Challenges in the implementation of an electronic referral system: A qualitative study in the Iranian context.

Referral chain reduces patient costs and results in more efficient use of workforce and equipment. Despite the implementation of the Family Physician Programme in Iran, the referral system does not function as intended. Therefore, this study was conducted to explain the challenges in the implementation of an electronic referral system in Iran. This qualitative study was performed in Golestan province in northern Iran. The participants were 46 family physicians, specialist physicians, healthcare managers, experts, and patients who were selected through purposive sampling. Data were collected using in-depth individual interviews and were analysed using content analysis. Implementation of the electronic referral system faces management challenges (planning, organisation, motivation, control), administrative challenges (scheduling, patient load and waiting time, visit and diagnosis, feedback), and educational, policy, sociocultural, technological, and economic challenges. Policymakers can adopt appropriate strategies to improve the quantity and quality of their electronic referral system according to the challenges identified herein.

Simulation and experimental studies in needle-tissue interactions.

This work aims to introduce a new needle insertion simulation to predict the deflection of a bevel-tip needle inside soft tissue. The development of such a model, which predicts the steering behavior of the needle during needle-tissue interactions, could improve the performance of many percutaneous needle-based procedures such as brachytherapy and thermal ablation, by means of the virtual path planning and training systems of the needle toward the target and thus reducing possible incidents of complications in clinical practices. The Arbitrary-Lagrangian-Eulerian (ALE) formulation in LS-DYNA software was used to model the solid-fluid interactions between the needle and tissue. Since both large deformation and fracture of the continuum need to be considered in this model, applying ALE method for fluid analysis was considered a suitable approach. A 150 mm long needle was used to bend within the tissue due to the interacting forces on its asymmetric bevel tip. Three experimental cases of needle steering in a soft phantom were performed to validate the simulation. An error measurement of less than 10 % was found between the predicted deflection by the simulations and the one observed in experiments, validating our approach with reasonable accuracy. The effect of the needle diameter and its bevel tip angle on the final shape of the needle was investigated using this model. To maneuver around the anatomical obstacles of the human body and reach the target location, thin sharp needles are recommended, as they would create a smaller radius of curvature. The insertion model presented in this work is intended to be used as a base structure for path planning and training purposes for future studies.

Effect of Motivational Interviewing on Weight Efficacy Lifestyle among Women with Overweight and Obesity: A Randomized Controlled Trial.

Obesity and overweight have become increasingly a major public health problem across the world. This study aimed at exploring the effects of motivational interviewing on weight efficacy lifestyle among women with obesity and overweight. A single-blind randomized clinical trial study was conducted on 100 overweight and obese women who attended a nutrition clinic. The samples were selected based on the clinical records and assigned into two groups, namely motivational interviewing arm (50 samples) and nutrition education arm (50 samples). Data were collected using a standard validated questionnaire entitled "weight efficacy lifestyle". The intervention was designed according to five motivation sessions and four nutrition education programs, such that the participants of the nutrition education arm were also provided with the nutrition pamphlets related to weight control. Data were finally analyzed using the SPSS statistical software by performing the independent t-test, chi-square, LSD and repeated measures ANOVA tests. P<0.05 were considered statistically significant. The mean age of women was 39.9±9.1 and 36.3±8.9 years in the control and motivational interviewing arms, respectively. Compared with the control group, the score of the motivational interviewing group was statistically significant in terms of weight efficacy lifestyle P=0.0001) and all subscales including social pressure (P=0.0001), physical discomfort (P=0.005), food accessibility (P=0.0001), positive and entertainment activities (P=0.0001), as well as negative emotions (P=0.003). Motivational interviewing appeared to be effective in increasing weight efficacy lifestyle among women with overweight and obesity. TRIAL REGISTRATION NUMBER: IRCT2014051817736N1.

The effect of green tea extract supplementation on sputum smear conversion and weight changes in pulmonary TB patients: A randomized controlled trial.

