scholarly journals Testing telediagnostic right upper quadrant abdominal ultrasound in Peru: A new horizon in expanding access to imaging in rural and underserved areas

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255919
Author(s):  
Thomas J. Marini ◽  
Daniel C. Oppenheimer ◽  
Timothy M. Baran ◽  
Deborah J. Rubens ◽  
Ann Dozier ◽  
...  
Keyword(s):  
Image Quality ◽  
Ultrasound Examination ◽  
Imaging Modality ◽  
Standard Of Care ◽  
Abdominal Ultrasound ◽  
The United States ◽  
Sonographic Examination ◽  
Ultrasound Technique ◽  
Excellent Image Quality ◽  
Experienced Radiologist

Background Hepatic and biliary diseases are prevalent worldwide, but the majority of people lack access to diagnostic medical imaging for their assessment. The liver and gallbladder are readily amenable to sonographic examination, and ultrasound is a portable, cost-effective imaging modality suitable for use in rural and underserved areas. However, the deployment of ultrasound in these settings is limited by the lack of experienced sonographers to perform the exam. In this study, we tested an asynchronous telediagnostic system for right upper quadrant abdominal ultrasound examination operated by individuals without prior ultrasound experience to facilitate deployment of ultrasound to rural and underserved areas. Methods The teleultrasound system utilized in this study employs volume sweep imaging and a telemedicine app installed on a tablet which connects to an ultrasound machine. Volume sweep imaging is an ultrasound technique in which an individual scans the target region utilizing preset ultrasound sweeps demarcated by easily recognized external body landmarks. The sweeps are saved as video clips for later interpretation by an experienced radiologist. Teleultrasound scans from a Peruvian clinic obtained by individuals without prior ultrasound experience were sent to the United States for remote interpretation and quality assessment. Standard of care comparison was made to a same-day ultrasound examination performed by a radiologist. Results Individuals without prior ultrasound experience scanned 144 subjects. Image quality was rated “poor” on 36.8% of exams, “acceptable” on 38.9% of exams, and “excellent” on 24.3% of exams. Among telemedicine exams of “acceptable” or “excellent” image quality (n = 91), greater than 80% of the liver and gallbladder were visualized in the majority of cases. In this group, there was 95% agreement between standard of care and teleultrasound on whether an exam was normal or abnormal, with a Cohen’s kappa of 0.84 (95% CI 0.7–0.98, p <0.0001). Finally, among these teleultrasound exams of “acceptable” or “excellent” image quality, the sensitivity for cholelithiasis was 93% (95% CI 68.1%-99.8%), and the specificity was 97% (95% CI 89.5%-99.6%). Conclusion This asynchronous telediagnostic system allows individuals without prior ultrasound experience to effectively scan the liver, gallbladder, and right kidney with a high degree of agreement with standard of care ultrasound. This system can be deployed to improve access to diagnostic imaging in low-resource areas.

scholarly journals Testing telediagnostic thyroid ultrasound in Peru: a new horizon in expanding access to imaging in rural and underserved areas

2021 ◽  
Author(s):  
T. J. Marini ◽  
S. L. Weiss ◽  
A. Gupta ◽  
Y. T. Zhao ◽  
T. M. Baran ◽  
...  
Keyword(s):  
Thyroid Nodule ◽  
Standard Of Care ◽  
The United States ◽  
Epidemiological Studies ◽  
Thyroid Ultrasound ◽  
Target Region ◽  
Experienced Radiologist ◽  
Significant Difference ◽  
Size Evaluation

