Reliance on sources of immunization information and vaccine uptake among older adults in a rural state: The mediating role of trust.

Older adults are more vulnerable to the negative impacts of infectious diseases than younger individuals. However, regardless of the importance and effectiveness of vaccines to reduce morbidity and mortality, issues remain with vaccine hesitancy among this population. Older adults' sources of immunization information and their level of trust in those sources may play a role in their vaccination behaviors. This research aimed to better understand the role of information sources and related issues of trust as related to vaccine uptake among older adults. A community-based, cross-sectional survey was conducted with 901 older adults in North Dakota in May-July 2022. Measures included extent of reliance on specific sources of immunization information, levels of trust, and uptake for influenza, pneumonia, shingles, and COVID-19 vaccinations. Immunization information sources were grouped into medical experts, informal, and public outlets. Results indicated older adults were more likely to rely on medical experts than informal sources or public outlets for immunization information. Greater reliance on medical experts was associated with a greater likelihood of vaccine uptake for all vaccines, while reliance on public outlets was associated with a greater likelihood of vaccine uptake only for COVID primary series and boosters. Reliance on informal sources for immunization information was associated with a reduced likelihood of vaccine uptake for all vaccines except shingles. Nearly half of respondents were uncertain who to trust for vaccine information. Uncertainty who to trust for immunization information significantly mediated the associations between reliance on medical experts and uptake for most vaccines indicating that trust in medical experts fosters vaccine uptake. Increasing reliance on medical experts as sources of immunization information is vital to increasing vaccine uptake among older adults. Additionally, this population must be assisted in increasing their ability to successfully assess the trustworthiness of immunization information sources.

Vaccination Motivators and Deterrents Among Undervaccinated Older Adults in North Dakota.

Despite increased risk of morbidity and mortality among older adults due to preventable infectious diseases such as influenza, shingles, pneumonia, and COVID-19, many forego receiving some, if not all, of these vaccinations. This study examines vaccination motivators and deterrents for undervaccinated older adults in North Dakota (ND). Adults aged 65+ in ND were mailed a survey (n = 901) with questions gauging vaccination behaviors and perceptions, with 132 of these indicating not receiving certain vaccinations. Further questions assessed reasons they have not been vaccinated against the following diseases: influenza, shingles, pneumonia, and COVID-19 (e.g., "Concerned about side effects", "Vaccines are dangerous", "I'm healthy and I do not need it") and what would make it more likely to get a vaccine (e.g., "More information", "Doctor recommendation", "Easy access to vaccines"). Reasons for remaining unvaccinated varied by vaccine. For influenza and pneumococcal vaccines, respondents were more likely to indicate they are healthy and do not need the vaccine. For shingles and COVID-19, respondents were more likely to indicate concerns about side effects. Factors reported to motivate increasing the likelihood of getting a vaccine were receiving a doctor recommendation, receiving more information, and having a vaccine provided at no cost. These results contribute to our understanding of vaccination behaviors among older adults and underscore specific issues around which to frame interventions tailored to increase vaccine uptake for this population.

Image Quality Enhancement for Digital Breast Tomosynthesis: High-Density Object Artifact Reduction.

Breast cancer has a high incidence and mortality rate among women, early diagnosis is essential as it gives insight regarding the most appropriate therapeutic strategy for each case. Among all imaging diagnostic methods, digital breast tomosynthesis (DBT) is effective for early breast cancer detection. In DBT images, high-density object artifacts are generated when imaging objects with high X-ray absorptivity, which include metal artifacts, ripple artifacts, and deformation artifacts. In this study, we analyze the causes of these artifacts and propose a set of high-density object reconstruction methods based on iterative algorithms. Our method includes a reprojection-based high-density object projection data segmentation algorithm and an iterative reconstruction algorithm based on volume expansion. The experiments on simulation data and the human breast data with artificial surgical needles prove the effectiveness of our method. By using our algorithm, the problem of distorting the shape, size, and position of high-density objects during DBT reconstruction is raised, the influence of these artifacts is reduced, and the quality of the DBT reconstructed image is improved. We hope that our algorithm might contribute to promoting the usage of DBT.

Estimating the prevalence of COVID-19 cases through the analysis of SARS-CoV-2 RNA copies derived from wastewater samples from North Dakota.

