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Epidermal inclusion cyst is a relatively common benign lesion of the skin, and it can occur anywhere in the hair-bearing area of the body. It usually appears as an asymptomatic mass, which is less than 4 cm in size. However, rarely it can occur as a large mass in the axilla, and in such cases, the location and size tend to cause more complications. The author encountered a patient with a large epidermal inclusion cyst of the axilla. Ultrasound examination showed an oval-shaped hypoechoic subcutaneous mass with dermal attachment, intralesional echogenic reflectors, filiform anechoic areas, and no vascularity. These characteristic imaging features could lead to an accurate preoperative imaging diagnosis without biopsy and avoid subsequent complications. Excision of the mass was performed due to discomfort because of the large size and growing nature of the lesion, and histological examination confirmed the diagnosis of an epidermal inclusion cyst. Therefore, recognition of diagnostic ultrasound features of this entity may enable an accurate preoperative diagnosis, even when it has an unusual size and location.

Introduction Musculoskeletal diagnostic ultrasound is an expanding clinical tool and increasingly used at point of care in clinical practice. Criticism around the accuracy of this modality is often attributed to operator dependence. This study evaluated the accuracy of a sonographer’s reporting against shoulder surgery. Methods A musculoskeletal sonographer performed same-day ultrasound scans prior to elective shoulder surgery procedures. The sonographer was blinded to clinical history and previous investigations. A brief physical examination of resisted external rotation and resisted abduction strength was performed prior to scanning. Scan results were reported using British Elbow and Shoulder Society (BESS) reporting criteria. The sonographer attended surgery to gain immediate visual feedback. Sonographic reports and magnetic resonance imaging (MRI) reports were graded (1= complete agreement; 2 = minor discrepancy unlikely to alter patient care; 3 = potentially significant discrepancy; 4 = definite, significant discrepancy) against surgical findings. The accuracy of sonographic reporting was correlated with patients’ body mass index (BMI). Results Fifty-four cases were compared and correlations evaluated. Grade 1 (complete agreement) was reported 87.0% ( n = 47), Grade 2 (minor discrepancy) 9.3% (n = 5) and Grade 3 (potentially significant discrepancy) 3.7% (n = 2). Sonographic reports closely correlated (Grade 1 or 2 scores) with surgical findings in 96% of cases. Conclusions The musculoskeletal sonographic reporting had a high correlation with surgery findings. Ultrasound was more accurate than MRI in reporting full thickness rotator cuff tears. Clinical weakness in resisted external rotation or abduction did not correlate with imaging. Ultrasound was found to be unreliable in detecting rotator cuff tears in participants with a BMI ≥ 35.

Pseudoaneurysms of the superficial temporal artery are rare. They commonly occur after blunt trauma to the frontotemporal region of the head. There have been less than 400 cases of superficial temporal artery pseudoaneurysms reported. We present a case of a patient referred for a pulsatile head mass. Physical examination and color Doppler ultrasound confirmed the diagnosis of a superficial temporal artery pseudoaneurysm (STA PSA). This was treated with ultrasound guided thrombin injection with complete resolution. Anatomical distribution, diagnosis, and treatment of STA PSA are discussed.

Many radiologists are interested in providing affordable care to underserved populations but are unsure how to accomplish it. We present a model for providing imaging services to the underserved with an emphasis on the challenges we encountered and strategies we used to overcome them. In partnership with our medical school's student-run free clinic, we developed a community-based ultrasound service that provides diagnostic ultrasound examinations to an uninsured urban population to address the need of timely access to care and integrated follow-up care. Image storage and reporting were fully integrated with our existing imaging informatics and electronic medical record systems. Radiology residents play a central role in the operation of the service while gaining hands-on ultrasound experience, in partnership with volunteer sonographers, radiology attendings, and medical students.

To assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) for additional MR-detected enhancing lesions and to determine whether or not kinetic pattern results comparable to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of the breast can be obtained using the quantitative analysis of CEUS.In this single-center prospective study, a total of 71 additional MR-detected breast lesions were included. CEUS examination was performed, and lesions were categorized according to the Breast Imaging-Reporting and Data System (BI-RADS). The sensitivity, specificity, and diagnostic accuracy of CEUS were calculated by comparing the BI-RADS category to the final pathology results. The degree of agreement between CEUS and DCE-MRI kinetic patterns was evaluated using weighted kappa.On CEUS, 46 lesions were assigned as BI-RADS category 4B, 4C, or 5, while 25 lesions category 3 or 4A. The diagnostic performance of CEUS for enhancing lesions on DCE-MRI was excellent, with 84.9% sensitivity, 94.4% specificity, and 97.8% positive predictive value. A total of 57/71 (80%) lesions had correlating kinetic patterns and showed good agreement (weighted kappa = 0.66) between CEUS and DCE-MRI. Benign lesions showed excellent agreement (weighted kappa = 0.84), and invasive ductal carcinoma (IDC) showed good agreement (weighted kappa = 0.69).The diagnostic performance of CEUS for additional MR-detected breast lesions was excellent. Accurate kinetic pattern assessment, fairly comparable to DCE-MRI, can be obtained for benign and IDC lesions using CEUS.자기공명영상에서 추가적으로 발견된 조영증강 병소에 대한 조영증강 초음파의 진단 능력을 평가하고 조영증강 초음파의 정량 분석을 사용하여 유방 동적 조영증강 자기공명영상과 유사한 운동 패턴 결과를 얻을 수 있는지 분석하였다.단일 센터 전향적 연구로 진행하였고, 총 71개의 자기공명영상에서 추가적으로 발견된 조영증강 병소가 포함되었다. 이러한 병소에 대해 조영증강 초음파를 시행하였고 Breast Imaging-Reporting and Data System (이하 BI-RADS)에 따라 분류하였다. 그리고 모든 병소의 BI-RADS 분류를 조직학적 결과와 비교하여 조영증강 초음파의 민감도, 특이도 및 진단 정확도를 계산하였다. 조영증강 초음파와 동적 조영증강 자기공명영상의 운동 패턴 사이의 일치도는 가중 카파 분석을 사용하여 평가되었다.조영증강 초음파에서 총 46개의 병소가 BI-RADS 4B, 4C, 5로 분류되었고, 25개의 병소가 BI-RADS 3, 4A로 분류되었다. 자기공명영상에서 추가적으로 발견된 조영증강 병소에 대한 조영증강 초음파의 진단 능력은 84.9%의 민감도, 94.4%의 특이도 및 97.8%의 긍정적 예측값으로 우수하였다. 총 57/71 (80%) 병소는 조영증강 초음파와 동적 조영증강 자기공명영상 운동 패턴 결과가 일치하였고 가중 카파 값 0.66으로 좋은 일치도를 나타냈다. 부분 군 분석에서 양성 병소는 우수한 일치를 보였고(가중 카파 값 = 0.84), 관내암종은 좋은 일치를 보였다(가중 카파 값 = 0.69).MRI에서 추가 검출된 유방 결절에 대한 조영증강 초음파의 진단 능력은 우수했다. 양성 및 관내암종 병소에서 동적 조영증강 자기공명영상과 조영증강 초음파의 운동 패턴 결과는 좋은 일치도를 보였다.