Abstract Purpose Thyroid ultrasound is a key tool in the evaluation of the thyroid, but billions of people around the world lack access to ultrasound imaging. In this study, we tested an asynchronous telediagnostic ultrasound system operated by individuals without prior ultrasound training which may be used to effectively evaluate the thyroid and improve access to imaging worldwide. Methods The telediagnostic system in this study utilizes volume sweep imaging (VSI), an imaging technique in which the operator scans the target region with simple sweeps of the ultrasound probe based on external body landmarks. Sweeps are recorded and saved as video clips for later interpretation by an expert. Two operators without prior ultrasound experience underwent 8 h of training on the thyroid VSI protocol and the operation of the telemedicine platform. After training, the operators scanned patients at a health center in Lima. Telediagnostic examinations were sent to the United States for remote interpretation. Standard of care thyroid ultrasound was performed by an experienced radiologist at the time of VSI examination to serve as a reference standard. Results Novice operators scanned 121 subjects with the thyroid VSI protocol. Of these exams, 88% were rated of excellent image quality showing complete or near complete thyroid visualization. There was 98.3% agreement on thyroid nodule presence between VSI teleultrasound and standard of care ultrasound (Cohen’s kappa 0.91, P < 0.0001). VSI measured the thyroid size, on average, within 5 mm compared to standard of care. Readers of VSI were also able to effectively characterize thyroid nodules, and there was no significant difference in measurement of thyroid nodule size (P = 0.74) between VSI and standard of care. Conclusion Thyroid VSI telediagnostic ultrasound demonstrated both excellent visualization of the thyroid gland and agreement with standard of care thyroid ultrasound for nodules and thyroid size evaluation. This system could be deployed for evaluation of palpable thyroid abnormalities, nodule follow-up, and epidemiological studies to promote global health and improve the availability of diagnostic imaging in underserved communities.

Incidental Findings of Gastrointestinal Tumours at Abdominal Ultrasound Examinations

1985 ◽  
Vol 26 (6) ◽  
pp. 671-675 ◽  
Author(s):  
K. Lyttkens ◽  
L. Forsberg
Keyword(s):  
Large Bowel ◽  
Ultrasound Examination ◽  
Abdominal Mass ◽  
Abdominal Ultrasound ◽  
Primary Diagnosis ◽  
Ultrasound Technique ◽  
Gastrointestinal Malignancy ◽  
Gastrointestinal Tumours ◽  
Conventional Ultrasound ◽  
Tumour Origin

A retrospective review was performed of 11 patients referred to ultrasound examination because of abdominal pain and/or a palpable abdominal tumour, which eventually was proven to be gastrointestinal malignancy. Primary gastric carcinoma was present in 4 cases, carcinoma of the small bowel in one case, and of the large bowel in 6 cases. All the patients were examined with conventional ultrasound technique using a 3.5 MHz and a 5.0 MHz transducer. In all the cases bowel wall thickness exceeded 10 mm. A correct organ localization and primary diagnosis of tumour was made in 6 cases, of which only 2 had a palpable abdominal mass. In the remaining cases a bowel tumour was revealed in 3 but the site was incorrectly defined. Reviewing the documentations made at ultrasonography in these cases the tumour origin corresponded well with radiologic and surgical findings. In 2 patients an abscess was diagnosed which later proved to be due to a large bowel carcinoma. Ultrasound examination of patients with uncharacteristic abdominal complaints can spare the patient unnecessary examinations when the findings are pointing at a tumour in the gastrointestinal tract, save time and therefore is of economical importance.

scholarly journals Feline abdominal ultrasonography: what’s normal? what’s abnormal? The adrenal glands

2021 ◽  
Vol 23 (1) ◽  
pp. 33-49 ◽  
Author(s):  
Sally Griffin
Keyword(s):  
Adrenal Glands ◽  
Ultrasound Examination ◽  
Abdominal Ultrasound ◽  
Evidence Base ◽  
Vital Role ◽  
Abdominal Ultrasonography ◽  
Operator Experience ◽  
High Resolution Images ◽  
Clinically Significant ◽  
Diagnostic Work

Practical relevance: Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the adrenal glands can provide important information pertaining to several conditions including hyperaldosteronism and hyperadrenocorticism. Clinical challenges: Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as adrenal mineralisation, and clinically significant pathological changes can be challenging. Aim: This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased adrenal glands. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material. Equipment: Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience. Evidence base: Information provided in this article is drawn from the published literature and the author’s own clinical experience.

scholarly journals Fast Focus Ultrasound Liver Technique for the Assessment of Cystic Echinococcosis in Sheep

