Ultrasound Imaging Measurements Research Articles

The Value of Coagulation-Related Indicators Combined with Vascular Ultrasound Parameters in the Risk Assessment of Deep Vein Thrombosis after Secondary Traumatic Fracture Surgery.

The incidence of deep vein thrombosis (DVT) after traumatic fracture is high, and DVT causes serious adverse effects on the postoperative recovery of patients. The purpose of this study was to explore the effect of coagulation-related indicators combined with vascular ultrasound measurements for the risk assessment of DVT after secondary traumatic fracture, and to provide a new method for predicting the occurrence of DVT. The clinical data of patients with secondary traumatic fracture surgery in our hospital from January 2019 to January 2022 were retrospectively analyzed. The patients were divided into a non-DVT group and a DVT group according to whether DVT was indicated in the medical record system. The coagulation-related indices and vascular ultrasound measurements of the two groups were compared, and the risk factors for postoperative DVT were analyzed by bivariate correlation and multivariate logistic regression. According to the medical record system, 55 patients (47.41%) had DVT, and 61 patients (52.59%) did not have DVT. There was no significant difference in prothrombin time (PT) or activated partial thromboplastin time (APTT) between the two groups (p > 0.05). The thrombin time (TT) in the DVT group was lower than that in the non-DVT group. The levels of fibrinogen (FIB) and D-dimer (D-D) in the DVT group were higher than those in the non-DVT group (t = 2.766, 3.242, 2.649, p = 0.007, 0.002, 0.009). Spearman correlation analysis showed that peak systolic velocity (Vs), end-diastolic velocity (Vd), pulsatility index (PI), resistance index (RI), FIB, and D-D were positively correlated with the risk of DVT after secondary traumatic fracture surgery (r = 0.264, 0.656, 0.293, 0.276, 0.287, 0.251, p < 0.05). TT was negatively correlated with DVT risk after secondary traumatic fracture surgery (r = -0.249, p < 0.05). The measurements of peak systolic velocity (Vs), end diastolic velocity (Vd), pulsatility index (PI) and resistance index (RI) in the DVT group were higher than those in the non-DVT group (t = 2.663, 2.998, 3.135, 2.953, p = 0.009, 0.003, 0.002, 0.004). FIB, D-D, Vs, Vd, PI, and RI were independent risk factors for DVT after secondary traumatic fracture surgery (Odds Ratio (OR) = 1.483, 2.026, 2.208, 1.893, 1.820, 1.644, p < 0.05). TT index was an independent protective factor for DVT after secondary traumatic fracture surgery (OR = 0.868, p < 0.05). The sensitivity and specificity for prediction of DVT based on combined coagulation-related indicators and vascular ultrasound imaging measurements were higher than those of individual measurements (p < 0.05). Coagulation-related indicators and vascular ultrasound parameters can effectively predict the formation of DVT. Through the analysis of factors related to DVT formation, screening of high-risk patients for effective intervention may help to reduce the risk of DVT. Further verification in additional, large-scale clinical trials is advocated.

Quantification of Cervical Elasticity During Pregnancy Based on Transvaginal Ultrasound Imaging and Stress Measurement.

To overcome these limitations, we develop a quantitative cervical elastography system by adding a stress sensor to a clinically used transvaginal ultrasound imaging system. In an imaging session, we use the ultrasound system to record the cervical deformation in B-mode images and use the stress sensor to record the probe-surface stress simultaneously. We develop a feature-tracking algorithm to quantify the deformation automatically and calculate the strain. Then we estimate the cervical Young's modulus through stress-strain linear regression. In phantom experiments, we demonstrate the elastography system's high accuracy (alignment with the quasi-static compression method, p-value = 0.369 > 0.05), robustness (alignment between 60°- and 90°-contact measurements, p-value = 0.638 > 0.05), repeatability (consistency of single sonographers' measurements, coefficient of variation < 0.06), and reproducibility (alignment between two sonographers' measurements, Pearson correlation coefficient = 0.981). Applying it to pregnant participants, we observe significant softening of the cervix during pregnancy (p-value < 0.001) with the cervical Young's modulus decreasing 3.95% per week. We estimate that geometric mean values of cervical Young's moduli during the first (11 to 13 weeks), second, and third trimesters are 13.07 kPa, 7.59 kPa, and 4.40 kPa, respectively. The proposed system is accurate, robust, and safe, and enables longitudinal measurements and comparisons between examiners. The system applies to different ultrasound machines with minor software updates, which allows for studies of cervical softening patterns in pregnancy for larger populations, facilitating insights into conditions such as preterm birth.

