Ultrasound Research Articles

6454 Identifying Gaps in Obtaining Germline RET Testing for Patients with Medullary Thyroid Cancer

Abstract Disclosure: A.N. Lim: None. J. Comeaux: None. C. Ricker: None. K.S. Wei: None. T.E. Angell: None. Background: Medullary thyroid carcinoma (MTC) occurs sporadically or from germline pathogenic variants of the RET proto-oncogene in multiple endocrine neoplasia type 2 (MEN2). Current ATA guidelines recommend germline RET testing in all patients with C-cell hyperplasia or MTC. Because disparities may exist in the implementation of this recommendation, we analyzed records of patients with MTC to identify variables associated with germline RET testing. Methods: Patients with MTC were identified from a cohort study of all adult patients undergoing thyroid surgery from 2015-2022 at two affiliated academic centers: a private hospital or a safety-net hospital. Patients were categorized as RET-tested or not RET-tested. Data collection included: patient age, gender, ethnicity, nodule and lymph nodule findings on ultrasound (US), calcitonin and CEA levels, and surgical pathology results. Medical reports were reviewed for reasons that RET testing was or was not obtained. Results: Of 24 MTC patients, 50% were female, mean age ± SD was 50.8 ± 12.3, and 15 (62.5%) had Hispanic ethnicity. RET testing was performed in 14 (58.3%) patients and 3 (21.4%) had a pathogenic variant. RET-tested patients had a median nodule size of 3.45 cm (IQR 2.40-4.53) vs. 2.40 cm (IQR 0.98-3.25) in not-RET tested patients (p<0.05). There were no significant differences between groups in age, gender, ethnicity, preoperative US findings, preoperative calcitonin or CEA levels, or histopathologic status. RET testing was performed in 11/14 (78.6%) patients at the private hospital vs. only 5/10 (50.0%) patients at the safety-net hospital (p=0.20). Considering this, we further investigated the use of RET testing in the initial management of MTC patients. RET testing was performed or planned during initial management in 13/14 (92.9%) patients at the private hospital vs. only 5/10 (50%) patients at the safety-net hospital (p=0.05). At the private hospital, RET testing was requested for apparent sporadic disease (n=11), family history of MTC (n=1), and coexistent pheochromocytoma (n=1). At the safety-net hospital, RET testing was requested for apparent sporadic disease (n=4) and family history of MTC (n=1), but reportedly was not pursued in 5 patients because MTC appeared to be sporadic. Discussion: In this cohort of patients with MTC, larger nodule size was significantly associated with the rate of germline RET testing. Larger MTC tumor size alone may have prompted greater attention to germline testing, but also may have been associated with other findings, which could be further assessed with a larger sample size by multivariable analysis. The disparity in RET testing as part of initial management at the safety-net hospital may be multifactorial, but future analyses should explore provider decision-making, as well as facility and patient variables. Presentation: 6/1/2024

Retrospective Review of the Image Quality of Monoplane Transesophageal Echocardiography in Prehospital Out-of-Hospital Cardiac Arrest: A Single Center Pilot Study

Objectives Out of Hospital Cardiac Arrest (OHCA) is a frequently encountered pathology with resultant poor outcomes in the majority of patients. Echocardiography has been utilized to help guide clinical decision making and monitor effectiveness of resuscitative efforts. Transthoracic echocardiography (TTE) the mainstay of point-of-care ultrasound (POCUS) real time resuscitative imaging has limitations, most notably is the disruption of closed chest compressions. Trans-esophageal echocardiography (TEE) is an emerging technology in emergency care and can potentially overcome these limitations but image quality and accuracy of use in the prehospital environment remains unknown. Our primary objective is to identify the accuracy of Emergency Medical Services (EMS) fellow physicians in performing TEE via the identification of key cardiac structures. Secondarily we assess image quality as well as accuracy on cardiac activity interpretation as compared to TEE-experienced cardiologists. Methods A pilot study using descriptive analysis of a retrospective case-series with specific focus on inter-rater reliability as well as pragmatic management alterations based on real-time image interpretation by EMS physicians. After focused education, 13 patients were eligible for prehospital TEE who suffering OHCA from July 2022 to June 2023. Ultrasound (US) images were interpreted by EMS fellow physicians and over-read by cardiologists with specific focus on inter-rater reliability. After collection of patients presenting data and US images, analysis was performed. Results Of 13 patients initially screened, 10 patients were included in a study with a median age of 50 years old (41–70). Three patients were excluded due to equipment malfunction or insufficient image capture. An interrater reliability identified a kappa of 0.96 with respect to identification of cardiac structures and a kappa of 0.65 for identification of cardiac activity. Conclusions In this small study of prehospital TEE, EMS fellow physicians had high inter-rater reliability in image interpretation pertaining to anatomy and cardiac activity when compared with cardiologists. Further research is needed to determine its efficacy, safety, and widespread application in the prehospital setting.