The color Doppler ultrasound twinkling artifact is a rapid color shift that appears on 43%-96% of kidney stones. Surface microbubbles on kidney stones are theorized to cause twinkling as exposure to elevated static pressures of 0.41-1.13 MPa (approximately 0.5-1 times diagnostic ultrasound pressure and 5-10 times ambient pressure) reduced twinkling. However, it is unclear what external and internal stone features support bubbles. Thirteen ex vivo kidney stones were scanned with color Doppler ultrasound at 2.5, 5 and 18.5 MHz. Select stones were imaged with environmental scanning electron microscopy or underwater micro-computed tomography to evaluate features that may cause twinkling. Results revealed that the lower frequencies produced larger volumes of twinkling. Condensation first occurred in the smallest (∼1 µm diameter) surface pores and may be indicative of where bubbles form. Gas pockets were seen inside two of three tested stones that may contribute to twinkling. Overall, these results provide evidence of cavity structures both externally and internally and their correlation to the twinkling artifact. This indicates that microbubbles may be present on and within kidney stones and may contribute to the twinkling artifact.

Background The use of multiparametric magnetic resonance imaging (mpMRI) within active surveillance of prostate cancer programmes is identified by the UK National Institute for Health and Care Excellence (NICE guideline NG 131 2019) as having a role for monitoring disease. The widespread demands on mpMRI capacity may limit its use in surveillance. It is therefore timely to review the options that modern ultrasound imaging present to this cohort of patients in the monitoring of prostate cancer. Methods Between April and September 2020, 10 databases were searched to recruit studies for the review. Three reviewers evaluated the publications for inclusion. Characteristics including the inclusion criteria for the study cohort, how disease was determined, identification of disease progression, and the modality and mode of imaging used were reviewed. Given the paucity of full text articles, a meta-analysis was not possible. A narrative review was undertaken. Results In total, 12 studies, utilising the range of ultrasound parameters of B-mode, micro-ultrasound, colour Doppler, contrast ultrasound and elastography were included. The review demonstrated that micro-ultrasound offers promise as an imaging tool comparable with mpMRI. However, this is an emerging technology with limited availability. Analysis of the data further demonstrated that by combining the diagnostic features provided by multiple modes reviewed, ultrasound has a role in the diagnostic imaging of patients on active surveillance. Conclusion Providing a multiparametric approach is utilised, stable ultrasound findings may allow for increased intervals between biopsy for men on surveillance. The advent of micro-US offers promise as an imaging modality within an active surveillance pathway but requires further verification.

Diagnostic ultrasound (DUS) is, arguably, the most common technique used in obstetrical practice. From A mode, first described by Ian Donald for gynecology in the late 1950s, to B mode in the 1970s, real-time and gray-scale in the early 1980s, Doppler a little later, sophisticated color Doppler in the 1990s and three dimensional/four-dimensional ultrasound in the 2000s, DUS has not ceased to be closely associated with the practice of obstetrics. The latest innovation is the use of artificial intelligence which will, undoubtedly, take an increasing role in all aspects of our lives, including medicine and, specifically, obstetric ultrasound. In addition, in the future, new visualization methods may be developed, training methods expanded, and workflow and ergonomics improved.

Background: Diagnostic ultrasound or sonography is an image which can provide valuable information for diagnosing and treating a variety of diseases and conditions. This experiment was done to check the performance and evaluate the ultrasonic imaging system. There were three tests performed in this experiment: dead zone (transducer ring-down), vertical measurement calibration, and horizontal measurement calibration. Methods: The evaluation was made by performed all the tests with different depth on two different multipurpose phantom model #539. The tests were also performed by two different probes which were curved and flat (linear probe). The images were taken, and the measurements were made by electronic calipers on the ultrasound machine system. Observations and evaluations were done via all images and measurements taken. Results: The images formed by two various probes were different. The penetration settings were different since the depths were different. The depth influenced the penetrations to the formed image. From the comparison of all results and measurements recorded were all under the accepted value of the standard that was given by the manufacture of the phantom. Conclusion: Therefore, it can be concluded that the measurements were all not exceeding 2% of the standard value given based on the result that we get.

OBJECTIVE Although epidemiological studies have failed to show the harmful effects of ultrasound in humans, as a form of energy, ultrasound has the potential to cause bio-effects in tissues. Therefore, clinical guidelines have been established for ultrasound technology related to human safety, which include Thermal (TI) and mechanical (MI) indices. The appropriate TI and MI ranges for embryonic examinations are between 0-1.0 and 0-0.4, respectively. The accepted TI and MI ranges are 0-2.0 and 0-1.9, respectively, for general ultrasound examinations. In addition, the scan duration should be kept as low as possible. Therefore, the present study aimed at evaluating the scan duration, TI, and MI as measures of acoustic output during ultrasound studies. METHODS A cross-sectional descriptive study was conducted for patients undergoing pregnancy checkups, routine checkups, and initial diagnosis ultrasound examinations. Samples were selected from imaging departments of 4 educational hospitals based on convenience sampling and 321 checklists completed by direct observation of ultrasound examinations. RESULTS For pregnancy scans, the mean TI and MI were obtained as 0.32 ± 0.27 and 1.15 ± 0.13, respectively. For non-pregnancy examinations, the mean value of TI and MI were 0.30 ± 0.29 and 1.07 ± 0.35, respectively. Therefore, mean TI for pregnancy and non-pregnancy examinations and mean MI for non-pregnancy studies obtained lower than the permitted values, while the mean MI was higher than the permitted level for first trimester of pregnancy. Also, relatively suitable scan durations were seen in reviewed studies. CONCLUSION From this study, it may be concluded that the reported ultrasound scans were safe.

FAST ultrasound is a medical procedure to assess for free fluid following physical trauma. FAST images can often be difficult to interpret and requires operators to be properly trained. Traditional...

The vast majority of clinicians associate diagnostic ultrasound with a tool that is designed for the living patient. However, it is of course possible to apply this imaging technology to evaluate the recently deceased patient for postmortem diagnosis, or even just examine postmortem tissue. We describe several cases in which ultrasound-enabled providers obtain answers in postmortem examinations and discuss potential future strategies and applications. In addition, we will also illustrate the use of sonography in minimally invasive post-mortem tissue sampling (MITS), an approach that can be used in post-mortem minimally invasive autopsies as well as for establishing ultrasound diagnostic parameters in new medical fields such as periodontal and dental implant specialties.