Development and validation of a gel wax phantom to evaluate geometric accuracy and measurement of a hyperechoic target diameter in diagnostic ultrasound imaging.

Diagnostic ultrasound (US) scanners are generally evaluated using proprietary quality assurance (QA) phantoms, but their prohibitively high cost may prevent organizations to perform the necessary tests. This study aimed to develop a low-cost gel wax phantom with targets to determine the lateral and axial resolution and diameter of a hyperechoic target in an US scanner. The acoustic property (AP) of gel wax, which includes the speed of sound (cus), acoustic impedance (Z), and attenuation coefficient (µ), were determined for multiple transducers operating at 2.25, 5, 10, 15, and 30MHz. These results were compared to the AP of soft tissue. Two polytetrafluoroethylene (PTFE) rectangular frames with holes separated by 5, 10, and 20mm were constructed. Nylon filaments and stainless-steel disc (SS disc) (diameter = 16.8mm) were threaded through the frames and suitably placed in gel wax to obtain orthogonal targets in the phantom. The target dimensions obtained from computerized tomography (CT) and US images of the phantom were compared for phantom validation. The average cus=1431.4m/s, mass density ρ = 0.87g/cm3, Z = 1.24 MRayls, and µ ranged from 0.7 to 0.98 dB/cm/MHz for gel wax at 22°C. The US image measurement exhibited a maximum error in determining the diameter of the SS disc, resulting in a value of 18mm instead of its actual value of 16.8mm. The phantom volume decreased by 1.8% in 62 weeks. The present phantom is affordable, stable, customizable, and can be used to evaluate diagnostic US scanners across multiple centers.

Ultrasound imaging measurements to determine reduced diaphragm thickness and relevance to breathing pattern disorders diagnosis in females

BackgroundBreathing pattern disorders (BPD) are commonly managed by physiotherapists. As no gold-standard assessment diagnostic tools are currently available, diagnosis is challenging. Ultrasound imaging has become popular in physiotherapy. This research examined diaphragm thickness using ultrasound imaging in females with BPD and healthy female controls to ascertain if diaphragm thickness at different measurement points related with reduced diaphragm thickness. MethodsObservational cross-sectional design was used. Two female groups were recruited from an outpatient setting: BPD group (n = 19) and control group (n = 18) with normal body mass index (BMI). BPD inclusion criteria assessment included: Nijmegen Questionnaire (NQ) score, respiratory rate, Hi-Lo test, and breath hold time. USI measured diaphragm thickness at the measurement points of: tidal exhalation (Tvex), tidal inhalation (Tvin), maximum inhalation (Tmax) and exhalation to residual volume (Tmin); diaphragm thickening fraction (TF) was calculated. ResultsResults indicated significant differences of diaphragm thickness between the BPD and control groups at Tvex, Tvin, Tmax and TF on the left and Tvex and Tvin on the right side (P < 0.05). ConclusionDiaphragm thickness is reduced in females with BPD when compared with healthy controls. Diaphragm measurement undertaken by USI may provide a useful assessment tool in BPD. Further research is required to validate this assessment and to broaden its use in BPD.

Reliability and validity of assessing lower-limb muscle architecture of patients with cerebral palsy (CP) using ultrasound: A systematic review.

To investigate the reliability, validity, and level of evidence of applying ultrasound in assessing the lower-limb muscles of patients with cerebral palsy (CP). Publications in Medline, PubMed, Web of Science, and Embase were searched on May 10, 2023, to identify and examine relevant studies investigating the reliability/validity of ultrasound in evaluating the architecture of CP lower-limb muscles systematically, following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 guidelines. Out of 897 records, 9 publications with 111 CP participants aged 3.8-17.0 years were included (8 focused on intra-rater and inter-rater reliability, 2 focused on validity, and 4 were with high quality). The ultrasound-based measurements of muscle thickness (intra-rater only), muscle length, cross-sectional area, muscle volume, fascicle length, and pennation angle showed high reliability, with the majority of intraclass correlation coefficient (ICC) values being larger than 0.9. Moderate-to-good correlations between ultrasound and magnetic resonance imaging measurements existed in muscle thickness and cross-sectional area (0.62 ≤ ICC ≤ 0.82). Generally, ultrasound has high reliability and validity in evaluating the CP muscle architecture, but this is mainly supported by moderate and limited levels of evidence. More high-quality future studies are needed.