BACKGROUND: Acceleration in sputum smear conversion helps faster improvement and decreased probability of the transfer of TB. In this study, we aimed to investigate the effect of green tea extract supplementation on sputum smear conversion and weight changes in smear positive pulmonary TB patients in Iran. METHODS: In this double blind clinical study, TB patients were divided into intervention, (n=43) receiving 500 mg green tea extract (GTE), and control groups (n=40) receiving placebo for two months, using balanced randomization. Random allocation and allocation concealment were observed. Height and weight were measured at the beginning, and two and six months post-treatment. Evaluations were performed on three slides, using the ZiehlNeelsen method. Independent and paired t test, McNemar's, Wilcoxon, Kaplan-Meier, Cox regression model and Log-Rank test were utilized. Statistical significance was set at p<0.05. This trial was registered under IRCT201212232602N11. RESULTS: The interventional changes and the interactive effect of intervention on weight were not significant (p>0.05). In terms of shortening the duration of conversion, the case to control proportion showed a significant difference (p=0.032). Based on the Cox regression model, the hazard ratio of the relative risk of delay in sputum smear conversion was 3.7 (p=0.002) in the higher microbial load group compared to the placebo group and 0.54 (95% CI: 0.31-0.94) in the intervention compared to the placebo group. CONCLUSION: GTE decreases the risk of delay in sputum smear conversion, but has no effect on weight gain. Moreover, it may be used as an adjuvant therapy for faster rehabilitation for pulmonary TB patients.

MR elastography and diffusion-weighted imaging of ex vivo prostate cancer: quantitative comparison to histopathology.

The purpose of this work was (1) to develop a magnetic resonance elastography (MRE) system for imaging of the ex vivo human prostate and (2) to assess the diagnostic power of mono-frequency and multi-frequency MRE and diffusion weighted imaging (DWI) alone and combined as correlated with histopathology in a patient study. An electromagnetic driver was designed specifically for MRE studies in small-bore MR scanners. Ex vivo prostate specimens (post-fixation) of 14 patients who underwent radical prostatectomy were imaged with MRE at 7 T (nine cases had DWI). In six patients, the MRE examination was performed at three frequencies (600, 800, 1000 Hz) to extract the power-law exponent Gamma. The images were registered to wholemount pathology slides marked with the Gleason score. The areas under the receiver-operator-characteristic curves (AUC) were calculated. The methods were validated in a phantom study and it was demonstrated that (i) the driver does not interfere with the acquisition process and (ii) the driver can generate amplitudes greater than 100 µm for frequencies less than 1 kHz. In the quantitative study, cancerous tissue with Gleason score at least 3 + 3 was distinguished from normal tissue in the peripheral zone (PZ) with an average AUC of 0.75 (Gd ), 0.75 (Gl ), 0.70 (Gamma-Gd ), 0.68 (apparent diffusion coefficient, ADC), and 0.82 (Gd + Gl + ADC). The differentiation between PZ and central gland was modest for Gd (p < 0.07), Gl (p < 0.06) but not significant for Gamma (p < 0.2). A correlation of 0.4 kPa/h was found between the fixation time of the prostate specimen and the stiffness of the tissue, which could affect the diagnostic power results. DWI and MRE may provide complementary information; in fact MRE performed better than ADC in distinguishing normal from cancerous tissue in some cases. Multi-frequency (Gamma) analysis did not appear to improve the results. However, in light of the effect of tissue fixation, the clinical implication of our results may be inconclusive and more experiments are needed.

MR elastography of prostate cancer: quantitative comparison with histopathology and repeatability of methods.