The SARS-CoV-2 virus was first detected in December 2019, which prompted many researchers to investigate how the virus spreads. SARS-CoV-2 is mainly transmitted through respiratory droplets. Symptoms of the SARS-CoV-2 virus appear after an incubation period. Moreover, the asymptomatic infected individuals unknowingly spread the virus. Detecting infected people requires daily tests and contact tracing, which are expensive. The early detection of infectious diseases, including COVID-19, can be achieved with wastewater-based epidemiology, which is timely and cost-effective. In this study, we collected wastewater samples from wastewater treatment plants in several cities in North Dakota and then extracted viral RNA copies. We used log-RNA copies in the model to predict the number of infected cases using Quantile Regression (QR) and K-Nearest Neighbor (KNN) Regression. The model's performance was evaluated by comparing the Mean Absolute Percentage Error (MAPE). The QR model performs well in cities where the population is >10000. In addition, the model predictions were compared with the basic Susceptible-Infected-Recovered (SIR) model which is the golden standard model for infectious diseases.

Vaccine attitudes and acceptance among older adults in North Dakota: Understanding demographic characteristic variability.

OBJECTIVES: Older adults face increased risks from infectious diseases which are often preventable with vaccines. The current study examines demographic variation in vaccine hesitancy among older adults in North Dakota. METHODS: A mailed survey assessing age, gender, years of education, self-rated health, rurality, and political leaning as well as vaccine attitudes and vaccine acceptance was conducted with 739 older adults (65+), oversampled from rural counties. RESULTS: Vaccine hesitant attitudes were significantly higher among rural and politically-conservative older adults; whereas, vaccine acceptance was significantly higher among older, healthier, and politically-liberal older adults. Vaccine attitudes were significantly associated with vaccine acceptance and mediated the association between political leaning and vaccine acceptance. DISCUSSION: These findings highlight the demographic characteristics predictive of older adults' vaccine attitudes and acceptance. By better understanding the nuanced factors leading to hesitation to be vaccinated, practitioners can develop strategies to increase vaccination rates among this at-risk population.

Ultrasound: Imaging, development, application.

A brief summary is given of my work in ultrasound imaging and therapy, with some information on the role of this journal in those fields.

Real-time, volumetric imaging of radiation dose delivery deep into the liver during cancer treatment.

Ionizing radiation acoustic imaging (iRAI) allows online monitoring of radiation's interactions with tissues during radiation therapy, providing real-time, adaptive feedback for cancer treatments. We describe an iRAI volumetric imaging system that enables mapping of the three-dimensional (3D) radiation dose distribution in a complex clinical radiotherapy treatment. The method relies on a two-dimensional matrix array transducer and a matching multi-channel preamplifier board. The feasibility of imaging temporal 3D dose accumulation was first validated in a tissue-mimicking phantom. Next, semiquantitative iRAI relative dose measurements were verified in vivo in a rabbit model. Finally, real-time visualization of the 3D radiation dose delivered to a patient with liver metastases was accomplished with a clinical linear accelerator. These studies demonstrate the potential of iRAI to monitor and quantify the 3D radiation dose deposition during treatment, potentially improving radiotherapy treatment efficacy using real-time adaptive treatment.

Collaborative approach to harm reduction by managed care pharmacy team for populations with substance use disorder.

BACKGROUND: Oregon has one of the highest rates of substance use and substance use disorders (SUDs) in the nation. To improve access to SUD treatment in Oregon, CareOregon clinical pharmacists in collaboration with the behavioral health team have implemented these best practices to support members with SUD. OBJECTIVE: The primary objective of this article is to describe the various harm reduction programs and interventions implemented by managed care clinical pharmacists at CareOregon to prevent overdose and ensure improved health outcomes for populations with SUD. PRACTICE DESCRIPTION: The CareOregon team of managed care clinical pharmacists acts as a liaison with provider networks by providing pharmacy benefit knowledge and implementing several interventions and best practices to improve health outcomes for populations with SUD. PRACTICE INNOVATION: The managed care clinical pharmacist team implemented a medication education (MEDS Ed) program to provide educational support to the CareOregon provider network on harm reduction, supported medication for opioid use disorder (MOUD) program initiatives to increase buprenorphine prescribing, and used programs to increase naloxone access for populations at high risk of overdose. EVALUATION METHODS: A mixed-method approach was applied to evaluate the impact of the practice innovations implemented. A qualitative self-assessment questionnaire was used to evaluate the impact of the harm reduction MEDS Ed. Quantitative data accessed via CareOregon's claims data were used to evaluate the effect of initiatives to expand naloxone access and increase buprenorphine prescribing. RESULTS: The CareOregon provider network reported an increase in knowledge about harm reduction by attending the MEDS Ed training. From the first quarter of 2019 to the second quarter of 2022, the number of naloxone prescriptions filled increased by 346%. From the third quarter of 2017 to the first quarter of 2022, the number of Drug Addiction Treatment Act-waivered providers prescribing buprenorphine increased by 331%. As a result, the number of prescriptions for MOUD doubled during this period. CONCLUSION: The harm reduction interventions implemented by the managed care clinical pharmacist team at CareOregon were successful in improving knowledge on harm reduction and increasing naloxone access and buprenorphine prescribing for populations at risk of opioid use disorder.