Polymer nanoparticles and microparticles have been used primarily for drug delivery. There is now growing interest in further developing polymer-based solid cavitation agents to also enhance ultrasound imaging. We previously reported on a facile method to produce hollow poly(lactic-co-glycolic acid) (PLGA) microparticles with different diameters and degrees of porosity. Here, we investigate the cavitation response from these PLGA microparticles with both therapeutic and diagnostic ultrasound transducers. Interestingly, all formulations exhibited stable cavitation; larger porous and multicavity particles also provided inertial cavitation at elevated acoustic pressure amplitudes. These larger particles also achieved contrast enhancement comparable to that of commercially available ultrasound contrast agents, with a maximum recorded contrast-to-tissue ratio of 28 dB. Therefore, we found that multicavity PLGA microparticles respond to both therapeutic and diagnostic ultrasound and may be applied as a theranostic agent. Ministry of Education (MOE) Ministry of Health (MOH) National Medical Research Council (NMRC) Accepted version The authors acknowledge the support from the Ministry of Education in Singapore under the Tier 1 grant scheme (RG144/18, RG127/19). This research is supported by the Singapore Ministry of Health’s National Medical Research Council under NMRC/OFYIRG/0034/2017.

A growing number of repaired and refurbished diagnostic ultrasound probes are supplied by a small number of original equipment manufacturers (OEMs) and many third-party vendors. OEMs ensure that their devices meet regulatory requirements; any repairs using non-OEM materials carry the risk of non-compliance. The aim of this study was to test examples of probe repairs using methods selected to illustrate their possible impact on function. Of 3212 used probes assessed, 21 were found to have undergone repair involving functional parts: 9 incorrectly wired, 11 non-OEM arrays and 1 relensed probe. For repairs not involving functional parts, before and after electronic probe testing may be sufficient to determine that no damage has occurred. For repairs involving functional parts, a more comprehensive suite of tests is necessary to determine that the materials, parts and final product match the performance of the OEM probe and meet regulatory requirements.

International audience; Objectives To assess prenatal changes in the volume of congenital pulmonary malformations (CPM) and examine whether these changes differ in lesions that appear cystic on ultrasound compared with hyperechoic lesions, and to study the relationship between CPM volume and risk of fetal compression. Methods We conducted a nationally representative, multicenter, prospective cohort study, which included 579 ultrasound examinations in 176 pregnant women with a diagnosis of fetal CPM, between March 2015 and November 2016. Several ultrasound examinations were performed between diagnosis and delivery, including measurement of CPM volume. We modeled changes in CPM volume ratio (CVR) as a function of gestational age, overall and for cystic/mixed vs hyperechoic malformations, and examined the association between CVR and signs of compression during pregnancy. Results When modeling CVR changes over time, there was a statistically significant decrease in CVR with increasing gestational age (P 0.4 vs CVR ≤ 0.4 cm2. Conclusions Predicted changes in CVR during pregnancy differ between cystic and hyperechoic malformations. This may be the result of different pathophysiological mechanisms or differences in the timing of occurrence of these different types of CPM. CVR measured at the initial diagnostic ultrasound examination was strongly associated with the odds of subsequent compression. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Pulmonary capillary hemorrhage (PCH) has been found in mammalian lungs exposed to diagnostic ultrasound (DUS), although the mechanism is poorly understood. This work investigates acoustic atomization and fountains at liquid-air interfaces subjected to DUS, which has been suggested as a possible PCH damage mechanism. Primarily using a SuperSonic Imagine Aixplorer DUS machine (SuperSonic Imagine, Aix-en-Provence, France), blood and water surfaces were excited in vitro by DUS and recorded with a high-speed camera. The surface was driven by B-mode, color Doppler, pulsed Doppler, and shear wave elastography imaging modes with center frequencies from 5.0-7.2 MHz and mechanical indexes (MI) up to 1.7. Fountains and atomization were only observed for SWE, for MI as low as 1.0. A comparison of the SWE waveforms with the surface dynamics suggests that fountains and atomization were driven by push-pulses and depended on pulse duration and intensity. However, we conclude that atomization and fountaining are unlikely primary mechanisms behind all DUS-induced PCH because neither phenomenon occurred for traditional diagnostic imaging modes.

Rationale and Objectives To design and validate a peer-teacher based musculoskeletal ultrasound curriculum for radiology residents. Materials and Methods A musculoskeletal ultrasound curriculum with hands-on scanning workshops was designed for radiology residents. Prior to the workshops, several residents received 3 hours of hands-on training in ultrasound scanning technique which was overseen by an attending musculoskeletal radiologist; these “peer teachers” then led small-group hands-on scanning during the workshops. Participants performed diagnostic ultrasound examinations at the conclusion of the workshops to assess skill acquisition and 2 months following the workshops to quantify skill retention. Participants also completed surveys to determine confidence in performing musculoskeletal ultrasound examinations. Median scores and interquartile range (25–75%) were calculated, and t test was used to compare results. Results Thirty seven residents from all years of training and six senior resident or fellow peer teachers participated in four workshops. Diagnostic ultrasound images were obtained in 100% at the conclusion of the workshop and in 79% 2 months later. Prior to the workshops, residents reported low level of musculoskeletal ultrasound knowledge (median 2, interquartile ranges 1–2), and low confidence in performing (1, 1–2) and interpreting (1, 1–2) musculoskeletal ultrasound examinations. There was a significant increase in knowledge (3, 3–4) and confidence performing (3, 3–4) and interpreting (3, 3–4) studies following the workshops (p Conclusion Hands-on musculoskeletal ultrasound workshops, utilizing a peer teacher led small group format is an effective method of teaching scanning skills to residents. There was excellent skill acquisition, good skill retention, and significant increase in confidence performing and interpreting these studies following completion of the curriculum.

Safety standards for clinical diagnostic ultrasonic devices were developed for use in relatively low-frequency systems (1–10 MHz), under the assumption that non-linear effects would be negligible. This article reviews ways in which neglecting non-linear wave propagation affects the measurements and calculations required to comply with safety standards and U.S. Food and Drug Administration guidance that recognizes these standards. An attempt is made to evaluate whether ignoring non-linear effects could result in significant error in the exposure quantities defined in these standards at either low or high frequencies, based on published literature. This article maintains that although non-linear effects have been considered in some parts of safety standards related to hydrophone requirements, the coverage is inadequate, especially for modern equipment with high working frequencies. A new approach is required to assess the magnitude of thermal heating for recently developed high-frequency systems to incorporate non-linear effects. In contrast, the current approach for evaluating the risk of cavitation can be used after appropriate modifications.

