Transmission buildup factors for adipose, bone, muscle, and skin human tissues, as well as for various combinations of these media for point isotropic photon source with energies of .15, 1.5 and 15 MeV, for different thickness of layers, were carried out using Geant4 (version 10.5) simulation toolkit. Also, we performed the analysis of existing multilayered shield fitting models (Lin and Jiang, Kalos, Burke and Beck) of buildup factor and the proposition of a new model. We found that the model combining those of Burke and Beck, for low atomic number (Z) followed by high Z materials and Kalos 1 for high Z followed by low Z materials, accurately reproduces simulation results with approximated deviation of 3 ± 3%, 2 ± 2%, and 3 ± 2% for 2, 3, and 4 layers, respectively. Since buildup factors are the key parameter for point kernel calculations, a correct study can be of great interest to the large community of radiation physicists, in general, and to medical imaging and radiotreatment physicists, especially.

Job Satisfaction of Radiographers in Saudi Arabia.

PURPOSE: To examine the various facets of job satisfaction among radiographers in Saudi Arabia and compare the influential contributing factors locally and internationally. METHODS: A cross-sectional survey was conducted in June and July 2020 with an electronic questionnaire distributed to radiographers in Saudi Arabia. The validated Job Satisfaction Survey was used to measure overall job satisfaction and specific satisfaction regarding pay, promotions, supervision, benefits, contingent rewards, operating conditions, coworkers, nature of work, and communication (total Job Satisfaction Survey score can range from 36 to 216). Additional personal and work-related characteristics were collected as explanatory variables. Data were analyzed with descriptive and inferential statistics, including 1-way analysis of variance, independent sample t test, and Spearman correlation. RESULTS: A total of 412 radiographers in Saudi Arabia completed the survey. The total job satisfaction score was 140.0 (95% confidence interval [CI], 138.7-141.2), showing that 6 respondents (1.5%) were dissatisfied with their job, while the remaining majority were neutral (63%) or satisfied (36%). The radiographers were satisfied with the nature of work, contingent rewards, and coworkers. However, they were less satisfied with promotions, pay, operating conditions, and benefits. The only significant variable in overall job satisfaction was the working sector (P = .03), with radiographers working at Ministry of Health hospitals who were more satisfied than were their colleagues who worked at other types of facilities. DISCUSSION: The radiographers in Saudi Arabia had higher overall job satisfaction than had other allied health science professionals in Saudi Arabia. The differences in job satisfaction subscales between radiographers from different countries suggest that their job satisfaction likely is related to culture and socioeconomics. Job satisfaction improvement programs should be tailored for each radiographer's community. CONCLUSION: Radiographers in Saudi Arabia expressed moderate to high job satisfaction, which is relatively higher than their international peers and national colleagues in physical therapy and nursing. These job satisfaction results call for governmental policymakers to focus their efforts on improving radiographer promotion schemes and career development.

Variability, Validity and Operator Reliability of Three Ultrasound Systems for Measuring Tissue Stiffness: A Phantom Study.

Introduction Ultrasound elastography is a method of measuring soft tissue stiffness to detect the presence of pathology. There are several ultrasound elastography devices on the market. The aim of this study was twofold. Firstly, to determine the validity of three different ultrasound systems used to measure tissue stiffness. Secondly, to determine the operator reliability and repeatability when using these three systems. Materials and methods Two observers undertook multiple stiffness measurements from a phantom model using three different ultrasound systems; the LOGIQ E9, the Aixplorer, and the Acuson S2000. The phantom model had four cylindrical-shaped inclusions (Type 1-4) of increasing stiffness values and diameter embedded within. The background phantom stiffness was fixed. The mean, standard deviation, and coefficient of variation (CV) were calculated from measured stiffness readings per diameter per inclusion. Intra-observer variability was assessed. The validity of the measured stiffness value was assessed by calculating the difference between the measured elasticities and actual phantom elasticities. Bland-Altman plots with limits of agreement were used to display the inter-observer agreement. The intraclass correlation coefficients (ICC) were used to measure intra-observer, inter-observer, and inter-system reliability. Results Each observer undertook 1020 measurements. All three systems generally underestimated the stiffness values for the inclusions; the higher the actual stiffness value, the more significant the underestimation. The percentage difference between measured stiffness and actual stiffness varied from -79.1% to 12.7%. The intra-observer variability was generally less than 5% for observers using the LOGIQ E9 and the Aixplorer systems but more than 10% over the stiffer inclusions (Types 3 and 4) for the Acuson system. There was 'almost perfect' intra-observer reliability and repeatability for both the LOGIQ E9 and the Aixplorer systems; this was 'moderate' for the Acuson system over specific inclusions. For all systems, there was 'almost perfect' inter-observer reliability and repeatability between Observer A and Observer B. The inter-system reliability and repeatability were 'almost perfect' between the LOGIQ E9 system and the Aixplorer system but 'poor' and 'moderate' when the Acuson system was matched with the LOGIQ E9 system and the Aixplorer system, respectively. Conclusion This study has demonstrated that the Acuson, LOGIQ E9, and Aixplorer ultrasound systems have low variability, high reproducibility, and good intra-observer and inter-observer reliability when used to measure tissue stiffness. However, they all underestimated the stiffness values during this in vitro study. This study also revealed that not all ultrasound systems are comparable when measuring tissue stiffness, with some having better inter-system reliability than others. Ongoing standardization of technology is required at the manufacturer level.

Geant4 Simulation of Gamma-Ray Transmission Buildup Factors for Human Tissues.