Antibiotic Prescribing Practices for Upper Respiratory Tract Infections Among Primary Care Providers: A Descriptive Study.

Background: Most antibiotics are prescribed in the ambulatory setting with estimates that up to 50% of use is inappropriate. Understanding factors associated with antibiotic misuse is essential to advancing better stewardship in this setting. We sought to assess the frequency of unnecessary antibiotic use for upper respiratory infections (URIs) among primary care providers and identify patient and provider characteristics associated with misuse. Methods: Unnecessary antibiotic prescribing was assessed in a descriptive study by using adults ≥18 years seen for common URIs in a large, Upper Midwest, integrated health system, electronic medical records from June 2017 through May 2018. Individual provider rates of unnecessary prescribing were compared for primary care providers practicing in the departments of internal medicine, family medicine, or urgent care. Patient and provider characteristics associated with unnecessary prescribing were identified with a logistic regression model. Results: A total of 49 463 patient encounters were included. Overall, antibiotics were prescribed unnecessarily for 42.2% (95% confidence interval [CI], 41.7-42.6) of the encounters. Patients with acute bronchitis received unnecessary antibiotics most frequently (74.2%; 95% CI, 73.4-75.0). Males and older patients were more likely to have an unnecessary antibiotic prescription. Provider characteristics associated with higher rates of unnecessary prescribing included being in a rural practice, having more years in practice, and being in higher volume practices such as an urgent care setting. Fifteen percent of providers accounted for half of all unnecessary antibiotic prescriptions. Conclusions: Although higher-volume practices, a rural setting, or longer time in practice were predictors, unnecessary prescribing was common among all providers.

Feasibility of ultrasound tomography-guided localized mild hyperthermia using a ring transducer: Ex vivo and in silico studies.

BACKGROUND: As of 2022, breast cancer continues to be the most diagnosed cancer worldwide. This problem persists within the United States as well, as the American Cancer Society has reported that ∼12.5% of women will be diagnosed with invasive breast cancer over the course of their lifetime. Therefore, a clinical need continues to exist to address this disease from a treatment and therapeutic perspective. Current treatments for breast cancer and cancers more broadly include surgery, radiation, and chemotherapy. Adjuncts to these methods have been developed to improve the clinical outcomes for patients. One such adjunctive treatment is mild hyperthermia therapy (MHTh), which has been shown to be successful in the treatment of cancers by increasing effectiveness and reduced dosage requirements for radiation and chemotherapies. MHTh-assisted treatments can be performed with invasive thermal devices, noninvasive microwave induction, heating and recirculation of extracted patient blood, or whole-body hyperthermia with hot blankets. PURPOSE: One common method for inducing MHTh is by using microwave for heat induction and magnetic resonance imaging for temperature monitoring. However, this leads to a complex, expensive, and inaccessible therapy platform. Therefore, in this work we aim to show the feasibility of a novel all-acoustic MHTh system that uses focused ultrasound (US) to induce heating while also using US tomography (UST) to provide temperature estimates. Changes in sound speed (SS) have been shown to be strongly correlated with temperature changes and can therefore be used to indirectly monitor heating throughout the therapy. Additionally, these SS estimates allow for heterogeneous SS-corrected phase delays when heating complex and heterogeneous tissue structures. METHODS: Feasibility to induce localized heat in tissue was investigated in silico with a simulated breast model, including an embedded tumor using continuous wave US. Here, both heterogenous acoustic and thermal properties were modeled in addition to blood perfusion. We further demonstrate, with ex vivo tissue phantoms, the feasibility of using ring-based UST to monitor temperature by tracking changes in SS. Two phantoms (lamb tissue and human abdominal fat) with latex tubes containing varied temperature flowing water were imaged. The measured SS of the water at each temperature were compared against values that are reported in literature. RESULTS: Results from ex vivo tissue studies indicate successful tracking of temperature under various phantom configurations and ranges of water temperature. The results of in silico studies show that the proposed system can heat an acoustically and thermally heterogenous breast model to the clinically relevant temperature of 42°C while accounting for a reasonable time needed to image the current cross section (200 ms). Further, we have performed an initial in silico study demonstrating the feasibility of adjusting the transmit waveform frequency to modify the effective heating height at the focused region. Lastly, we have shown in a simpler 2D breast model that MHTh level temperatures can be maintained by adjusting the transmit pressure intensity of the US ring. CONCLUSIONS: This work has demonstrated the feasibility of using a 256-element ring array transducer for temperature monitoring; however, future work will investigate minimizing the difference between measured SS and the values shown in literature. A hypothesis attributes this bias to potential volumetric average artifacts from the ray-based SS inversion algorithm that was used, and that moving to a waveform-based SS inversion algorithm will greatly improve the SS estimates. Additionally, we have shown that an all-acoustic MHTh system is feasible via in silico studies. These studies have indicated that the proposed system can heat a tumor within a heterogenous breast model to 42°C within a narrow time frame. This holds great promise for increasing the accessibility and reducing the complexity of a future all-acoustic MHTh system.