Background Telesonography systems have been developed to overcome barriers to accessing diagnostic ultrasound for patients in rural and remote communities. However, most previous telesonography systems have been designed for performing only abdominal and obstetrical exams. In this paper, we describe the development and assessment of a musculoskeletal (MSK) telesonography system. Methods We developed a 4-degrees-of-freedom (DOF) robot to manipulate an ultrasound probe. The robot was remotely controlled by a radiologist operating a joystick at the master site. The telesonography system was used to scan participants’ forearms, and all participants were conventionally scanned for comparison. Participants and radiologists were surveyed regarding their experience. Images from both scanning methods were independently assessed by an MSK radiologist. Results All ten ultrasound exams were successfully performed using our developed MSK telesonography system, with no significant delay in movement. The duration (mean ± standard deviation) of telerobotic and conventional exams was 4.6 ± 0.9 and 1.4 ± 0.5 min, respectively (p = 0.039). An MSK radiologist rated quality of real-time ultrasound images transmitted over an internet connection as “very good” for all telesonography exams, and participants rated communication with the radiologist as “very good” or “good” for all exams. Visualisation of anatomic structures was similar between telerobotic and conventional methods, with no statistically significant differences. Conclusions The MSK telesonography system developed in this study is feasible for performing soft tissue ultrasound exams. The advancement of this system may allow MSK ultrasound exams to be performed over long distances, increasing access to ultrasound for patients in rural and remote communities.

In this study, 3-D non-linear ultrasound simulations and experimental measurements were used to estimate the range of in situ pressures that can occur during transcutaneous abdominal imaging and to identify the sources of error when estimating in situ peak rarefaction pressures (PRPs) using linear derating, as specified by the mechanical index (MI) guideline. Using simulations, it was found that, for a large transmit aperture (F/1.5), MI consistently over-estimated in situ PRP by 20%–48% primarily owing to phase aberration. For a medium transmit aperture (F/3), the MI accurately estimated the in situ PRP to within 8%. For a small transmit aperture (F/5), MI consistently underestimated the in situ PRP by 32%–50%, with peak locations occurring 1–2 cm before the focal depth, often within the body wall itself. The large variability across body wall samples and focal configurations demonstrates the limitations of the simplified linear derating scheme. The results suggest that patient-specific in situ PRP estimation would allow for increases in transmit pressures, particularly for tightly focused beams, to improve diagnostic image quality while ensuring patient safety.

Current descriptions of ultrasound evaluations, including use of the term "point-of-care ultrasound" (POCUS), are imprecise because they are predicated on distinctions based on the device used to obtain images, the location where the images were obtained, the provider who obtained the images, or the focus of the examination. This is confusing because it does not account for more meaningful distinctions based on the setting, comprehensiveness, and completeness of the evaluation. In this article, the Society of Radiologists in Ultrasound and the members of the American College of Radiology Ultrasound Commission articulate a map of the ultrasound landscape that divides sonographic evaluations into four distinct categories on the basis of setting, comprehensiveness, and completeness. Details of this classification scheme are elaborated, including important clarifications regarding what ensures comprehensiveness and completeness. Practical implications of this framework for future research and reimbursement paradigms are highlighted.

BackgroundPoint-of-care ultrasound (POCUS) has a major role in the management of patients with acute hypoxic respiratory and circulatory failure and guides hemodynamic management. There is scarce literature on POCUS assessment characteristics in COVID-19 pneumonia with hypoxic respiratory failure.MethodsThe study is an observational, prospective, single‐center study conducted in the intensive care unit of Adan General Hospital from May 1st, 2020, to June 25, 2020. The study included adults suspected to have COVID-19 transferred to the intensive care unit (ICU) with fever or suspected respiratory infection. Patients were transferred to the ICU directly from the ED or general medical wards after reverse transcriptase-polymerase chain reaction (RT-PCR) testing. A certified intensivist in critical care ultrasound who was blinded to the RT-PCR results, if available at the time of examination, performed the lung ultrasound and echocardiology within 12 hours of the patient’s admission to the ICU. We calculated the E/e’, E/A ratio, left ventricular ejection fraction EF, IVC diameter, RV size and systolic function. We performed ultrasound in 12 chest areas.ResultsOf 92 patients with suspected COVID-19 pneumonia, 77 (84%) cases were confirmed. The median age of the patients was 53 (82-36) years, and 71 (77%) were men.In the group of patients with confirmed COVID-19 pneumonia, echocardiographic findings showed normal E/e’, deceleration time (DT), and transmittal E/A ratio in comparison to the non-COVID19 patients (P .001 for both). The IVC diameter was 50% collapsibility in 62 (81%) patients with COVID-19 pneumonia; a diameter of > 2 cm and < 50% collapsibility in all patients, with a P value of 0.001, was detected among those with non-COVID-19 pneumonia. There were 3 cases of myocarditis with poor EF (5.5%), severe RV dysfunction was seen in 9 cases (11.6%), and 3 cases showed RV thrombus.Chest US revealed four signs suggestive of COVID-19 pneumonia in 77 patients (98.6%) (sensitivity 96.9%, CI 85%‐99.5%) when compared with RT-PCR results.ConclusionPOCUS plays an important role in bedside diagnosis, hemodynamic assessment and management of patients with acute hypoxic respiratory and circulatory failure in patients with COVID-19 pneumonia.

Purpose Chest computed tomography (CT) is considered a reliable imaging tool for COVID-19 pneumonia diagnosis, while lung ultrasound (LUS) has emerged as a potential alternative to characterize lung involvement. The aim of the study was to compare diagnostic performance of admission chest CT and LUS for the diagnosis of COVID-19. Methods We included patients admitted to emergency department between February 21-March 6, 2020 (high prevalence group, HP) and between March 30-April 13, 2020 (moderate prevalence group, MP) undergoing LUS and chest CT within 12 h. Chest CT was considered positive in case of “indeterminate”/“typical” pattern for COVID-19 by RSNA classification system. At LUS, thickened pleural line with ≥ three B-lines at least in one zone of the 12 explored was considered positive. Sensitivity, specificity, PPV, NPV, and AUC were calculated for CT and LUS against real-time reverse transcriptase polymerase chain reaction (RT-PCR) and serology as reference standard. Results The study included 486 patients (males 61 %; median age, 70 years): 247 patients in HP (COVID-19 prevalence 94 %) and 239 patients in MP (COVID-19 prevalence 45 %). In HP and MP respectively, sensitivity, specificity, PPV, and NPV were 90–95 %, 43–69 %, 96−72 %, 20–95 % for CT and 94−93 %, 7–31 %, 94−52 %, 7–83 % for LUS. CT demonstrated better performance than LUS in diagnosis of COVID-19, both in HP (AUC 0.75 vs 0.51; P