5118 When Thyroid Gland Is Not Made Of Thyroid Cells

Abstract Disclosure: A. Bulut: None. L. Ma: None. J.P. Noordzij: None. S.Y. Lee: None. Introduction: Neurofibroma is a type of peripheral nerve tumor that can arise sporadically or be a part of neurofibromatosis type 1 (NF1), a rare genetic disorder. Neurofibromas within the thyroid gland are extremely rare. Here, we present the fifth reported case of primary neurofibroma of thyroid gland. Case: A 60-year-old woman with history of systemic lupus erythematosus and hypertension presented with enlargement of left thyroid gland. She was diagnosed with Graves’ disease 40 years ago, which was treated with right thyroid lobectomy one year after the initial diagnosis. Five years after the surgery, she had recurrence of her symptoms and received radioactive iodine ablation with subsequent hypothyroidism. On presentation to endocrine clinic, she had thyroid ultrasound (US), which showed surgically absent right thyroid lobe and enlarged heterogenous left thyroid lobe measuring 5.1 cm x 3.8 cm x 3.9 cm with scant blood flow without discrete nodules. In interim, patient developed dysphagia and globus sensation. Repeat thyroid US showed enlargement of left lobe to 5.6 cm x 3.7 cm x 4.7 cm. Patient underwent completion thyroidectomy. Surgical pathology showed neurofibroma (S-100+, CD34+ and MSA-) without any thyroid parenchyma. Whole-body scan revealed no other evidence of tumors. Patient was referred for genetic analysis. Discussion: Neurofibromas are benign peripheral nerve system tumors primarily consist of Schwann cells along with other components of perineurium. They can occur as a sporadic lesion which accounts for 90% of solitary neurofibroma cases or be a part of NF1 on rare occasions. NF1 is an autosomal dominant genetic disorder due to germline mutation in NF1 gene located on chromosome 17q11.2, whose manifestations include café-au-lait macules, Lisch nodules, skeletal abnormalities, neurological deficits, and other benign and malignant tumors. Neurofibromas are the hallmarks of NF1. There are only few cases in the literature reported neurofibromas adjacent to or originating from thyroid gland. To the best of our knowledge, there have been only four other cases reporting primary neurofibroma of thyroid gland, one of which developed from thyroid capsule. Our patient most likely has primary neurofibroma of thyroid gland given the lack of syndromic features, however, genetic testing is needed in order to rule out NF1. In conclusion, clinicians should consider neurofibroma in their differential in cases of enlarging thyroid gland or nodules, especially in the presence of other clinical features. Presentation: 6/1/2024