Characterizing the aggressiveness of prostate cancer using an all-optical needle photoacoustic sensing probe: feasibility study.

In our previous studies, we have developed a prototype interstitial needle sensing probe that can acquire broadband A-line photoacoustic (PA) signals encoding both tissue microarchitecture and histochemical information comparable to that accessible by histology. Paving the road toward clinical translation of this technology, we replaced the piezoelectric hydrophone in the needle PA probe with a fiber optic hydrophone that enabled both broader bandwidth and sufficient signal-to-noise ratio (SNR) for PA signal detection. Such an all-optical design also facilitated disposability and significantly reduced the footprint of the needle PA sensing probe. Experiments were performed on well-controlled phantoms and human prostate tissues. The microarchitectures in each sample were quantitatively evaluated by both the nonlinear spectral slope of the PA signal power spectrum and the generalized gamma (GG) parameter a by implementing envelope statistics to the PA signal. In the studies on phantoms containing optically absorbing microspheres with various sizes and concentrations, the nonlinear spectral slope showed a strong correlation of r=-0.80 with the microsphere dimensions, and a relatively weak correlation of r=-0.54 with the microsphere concentrations, while the GG parameter a showed a strong correlation with the microsphere dimensions (r=0.72) and a moderate correlation with the microsphere concentrations (r=0.63). In the studies on human prostate tissues containing progressive cancer stages, both the nonlinear spectral slope and the GG parameter a demonstrated a statistically significant difference between benign and nonaggressive cancer tissues (p<0.01), and between nonaggressive and aggressive cancer tissues (p<0.01). In addition, a multivariate analysis combining the two quantitative measurements demonstrated the boundaries among the different progressive stages of prostate cancer.

A simulation study of ionizing radiation acoustic imaging (iRAI) as a real-time dosimetric technique for ultra-high dose rate radiotherapy (UHDR-RT).