OBJECTIVE. Compared with other guidelines, the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) has decreased the number of nodules for which fine-needle aspiration is recommended. The purpose of this study was to evaluate the characteristics of malignant nodules that would not be biopsied when the ACR TI-RADS recommendations are followed. MATERIALS AND METHODS. We retrospectively reviewed a total of 3422 thyroid nodules for which a definitive cytologic diagnosis, a definitive histologic diagnosis, or both diagnoses as well as diagnostic ultrasound (US) examinations were available. All nodules were categorized using the ACR TI-RADS, and they were divided into three groups according to the recommendation received: fine-needle aspiration (group 1), follow-up US examination (group 2), or no further evaluation (group 3). RESULTS. Of the 3422 nodules, 352 were malignant. Of these, 240 nodules were assigned to group 1, whereas 72 were assigned to group 2 and 40 were included in group 3. Sixteen of the 40 malignant nodules in group 3 were 1 cm or larger, and, on the basis of analysis of the sonographic features described in the ACR TI-RADS, these nodules were classified as having one of five ACR TI-RADS risk levels (TR1-TR5), with one nodule classified as a TR1 nodule, eight as TR2 nodules, and seven as TR3 nodules. If the current recommendation of no follow-up for TR2 nodules was changed to follow-up for nodules 2.5 cm or larger, seven additional malignant nodules and 316 additional benign nodules would receive a recommendation for follow-up. If the current size threshold (1.5 cm) used to recommend US follow-up for TR3 nodules was decreased to 1.0 cm, seven additional malignant nodules and 118 additional benign nodules would receive a recommendation for follow-up. CONCLUSION. With use of the ACR TI-RADS, most malignant nodules that would not be biopsied would undergo US follow-up, would be smaller than 1 cm, or would both undergo US follow-up and be smaller than 1 cm. Adjusting size thresholds to decrease the number of missed malignant nodules that are 1 cm or larger would result in a substantial increase in the number of benign nodules undergoing follow-up.

— An understanding of the acoustic cavitation threshold is essential for minimizing cavitation bio-effects in diagnostic ultrasound and for controlling cavitation-mediated tissue ablation in focused ultrasound procedures. The homogeneous cavitation threshold is an intrinsic material property of recognized importance to biomedical ultrasound as well as a variety of other applications requiring cavitation control. However, measurements of the acoustic cavitation threshold in water differ from those predicted by classic nucleation theories. This persistent discrepancy is explained by combining recently developed methods for acoustically nucleating single bubbles at threshold with numerical modeling to obtain a nucleus size distribution consistent with first-principles estimates for ion-stabilized nuclei. We identify acoustic cavitation at threshold as a reproducible subtype of heterogeneous cavitation with a characteristic nucleus size distribution. Knowledge of the nucleus size distribution could inspire new approaches to achieving cavitation control in water, tissue and a variety of other media.

PURPOSE: To determine patient understanding and expectations of ultrasound imaging and its safety, sources of examination information and levels of examination anxiety. METHODS: 1070 consecutive patients presenting to a private, regional radiology practice in New South Wales, Australia between 16(th) May and 14(th) June 2019, were invited to complete a survey while waiting for their non‐interventional ultrasound examination. The survey included questions on demographic characteristics, knowledge such as examination risks and safety, ultrasound expectations such as dissemination of results, sources of examination information and levels of participant anxiety. Data were analysed using Kruskal–Wallis tests (SPSS v. 25) to determine statistical associations between participant demographic factors, knowledge, anxiety level and the main source of examination information. RESULTS: A total of 215/1070 (20%) patients voluntarily participated in the study. Most were female (74%, 159/215), with a median (range) age of 55 (18–92) years. Participant's median (range) score of ultrasound imaging knowledge was 3 (0–5) scored out of six and indicated uncertainty regarding the ultrasound procedure, result dissemination and ultrasound safety. Participants with previous personal experience had significantly higher levels of ultrasound imaging knowledge than those whose primary information source was their referring doctor (P = 0.0005) or the internet (P = 0.026). Significantly higher levels of ultrasound examination knowledge were also associated with lower self‐reported levels of anxiety (P = 0.002). CONCLUSION: Participants had incomplete ultrasound examination knowledge, including misconceptions regarding safety and result dissemination, some of which could be clarified by the sonographer at the beginning of the ultrasound examination.

In recent years, women and girls are increasing their sport participation, and female sports are becoming more challenging. While more women and girls are participating in sports, there is still a lack of information about gender-specific lesions. We will therefore evaluate gender differences in sports injuries, analyzing the five sports and sporting activities that are most widespread in the western world: running, soccer, basketball, water sports, and winter sports. The ability to make correct ultrasonographic diagnoses in sports injuries is improving as the technology is advancing. Ultrasonography demonstrates tissue structure with two-dimensional grayscale images, while blood flow can be visualized with color and power Doppler. Furthermore, ultrasonography is the preferred imaging modality for studying soft-tissue lesions dynamically. High-quality diagnostic ultrasound cannot be performed without the knowledge of the underlying clinical background, and an understanding of gender-specific injuries and mechanisms of injuries is therefore important for assessing proper diagnostic and treatment guidelines tailored to phenotypic differences in professional and amateur athletes between male and female.

Tumor angiogenesis is characterized by a defective, leaky and fragile microvascular construction, and microbubble-enhanced ultrasound (MEUS) with high-pressure amplitude is capable of disrupting tumor microvasculature and arresting blood perfusion. In this study, we tried to investigate whether the blood perfusion of a malignant tumor can be characteristically interrupted by combining microbubbles and diagnostic ultrasound (US). Twenty-nine Sprague-Dawley (SD) rats with subcutaneous Walker 256 tumors and seven healthy SD rats were included. Fifteen tumors were treated by MEUS, which combined constant microbubble injection and 20 episodes of irradiation by diagnostic US (i.e., acoustic radiation force impulse [ARFI] imaging). The other 14 tumors were treated by ARFI or sham US only. Seven skeleton muscles from healthy SD rats were also treated with MEUS, serving as the control. Contrast-enhanced ultrasound (CEUS) was performed before and after all treatments. The blood perfusion of the tumor MEUS group showed a significant drop immediately after treatment, followed by a quick, incomplete perfusion recovery within 10-20 min. The visual perfusion scoring result was consistent with the quantitative analysis by CEUS peak intensity. However, there were no significant perfusion changes in the tumor control groups or the muscle control group. Histologic examination found severe microvascular disruption and hemorrhage in the MEUS-treated tumors but not in the control groups. Therefore, the treatment combining diagnostic US and microbubbles can specifically decrease or interrupt the blood perfusion of Walker 256 tumors, which could be a potential new imaging method for diagnosing malignant tumors.