5118 When Thyroid Gland is Not Made of Thyroid Cells

Abstract Disclosure: A. Bulut: None. L. Ma: None. J.P. Noordzij: None. S.Y. Lee: None. Introduction: Neurofibroma is a type of peripheral nerve tumor that can arise sporadically or be a part of neurofibromatosis type 1 (NF1), a rare genetic disorder. Neurofibromas within the thyroid gland are extremely rare. Here, we present the fifth reported case of primary neurofibroma of thyroid gland. Case: A 60-year-old woman with history of systemic lupus erythematosus and hypertension presented with enlargement of left thyroid gland. She was diagnosed with Graves’ disease 40 years ago, which was treated with right thyroid lobectomy one year after the initial diagnosis. Five years after the surgery, she had recurrence of her symptoms and received radioactive iodine ablation with subsequent hypothyroidism. On presentation to endocrine clinic, she had thyroid ultrasound (US), which showed surgically absent right thyroid lobe and enlarged heterogenous left thyroid lobe measuring 5.1 cm x 3.8 cm x 3.9 cm with scant blood flow without discrete nodules. In interim, patient developed dysphagia and globus sensation. Repeat thyroid US showed enlargement of left lobe to 5.6 cm x 3.7 cm x 4.7 cm. Patient underwent completion thyroidectomy. Surgical pathology showed neurofibroma (S-100+, CD34+ and MSA-) without any thyroid parenchyma. Whole-body scan revealed no other evidence of tumors. Patient was referred for genetic analysis. Discussion: Neurofibromas are benign peripheral nerve system tumors primarily consist of Schwann cells along with other components of perineurium. They can occur as a sporadic lesion which accounts for 90% of solitary neurofibroma cases or be a part of NF1 on rare occasions. NF1 is an autosomal dominant genetic disorder due to germline mutation in NF1 gene located on chromosome 17q11.2, whose manifestations include café-au-lait macules, Lisch nodules, skeletal abnormalities, neurological deficits, and other benign and malignant tumors. Neurofibromas are the hallmarks of NF1. There are only few cases in the literature reported neurofibromas adjacent to or originating from thyroid gland. To the best of our knowledge, there have been only four other cases reporting primary neurofibroma of thyroid gland, one of which developed from thyroid capsule. Our patient most likely has primary neurofibroma of thyroid gland given the lack of syndromic features, however, genetic testing is needed in order to rule out NF1. In conclusion, clinicians should consider neurofibroma in their differential in cases of enlarging thyroid gland or nodules, especially in the presence of other clinical features. Presentation: 6/1/2024

7407 Normosmic Idiopathic Hypogonadotropic Hypogonadism in Women: A Case Report and Comprehensive Review

Abstract Disclosure: E.G. Bustamante: None. M. Sulehri: None. I. Patoli: None. A. Karunakaran: None. Normosmic Idiopathic Hypogonadotropic Hypogonadism (nIHH) in Women: A Case Report and Literature ReviewIntroduction: IHH is a rare genetic disorder affecting gonadotropic-releasing hormone (GnRH) production and/or action, resulting in diminished sex steroid levels. Characterized by the absence of spontaneous pubertal development. In women, it manifests with normal adrenarche but absent thelarche and menarche. Our case highlight a late diagnosis of IHH in a 34-year-old woman with primary amenorrhea. Case report: A 34 year old lady with a history of primary amenorrhea sought evaluation. At age 16, she underwent assessment for short stature and primary amenorrhea, denying anosmia, headache, visual disturbances. Evaluation revealed bone age concordant with chronological age and normal MRI Brain. Pelvic ultrasound (US) showed small premenarchal uterus and ovaries. She initiated oral contraceptive pills (OCP) and experienced regular menses. Seeking fertility assistance at age 24, a normal Hysterosalpingogram was followed by successful delivery of twins after ovarian stimulation. Post-delivery menses did not resume and OCP was not restarted. Family history revealed a sister with irregular periods requiring OCP.Subsequently workup at age 30 showed Estradiol 22 pg/ml, FSH/LH 4.1/2.3 mUI/mL; normal PRL, TFT, DHEAS, 17OHP. Repeat Pelvic US showed normal uterus, endometrial stripe normal at 0.24 cm and non-visualized ovaries. PCOS testing negative for hyperandrogenism. Progesterone challenge resulted in no withdrawal bleeding. Brain MRI demonstrated a 2.2 x 1.3 mm hypoenhancing ovoid mass in the pars Intermedia of the pituitary gland suggestive of pituitary microadenoma. Pituitary axis hormonal testing was normal. Karyotype revealed 46 XX (normal female). Genetic evaluation identified a pathogenic variant (p.R35C) in GNRH1 gene. Her final diagnosis: nIHH. Discussion HH is diagnosed in 5% of all women with primary amenorrhea and is divided into 2 major categories: Kallmann syndrome and nIHH. The majority of known causes of HH can be attributed to mutations in KAL1, FGFR1, or GNRHR. The p.R35C variant has been associated with autosomal dominant nIHH. Diagnosis involves clinical suspicious, low LH/FSH and sex steroid levels, normal hypothalamic–pituitary imaging, and exclusion of differentials.Treatment goal for female focus on regular breast and uterine development, as well as the capability to conceive. Use of hormonal replacement therapy and/or gonadotropins or pulsatile GnRH for ovarian stimulation are essential. ConclusionWhile IHH predominantly affects men, limited literature explores its manifestation in women and its impact on fertility. The identification of a GNRH1-related nIHH variant highlights the role of genetic testing in specific HH diagnoses. Failure to diagnose in adolescence may compromise women overall well-being Presentation: 6/1/2024