The purpose of this work was to assess trans-perineal prostate magnetic resonance elastography (MRE) for (1) repeatability in phantoms/volunteers and (2) diagnostic power as correlated with histopathology in prostate cancer patients. The three-dimensional (3D) displacement field was obtained using a fractionally encoded gradient echo sequence using a custom-made transducer. The repeatability of the method was assessed based on three repeat studies and by changing the driving frequency by 3% in studies on a phantom and six healthy volunteers. Subsequently, 11 patients were examined with MRE prior to radical prostatectomy. The areas under the receiver operating characteristic curves were calculated using a windowed voxel-to-voxel approach by comparing the 2D registered slides, masked with the Gleason score. For the repeatability study, the average intraclass correlation coefficient for elasticity images was 99% for repeat phantom studies, 98% for ±6 Hz phantom studies, 95% for volunteer repeat studies with 2 min acquisition time, 82% for ±2 Hz volunteer studies with 2 min acquisition time and 73% for repeat volunteer studies with 8 min acquisition time. For the patient study, the average elasticity was 8.2 ± 1.7 kPa in the prostate capsule, 7.5 ± 1.9 kPa in the peripheral zone (PZ), 9.7 ± 3.0 kPa in the central gland (CG) and 9.0 ± 3.4 kPa in the transition zone. In the patient study, cancerous tissue with Gleason score at least 3 + 3 was significantly (p < 0.05) different from normal tissue in 10 out of 11 cases with tumors in the PZ, and 6 out of 9 cases with tumors in the CG. However, the overall case-averaged area under the curve was 0.72 in the PZ and 0.67 in the CG. Cancerous tissue was not always stiffer than normal tissue. The inversion algorithm was sensitive to (i) vibration amplitude and displacement nodes and (ii) misalignment of the 3D wave field due to subject movement.

Prostate MR elastography with transperineal electromagnetic actuation and a fast fractionally encoded steady-state gradient echo sequence.

Our aim is to develop a clinically viable, fast-acquisition, prostate MR elastography (MRE) system with transperineal excitation. We developed a new actively shielded electromagnetic transducer, designed to enable quick deployment and positioning within the scanner. The shielding of the transducer was optimized using simulations. We also employed a new rapid pulse sequence that encodes the three-dimensional displacement field in the prostate gland using a fractionally encoded steady-state gradient echo sequence, thereby shortening the acquisition time to a clinically acceptable 8-10 min. The methods were tested in two phantoms and seven human subjects (six volunteers and one patient with prostate cancer). The MRE acquisition time for 24 slices, with an isotropic resolution of 2 mm and eight phase offsets, was 8 min, and the total scan, including positioning and set-up, was performed in 15-20 min. The phantom study demonstrated that the transducer does not interfere with the acquisition process and that it generates displacement amplitudes that exceed 100 µm even at frequencies as high as 300 Hz. In the in vivo human study, average wave amplitudes of 30 µm (46 µm at the apex) were routinely achieved within the prostate gland at 70 Hz. No pain or discomfort was reported. Results in a single patient suggest that MRE can identify cancer tumors, although this result is preliminary. The proposed methods allow the integration of prostate MRE with other multiparametric MRI methods. The results of this study clearly motivate the clinical evaluation of transperineal MRE in patients.

Effectiveness of an Informal Home Care Support Intervention Program to Reduce Loneliness and Improve Quality of Life among Lonely Community-Dwelling Older Adults: A Feasibility Study.

Background: Establishing cost-effective informal care services for lonely older adults living at home in developing countries can be an innovative approach for improving their well-being. This study investigated the effectiveness of an informal home care support intervention program (HoSIP) reducing the loneliness and improving quality of life of lonely community-dwelling older adults. Methods: This quasi-experimental pre-post study employed a non-randomized control group design with a 12-week intervention period and three follow-up points at the end of the HoSIP. Questionnaires were used to measure feelings of loneliness (20-item UCLA Loneliness Scale), quality of life (Control, Autonomy, Self-Realization and Pleasure Scale), general health (12-item General Health Questionnaire), social network (six-item Lubben Social Network Scale), social support (12-item Multidimensional Scale of Perceived Social Support), and self-care ability (17-item Self-care Ability Scale for the Elderly). Repeated-measures analysis of variance was used to gauge the effect of the intervention program over time and in comparison to the control group. Data analyses were performed using the IBM SPSS Statistics software (IBM Corp., USA). Results: We found a significant relationship between the outcome variables, including feelings of loneliness (P<0.001) and quality of life (P<0.001), at different stages of measurement. Despite the positive feasibility results, the implementation of the HoSIP faced challenges due to a lack of facilities (e.g., place restriction for holding educational classes, educational facilities like computers, video projector, and whiteboard at daycare center) and the absence of supporting organizations. Conclusion: Utilizing the existing capabilities of older adults to provide online and face-to-face care services can be a cost-effective way to improve their quality of life and reduce loneliness. The process of facilitating such informal care services for lonely older adults should be managed by either governmental or non-governmental organizations to reduce the rate of social isolation among this vulnerable population.