PURPOSE: Electron-based ultra-high dose rate radiation therapy (UHDR-RT), also known as Flash-RT, has shown the ability to improve the therapeutic index in comparison to conventional radiotherapy (CONV-RT) through increased sparing of normal tissue. However, the extremely high dose rates in UHDR-RT have raised the need for accurate real-time dosimetry tools. This work aims to demonstrate the potential of the emerging technology of Ionized Radiation Acoustic Imaging (iRAI) through simulation studies and investigate its characteristics as a promising relative in vivo dosimetric tool for UHDR-RT. METHODS: The detection of induced acoustic waves following a single UHDR pulse of a modified 6 MeV 21EX Varian Clinac in a uniform porcine gelatin phantom that is brain-tissue equivalent was simulated for an ideal ultrasound transducer. The full 3D dose distributions in the phantom for a 1 × 1 cm2 field were simulated using EGSnrc (BEAMnrc∖DOSXYZnrc) Monte Carlo (MC) codes. The relative dosimetry simulations were verified with dose experimental measurements using Gafchromic films. The spatial dose distribution was converted into an initial pressure source spatial distribution using the medium-dependent dose-pressure relation. The MATLAB-based toolbox k-Wave was then used to model the propagation of acoustic waves through the phantom and perform time-reversal (TR)-based imaging reconstruction. The effect of the various linear accelerator (linac) operating parameters, including linac pulse duration and pulse repetition rate (frequency), were investigated as well. RESULTS: The MC dose simulation results agreed with the film measurement results, specifically at the central beam region up to 80% dose within approximately 5% relative error for the central profile region and a local relative error of <6% for percentage dose depth. IRAI-based FWHM of the radiation beam was within approximately 3 mm relative to the MC-simulated beam FWHM at the beam entrance. The real-time pressure signal change agreed with the dose changes proving the capability of the iRAI for predicting the beam position. IRAI was tested through 3D simulations of its response to be based on the temporal changes in the linac operating parameters on a dose per pulse basis as expected theoretically from the pressure-dose proportionality. The pressure signal amplitude obtained through 2D simulations was proportional to the dose per pulse. The instantaneous pressure signal amplitude decreases as the linac pulse duration increases, as predicted from the pressure wave generation equations, such that the shorter the linac pulse the higher the signal and the better the temporal (spatial) resolutions of iRAI. The effect of the longer linac pulse duration on the spatial resolution of the 3D constructed iRAI images was corrected for linac pulse deconvolution. This correction has improved the passing rate of the 1%/1 mm gamma test criteria, between the pressure-constructed and dosimetric beam characteristics, to as high as 98%. CONCLUSIONS: A full simulation workflow was developed for testing the effectiveness of iRAI as a promising relative dosimetry tool for UHDR-RT radiation therapy. IRAI has shown the advantage of 3D dose mapping through the dose signal linearity and, hence, has the potential to be a useful dosimeter at depth dose measurement and beam localization and, hence, potentially for in vivo dosimetry in UHDR-RT.

Biomedical Photoacoustic Imaging With Unknown Spatially Distributed Ultrasound Sensor Array.

OBJECTIVE: With the growth of interest in different medical study on biological function, non-invasive photoacoustic imaging of biological tissue attracts the interests for researchers. To eliminate the limited angle effect of photoacoustic imaging based on ultrasound linear array, spatially distributed ultrasound sensor array is applied. The accurate sensor array position determines the quality of the imaging results. In this study, we proposed three methods based on photoacoustic and ultrasound signals to enhance the imaging quality using a 256-element full-ring array. METHODS: Groups of photoacoustic and ultrasound signals are used to regress the position of each element sensor. RESULT: In phantom study and mouse brain study, photoacoustic imaging results can both yield details clearly with average error rate of less than 1% (50 [Formula: see text]). CONCLUSION: The performance of our three methods have proved that they can be potentially applied to other ultrasound-based medical imaging studies with unknown distributed positions of sensor array to enhance the imaging quality. SIGNIFICANCE: The proposed methods can contribute to precise biomedical imaging with unknown distributed positions of sensor array in different application scenarios.

Prevalence of SARS-CoV-2 antibodies among North Dakota community pharmacy personnel: A seroprevalence survey.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of the coronavirus disease 2019 (COVID-19) pandemic, has disrupted much of the health care system. Despite changes in routine practices, community pharmacists have continuously served their patients throughout the pandemic. Frontline health care workers, including community pharmacy personnel, are at risk of becoming infected with SARS-CoV-2. OBJECTIVE: The purpose of this observational study was to report the prevalence of antibodies to SARS-CoV-2 from a sample of North Dakota community pharmacy personnel. METHODS: This observational study was conducted in 2 cities in North Dakota with the highest COVID-19 rates at the time of investigation. Community pharmacy personnel were tested for the presence of the SARS-CoV-2 IgG and IgM antibodies using a rapid antibody test. In addition to antibody testing, participants completed a questionnaire reporting on demographics, previous COVID-19 exposure, previous COVID-19 symptoms, and personal protection equipment (PPE) practices. RESULTS: A total of 247 pharmacy personnel from 29 pharmacies were tested for SARS-CoV-2 antibodies. The timing and use of PPE varied by location. Among the 247 community pharmacy personnel, 14.6% tested positive for IgM, IgG, or both. Survey data revealed a statistically significant association (P < 0.05) between a positive antibody test and direct contact with an individual who tested positive for COVID-19 (odds ratio: 2.65 [95% CI: 1.18-5.95]), but there were no statistically significant effects related to the workplace, including PPE use, personnel role, or the number of hours worked. The self-reported loss of taste or smell was the only significant symptom associated with a positive antibody test (18.91 [3.10-115.59]). CONCLUSION: Community pharmacy personnel may be at an increased risk for SARS-CoV-2 exposure compared with the general population.