8788 Implications of NTRK gene fusion in Papillary thyroid cancer

Abstract Disclosure: W. Medina-Torres: None. L. El Musa Penna: None. J. Segarra-Villafane: None. L.R. Sepulveda-Garcia: None. Z. Maisonet -Feliciano: None. I.C. Arroyo: None. M. Ramirez: None. M. Alvarado: None. L.A. Gonzalez-Rodriguez: None. V.J. Carlo: None. Thyroid cancer (TC) is the most common endocrine cancer. Papillary thyroid carcinoma (PTC) is the predominant contributor of this occurrence, comprising approximately 80% of all thyroid carcinomas. PTC has a good prognosis with a 5-year survival rate of more than 90% after resection. Nonetheless, factors such as tumor size, multifocality, nodal and distant metastases, characterize more aggressive cases including tall cell variant, columnar cell variant, and hobnail variant Aside from staging parameters, PTC behavior is mostly determined by morphologic variant. This is the case of 31 y/o female without known past medical history who was evaluated at endocrinology clinic due to a fine needle thyroid aspiration (FNA) positive for PTC, tall cell variant. Total thyroidectomy with central compartment dissection was performed. Pathology report presented a main tumoral mass of 3 cm but permeating multinodular pattern involving the entire gland with focal extrathyroidal extension, positive margins and six level VI positive lymph nodes. As per report, the tumor presented both papillary and follicular patterns of growth and other findings including oncocytic change, foci of clear cell change, low mitotic rate, and most notably "reverse polarization”. This pattern has the pathological features suggestive of the novel NTRK gene fusion mutation. The patient was treated with radioactive iodine (RAI) and one year post treatment there was evidence of elevated Thyroglobulin level at 904 ng/mLand thyroglobulin Ab at 2.48 IU/mL. A WBS +SPECT was done resulting in small uptake at left posterior thyroid bed and pulmonary intake. A chest CT revealed multiple bilateral sub centimeter nodules. Based on this result, a second course of RAI was given. Follow up neck ultrasound and chest CT presented persistent left level VI lymph nodes, increased amount of bilateral sub-centimeter pulmonary nodules and new thoracic(T11) lesion. FNA of left neck lymph nodes were positive for metastatic PTC for which left neck dissection was performed. Evaluation for actionable somatic mutations was requested based on resistance behavior, remarkable for TRIM33-NTRK1 chromosomal rearrangement. Patient was evaluated by Oncology service who started Larotrectinib treatment since it was approved for NTRK driven malignancies. Six-month post therapy patient achieved clinical and biochemical improvement. In the thyroid, NTRK-driven malignancies are rare and aggressive but treatable, in the evolving genomic era. As reviewed in the literature, NTRK fusion-positive TC exhibits distinctive clinicopathological features that could aid in identifying potential patients. Thus, in such patients who have PTC with non-classic pathologic patterns, specific molecular profile of the main tumor may have significant prognostic value that must be integrated into stratification system in order to provide target therapy on time. Presentation: 6/3/2024

Fast concrete crack depth detection using low frequency ultrasound array SH waves data