Comparison of the Effectiveness of Ultrasound Imaging and Perioperative Measurement in the Diagnosis and Characterization of Incisional Hernia.

Incisional hernia (IH) is a common complication after abdominal surgery, and there is no gold standard imaging modality for its diagnosis. Although computed tomography is frequently used in clinical practice, it has limitations such as radiation exposure and relatively high cost. The aim of this study is to establish standardization and hernia typing by comparing preoperative ultrasound (US) measurements and perioperative measurements in IH cases. The patients who were operated for IH in our institution between January 2020 and March 2021 were reviewed, retrospectively. In result, 120 patients were included in the study, and the cases had preoperative US images and perioperative hernia measurements. IH was divided into three subtypes as omentum (Type I), intestinal (Type II), and mixed (Type III) according to the defect content. Type I IH was detected in 91 cases, Type II IH in 14 cases, and Type III IH in 15 cases. When the diameters of IH types were compared for preoperative US and perioperative measurements, respectively, there was no statistical significance (P = 0.185 and P = 0.262). According to Spearman correlation, there was a positive very strong correlation between preoperative US measurements and perioperative measurements (ρ = 0.861 and P < 0.001). As stated by our results, US imaging can be performed easily and quickly, providing a reliable way to accurately detect and characterize an IH. It can also facilitate the planning of surgical intervention in IH by providing anatomical information.

Optically excited nanoparticle enhanced high intensity focused ultrasound therapy of in vivo cancer models

The use of plasmonic gold nanoparticles (AuNP) that have been actively targeted to a specific tumour region is a highly active area of research for both drug delivery and hypothermia applications. One application is providing in situ cavitation nuclei for enhancing high intensity focused ultrasound (HIFU) ablation. When the nanoparticles are simultaneously exposed to HIFU and pulsed laser illumination, microscopic vapour bubbles form providing a controllable way to nucleate cavitation. Using an EGFR-expressing head and neck xenograft model, the biodistribution of targeted and untargeted AuNPs were examined using multispectral, whole body photoacoustic imaging, and inductively coupled plasma mass spectrometry (ICP-MS) analysis following systemic or intratumoral injections. Systemic delivery showed negligible concentration of AuNRs in the tumour; however, intratumoral injection increased its concentration, but remained in the tumour at high concentration for the first 48hrs. Evaluation of ablation performance was undertaken using the same tumour model. An intratumoural injection of untargeted particles, with single 10 s continuous wave HIFU exposures for peak positive/negative pressures of 2.4/2.0 MPa, with simultaneous illumination of 1064 nm pulsed laser light with a surface energy density of 70 mJ/cm2. Post treatment tumour volume was monitored using high frequency ultrasound imaging and calliper measurements, to evaluate exposure efficacy.

Protocol and reference values for minimal detectable change of MyotonPRO and ultrasound imaging measurements of muscle and subcutaneous tissue

The assessment of muscle health is of paramount importance, as the loss of muscle mass and strength can affect performance. Two non-invasive tools that have been found to be useful in this are the MyotonPRO and rehabilitative ultrasound imaging, both have shown to be reliable in previous studies many of which conducted by the research team. This study aims to determine the reliability of previously unassessed local body structures and to determine their minimal detectable changes (MDC) to support both researchers and clinicians. Twenty healthy participants were recruited to determine the reliability of seven skin positions out of a previously established protocol. Reliability was determined between three independent raters, and day to day reliability was assessed with one rater a week apart. Intraclass Correlation Coefficients (ICC) between raters and between days for tissue stiffness, tone and elasticity range from moderate to excellent (ICC 0.52–0.97), with most good or excellent. ICCs for subcutaneous thickness between days was good or excellent (ICC 0.86–0.91) and moderate to excellent between raters (ICC 0.72–0.96), in muscles it was moderate to excellent between raters and days (ICC 0.71–0.95). The protocol in this study is repeatable with overall good reliability, it also provides established MDC values for several measurement points.