Radiological Society of North America/Quantitative Imaging Biomarker Alliance Shear Wave Speed Bias Quantification in Elastic and Viscoelastic Phantoms.

OBJECTIVES: To quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms. METHODS: Two elastic phantoms, representing healthy through fibrotic liver, were measured with 5 different ultrasound platforms, and 3 viscoelastic phantoms, representing healthy through fibrotic liver tissue, were measured with 12 different ultrasound platforms. Measurements were performed with different systems at different sites, at 3 focal depths, and with different appraisers. The SWS bias across the systems was quantified as a function of the system, site, focal depth, and appraiser. A single MRE research system was also used to characterize these phantoms using discrete frequencies from 60 to 500 Hz. RESULTS: The SWS from different systems had mean difference 95% confidence intervals of ±0.145 m/s (±9.6%) across both elastic phantoms and ± 0.340 m/s (±15.3%) across the viscoelastic phantoms. The focal depth and appraiser were less significant sources of SWS variability than the system and site. Magnetic resonance elastography best matched the ultrasonic SWS in the viscoelastic phantoms using a 140 Hz source but had a - 0.27 ± 0.027-m/s (-12.2% ± 1.2%) bias when using the clinically implemented 60-Hz vibration source. CONCLUSIONS: Shear wave speed reconstruction across different manufacturer systems is more consistent in elastic than viscoelastic phantoms, with a mean difference bias of < ±10% in all cases. Magnetic resonance elastographic measurements in the elastic and viscoelastic phantoms best match the ultrasound systems with a 140-Hz excitation but have a significant negative bias operating at 60 Hz. This study establishes a foundation for meaningful comparison of SWS measurements made with different platforms.

COVID-19 Policy-Making in a Country Divided: Catholic Social Teaching as a Path to Unity.

Because no vaccines or specific treatments are available, governments around the globe have responded to the Coronavirus Virus Disease 2019 (COVID-19) pandemic with a variety of nonpharmaceutical interventions (NPIs) that include sheltering-in-place orders, social distancing, and school and business closures. While the actual and potential harm due to COVID-19 is far more severe than influenza, the harms due to the NPIs-that have clearly reduced mortality due to COVID-19-are also significant. With government-ordered "lockdowns" across the globe, many arguments for and against returning to normal social and economic activity have been reported, and in fact, Americans are divided about how and when to "open up." These arguments seem to fall into two major categories. Utilitarianism suggests that suspension of civil liberties and constitutional rights is a necessary response, while Libertarianism supports individual decision-making and greatly reduced government mandates. Protesters around the country have been vocal about one or the other points of view. First, we consider in detail the potential harms of severe acute respiratory syndrome virus-2 (SARS-CoV-2) if left unchecked by NPIs. Second, we look at harms due to restricted social and economic activity on human morbidity and mortality. Finally, we offer a framework based on the four pillars of Catholic Social Teaching and the principle of double effect that offers a more humane solution than Utilitarian or Libertarian principles alone.

Evaluation of the Reproducibility of Bolus Transit Quantification With Contrast-Enhanced Ultrasound Across Multiple Scanners and Analysis Software Packages-A Quantitative Imaging Biomarker Alliance Study.