Fast detection of the depths of surface-open cracks plays an important role in evaluating the damage conditions of concrete elements. The presence of surface-open cracks and other anomalies inside concrete complicates the ultrasonic wave field and thus severely undermines the precision of traditional nondestructive testing methods. This study introduces independently developed low-frequency ultrasonic array detection equipment. The detector adopts a doubled-ray coverage strategy to enhance the imaging stability under noisy conditions. Moreover, we propose an imaging method called the crack focusing-synthetic aperture focusing technique (CF-SAFT), through which both reflected and transmitted surface waves are removed so that only diffracted SH waves converge to their origins. An extra instantaneous phase analysis is supplemented to highlight the diffraction points. We test the effectiveness of our method through a multitude of numerical examples and a model experiment. Successful depth identification was obtained regardless of different geometries of the cracks or interference from the steel reinforcements. The superiority of our method is further verified through noisy ultrasonic data and complex scenarios.

Macrofollicular subtype of papillary thyroid carcinoma: Ultrasonographic findings and clinical implications.

The macrofollicular subtype of papillary thyroid cancer (MFS-PTC) is a rare subtype often leading to a challenging diagnosis. To evaluate the ultrasonographic (US) features and clinical implication of MFS-PTC. Records of 14 patients histologically diagnosed with MFS-PTC at our institution over a period of 16 years were retrospectively reviewed. Preoperative US features, Bethesda categories determined by fine-needle aspiration (FNA) or core needle biopsy (CNB), and final pathology were assessed in all patients with MFS-PTC. Of the 14 MFS-PTC cases, most nodules were noted as smooth marginated, solid or predominantly solid isoechoic on US and were categorized as low suspicion in 12 cases and intermediate suspicion in 2 cases. The median tumor size was 1.2 cm (range, 0.6-5.6 cm). Of 11 cases that underwent FNA or CNB, 4 (36.4%) with Bethesda category II or III underwent the follow-up because of benign-looking appearance on US and benign results in subsequent CNBs. However, the patients underwent delayed surgery (31.3 months, range 12-41 months) because of serially increased tumor size. Seven patients diagnosed with Bethesda type IV, V, and VI subsequently underwent surgery. Gross extrathyroidal extension into subcutaneous fat tissue and lateral lymph node metastasis were noted in a patient who underwent follow-up. No distant metastases or recurrence was detected. MFS-PTC is representative of a benign sonographic appearance of PTC subtypes. Tumor growth on serial US images is the only suspicious finding for MFS-PTC because FNA or CNB is often false negative.

Blood flow signals through the bone cortex on ultrasonography can be used as a screening test for detecting bone marrow lesions on magnetic resonance imaging in patients with early knee osteoarthritis.

Blood flow signals (BFSs) through the bone cortex on ultrasonography (US) and bone marrow lesions (BMLs) detected on magnetic resonance imaging (MRI) can be used to assess bone lesions; however, no studies have reported their relationship. Therefore, this study aimed to assess whether BFSs through the bone cortex on US can serve as a screening test for detecting BMLs on MRI in patients with early knee osteoarthritis (OA). This study enrolled patients with knee joint pain who were diagnosed with early knee OA between January 2018 and January 2024. We targeted 77 patients who underwent MRI and in whom the presence or absence of BFSs through the bone cortex was confirmed on US. The association between BFSs and BMLs was evaluated using the chi-square test, and the sensitivity and specificity of BFSs for detecting BMLs on MRI were calculated. The chi-square test showed that BFSs and BMLs were significantly associated in the femur and tibia (femur: χ2 [1] = 52.9, p < 0.001; Tibia: χ2 [1] = 44.8, p < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of BFSs for detecting BMLs on MRI were 85.0%, 96.5%, 89.5%, and 94.8%, respectively, for the femur, and 84.0%, 92.3%, 84.0%, and 92.3%, respectively, for the tibia. BFSs through the bone cortex on US can be used as a screening test for detecting BMLs on MRI in patients with early knee OA.

Incidentally detected pancreatic duct dilatation on ultrasound and role of MRI.