Pulmonary capillary hemorrhage (PCH) can be induced by diagnostic ultrasound-a potential safety issue. Anesthetized rats were intubated for intermittent positive-pressure ventilation (IPPV) with 0 end-expiratory pressure, +4 cm H2O end-expiratory pressure (PEEP) and -4 cm H2O end-expiratory pressure (NEEP). Rats were imaged at 7.6 MHz with a Philips HDI 5000 ultrasound machine. The output was low (mechanical index [MI] = 0.22) for aiming and then was raised for 5 min in 20 different exposure groups with n = 8. Peak rarefactional pressure amplitudes were measured in water and de-rated for chest attenuation. The PCH areas were measured on the lung surface. At 2.2 MPa, PCH was 9.3 ± 6.6 mm2 for IPPV, 1.6 ± 3.2 mm2 for PEEP (p

Objective: To present a quantitative system for assessing the quality of ultrasound examinations-SQUALUS-and to determine its reproducibility, taking into consideration the images on file, as well as the consistency between the images obtained and the final report. Materials and Methods: The system includes questions related to the number of images; the appropriateness of images in relation to the protocol established; focus adjustment; depth; gain; and appropriateness of the measurements for B-mode examinations. For Doppler examinations, the system includes questions related to the appropriateness of color images, the spectral analysis, and correction of the insonation angle. To assess the quality of the report, the system includes questions related to the consistency between the images obtained and the contents of the report. An overall numerical score was assigned by averaging the scores for image quality and for the contents of the report. Two independent examiners, each blinded to the evaluation of the other, assessed 30 different types of ultrasound examinations. Results: There was statistically significant agreement between the two examiners for 8 of the 10 questions related to image quality. For the questions related to the quality of the reports, the interexaminer agreement was almost perfect. Conclusion: The proposed quantitative system for assessing the quality of ultrasound examinations is a reproducible tool that can be used in audits and accreditation programs. Resumo Objetivo: Apresentar e verificar a reprodutibilidade de um sistema quantitativo de avaliação da qualidade de exames de ultrassonografia (SQUALUS), levando em consideração as imagens documentadas e a coerência entre as imagens obtidas e o laudo final. Materiais e Métodos: Foram elaborados quesitos considerando o número de imagens, a adequação das imagens ao protocolo estabelecido, o ajuste do foco, a profundidade e ganho e a adequação das medidas. Para exames com Doppler também foram avaliadas a adequação das fotos coloridas, a análise espectral e a correção do ângulo. Para a qualidade do laudo foi considerada a coerência com as imagens documentadas e seu conteúdo. Um sistema numérico foi atribuído conferindo uma nota final à qualidade das imagens, ao conteúdo do laudo e à média das duas avaliações. Trinta exames de ultrassonografia de diferentes tipos foram avaliados por dois examinadores independentes, cegos à avaliação um do outro. Resultados: Os avaliadores apresentaram concordância estatisticamente significante em 8 de 10 quesitos para avaliação da qualidade da imagem. Na avaliação dos laudos, a concordância entre os avaliadores foi quase perfeita. Conclusão: O sistema quantitativo de avaliação da qualidade de exames ultrassonográficos proposta é uma ferramenta reprodutível que pode ser utilizada em auditorias e em programas de acreditação.

A recently proposed two-criterion model for cavitational bioeffects in tissue with microbubbles (MBs) was tested. The glomerular capillary hemorrhage bioeffect was observed in rat kidney for contrast agent MB suspensions with mean diameters of 1.6, 3.1 and 5.5 µm. A diagnostic ultrasound machine was used at 3.6 MHz and 5.5 MHz for intermittent scans at power settings 2 dB apart. Petechial hemorrhage counts scored on the surface of the kidneys, and glomeruli were scored in histology. Thresholds for the petechial hemorrhage measurements were the same for the large and medium MB suspensions but substantially higher for the small MBs. For the histology, the medium MBs gave a higher threshold than the large MBs at 5.5 MHz. The pressure amplitude thresholds are in approximate agreement with theory, and the optimum MB size counterintuitively increased for increasing ultrasound frequency, as predicted. The two-criterion model of MB-associated capillary hemorrhage is supported.

OBJECTIVES Pulmonary diagnostic ultrasound (US) can induce pulmonary capillary hemorrhage (PCH) in mammals. This singular biological effect of diagnostic US imaging was discovered more than 25 years ago but remains poorly understood. Our objective here was to investigate rapid infusion of intravenous fluids as a possible stressor for capillaries, which might enhance pulmonary diagnostic US-induced PCH. METHODS Rats were anesthetized with Telazol (Zoetis, Inc, Kalamazoo, MI), which yielded relatively low pulmonary diagnostic US-induced PCH, or Telazol and xylazine, which yielded relatively high pulmonary diagnostic US-induced PCH. Groups of rats were not infused or infused either with normal saline, 10% mannitol, or 5% albumin. Rats were scanned in a warmed water bath with B-mode US for 5 minutes with a 7.6-MHz linear array set to different mechanical index values to obtain exposure response information. Pulmonary capillary hemorrhage was observed as comet tail artifacts in the image and measured on the lung surface. RESULTS For Telazol anesthesia, all of the PCH results were very low, with no significant differences at the maximum output with an in situ peak rarefactional pressure amplitude of 2.1 MPa (on-screen mechanical index, 0.9). The addition of xylazine to the Telazol anesthetic significantly enhanced the PCH (P

Introduction Duplex ultrasound is often the sole imaging modality used in diagnosing carotid artery disease. However, the reproducibility and repeatability of scientists in determining the peak systolic velocity and end diastolic velocity of the internal carotid artery and common carotid artery (CCA) is widely debated. Study aim To investigate intra- and inter-operator variability in diagnostic ultrasound of the carotid arteries across a centralised vascular network using a healthy test subject. To identify potential causes of variability and highlight areas for improvement. Methods Fifteen vascular scientists across four hospital Trusts in the Bristol, Bath and Weston vascular network measured the peak systolic velocity and end diastolic velocity of the internal carotid artery and common carotid artery in a subject using a single portable ultrasound machine. A double blind assessment of spectral Doppler images was performed by two vascular clinical scientists for optimal caliper placement, spectral gain and angle correction. Results were compared for intra- and inter-operator variability. Results Initial quality assessment of the Doppler images revealed that three out of 15 scientists produced suboptimal results. Box plot analysis of the common carotid artery and internal carotid artery for each scientist revealed significant variance (ANOVA p Conclusion This study highlights the difficulty in obtaining consistent velocity measurements from a subject. Despite the variability in absolute peak systolic velocity and end diastolic velocity, scientists were generally consistent in obtaining an optimal spectral Doppler trace. Some issues with consistency were, however, identified which were subsequently addressed.