OBJECTIVES: Contrast enhanced ultrasound (CEUS) is now broadly used clinically for liver lesion detection and characterization. Obstacles to the efforts to quantify perfusion with CEUS have been the lack of a standardized approach and undocumented reproducibility. The use of multiple scanners and different analysis software packages compounds the degree of variability. Our objectives were to standardize a CEUS-based approach for quantification of perfusion-related parameters of liver lesions and to evaluate the variability of bolus transit parameters (rise time [RT], mean transit time [MTT], peak intensity, and area under the curve) obtained from various clinical ultrasound scanners and analysis software. MATERIALS AND METHODS: Bolus transit as a way of evaluating perfusion has been investigated both in vivo and in vitro in the past but without establishing its reproducibility. We developed a tissue flow phantom that produces time-intensity curves very similar to those extracted from clinical cine loops of liver lesions. We evaluated the variability of the bolus transit parameters with 4 commercial scanners (Philips iU22, Philips EPIQ, GE LOGIQ E9, and Siemens Acuson Sequoia) and 3 different analysis software packages in multiple trials (15 per scanner). RESULTS: The variability (coefficient of variation) from repeated trials and while using a single scanner and software was less than 8% for RT, less than 12% for MTT, less than 49% for peak intensity, and less than 50% for area under the curve. Currently, it is not possible to directly compare amplitude values from different scanners and analysis software packages owing to the arbitrary linearization algorithm used among manufacturers; however, it is possible for time parameters (RT and MTT). The variability when using a different scanner with the same analysis software package was less than 9% for RT and less than 21% for MTT. The variability when using a different analysis software with the same scanner was less than 9% for RT and less than 15% for MTT. In all the evaluations we have performed, RT is the least variable parameter, while MTT is only slightly more variable. CONCLUSIONS: The present study will lay the groundwork for multicenter patient evaluations with CEUS quantification of perfusion-related parameters with the bolus transit technique. When using the protocol and method developed here, it is possible to perform perfusion quantification on different scanners and analysis software and be able to compare the results. The current work is the first study that presents a comparison of bolus transit parameters derived from multiple systems and software packages.

Three-dimensional US for Quantification of Volumetric Blood Flow: Multisite Multisystem Results from within the Quantitative Imaging Biomarkers Alliance.

Background Quantitative blood flow (QBF) measurements that use pulsed-wave US rely on difficult-to-meet conditions. Imaging biomarkers need to be quantitative and user and machine independent. Surrogate markers (eg, resistive index) fail to quantify actual volumetric flow. Standardization is possible, but relies on collaboration between users, manufacturers, and the U.S. Food and Drug Administration. Purpose To evaluate a Quantitative Imaging Biomarkers Alliance-supported, user- and machine-independent US method for quantitatively measuring QBF. Materials and Methods In this prospective study (March 2017 to March 2019), three different clinical US scanners were used to benchmark QBF in a calibrated flow phantom at three different laboratories each. Testing conditions involved changes in flow rate (1-12 mL/sec), imaging depth (2.5-7 cm), color flow gain (0%-100%), and flow past a stenosis. Each condition was performed under constant and pulsatile flow at 60 beats per minute, thus yielding eight distinct testing conditions. QBF was computed from three-dimensional color flow velocity, power, and scan geometry by using Gauss theorem. Statistical analysis was performed between systems and between laboratories. Systems and laboratories were anonymized when reporting results. Results For systems 1, 2, and 3, flow rate for constant and pulsatile flow was measured, respectively, with biases of 3.5% and 24.9%, 3.0% and 2.1%, and -22.1% and -10.9%. Coefficients of variation were 6.9% and 7.7%, 3.3% and 8.2%, and 9.6% and 17.3%, respectively. For changes in imaging depth, biases were 3.7% and 27.2%, -2.0% and -0.9%, and -22.8% and -5.9%, respectively. Respective coefficients of variation were 10.0% and 9.2%, 4.6% and 6.9%, and 10.1% and 11.6%. For changes in color flow gain, biases after filling the lumen with color pixels were 6.3% and 18.5%, 8.5% and 9.0%, and 16.6% and 6.2%, respectively. Respective coefficients of variation were 10.8% and 4.3%, 7.3% and 6.7%, and 6.7% and 5.3%. Poststenotic flow biases were 1.8% and 31.2%, 5.7% and -3.1%, and -18.3% and -18.2%, respectively. Conclusion Interlaboratory bias and variation of US-derived quantitative blood flow indicated its potential to become a clinical biomarker for the blood supply to end organs. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Forsberg in this issue.

An ionizing radiation acoustic imaging (iRAI) technique for real-time dosimetric measurements for FLASH radiotherapy.