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 452 ◽  
Author(s):  
Giuliano Borriello ◽  
Jacopo Guccione ◽  
Antonio Di Loria ◽  
Antonio Bosco ◽  
Paola Pepe ◽  
...  
Keyword(s):  
Body Weight ◽  
Focused Ultrasound ◽  
Ultrasound Examination ◽  
Focus Ultrasound ◽  
The Body ◽  
Weight Group ◽  
Ultrasound Technique ◽  
Female Sheep ◽  
Weight Groups ◽  
Diagnostic Outcomes

A complete ultrasound examination (cUS) of the liver was performed on 172 female sheep and compared to the performance of a fast-focused ultrasound technique to diagnose echinococcal cysts. The scanned area was divided in: HYP (right hypocondrium), zone (Z)1 from HYP to the 11th intercostal space (IS), Z2 (10th–8th IS) and Z3 (7th–5th IS). Contiguous scans were also examined (HYP + Z1, Z1 + Z2, Z2 + Z3). Furthermore, during the procedures, the sheep were divided into three groups according to the body weight: Group (G) 1 (lighter), G2 (medium), and G3 (heavier). Finally, diagnostic outcomes were compared with necropsy findings. cUS obtained the highest values of sensitivity (Se) (91%), Specificity (Sp) (80%), and positive-zones (124/138, 90%), as compared to the other scans. cUS was also characterized by high values of Se and Sp and was able to identify a great number of positive-zones, when sheep were divided by body-weight groups. Similar performances were obtained in G1 by HYP (Se: 91%–Sp: 82%; 18/20, 90% of positive-zones) and HYP + Z1 scans (Se: 91%–Sp: 82; 90% of positive-zones, 18/20). Thus, in lighter breeds, the examination of HYP and HYP + Z1 scan windows could be considered reliable techniques for identifying the infected animals, while in heavier sheep the cUS still represents the best option.

scholarly journals Estimation of contrast-to-noise ratio in CT and CBCT images with varying scan settings in presence of different implant materials

2019 ◽  
Vol 48 (8) ◽  
pp. 20190139
Author(s):  
Emine Şebnem Kursun-Cakmak ◽  
Husniye Demirturk Kocasarac ◽  
Seval Bayrak ◽  
Gülbahar Ustaoğlu ◽  
Marcel Noujeim
Keyword(s):  
Image Quality ◽  
Imaging Modality ◽  
Cone Beam Ct ◽  
Medical Systems ◽  
Plastic Container ◽  
Implant Materials ◽  
Different Types ◽  
Noise Ratio ◽  
Titanium Grade ◽  
Imagej Software

Objectives: To assess the contrast-to-noise ratio (CNR) of four different types of dental implant materials in CT and cone beam CT (CBCT) images with varying scan settings. Methods: Four different types of implants: zirconium (Zr), titanium (Ti) Grade 4 and 5 and titanium–zirconium (Ti–ZrO2) alloy were placed in a 3% gelatin phantom in a cylindrical plastic container and scanned with two different CT machines (GE Medical systems and Toshiba Medical Systems) and one CBCT machine (I-CAT, Imaging Sciences International) with different voxel sizes of 0.2, 0.25, 0.3 and 0.4 mm. Images were analyzed using ImageJ software with the purpose of estimating the CNR. Results: The CNR obtained from images acquired with CT was lower than the CBCT with all voxel sizes tested. 0.3 and 0.4 mm voxel sizes exhibited the highest CNR (p < 0.05) that gives the best image quality. Among the implant materials tested, titanium Grade 5 has the highest levels of CNR while Zirconium has the lowest (p < 0.05). Conclusions: The optimum protocol for radiographic follow-up in areas near implants on the I-CAT is low-resolution settings (0.3 and 0.4 mm voxel sizes) which gave the highest CNR thus image quality. In presence of Zr implants, an alternative imaging modality (i.e., MRI) may be considered to avoid low-quality images.

scholarly journals Metal artifacts in intraoperative O-arm CBCT scans

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juha I. Peltonen ◽  
Touko Kaasalainen ◽  
Mika Kortesniemi
Keyword(s):  
Image Quality ◽  
Imaging Modality ◽  
Nonlinear Effects ◽  
Exposure Level ◽  
Metal Artifacts ◽  
Imaging Protocol ◽  
Metal Implants ◽  
Comprehensive Determination