This document is the updated 2019 revision of the EFSUMB Clinically Safety Statement. A Safety Statement has been published by EFSUMB annually since 1994 by the Safety Committee (ECMUS) of the federation. The text is deliberately brief and gives a concise overview of safety in the use of diagnostic ultrasound.Dieses Dokument ist die 2019 aktualisierte Revision des EFSUMB-Clinically-Safety-Statements. Diese Stellungnahme zur Sicherheit wird von der EFSUMB seit 1994 jährlich durch das Sicherheitskomitee (ECMUS) der EFSUMB veröffentlicht. Der Text ist bewusst kurz gehalten und gibt einen prägnanten Überblick über die Sicherheit bei Anwendung des diagnostischen Ultraschalls.

Objectives The objective of this study was to investigate if the on-screen displayed thermal index for bone (TIB) was an adequate predictor for the derated spatial-peak temporal-average (ISPTA.3) and spatial-peak pulse-average (ISPPA.3) acoustic intensity in a selection of clinical diagnostic ultrasound machines and transducers. Methods Five clinical diagnostic ultrasound scanners and 10 transducers imaging in 2D greyscale, color Doppler, and pulsed wave Doppler, both close to and far from the transducer, with a thermal index for bone between 0.1 and 4.0, were calibrated resulting in 103 unique measurements. Acoustic measurements were performed in a bespoke 3-axis computer-controlled scanning tank using a 200-µm diameter calibrated needle hydrophone. Results Significant but poor correlation was observed between the acoustic intensities and the on-screen TIB. At TIB 0.1, the ISPTA.3 range was 0.51 – 50.49 mW/(cm)2 and the ISPPA.3 range was 0.01–207.29 W/(cm)2. At TIB of 1.1, the ISPTA.3 range was 19.02 – 309.44 mW/(cm)2 and the ISPPA.3 range was 3.87–51.89 W/(cm)2. Conclusions The TIB is a poor predictor for spatial-peak temporal-average intensity, spatial-peak pulse-average acoustic intensity and potential bioeffects from clinical diagnostic ultrasound scanners.

The objective of our study was to retrospectively assess for differences in imaging appearances of Morton neuromas before and after laser therapy using diagnostic ultrasound (US).A retrospective review was performed to identify patients who underwent US imaging to evaluate for Morton neuroma during the study period (June 1, 2013-July 1, 2014); of the 42 patients identified, 21 underwent US evaluations before and after laser therapy. US reports and images were reviewed and correlated with clinical history. The final study group consisted of 21 patients who had a total of 31 Morton neuromas evaluated using US after treatment. A retrospective review was then performed to characterize the appearances of these lesions before and after therapy followed by an analysis of variables.Retrospective US review of 31 pretreatment Morton neuromas showed fusiform, heterogeneously hypoechoic masses with well-defined borders in most cases and that pain was reported when transducer pressure was applied in 97% (30/31) of cases. After treatment, lesions showed ill-defined borders (23/31), and pain with application of transducer pressure was either significantly decreased or absent (29/31); these findings were concordant with the clinical findings. Both of these characteristics were statistically significant (p0.0001). In addition, more Morton neuromas occurred in the second intermetatarsal space than in the third intermetatarsal space (p0.0001).US may be used to identify posttreatment changes after laser therapy of Morton neuromas. Posttreatment changes include ill-defined borders and less pain or the absence of pain with the application of transducer pressure. These criteria may be applied in future clinical studies evaluating the efficacy of laser therapy for Morton neuroma.

Pulmonary capillary hemorrhage induction by diagnostic ultrasound (DUS-PCH) was investigated with respect to the influence of the fraction of inspired oxygen (FiO2). Sprague-Dawley rats were anesthetized with Telazol only (TO) or Telazol plus xylazine (TX), which can enhance DUS-PCH. A linear array probe (10 L, GE Vivid 7 Dimension) was used in B-mode at 7.5 MHz to expose the right lung. FiO2 at 10%, 20%, 60% and 100% was delivered through a nose cone. On the ultrasound images, the PCH effect was observed as growing comet tail (B-line) artifacts and as subpleural consolidated segments at higher FiO2. PCH for TO with 20% and 60% FiO2 were significantly greater (p < 0.05) than for the 10% FiO2. PCHs with TX at 10% and 20% FiO2 were significantly greater (p < 0.02) than those for TO anesthesia. Added xylazine and high percentages of FiO2 reduced PCH thresholds, but xylazine and high percentages of FiO2 together did not lower the PCH threshold further. The lowest threshold observed, 1.4 MPa, corresponded to an in situ mechanical index of 0.5.

High-intensity focused ultrasound (HIFU) is a promising modality that is used to noninvasively ablate soft tissue tumors. Nevertheless, real-time treatment monitoring with diagnostic ultrasound still poses a significant challenge since tissue necrosis, in the absence of cavitation or boiling, provides little acoustic contrast with normal tissue. In comparison, the optical properties of tissue are significantly altered accompanying lesion formation. A photorefractive crystal-based acousto-optic (AO) sensing system that uses a single HIFU transducer to simultaneously generate tissue necrosis and pump the AO interaction is used to monitor the real-time optical changes associated with thermal lesions induced in chicken breast ex vivo . It is found that the normalized change in AO response increases proportionally with the volume of necrosis. This study demonstrates AO sensing can identify the onset and growth of lesion formation in real time and, when used as feedback to guide exposures, results in more predictable lesion formation. (E-mails: laipuxiang@gmail.com or ronroy@bu.edu )

Knowledge of the acoustic attenuation characteristics of the chest wall is necessary to estimate the acoustic exposure at the pleural surface during lung ultrasound and is useful in the prediction of bio-effects (e.g., pulmonary capillary hemorrhage) and the development of safe, effective lung imaging. Currently, this property is not well characterized in humans. The aim of this work was to characterize ultrasonic attenuation in human chest wall such that the ultrasound exposures of the lung can be estimated for clinically relevant conditions. In this study, we experimentally measured ultrasound transmitted through the intercostal tissue of 15 human cadaver chest wall samples relative to ultrasound transmitted through saline to determine attenuation coefficients for each sample. A GE Vivid 7 diagnostic ultrasound machine (GE Vingmed, Horten, Norway) and 3 S and 5 S phased array probes were used at center frequencies from 1.6 to 5 MHz. The chest wall samples varied in thickness from 2.3-5.5 cm with a median thickness of 3.8 cm. The frequency-normalized attenuation coefficient was approximately 1.44 dB/cm/MHz based on a linear best fit through all attenuation measurements. Attenuation characteristics varied appreciably between samples, and the sample-averaged linear attenuation coefficient was 1.43 ± 0.32 (mean ± standard deviation) dB/cm/MHz. This attenuation is higher than that previously measured in mammalian chest wall samples (1.1-1.3 dB/cm/MHz for mice and rats) and is much greater than that used by the mechanical index (0.3 dB/cm/MHz). Mechanical index values calculated using saline values de-rated by 0.3 dB/cm/MHz were up to 1.2 MPa/MHz1/2 greater than those calculated using the measured through-tissue ultrasound waves. We conclude that the mechanical index overestimates exposures for lung ultrasound and thus may not be an appropriate dosimetry metric for pulmonary ultrasound.