Considerations about L2- and L1-norm regularizations for ultrasound reverberation characteristics imaging and vectoral Doppler measurement.

The L1-norm regularization is applied to ultrasonic reverberation characteristics imaging and vectoral Doppler measurement, of which performances are compared with those of L2-norm regularizations. The L1 regularization yields the sharper image than the L2 regularization. Alternatively, for the Doppler measurement, the L1 regularization yields less accuracy than the L2 regularization. Clinical Relevance- This study will permit us to perform quantitative ultrasonic reverberation characteristics and accurate vectoral Doppler observation.

Subclinical carotid artery atherosclerosis and cognitive function in older adults

BackgroundThe combined effects of increased life expectancy and the considerable number of persons reaching old age will magnify the dementia epidemic in the USA. Demonstration that subclinical atherosclerosis precedes and is associated with cognitive impairment suggests a modifiable risk factor for age-associated cognitive impairment and dementia. The purpose of this study is to determine whether subclinical atherosclerosis as measured by carotid artery intima-media thickness (CIMT) is associated with changes in cognitive function over time in older adults.MethodsThis study combined longitudinal data from three clinical trials conducted between 2000 and 2013: the B-Vitamin Atherosclerosis Intervention Trial (BVAIT), the Women’s Isoflavone Soy Health (WISH) trial, and the Early versus Late Intervention Trial with Estradiol (ELITE). Participants were recruited from the general population in the Greater Los Angeles area and were free of cardiovascular disease and diabetes; no cognitive or psychiatric exclusion criteria were specified. The same standardized protocol for ultrasound image acquisition and measurement of CIMT was used in all trials. CIMT measurements performed at baseline and 2.5 years were used in these analyses. Cognitive function was assessed at baseline and 2.5 years using a battery of 14 standardized cognitive tests. All clinical trials were conducted at the University of Southern California Atherosclerosis Research Unit, Los Angeles, and had at least 2.5 years of cognitive follow-up.ResultsA total of 308 men and 1187 women, mean age of 61 years, were included in the combined longitudinal dataset for the primary analysis. No associations were found between CIMT and cognitive function at baseline or at 2.5 years. There was a weak inverse association between CIMT measured at baseline and change in global cognition assessed over 2.5 years (β (SE) = − 0.056 (0.028) units per 0.1 mm CIMT, 95% CI − 0.110, − 0.001, p = 0.046). No associations between CIMT at baseline and changes in executive function, verbal memory, or visual memory were found.ConclusionsIn this sample of healthy older adults, our findings suggest an association between subclinical atherosclerosis and change in global cognitive function over 2.5 years. Stronger associations were observed longitudinally over 2.5 years than cross-sectionally. When analysis was stratified by age group (<65 and ≥65 years old), the inverse association remained statistically significant for participants in the older age group. Subclinical atherosclerosis of the carotid artery may be a modifiable correlate of cognitive decline in middle and older age.Trial registrationBVAIT, NCT00114400. WISH, NCT00118846. ELITE, NCT00114517.

Reliability of muscle thickness and echo intensity measurements of the quadriceps: A novice examiner

IntroductionThis study aimed to investigate the reliability of muscle thickness (MT) and echo intensity (EI) of the quadriceps muscles using ultrasound imaging for a novice examiner. MethodsSixteen healthy adult women were included in the study, and images of the rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis were obtained on the same day and after one week by an examiner who had not performed an experiment on the measurement of ultrasound imaging. The measurers who analyzed all images were completely blind to the subject's name and date and order of measurements. Intraclass correlation coefficients (ICCs) were used as relative within-day and between-day reliability of measurement. Absolute reliability was based on Bland–Altman analysis, standard error of measurement, and minimum detectable change. ResultsThe ICCs ranged from 0.76 to 0.95. As the results of the Bland–Altman analysis, all MTs and EIs included 0 in the 95% confidence interval of the mean difference. DiscussionOur results suggest that quadriceps ultrasound images have high reliability for MT and EI for all muscles. There were no systematic errors in both MT and EI. ConclusionIt might indicate that even novice examiners could obtain MT and EI measurements without systematic error after a few hours of practice.