The clinical significance of incidentally detected pancreatic duct (PD) dilatation at ultrasound (US) without a visualized underlying cause is unclear. We aimed to assess the role of subsequent MRI (including MRCP) and to identify US imaging and laboratory findings predictive of underlying pancreaticobiliary malignancy at the time of initial US. Patients with incidentally detected PD dilatation at ultrasound from 2011 to 2019 that had an ensuing MRI were included. Based on MRI results patients were divided into three groups: malignant pancreaticobiliary causes, benign causes and idiopathic PD dilatation. Subsequently the diagnostic ability of MRI was assessed. Initial ultrasound findings and laboratory results were compared between groups to identify predictors of underlying pancreaticobiliary pathology. A p-value < .05 was considered statistically significant. In 37/59 (63%) patients PD dilatation was confirmed on MRI. MRI demonstrated malignant 7/59 (12%) and benign 10/59 (17%) causes of PD dilatation detected at initial ultrasound. Sensitivity, specificity, negative predictive value, positive predictive value and accuracy of MRI to ascertain the cause of PD dilatation was 89%, 100%, 95%, 100% and 97% respectively. Patients with a larger magnitude of PD dilatation, concomitant CBD dilatation and elevated lipase values were more likely to have underlying pancreaticobiliary malignancy (p < 0.05). No patient with initial negative MRI had pancreaticobiliary malignancy on subsequent work-up. Incidentally detected PD dilatation on ultrasound is an important finding and should prompt referral to MRI. MRI is an accurate, noninvasive method for identifying the underlying cause of PD dilatation in these patients and in excluding pancreaticobiliary malignancy.

Utility of ultrasound in measuring quadriceps muscle thickness in patients receiving maintenance hemodialysis: comprehensive systematic review and meta-analysis.

Muscle wasting, a prevalent issue in hemodialysis patients, is effectively assessed by measuring quadriceps muscle thickness, a crucial health indicator. This meta-analysis integrates findings from various studies on the application of ultrasonography (US) for measuring the thickness of quadriceps muscles in patients undergoing maintenance hemodialysis. We conducted a thorough literature search across PubMed, Scopus, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science up to April 2023. The R software's Meta package was used for mean difference analysis of quadriceps rectus femoris thickness (QRFT) and quadriceps vastus intermedius thickness (QVIT) between hemodialysis patients and healthy controls. All of the patients entered the meta-analysis are Caucasians. Sub-group analyses based on measurement sites and pre- and post-dialysis comparisons were performed. Among 15 studies with 1584 patients, a significant decrease in QRFT and QVIT was observed in hemodialysis patients compared to healthy controls (mean difference = 0.40cm, 95% CI: -0.49 to -0.31 and 0.46cm, respectively). Right and left QRFT were notably thinner in hemodialysis patients (RT: mean difference = 0.39cm; LT: mean difference = 0.42cm). Similarly, right and left QVIT were notably thinner in hemodialysis patients (RT: mean difference = 0.45cm; LT: mean difference = 0.47cm). No significant pre- and post-dialysis QRFT differences were found. Ultrasonography is a reliable, accessible tool for assessing quadriceps muscle thickness in hemodialysis patients, revealing consistent muscle thickness reduction. These findings emphasize the need for routine muscle health monitoring in this population and support ultrasound use for regular assessments.

Study and modeling of the ultrasonic ambient noise induced by the fluid-structure interaction in a pipe

An elastic guided wave-based structural health monitoring (SHM) system consists in examining the integrity of a structure through the propagation of elastic waves. In this context, passive methods turn initial hindrances into advantages by making use of the ambient ultrasonic noise in a structure in operation, through the cross-correlation. Although they have been empirically applied in several configurations, no model is available to predict the link between the flow regime and the convergence of the ambient noise correlation towards the impulse response of the system. Considering the different parameters involved in the case of a pipe, a physical approach of this issue may be studied through the turbulent boundary layer, which has long been described by the Corcos model. Corcos-like models have essentially been applied so far on the audible range, below 1 kHz, where we are interested in frequencies around 100 kHz, typical for SHM applications. The semi-empirical model allows to determine a wall boundary pressure, which, applied at the pipe's inner boundaries, acts as a source term for ultrasonic elastic waves propagating in the pipe. Our goal is then to study if such a model can be used at these high frequencies to reproduce the experimental observations.