Abstract Background Cone-beam computed tomography (CBCT) has become an increasingly important medical imaging modality in orthopedic operating rooms. Metal implants and related image artifacts create challenges for image quality optimization in CBCT. The purpose of this study was to develop a robust and quantitative method for the comprehensive determination of metal artifacts in novel CBCT applications. Methods The image quality of an O-arm CBCT device was assessed with an anthropomorphic pelvis phantom in the presence of metal implants. Three different kilovoltage and two different exposure settings were used to scan the phantom both with and without the presence of metal rods. Results The amount of metal artifact was related to the applied CBCT imaging protocol parameters. The size of the artifact was moderate with all imaging settings. The highest applied kilovoltage and exposure level distinctly increased artifact severity. Conclusions The developed method offers a practical and robust way to quantify metal artifacts in CBCT. Changes in imaging parameters may have nonlinear effects on image quality which are not anticipated based on physics.

scholarly journals Correlation of image quality parameters with tube voltage in X-ray dark-field chest radiography: a phantom study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreas P. Sauter ◽  
Jana Andrejewski ◽  
Manuela Frank ◽  
Konstantin Willer ◽  
Julia Herzen ◽  
...  
Keyword(s):  
Image Quality ◽  
Imaging Modality ◽  
Signal Strength ◽  
Dark Field ◽  
Tube Voltage ◽  
X Ray ◽  
Dose Area Product ◽  
Dark Field Imaging ◽  
Field Imaging

AbstractGrating-based X-ray dark-field imaging is a novel imaging modality with enormous technical progress during the last years. It enables the detection of microstructure impairment as in the healthy lung a strong dark-field signal is present due to the high number of air-tissue interfaces. Using the experience from setups for animal imaging, first studies with a human cadaver could be performed recently. Subsequently, the first dark-field scanner for in-vivo chest imaging of humans was developed. In the current study, the optimal tube voltage for dark-field radiography of the thorax in this setup was examined using an anthropomorphic chest phantom. Tube voltages of 50–125 kVp were used while maintaining a constant dose-area-product. The resulting dark-field and attenuation radiographs were evaluated in a reader study as well as objectively in terms of contrast-to-noise ratio and signal strength. We found that the optimum tube voltage for dark-field imaging is 70 kVp as here the most favorable combination of image quality, signal strength, and sharpness is present. At this voltage, a high image quality was perceived in the reader study also for attenuation radiographs, which should be sufficient for routine imaging. The results of this study are fundamental for upcoming patient studies with living humans.

scholarly journals Recommendations for Increasing Physician Provision of Pre-Exposure Prophylaxis: Implications for Medical Student Training

2021 ◽  
Vol 58 ◽  
pp. 004695802110176
Author(s):  
Robert L. Cooper ◽  
Paul D. Juarez ◽  
Matthew C. Morris ◽  
Aramandla Ramesh ◽  
Ryan Edgerton ◽  
...  
Keyword(s):  
Care Management ◽  
Financial Constraints ◽  
Standard Of Care ◽  
The United States ◽  
Risk Compensation ◽  
Continuous Care ◽  
Student Training ◽  
Hiv Acquisition ◽  
Hiv Risk Assessment ◽  
Exposure Prophylaxis

There is growing evidence that pre-exposure prophylaxis (PrEP) prevents HIV acquisition. However, in the United States, approximately only 4% of people who could benefit from PrEP are currently receiving it, and it is estimated only 1 in 5 physicians has ever prescribed PrEP. We conducted a scoping review to gain an understanding of physician-identified barriers to PrEP provision. Four overarching barriers presented in the literature: Purview Paradox, Patient Financial Constraints, Risk Compensation, and Concern for ART Resistance. Considering the physician-identified barriers, we make recommendations for how physicians and students may work to increase PrEP knowledge and competence along each stage of the PrEP cascade. We recommend adopting HIV risk assessment as a standard of care, improving physician ability to identify PrEP candidates, improving physician interest and ability in encouraging PrEP uptake, and increasing utilization of continuous care management to ensure retention and adherence to PrEP.