Concurrent Validity and Test-Retest Reliability of The Core Stability Test Using Ultrasound Imaging and Electromyography Measurements

<h3>Research Objectives</h3> To establish the concurrent validity and test-retest reliability of the formal test. <h3>Design</h3> Two-group test-retest reliability design. <h3>Setting</h3> 1) A certified physical therapist uses a formal test as a pressure biofeedback unit (PBU) to classify the participants into core stability groups and instability groups. 2) Perform a formal test on each group and measure the thickness of abdominal muscles with real-time ultrasound (US). 3) Investigate the correlation between the thickness of abdominal muscles and PBU pressure. 4) Re-measure after 24 hours to verify test-retest reliability. <h3>Participants</h3> 11 young adults with core instability (8 men and 3 women) were able to successfully perform the formal test three consecutive times and completed the abdominal draw-in maneuver core stabilization training augmented by PBU-US-EMG feedback, for 20 minutes a day, 7 days a week, over two weeks.11 young adults with core stability (8 men and 3 women) were unable to successfully perform the formal test three consecutive times. <h3>Interventions</h3> No intervention. <h3>Main Outcome Measures</h3> 1) Real-time US and surface EMG to measure the thickness of deep abdominal and superficial trunk muscle activity. 2) PBU pressure under the abdomen. <h3>Results</h3> The Pearson's correlation analysis showed an excellent correlation between transverse abdominal (TrA) thickness and PBU pressure as well as internal oblique (IO) thickness and PBU pressure, ranging from r=0.856 – 0.980, P < 0.05. The test-retest reliability was good, ICC1,2 = 0.876 for the core stability pressure measure and ICC1,2 = 0.939 to 0.989 for the abdominal muscle thickness measure. <h3>Conclusions</h3> Our findings demonstrate that the formal test, using a PBU and real-time US imaging without confirming the minimal contraction of superficial trunk muscles, as evidenced by EMG, leads to incorrect results. For example, such results in adults or individuals with core instability pathology ultimately influence rehabilitation programs designed to improve core stability. Therefore, the combination of a PBU, real-time US, and surface EMG measurements may help obtain more reliable results from the formal tests and better understand the neuromuscular control mechanisms of core stability. <h3>Author(s) Disclosures</h3> There are no conflicts.

Ultrasound imaging measures of vertebral bony landmark distances are weakly to moderately correlated with intervertebral disc height as assessed by MRI.

ObjectivesTo assess the validity and reliability of ultrasound-derived interbony landmark distances as a proxy for MRI-derived intervertebral disc (IVD) height.MethodsThis is a cross-sectional criterion validity study. Twelve college-aged participants without current low back pain completed both MRI and ultrasound imaging of the lumbar spine in a prone position. Single-segment and multisegment distances between the spinous and mammillary processes at the lumbar segments (L2/L3, L3/L4, L4/L5) were measured twice using ultrasound and analysed digitally. Sagittal slices of the lumbar spine were taken via T1-weighted MRI and IVD height, and the overall distance between IVDs L2/L3 and L4/L5 was imaged once and measured twice.ResultsThere was moderate correlation between multilevel-based measurements (overall distance between L2 and L5, r=0.677, p=0.016) and the average across three levels (r=0.596, p=0.041) when using the spinous processes as bony landmarks. Single-segment measures were not significantly correlated (all: p>0.092). Accuracy and precision were better for the overall MRI-derived distance between the three IVDs from L2 and L5 MRI and the distance measured between the spinous processes L2–L5. There was excellent reliability within multiple measurements at each location, with intraclass correlation coefficient, ICC(3,1), ranging from 0.93 to 0.99 (95% CI 0.82 to 0.99) for ultrasound and from 0.98 to 0.99 (95% CI 0.92 to 0.99) for MRI.ConclusionFindings do not support the use of ultrasound imaging for estimating single-segment IVD height, yet it may be used to measure the change in distance over time with a certain degree of precision based on its excellent reliability.

Anterior Lens Curvature Matters in the Course of Primary Angle Closure: An Analysis Based on Ultrasound Biomicroscopic Imaging.