Quantification of scattered photons in addition to unscattered primary particles, under realistic exposure scenario, is best dealt with a parameter called "Buildup factor". The aim of this work is to simulate the transmission buildup factor (BUF) of gamma-ray in the energy range .15-15 MeV for 20 human tissues and organs using the Geant4 (version 10.5) Monte Carlo simulation followed by a geometrical progression (GP) parameterization procedure. Firstly, we verified the accuracy of Geant4 ability to predict the effective transmitted dose according to published data. Also, a comparison of simulated BUF for different geometrical configurations was carried out for some tissues and source energies. Then, we checked out the linear dependency of the K parameter (BUF is function of K) function of mean free path (mfp). Finally, we developed a fitting procedure according to GP method for BUF corresponding to 20 tissues and organs and different mfp (from 1 to 8) for energy range .15-15 MeV. We found a good agreement with previous published data. Proper comprehension of BUF for tissues leads to carefully controlling the energy absorption in the human body. Consequently, provided BUF could be of great interest for estimating safe dose levels in medical imaging and radiation therapy.

The incidence of deltoid tear among patients with full-thickness rotator cuff tear.

Backgroun: Full-thickness rotator cuff tear is common in the older population. The incidence of traumatic deltoid tears post-surgery is well addressed. However, non-traumatic spontaneous injury is not well recognized despite a few case reports and previous studies. The aim of the study is to determine the incidence and association of deltoid tear among patients with non-traumatic full-thickness rotator cuff tear using shoulder magnetic resonance imaging. Methods: A retrospective cross-sectional study was conducted of 271 shoulders magnetic resonance imaging examinations with full-thickness rotator cuff tear between 2012 and 2022. The analyzed variables were full-thickness rotator cuff tear size, tear grading (small, medium, large, and massive), muscle fatty degeneration, and deltoid tear. Acromio-humeral interval was also recorded and analyzed on the anteroposterior projection of shoulder radiographs. Results: The incidence of deltoid tear was 7% (19 cases), encountered in eleven females (6.4%) and eight males (8%) with a mean age of 65 years. Deltoid tears were located on the right side in fifteen patients (9.4%) and on the left side in four patients (3.6%). The Man-Whitney U test indicated a significant association between deltoid tears and full-thickness rotator cuff tear, P < 0.001. The deltoid tear was more notably associated with large and massive full-thickness rotator cuff tear (16.7% and 42.3%, respectively), P < 0.001. Acromio-humeral interval showed a significant difference between the deltoid and non-deltoid cases, P = 0.045. Conclusion: The incidence and association of deltoid tears with full-thickness rotator cuff tear with no prior surgical intervention or traumatic insults were considered significant, with a positive impact of large and massive tear size and association of muscle fatty degeneration. This association is statistically significant and should be adequately evaluated by the radiologist.

Investigating Confidence Levels of Saudi Clinical Supervisors in Radiology Departments.

Background: Effective teaching and supervision within hospitals play an essential role in training radiography students. However, inadequate preparation of teaching roles has been highlighted over the last three decades as a problem for many radiographers. This can lead to inadequate preparation and a lack of confidence in the supervisory role, which may affect the students' learning experience. Few studies in Saudi Arabia have investigated the skills and resources needed by radiographers to become effective and confident teachers. Therefore, this study aimed to explore the experiences and confidence of clinical radiographers in teaching radiography students and establish the areas of support they require to be more effective in their clinical teaching role. Methods: An online questionnaire and semi-structured interviews were used to collect data from radiographers working in Saudi Arabia's radiology departments. Radiographers who were involved in the supervision of students are included in the study. A total of 159 radiographers participated in the study. Results: The findings showed that radiographers were reasonably confident in four domains: introducing students and familiarizing them within the practice environment, supervision, facilitating students' learning, and assisting students to integrate into the practice environment while some areas required further development. The finding also indicated high number of students believed that providing an accurate perspective on the philosophy of the environment is not applicable to them. Conclusion: The article concludes with a recommendation for further support and guidance for radiographers in teaching roles from institutions. The study provided insights into the world of clinical supervisors in radiology departments. Informative feedback to students during their clinical training by clinical supervisors is a key strategy to fill the gap between theory and practice experienced by students. Additionally, the importance for implementation of ongoing professional development for radiographers is advised to ensure the quality of clinical placement for radiography students.

Investigation of 18F and 89Zr Isotopes Self-Absorption and Dose Rate Parameters for PET Imaging.

This work concerns study of self-absorption factor (SAF) and dose rate constants of zirconium-89 (89Zr) for the purpose of radiation protection in positron emission tomography (PET) and to compare them with those of 18F-deoxyglucose (18F-FDG). We analyzed the emitted energy spectra by 18F and 89Zr through anthropomorphic phantom and calculated the absorbed energy using Monte Carlo method. The dose rate constants for both radionuclides were estimated with 2 different fluence-to-effective dose conversion coefficients. Our estimated SAF value of 0.65 for 18F agreed with the recommendation of the American Association of Physicists in Medicine (AAPM). The SAF for 89Zr was in the range of 0.61-0.66 depending on the biodistribution. Using the fluence-to-effective dose conversion coefficients recommended jointly by the American National Standards Institute and the American Nuclear Society (ANSI/ANS), the dose rate at 1 m from the patient for 18F was 0.143 µSv·MBq-1·hr-1, which is consistent with the AAPM recommendation, while that for 89Zr was 0.154 µSv·MBq-1·hr-1. With the conversion coefficients currently recommended by the International Committee on Radiological Protection (ICRP), the dose rate estimates were lowered by 2.8% and 2.6% for 89Zr and 18F, respectively. Also, we observed that the AAPM derived dose is an overestimation near the patient, compared to our simulations, which can be explained by the biodistribution nature and the assumption of the point source. Thus, we proposed new radiation protection factors for 89Zr radionuclide.