Potential ultrasound exposure safety issues are reviewed, with guidance for prudent use of point-of-care ultrasound (POCUS). Safety assurance begins with the training of POCUS practitioners in the generation and interpretation of diagnostically valid and clinically relevant images. Sonographers themselves should minimize patient exposure in accordance with the as-low-as-reasonably-achievable principle, particularly for the safety of the eye, lung, and fetus. This practice entails the reduction of output indices or the exposure duration, consistent with the acquisition of diagnostically definitive images. Informed adoption of POCUS worldwide promises a reduction of ionizing radiation risks, enhanced cost-effectiveness, and prompt diagnoses for optimal patient care.

Contrast enhanced diagnostic ultrasound (CEDUS) can lead to microvascular injury and petechial hemorrhage by the cavitational mechanism of ultrasonic bioeffects. Capillary hemorrhage has been noted in heart and kidney, which are common subjects of CEDUS examination. CEDUS has also become useful for monitoring intestinal inflammation. In the 1990s, the risk of intestinal microvascular hemorrhage was investigated both for incidental exposure by lithotripter shockwaves and for contrast agent microbubbles acting as cavitation nuclei with laboratory pulsed ultrasound systems. This study was initiated to update the risk assessment for intestine for exposure by diagnostic imaging simulating CEDUS. The abdomens of anesthetized rats were scanned by a 1.6 MHz phased array probe during infusion of microbubble suspensions simulating Definity ultrasound contrast agent. Dual image frames were triggered intermittently, and the output power was varied to assess the exposure-response. Petechiae counts in small intestine mucosa and muscle layers increased with increasing trigger interval from 2 s to 10 s, indicative of a slow refill after microbubble destruction. The counts increased with increasing output above a threshold of 1.4 MPa peak rarefactional pressure amplitude. Petechiae were also seen in Peyer’s patches, and occult blood was detected in many affected segments of intestine. These results are consistent with early laboratory pulsed-ultrasound results.

The mechanical index (MI) is a theoretical exposure parameter for cavitational bioeffects of diagnostic ultrasound. The theory for the MI assumed that bubbles of all relevant sizes exist in tissue, a condition that is approximated for tissues that include a microbubble contrast agent. Therefore, the MI should allow science-based safety guidance for contrast-enhanced diagnostic ultrasound. However, theoretical predictions of bioeffects thresholds based on the MI typically do not concur with the frequency dependence of experimentally measured thresholds for bioeffects. For example, experimental thresholds for glomerular capillary hemorrhage in rats infused with contrast microbubbles increased approximately linearly with frequency (Miller et al. UMB 2008b; 34:1678), while the MI predicted a square-root dependence. Here, cavitation thresholds were computed for linear versions of the acoustic pulses used in that study assuming bubbles containing either air, C3F8, or a 1:1 mixture of the two and surrounded by either blood or kidney tissue. While no single threshold criterion was successful, combining results for one criterion that maximized circumferential stress in the capillary wall with another that ensured an inertial collapse produced thresholds that were consistent with experimental data. This suggests that a contrast-specific safety metric may be achieved following validation of this 2-criterion model.

Biological effects of megahertz-frequency diagnostic ultrasound are thoroughly monitored by professional societies throughout the world. A corresponding, thorough, quantitative evaluation of the archival literature on the biological effects of low-frequency vibration is needed. Biological effects, of course, are related directly to what those exposures do physically to the tissue-specifically, to the shear strains that those sources produce in the tissues. Instead of the simple compressional strains produced by diagnostic ultrasound, realistic sources of low-frequency vibration produce both fast (∼1,500 m/s) and slow (1-10 m/s) waves, each of which may have longitudinal and transverse shear components. Part 1 of this series illustrates the resulting strains, starting with those produced by longitudinally and transversely oscillating planes, through monopole and dipole sources of fast waves and, finally, to the case of a sphere moving in translation-the simplest model of the fields produced by realistic sources.

Because of the physiological changes that occur during pregnancy and lactation, diagnostic ultrasound of the breast during these periods is a challenge for physicians. Therefore, a comprehensive understanding of imaging, anatomy, and physiology of the breast is important to effectively diagnosing diseases that can arise in women who are pregnancy or lactating. The aim of this article was to review the physiological changes that occur in the breasts during pregnancy and lactation, as well as to describe the main features of the breast diseases that occur most frequently during these periods.O diagnóstico ultrassonográfico das mamas durante a gravidez e lactação representa um desafio para o médico, em função das alterações fisiológicas próprias destes períodos. Para tanto, é essencial uma compreensão das imagens, da anatomia e da fisiologia mamárias para diagnosticar mais eficazmente doenças concomitantes. O presente artigo teve como objetivo fazer uma revisão das alterações fisiológicas que ocorrem nas mamas durante a gravidez e lactação, bem como relatar as principais características ultrassonográficas das doenças mamárias mais frequentes nestes períodos.

The purpose of this study is to compare diagnostic outcomes of digital breast tomosynthesis screen-detected masses worked up with mammography first with those evaluated with diagnostic ultrasound initially. METHODS: All masses recalled from screening digital breast tomosynthesis between July 1, 2017 and December 31, 2017 that were sent either to diagnostic mammography or ultrasound were compared. Size, shape, margins, visibility on ultrasound, diagnostic assessment and pathology of all masses along with breast density were evaluated. RESULTS: 102/212 digital breast tomosynthesis screen-detected masses were worked up with diagnostic mammography initially and 110/212 were worked up with ultrasound directly. There was no significant difference in ultrasound visibility of masses sent to diagnostic mammography first with those sent to ultrasound first (p = 0.42). 4 (4%) masses sent to mammogram first and 2 (2%) masses sent to ultrasound first were not visualized. There was a significant difference in size between masses that were visualized under ultrasound versus those that were not (p = 0.01), when masses in both groups were assessed cumulatively. CONCLUSIONS: 98% of digital breast tomosynthesis screen-detected masses sent to ultrasound directly were adequately assessed without diagnostic mammography. ADVANCES IN KNOWLEDGE: There is potential for avoiding a diagnostic mammogram for evaluation of majority of digital breast tomosynthesis screen-detected masses.