Transperineal prostate MR elastography: initial in vivo results.

This article presents a new approach to magnetic resonance elastography of the prostate using transperineal mechanical excitation. This approach is validated using a prostate elasticity phantom and in vivo studies of healthy volunteers. It is demonstrated that the transperineal approach can generate shear wave amplitudes on the order of 6-30 µm in the mid-gland region. The driver was implemented using an electromagnetic actuator with a hydraulic transmission system. The magnetic resonance elastography acquisition time has been reduced significantly by using a "second harmonic" approach. Displacement fields are processed using the established three-dimensional local frequency estimation algorithm. The three-dimensional curl-based direct inversion was used to calculate the local wavelength. The traveling wave expansion algorithm was used to reconstruct the wave damping image for one case. Using the proposed method, it was possible to resolve lesions of 0.5 cc in the phantom study. Repeatability experiments were performed and analyzed. The results from this study indicate that transperineal magnetic resonance elastography--without an endorectal coil--is a suitable candidate for a patient study involving multiparametric magnetic resonance imaging of prostate cancer, where magnetic resonance elastography may provide additional information for improved diagnosis and image-based surveillance.

Incidence and treatment outcomes of pulmonary tuberculosis in Islamic Republic of Iran.

Background: Pulmonary tuberculosis is the most common type of tuberculosis and few studies have investigated the incidence and treatment outcome of smear-positive pulmonary tuberculosis in Golestan Province, Islamic Republic of Iran. Aims: To estimate the cumulative incidence and trends in incidence of smear-positive pulmonary tuberculosis in Golestan Province between 2014 and 2019, and to determine the treatment outcomes. Methods: All smear-positive pulmonary tuberculosis cases between 2014 and 2019 recorded in the tuberculosis registry in Golestan Province, Islamic Republic of Iran, were included in this study. The yearly incidence and cumulative incidence were calculated, and differences by sex and residence were examined. Treatment outcomes classified as success and failure were determined. The Mann-Kendall test was used to assess the significance of the trend in incidence. Results: A total of 2047 smear-positive pulmonary tuberculosis cases were evaluated. The cumulative incidence was 18.52 [95% confidence intervals (CI): 17.72-19.33] per 100 000 population during 2014-2019. The incidence of smear-positive pulmonary tuberculosis declined from 23.84 (95% CI: 21.57-26.11) per 100 000 population in 2014 to 15.02 (95% CI: 13.29- 16.75) in 2019. Incidence rate was higher among men and among rural residents. Most patients (85.34%) were cured, 2.05% completed their treatment, 1.17% were lost to follow-up, 4.40% had treatment failure, and 6.45% died. Conclusion: The incidence of pulmonary tuberculosis in Golestan Province, Islamic Republic of Iran, declined during the period of study. However, the proportion of patients who were cured decreased and the proportion who died increased. Interventions are needed to improve the treatment success rate for pulmonary tuberculosis in the province.

Household food insecurity and associated factors in the Northeast of Iran: a cross-sectional study : Household food security in Northern Iran.

BACKGROUND: Food Insecurity (FI) is a global health concern. For the first time, this study evaluated households' food insecurity and factors related to it in Golestan province, North of Iran. METHODS: This cross-sectional study was conducted on 5129 randomly selected households in the Golestan Province in 2016. Sociodemographic characteristics, including age, ethnicity, household size, education level, and occupation status, were collected via interview. The prevalence and severity of food insecurity were identified by the Household Food Insecurity Access Scale (HFIAS), whose scores are between 0 and 27, with larger values indicating more severe food insecurity. The prevalence of food insecurity based on the geographical area was presented using GIS. RESULTS: Out of 5129 households, 2216 (43.21%) had food security, and 2913 (56.79%) households had food insecurity, with a Mean ± SD HFIAS score of 4.86 ± 5.95. Out of 2913 households with FI, 1526 (52.39%), 956 (32.82%), and 431 (14.79%) had mild, moderate, and severe food insecurity, respectively. Among 14 regions of the province, three regions had the most cases of food insecurity. Food insecurity (moderate or severe) was significantly associated with mothers as the household head (adjusted OR = 1.67, 95% CI: 1.03-2.70) and lower education level of the household head. CONCLUSION: The prevalence of household food insecurity in the Golestan Province is higher than the national average. Factors such as literacy, employment status, and gender of the household head can be significantly associated with food insecurity.