scholarly journals Testing telediagnostic obstetric ultrasound in Peru: a new horizon in expanding access to prenatal ultrasound

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Marika Toscano ◽  
Thomas J. Marini ◽  
Kathryn Drennan ◽  
Timothy M. Baran ◽  
Jonah Kan ◽  
...  
Keyword(s):  
Excellent Agreement ◽  
Rural Areas ◽  
Intraclass Correlation ◽  
Standard Of Care ◽  
The United States ◽  
Categorical Variables ◽  
Continuous Variables ◽  
Second Trimester ◽  
Obstetric Ultrasound ◽  
Biometric Measurements

Abstract Background Ninety-four percent of all maternal deaths occur in low- and middle-income countries, and the majority are preventable. Access to quality Obstetric ultrasound can identify some complications leading to maternal and neonatal/perinatal mortality or morbidity and may allow timely referral to higher-resource centers. However, there are significant global inequalities in access to imaging and many challenges to deploying ultrasound to rural areas. In this study, we tested a novel, innovative Obstetric telediagnostic ultrasound system in which the imaging acquisitions are obtained by an operator without prior ultrasound experience using simple scan protocols based only on external body landmarks and uploaded using low-bandwidth internet for asynchronous remote interpretation by an off-site specialist. Methods This is a single-center pilot study. A nurse and care technician underwent 8 h of training on the telediagnostic system. Subsequently, 126 patients (68 second trimester and 58 third trimester) were recruited at a health center in Lima, Peru and scanned by these ultrasound-naïve operators. The imaging acquisitions were uploaded by the telemedicine platform and interpreted remotely in the United States. Comparison of telediagnostic imaging was made to a concurrently performed standard of care ultrasound obtained and interpreted by an experienced attending radiologist. Cohen’s Kappa was used to test agreement between categorical variables. Intraclass correlation and Bland-Altman plots were used to test agreement between continuous variables. Results Obstetric ultrasound telediagnosis showed excellent agreement with standard of care ultrasound allowing the identification of number of fetuses (100% agreement), fetal presentation (95.8% agreement, κ =0.78 (p < 0.0001)), placental location (85.6% agreement, κ =0.74 (p < 0.0001)), and assessment of normal/abnormal amniotic fluid volume (99.2% agreement) with sensitivity and specificity > 95% for all variables. Intraclass correlation was good or excellent for all fetal biometric measurements (0.81–0.95). The majority (88.5%) of second trimester ultrasound exam biometry measurements produced dating within 14 days of standard of care ultrasound. Conclusion This Obstetric ultrasound telediagnostic system is a promising means to increase access to diagnostic Obstetric ultrasound in low-resource settings. The telediagnostic system demonstrated excellent agreement with standard of care ultrasound. Fetal biometric measurements were acceptable for use in the detection of gross discrepancies in fetal size requiring further follow up.

scholarly journals Introducing a frequency-tunable magnetic particle spectrometer

2015 ◽  
Vol 1 (1) ◽  
pp. 249-253 ◽  
Author(s):  
André Behrends ◽  
Matthias Graeser ◽  
Thorsten M. Buzug
Keyword(s):  
Magnetic Nanoparticles ◽  
Image Quality ◽  
Magnetic Particle ◽  
Imaging Modality ◽  
Magnetic Particle Imaging ◽  
Common Technique ◽  
Frequency Tunable ◽  
Excitation Frequencies ◽  
Particle Imaging

AbstractImage quality in the new imaging modality magnetic particle imaging (MPI) heavily relies on the quality of the magnetic nanoparticles in use. Therefore, it is crucial to understand the behaviour of such particles. A common technique to analyze the behaviour of the particles is magnetic particle spectrometry (MPS). However, most spectrometers are limited to measurements at a single or multiple discrete excitation frequencies. This paper introduces a frequency-tunable spectrometer, able to perform measurements in the range of 100 Hz - 24kHz.

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