Purpose To evaluate the effect of anterior lens curvature in primary angle closure (PAC) and find additional anatomical features of crystalline lens that may predispose primary angle closure to the acute course. Methods 435 eyes (263 subjects) were enrolled in this study. Four groups of eyes were included based on angle configurations and clinical features: (i) acute primary angle closure (APAC, 140 eyes); (ii) chronic primary angle closure (CPAC, 116 eyes); (iii) primary angle closure suspect (PACS, 84 eyes); and (iv) normal controls (95 eyes). All patients underwent thorough ophthalmic exams including applanation tonometry, gonioscopy, low-coherence interferometry, and ultrasound biomicroscopic imaging. Based on the panoramic anterior segment images from ultrasound biomicroscopic imaging measurements, the radius of anterior lens curvature (ALR) was calculated using the least-squares curve fitting technique. ALR, in addition to axial length (AL), anterior chamber depth (ACD), and lens thickness (LT), was compared among different groups using univariate and multivariate analysis with mixed effects linear model. Results APAC, CPAC, and PACS groups all had steeper ALR, shorter AL, shallower ACD, and thicker LT than normal control group. ACD and LT further differ between APAC and CPAC or PACS eyes. Moreover, a steeper ALR was also found in the APAC group as compared to CPAC, PACS, and normal control groups. Conclusions A steeper ALR may predispose the acute attack of PAC. In addition to the relative lens position and size, lens curvature is another variable that contributes to the pathophysiological mechanisms of primary angle closure.

NHBS-Net: A Feature Fusion Attention Network for Ultrasound Neonatal Hip Bone Segmentation.

Ultrasound is a widely used technology for diagnosing developmental dysplasia of the hip (DDH) because it does not use radiation. Due to its low cost and convenience, 2-D ultrasound is still the most common examination in DDH diagnosis. In clinical usage, the complexity of both ultrasound image standardization and measurement leads to a high error rate for sonographers. The automatic segmentation results of key structures in the hip joint can be used to develop a standard plane detection method that helps sonographers decrease the error rate. However, current automatic segmentation methods still face challenges in robustness and accuracy. Thus, we propose a neonatal hip bone segmentation network (NHBS-Net) for the first time for the segmentation of seven key structures. We design three improvements, an enhanced dual attention module, a two-class feature fusion module, and a coordinate convolution output head, to help segment different structures. Compared with current state-of-the-art networks, NHBS-Net gains outstanding performance accuracy and generalizability, as shown in the experiments. Additionally, image standardization is a common need in ultrasonography. The ability of segmentation-based standard plane detection is tested on a 50-image standard dataset. The experiments show that our method can help healthcare workers decrease their error rate from 6%-10% to 2%. In addition, the segmentation performance in another ultrasound dataset (fetal heart) demonstrates the ability of our network.

Concurrent Validity and Test-retest Reliability of the Core Stability Test Using Ultrasound Imaging and Electromyography Measurements

Background: While the formal test has been used to provide a quantitative measurement of core stability, studies have reported inconsistent results regarding its test-retest and intraobserver reliabilities. Furthermore, the validity of the formal test has never been established. Objects: This study aimed to establish the concurrent validity and test-retest reliability of the formal test. Methods: Twenty-two young adults with and without core instability (23.1 ± 2.0 years) were recruited. Concurrent validity was determined by comparing the muscle thickness changes of the external oblique, internal oblique, and transverse abdominal muscle to changes in core stability pressure during the formal test using ultrasound (US) imaging and pressure biofeedback, respectively. For the test-retest reliability, muscle thickness and pressure changes were repeatedly measured approximately 24 hours apart. Electromyography (EMG) was used to monitor trunk muscle activity during the formal test. Results: The Pearson’s correlation analysis showed an excellent correlation between transverse abdominal thickness and pressure biofeedback unit (PBU) pressure as well as internal oblique thickness and PBU pressure, ranging from r = 0.856–0.980, p < 0.05. The test-retest reliability was good, intraclass correlation coefficient (ICC1,2) = 0.876 for the core stability pressure measure and ICC1,2 = 0.939 to 0.989 for the abdominal muscle thickness measure. Conclusion: Our results provide clinical evidence that the formal test is valid and reliable, when concurrently incorporated into EMG and US measurements.

Implementation of a real-time, ultrasound-guided prostate HDR brachytherapy program.