3-D Transducer Mounted Shear Wave Absolute Vibro-Elastography: Proof of Concept.

Quantitative tissue stiffness characterization using ultrasound (US) has been shown to improve prostate cancer (PCa) detection in multiple studies. Shear wave absolute vibro-elastography (SWAVE) allows quantitative and volumetric assessment of tissue stiffness using external multifrequency excitation. This article presents a proof of concept of a first-of-a-kind 3-D hand-operated endorectal SWAVE system designed to be used during systematic prostate biopsy. The system is developed with a clinical US machine, requiring only an external exciter that can be mounted directly to the transducer. Subsector acquisition of radio frequency (RF) data allows imaging of shear waves with a high effective frame rate (up to 250 Hz). The system was characterized using eight different quality assurance phantoms. Due to the invasive nature of prostate imaging, at this early stage of development, validation of in vivo human tissue was instead carried out by intercostally scanning the livers of n = 7 healthy volunteers. The results are compared with 3-D magnetic resonance elastography (MRE) and an existing 3-D SWAVE system with a matrix array transducer (M-SWAVE). High correlations were found with MRE (99% in phantoms, 94% in liver data) and with M-SWAVE (99% in phantoms, 98% in liver data).

Model-Based Quantitative Elasticity Reconstruction Using ADMM.

We introduce two model-based iterative methods to obtain shear modulus images of tissue using magnetic resonance elastography. The first method jointly finds the displacement field that best fits tissue displacement data and the corresponding shear modulus. The displacement satisfies a viscoelastic wave equation constraint, discretized using the finite element method. Sparsifying regularization terms in both shear modulus and displacement are used in the cost function minimized for the best fit. The second method extends the first method for multifrequency tissue displacement data. The formulated problems are bi-convex. Their solution can be obtained iteratively by using the alternating direction method of multipliers. Sparsifying regularizations and the wave equation constraint filter out sensor noise and compressional waves. Our methods do not require bandpass filtering as a preprocessing step and converge fast irrespective of the initialization. We evaluate our new methods in multiple in silico and phantom experiments, with comparisons with existing methods, and we show improvements in contrast to noise and signal-to-noise ratios. Results from an in vivo liver imaging study show elastograms with mean elasticity comparable to other values reported in the literature.

Tractor Ambulance: An Initiative of Emergency Medical Services Response to the Flood of Golestan, Iran in 2019.

Heavy rains in March 2019 led to severe floods in large parts of Iran, with severe financial and physical casualties (in the Golestan province, 11 districts were trapped in water). An increase in the EMS missions while serving a big portion of the needed population was a big problem for the health system during the flood; Therefore, a new solution was needed to overcome this problem. Using a farm tractor for transporting the patients and injured people was the first relief experience ever documented in the whole country. In the present report, despite the limitations and challenges, the tractor has been shown to be a proper and effective disaster relief vehicle. This report could help other similar countries face disasters, especially floods.

Design, implementation and evaluation of informal home care support intervention program for lonely older adults in the community: Protocol for a feasibility study.

BACKGROUND: Providing lonely older adults with informal home care services is important to improving their health and quality of life. The study aims to evaluate the feasibility of design, implementation and evaluation of an informal home care support intervention program (HoSIP) for community-dwelling lonely older adults in Gorgan, Iran. METHOD/DESIGN: This feasibility study is a mixed-method with a concurrent nested design. Lonely older adults will be enrolled as the HoSIP intervention group and will receive 12-weeks of informal home care service by peer supporters. The purpose of this feasibility study is to determine the recruitment capability and resulting sample characteristics, data collection procedure and outcome measures, the acceptability and suitability of the intervention and study procedures, the resource and ability to manage the study and intervention, and preliminary evaluation of participant response to intervention. Primary outcomes including participant feelings of loneliness, quality of life, general health, social network, social support, and self-care ability, will be assessed at baseline and post-intervention for the intervention and control groups. Semi-structured interviews will be conducted immediately after the intervention using content qualitative approach to describe participants' experiences with HoSIP. DISCUSSION: Through this study we will examine the feasibility of delivering informal home care services to community-dwelling lonely older adults in a developing country through employing a concurrent nested mixed-method design. TRIAL REGISTRATION: IRCT20190503043455N.