Sound absorption coefficient in the audible and ultrasonic frequency range measured in a reverberation chamber with an omnidirectional parametric loudspeaker

An omnidirectional parametric loudspeaker (OPL) is a sound source that contains hundreds of ultrasonic transducers set on the surface of a sphere. Each transducer emits an ultrasonic collimated beam consisting of an audible exponential sweep sine (ESS) modulated in amplitude. This results in hundreds of ultrasonic sound waves emitted in all directions, but also audible sound waves generated by the parametric acoustic array (PAA) phenomenon, by which a modulated signal returns to the audible range thanks to nonlinear propagation in the air. This work examines how the OPL performs in assessing room acoustics, specifically in determining material sound absorption coefficients within reverberation chambers. The ISO 354 standard requires measuring reverberation times with the chamber empty and with the material sample. These are measured using ESS, which has proven effective for the OPL performance. This signal concentrates all the sound power into a single frequency, which improves ultrasonic power levels and thus the signal-to-noise ratio of the audible sound field. The absorption coefficient is next evaluated following the standard, and the results are compared with those obtained using a standard dodecahedral loudspeaker. Finally, the absorption coefficient in the ultrasonic range is examined to evaluate the OPL performance in this frequency range.

A study of the ultrasonic and audible frequency response of commercial loudspeakers for use as parametric acoustic arrays

Parametric acoustic loudspeakers (PAL), also known as parametric acoustic arrays (PAA), are speakers that use ultrasonic waves to generate directive audible sound. They emit an ultrasonic carrier modulated in amplitude by the desired audible signal, and due to non-linear propagation in air, this signal is reproduced in the audible range. Typical applications include audio reproduction for entertainment, but also active noise control and acoustic measurement of material properties. PAA typically consist of an array of piezoelectric transducers set on a surface. However, there are other speakers in the market that, due to their characteristics, could also achieve the PAL effect. This work examines the performance of commercial speakers when reproducing. First, the ultrasonic frequency response of each speaker is examined in free-field conditions using exponential sine sweeps (ESS). This enables searching for potential carrier frequencies to modulate the ESS in the ultrasonic range. The ESS are next modulated in the desired ultrasonic region and emitted through each speaker, obtaining their audible and ultrasonic impulse responses. The results show that some commercial speakers can also operate as PALs, which is interesting from an industrial point of view as it lowers costs and simplifies the assembly process.

Investigation of ultrasonic propagation in high attenuation porous materials

This research examines ultrasonic wave propagation in air-saturated plastic foams used for noise pollution reduction, questioning the effectiveness of current models such as the well known Johnson-Champoux-Allard model at high frequencies. These foams present a challenge for existing models to accurately depict visco-inertial and thermal interactions within their pores. The study highlights the model's failure to align experimental results with theoretical predictions. It introduces novel parameters denoted as Σ and V for viscous effects, and Σ′ and V ′ for thermal effects, to improve the representation of fluid-sturcture interactions. These parameters suggest a more significant boundary layer effect within the pores than previously considered. This approach aims to provide additional physical context for the principles governing the behavior of highly attenuating porous media and to explore new avenues for material characterization that surpass the limitations of existing models.

Blood Flow of the Infraspinatus Muscle in Individuals With and Without Shoulder Pain and Myofascial Trigger Points: A Color Doppler Ultrasound and Reliability Study.