This work presents a comprehensive commissioning and workflow development process of a real‐time, ultrasound (US) image‐guided treatment planning system (TPS), a stepper and a US unit. To adequately benchmark the system, commissioning tasks were separated into (1) US imaging, (2) stepper mechanical, and (3) treatment planning aspects. Quality assurance US imaging measurements were performed following the AAPM TG‐128 and GEC‐ESTRO recommendations and consisted of benchmarking the spatial resolution, accuracy, and low‐contrast detectability. Mechanical tests were first used to benchmark the electronic encoders within the stepper and were later expanded to evaluate the needle free length calculation accuracy. Needle reconstruction accuracy was rigorously evaluated at the treatment planning level. The calibration length of each probe was redundantly checked between the calculated and measured needle free length, which was found to be within 1 mm for a variety of scenarios. Needle placement relative to a reference fiducial and coincidence of imaging coordinate origins were verified to within 1 mm in both sagittal and transverse imaging planes. The source strength was also calibrated within the interstitial needle and was found to be 1.14% lower than when measured in a plastic needle. Dose calculations in the TPS and secondary dose calculation software were benchmarked against manual TG‐43 calculations. Calculations among the three calculation methods agreed within 1% for all calculated points. Source positioning and dummy coincidence was tested following the recommendations of the TG‐40 report. Finally, the development of the clinical workflow, checklists, and planning objectives are discussed and included within this report. The commissioning of real‐time, US‐guided HDR prostate systems requires careful consideration among several facets including the image quality, dosimetric, and mechanical accuracy. The TPS relies on each of these components to develop and administer a treatment plan, and as such, should be carefully examined.

Evaluating the agreement of ultrasound imaging and beta-human chorionic gonadotropin (β-hCG) measurement in confirming completed medical abortion: cross-sectional study.

Objective: Clinical methods that are generally used to evaluate the completeness of medical abortion are not reliable. Ultrasound imaging and beta-human chorionic gonadotropin (β-hCG) measurements are used to diagnose completed medical abortion, but a precise evaluation of these two methods has shown contradictory results. The purpose of this study is to evaluate the agreement of serum β-hCG measurement and ultrasound imaging to confirm complete medical abortion.Materials and Methods: This study was conducted on pregnant women who had been referred to our center for medical abortion from 2015 to 2017. All cases occurred in the first trimester of pregnancy. They obtained one or two doses of vaginal misoprostol for medical abortion. Success rate of medical abortion was measured by both transvaginal ultrasound imaging and consecutive serum β-hCG measurements two to four weeks after initial treatment.Results: Among the 275 women who completed the study, complete medical abortion was confirmed by serum β-hCG in 231 women (84.3%) and transvaginal ultrasound imaging in 195 women (70.8%) after two weeks. All remaining cases completed the medical abortion after an additional two weeks, confirmed by both transvaginal ultrasound imaging and serum β-hCG. The sensitivity, specificity, positive, and negative predictive values of β-hCG were 95.2%, 86.7%, 84%, and 70%, respectively; and these values for transvaginal ultrasound imaging were 68.5% 64.5%,77%, and 30.%, respectively, for the diagnosis of completed medical abortion.Conclusion: Serum β-hCG measurement is as effective as transvaginal ultrasound imaging to confirm successful medical abortion in early pregnancy.

PO38: Commissioning and Workflow Development for a Real-Time, Ultrasound-Guided Prostate HDR Brachytherapy Program

Purpose: This work presents the commissioning of a real-time, ultrasound (US)-guided HDR brachytherapy system (Elekta AB, Inc.), including the hardware, US imaging system, treatment planning system (TPS) (Oncentra Prostate), and the developed workflow.Materials and Methods: Commissioning tasks were separated into (1) US imaging, (2) stepper mechanicals, and (3) treatment planning aspects. Quality assurance US imaging measurements consisted of benchmarking the spatial resolution, accuracy, and low-contrast detectability. Mechanical tests were first performed to validate the electronic encoders used within the stepper and were later expanded to evaluate the needle free length calculation accuracy. Several system-integrated measurements were performed to verify needle positioning accuracy and imaging origin coincidence measurements using the needle free length measurement as a surrogate marker, as this remains one of the largest potential sources of error. The workflow was developed through a multi-disciplinary team, including physicians, radiation-therapists, nurses, physicists, administration staff, sterilization and anesthesia staff and included multi-dry-runs of the full procedure. A detailed description of each party's role was also developed, including checklists for the planning physicist, a secondary check physicist, and a radiation therapist.Results: Needle placement accuracy was verified to within 1 mm for both sagittal and transverse imaging planes. Needle reconstruction accuracy was also rigorously evaluated. The source strength was also calibrated with the interstitial needle and was found to be 1.14% lower than when measured in a plastic needle. The calibration length of each probe was redundantly check between the calculated and measured needle free length, which was found to be within 1 mm for a variety of scenarios. Dose calculations in the TPS and secondary dose calculation software were benchmarked against manual TG-43 calculations, which were within 1% for all calculated points. Source positioning and dummy coincidence was also verified. The US-guided HDR prostate procedure consisted of six primary components: (1) the delineation of personnel and their roles, (2) HDR suite preparation prior to the treatment day, (3) day of treatment preparations, (4) patient setup, (4) pre-needle insertion plan, (5) initial insertion and live reconstruction, and (6) final imaging and planning. A set of plan evaluation metrics were established based on the currently available guidelines (ABS, ESTRO, and RTOG) and the culmination of clinical experiences across multiple institutions.Conclusions: The commissioning of real-time, US-guided HDR prostate systems requires careful consideration among several facets including the image quality, dosimetric and mechanical accuracy. The TPS relies on each of these components to develop and administer a treatment plan, and as such, should be carefully examined.