RT-LAMP in SARS-CoV-2 detection: point to improve primer designing and decrease molecular diagnosis pitfalls.

BACKGROUND: Due to the high transmission rate of SARS-CoV-2, diagnostic tests have become tools for identifying patients. The key points were the virus genomes survey to design RT-LAMP primers; comparing the sensitivity and specificity of RT-LAMP and RT-qPCR; and determining the relationship among clinical symptoms, CT scan, RT-qPCR, and RT-LAMP results. METHODS: This cohort study included 444 symptomatic patients. The specificity and sensitivity of RT-LAMP were assayed. The five statistical models, simultaneously, by RapidMiner to find the best method for detecting the virus were done through the correlation between the clinical symptoms, RT-LAMP, RT-qPCR, and CT scan results. The chi-square test by SPSS 26.0 was used to calculate kappa agreement. RESULTS: The virus genome was detected in all the positive samples (198) by RT-qPCR and RT-LAMP. In addition, 246 samples were negative by RT-qPCR, while 88 were positive by RT-LAMP. Data mining analysis indicated that there were most associations between the RT-LAMP and CT scan data compared to RT-qPCR and CT scan data. CONCLUSIONS: RT-LAMP could detect SARS-CoV-2 with great simplicity, speed, and cheapness. Therefore, it is logical to screen, a large number of patients by RT-LAMP, and then RT-qPCR can be used on the limited samples.

A multiparametric volumetric quantitative ultrasound imaging technique for soft tissue characterization.

Quantitative ultrasound (QUS) offers a non-invasive and objective way to quantify tissue health. We recently presented a spatially adaptive regularization method for reconstruction of a single QUS parameter, limited to a two dimensional region. That proof-of-concept study showed that regularization using homogeneity prior improves the fundamental precision-resolution trade-off in QUS estimation. Based on the weighted regularization scheme, we now present a multiparametric 3D weighted QUS (3D QUS) method, involving the reconstruction of three QUS parameters: attenuation coefficient estimate (ACE), integrated backscatter coefficient (IBC) and effective scatterer diameter (ESD). With the phantom studies, we demonstrate that our proposed method accurately reconstructs QUS parameters, resulting in high reconstruction contrast and therefore improved diagnostic utility. Additionally, the proposed method offers the ability to analyze the spatial distribution of QUS parameters in 3D, which allows for superior tissue characterization. We apply a three-dimensional total variation regularization method for the volumetric QUS reconstruction. The 3D regularization involving N planes results in a high QUS estimation precision, with an improvement of standard deviation over the theoretical 1/N rate achievable by compounding N independent realizations. In the in vivo liver study, we demonstrate the advantage of adopting a multiparametric approach over the single parametric counterpart, where a simple quadratic discriminant classifier using feature combination of three QUS parameters was able to attain a perfect classification performance to distinguish between normal and fatty liver cases.

Epidemiological and clinical characteristics of the COVID-19 epidemic and associated factors for mortality in Golestan province, Iran: a retrospective cohort study.