PURPOSE: FLASH radiotherapy (FLASH-RT) is a novel irradiation modality with ultra-high dose rates (>40 Gy/s) that have shown tremendous promise for its ability to enhance normal tissue sparing while maintaining comparable tumor cell eradication toconventional radiotherapy (CONV-RT). Due to its extremely high dose rates, clinical translation of FLASH-RT is hampered by risky delivery and current limitations in dosimetric devices, which cannot accurately measure, in real time, dose at deeper tissue. This work aims to investigate ionizing radiation acoustic imaging (iRAI) as a promising image-guidance modality for real-time deep tissue dose measurements during FLASH-RT. The underlying hypothesis is that iRAI can enable mapping of dose deposition with respect to surrounding tissue with a single linear accelerator (linac) pulse precision in real time. In this work, the relationship between iRAI signal response and deposited dose was investigated as well as the feasibility of using a proof-of-concept dual-modality imaging system of ultrasound and iRAI for treatment beam co-localization with respect to underlying anatomy. METHODS: Two experimental setups were used to study the feasibility of iRAI for FLASH-RT using 6 MeV electrons from a modified Varian Clinac. First, experiments were conducted using a single element focused transducer to take a series of point measurements in a gelatin phantom, which was compared with independent dose measurements using GAFchromic film. Secondly, an ultrasound and iRAI dual-modality imaging system utilizing a phased array transducer was used to take coregistered two-dimensional (2D) iRAI signal amplitude images as well as ultrasound B-mode images, to map the dose deposition with respect to surrounding anatomy in an ex vivo rabbit liver model with a single linac pulse precision. RESULTS: Using a single element transducer, iRAI measurements showed a highly linear relationship between the iRAI signal amplitude and the linac dose per pulse (r2  = 0.9998) with a repeatability precision of 1% and a dose resolution error <2.5% in a homogenous phantom when compared to GAFchromic film dose measurements. These phantom results were used to develop a calibration curve between the iRAI signal response and the delivered dose per pulse. Subsequently, a normalized depth dose curve was generated that agreed with film measurements with an RMSE of 0.0243, using correction factors to account for deviations in measurement conditions with respect to calibration. Experiments on the ex-vivo rabbit liver model demonstrated that a 2D iRAI image could be generated successfully from a single linac pulse, which was fused with the B-mode ultrasound image to provide information about the beam position with respect to surrounding anatomy in real time. CONCLUSION: This work demonstrates the potential of using iRAI for real-time deep tissue dosimetry in FLASH-RT. Our results show that iRAI signals are linear with dose and can accurately map the delivered radiation dose with respect to soft tissue anatomy. With its ability to measure dose for individual linac pulses at any location within surrounding soft tissue while identifying where that dose is being delivered anatomically in real time, iRAI can be an indispensable tool to enable safe and efficient clinical translation of FLASH-RT.

Increasing adult immunization rates in a rural state through targeted pharmacist education.

BACKGROUND: Most immunization rates fall below the Healthy People 2020 goals for adults. Pharmacists have the potential to have a positive effect on immunization rates through vaccine administration. OBJECTIVE: The purpose of this study was to assess if an educational program developed for pharmacists could increase pharmacist-delivered statewide immunization rates. PRACTICE DESCRIPTION: This study was conducted in the state of North Dakota. North Dakota law allows authorized pharmacists to provide any immunization to individuals aged 11 years or older. PRACTICE INNOVATION: In collaboration with the state health department, a needs assessment of North Dakota pharmacists was conducted to determine what resources and education could increase the delivery of immunizations within the pharmacy. The results were used to develop focused continuing pharmacy education material, create an online toolkit, and provide immunization administration certification. EVALUATION: The number and proportion of pharmacist-delivered immunizations and overall adult immunizations rates were compared pre- and postintervention. The North Dakota Immunization Information System was used for data comparison. In addition, the number of pharmacists registered to provide immunizations with the State Board of Pharmacy was tabulated. RESULTS: The number of pharmacist-provided immunizations increased by more than 3900 doses. In addition, the percentage of adult immunizations provided by pharmacists and overall adult immunization rates increased throughout the state. After adjusting for seasonality, there was an increase in the number of pharmacist-delivered pneumococcal polysaccharide vaccine immunizations (P < 0.001). The number of pharmacists registered to provide immunizations increased throughout the study period by 39%. CONCLUSION: This study suggests that focused education and resources delivered to pharmacists can increase pharmacy-based immunization rates and adult immunization rates overall. Improving adult immunization rates through greater pharmacist engagement may help to decrease overall infectious disease threats.