Biological measures of synovial inflammation predict pain, symptoms, and ultrasound measures of synovitis in knee OA

Purpose: Synovial inflammation (synovitis or effusion-synovitis) measured via clinical imaging (i.e., magnetic resonance imaging (MRI), ultrasound (US)) has been shown to be related to worse outcomes in people with knee OA, including worse pain, higher risk of OA incidence and progression, and increased risk of requiring a total knee arthroplasty (TKA). Recent studies have shown associations between synovial histopathology and structural features of knee OA and MRI measures of synovitis. However, the relationship between histopathology and patient symptoms remains unclear. Histopathology measures of synovial inflammation represent a set of measures that are related to biological disease activity in OA. Therefore, the aim of this study was to establish the link between synovial inflammation and clinical outcomes. Methods: Patients were recruited from the Western Ontario Registry for Early Osteoarthritis (WOREO): Knee Study. Ninety-two people with severe symptoms and radiographic damage (Kellgren-Lawrence (KL) grades 3 or 4) undergoing surgery for end-stage knee OA were included. Patients completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire specific to each knee and a self-reported patient global assessment (PGA). An investigator global assessment (IGA) was also completed for each patient. Musculoskeletal-US was used to measure effusion-synovitis in suprapatellar mid-line, lateral, and medial windows (0-3; None-Severe; summed (0-9) and maximum effusion depth (mm). Power Doppler signal was also assessed as absent or present (0 or 1). Lateral suprapatellar synovial biopsies were obtained at time of surgery. Routine histopathology was scored in six domains, on 5 slides per patient; mean scores were binned into categories 0, 0.5-1.5, and 2-3 (none, mild, moderate-severe). Composite histopathology scores were created based on previously published literature, principal component analysis (Eigen values ≥ 1.0), and biological rationale. We fitted a series of multivariate linear or logistic regression models to evaluate the association of histopathology (individual and composite) scores with clinical outcomes and US imaging measures of synovitis. All analyses were adjusted for age, sex, and body mass index (BMI). Robust sandwich estimators were used. Results include unstandardized β coefficients or odds ratios (OR) with 95% confidence intervals (CIs). All analyses completed using StataIC 15.1. Results: A total of 92 patients were included (Table 1). Of the 6 histopathology domains, more severe perivascular edema was most strongly associated with lower (worse) KOOS pain, ADL, and QoL subscale scores (Table 2). Synovial lining and sub-synovial infiltrate scores were significantly associated with more severe effusion-synovitis measured by US grading and maximum effusion depth (Table 3). Vascularization was associated with higher synovitis score, while more severe fibrosis was associated with high QoL scores (Table 2) and lower US synovitis score (Table 3). Synovial histopathology principal components accounted for approximately 70% of the variance in the dataset but there were minimal associations with clinical and imaging outcomes (Table 4). The histopathology inflammatory composite scores were most strongly associated with KOOS subscale scores (Table 4). Conclusions: Inflammation measured with synovial histopathology is associated with knee-specific pain, symptoms and US imaging measures of inflammation in patients with end-stage knee OA. These findings may help us to better understand OA overall. We provide biological evidence supporting the known relationship between knee inflammation and OA outcomes, which is largely based on imaging assessment in the literature.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)