BACKGROUND: We aimed to further clarify the epidemiological and clinical characteristics of 2019-nCoV pneumonia and risk factors associated for mortality. METHODS: In this study, we included inpatient with acute respiratory distress syndrome at Golestan Hospitals who had been discharged or had died in 2020. Epidemiological, and clinical data were extracted from electronic medical records and compared between recovered and died cases. We used multiple logistic regression methods to explore the risk factors associated with in-hospital death. RESULTS: Overall 2,835 acute respiratory distress syndrome patients were included in this study, and 874 (30.83%) were positive for 2019-nCoV. Five hundred and sixty-three patients (19.86%) died, 1,687 patients (59.51%) were recovered. Of the total deaths, only 288 (10.15%) were attributed to COVID-19. The most common symptoms at onset of illness were respiratory distress [1,795 (63.32%)], fever [1,601 (56.47%)], dry cough [1,595 (56.26%)], sore throat [445 (15.70%)], and myalgia [342 (12.06%)]. One thousand and twelve (35.7%) had 1 or more coexisting medical conditions. In multiple logistic regression analysis, risk factors associated with the death included older age [OR (Odds Ratio) = 1.03; 95% CI; 1.02-1.04], blood oxygen level (SPO2 < 93%) (OR = 2.44; 95% CI; 1.79-3.31), comorbidities (OR = 2.15; 95% CI; 1.62-2.84), respiratory distress (OR = 1.74; 95% CI; 1.28-2.37), and headache (OR = 0.44 95% CI; 0.21-0.92). CONCLUSIONS: The 2019-nCoV infection caused collections of severe respiratory illness and was associated to a high ratio of hospitalization in ICU and high mortality. Older age and comorbidities were associated with more risk of death among patients with 2019-nCoV.

Three-Dimensional Multi-Frequency Shear Wave Absolute Vibro-Elastography (3D S-WAVE) With a Matrix Array Transducer: Implementation and Preliminary In Vivo Study of the Liver.

Magnetic resonance elastography (MRE) is commonly regarded as the imaging-based gold-standard for liver fibrosis staging, comparable to biopsy. While ultrasound-based elastography methods for liver fibrosis staging have been developed, they are confined to a 1D or a 2D region of interest and to a limited depth. 3D Shear Wave Absolute Vibro-Elastography (S-WAVE) is a steady-state, external excitation, volumetric elastography technique that is similar to MRE, but has the additional advantage of multi-frequency excitation. We present a novel ultrasound matrix array implementation of S-WAVE that takes advantage of 3D imaging. We use a matrix array transducer to sample axial multi-frequency steady-state tissue motion over a volume, using a Color Power Angiography sequence. Tissue motion with the frequency components {40,50,60} and {45,55,65} Hz are acquired over a (90° lateral) × (40° elevational) × (16 cm depth) sector with an acquisition time of 12 seconds. We compute the elasticity map in 3D using local spatial frequency estimation. We characterize this new approach in tissue phantoms against measurements obtained with transient elastography and MRE. Six healthy volunteers and eight patients with chronic liver disease were imaged. Their MRE and S-WAVE volumes were aligned using T1 to B-mode registration for direct comparison in common regions of interest. S-WAVE and MRE results are correlated with R2 = 0.92, while MRE and TE results are correlated with R2 = 0.71. Our findings show that S-WAVE with matrix array has the potential to deliver a similar assessment of liver fibrosis as MRE in a more accessible, inexpensive way, to a broader set of patients.

3D Global Time-Delay Estimation for Shear-Wave Absolute Vibro-Elastography of the Placenta.

The placenta is a vital organ for growth and development of the fetus. Shear Wave Absolute Vibro-Elastography (SWAVE) is a new elastography technique proposed to detect placenta disorders. Elastography involves applying a force on the tissue and measuring the resulting tissue deformation. All types of compression cause the tissue to expand in three directions given the biological tissues are nearly incompressible. Hence, 3D displacement estimation should lead to the most accurate elasticity reconstruction compared to the traditional 1D methods. Previous studies estimated 3D displacements over ultrasound volumes mostly for quasi-static compression to generate strain images. However, accurate displacement tracking of dynamic motion continues to be a challenge. In this work, a novel volumetric regularized algorithm, 3D GLobal Ultrasound Elastography (GLUE3D), is presented to estimate the 3D displacement over a volume of ultrasound data, following by a 3D Young's modulus reconstruction. The proposed method outperforms the previous 2D method over a volume and is compared with a 3D technique using phantom data for which the elasticity are provided by the values from magnetic resonance elastography on the same phantom and also the manufacturer reference numbers. We then present Young's modulus reconstruction results obtained from clinical data of placenta which shows more uniform elasticity maps compared to the traditional 1D displacement measurements over a volume of ultrasound data. Furthermore, the dependency of the elasticity values to the frequency is investigated in this study.