Myofascial trigger points (MTrPs) are potential contributors to shoulder pain and can lead to local ischemia and hypoxia, thus causing pain. Color Doppler ultrasound (US) has been used to examine the vascular environment around MTrPs, but has not been used to examine blood flow impairments in patients with shoulder pain and MTrPs. The reliability of color Doppler US for measuring infraspinatus muscle blood flow also has not been established. This study aimed to investigate differences in blood flow between individuals with and without shoulder pain and the reliability of Doppler US for measuring infraspinatus muscle blood flow. Forty participants were enrolled, 20 with shoulder pain and MTrPs and 20 without. Color Doppler US examination was performed twice on each participant to measure peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), and pulsatile index (PI) of the infraspinatus muscle. The symptomatic participants had significantly higher PSV (ie, impaired blood flow) than the asymptomatic participants. There were no significant between-group differences in EDV, RI, and PI. The results also demonstrated good-to-excellent intra-rater reliability for color Doppler US measurements of PSV, EDV, RI, and PI for both groups. This study demonstrated differences in blood flow near MTrPs in the infraspinatus muscle between individuals with and without shoulder pain. It also established good-to-excellent reliability of color Doppler US in measuring infraspinatus muscle blood flow. These findings suggest color Doppler US is a useful tool to identify vascular impairments for shoulder pain associated with MTrPs.

Multi-Organ Foundation Model for Universal Ultrasound Image Segmentation with Task Prompt and Anatomical Prior.

Semantic segmentation of ultrasound (US) images with deep learning has played a crucial role in computer-aided disease screening, diagnosis and prognosis. However, due to the scarcity of US images and small field of view, resulting segmentation models are tailored for a specific single organ and may lack robustness, overlooking correlations among anatomical structures of multiple organs. To address these challenges, we propose the Multi-Organ FOundation (MOFO) model for universal US image segmentation. The MOFO is optimized jointly from multiple organs across various anatomical regions to overcome the data scarcity and explore correlations between multiple organs. The MOFO extracts organ-invariant representations from US images. Simultaneously, the task prompt is employed to refine organ-specific representations for segmentation predictions. Moreover, the anatomical prior is incorporated to enhance the consistency of the anatomical structures. A multi-organ US database, comprising 7039 images from 10 organs across various regions of the human body, has been established to evaluate our model. Results demonstrate that the MOFO outperforms single-organ methods in terms of the Dice coefficient, 95% Hausdorff distance and average symmetric surface distance with statistically sufficient margins. Our experiments in multi-organ universal segmentation for US images serve as a pioneering exploration of improving segmentation performance by leveraging semantic and anatomical relationships within US images of multiple organs.

Correlation of Necrotizing Enterocolitis (Nec) on Radiology Examination of Plain Abdomen Photo and Ultrasonography (USG)

Introduction: Necrotizing enterocolitis (NEC) is an inflammatory condition caused by infectious agents with a background of immaturity of local defense mechanisms and hypoxic-ischemic damage to the intestinal mucosa. Plain abdominal radiography can be used to examine this condition. The results of diagnostic imaging of the neonatal gastrointestinal tract have relatively limited accuracy, and limit improvements in diagnostic efforts and determine the severity. The results of the examination can also be used with ultrasound. This study aims to analyze the correlation of NEC examination using plain radiography and ultrasound. Methods: This type of research uses a retrospective cohort study. The subjects of the study were 39 patients who underwent plain radiography and ultrasound examinations related to NEC conditions. The data source for this study is secondary data obtained through an intermediary media, namely PACS. The secondary data source for this study is data that has been recorded at the Radiology Installation of Hasan Sadikin Hospital in the period January 2023-June 2024. The Spearman correlation test was used to test the hypothesis of a correlation between NEC examinations using plain radiography and ultrasound. Results: The results of the Spearman correlation test showed no significant correlation between NEC examination using plain radiographs and USG with a correlation coefficient value of 0.138. The findings that can be taken from this study are that there is an increase in grade in patients who undergo USG examination. This finding proves the importance of conducting USG examination to confirm NEC conditions more accurately. Conclusion: There is no significant correlation between NEC examination using plain radiographs and USG. Examination using USG can confirm NEC more accurately, as evidenced by an increase in grade in 43.58% of study subjects.

Ultrasonography-Guided Dental Implant Surgery: A Feasibility Study.

To evaluate the feasibility of ultrasound-image-based computer-assisted implant planning and placement. Intraoral scans, cone-beam computerized tomography (CBCT), and ultrasound (US) scans with a custom positioning device were acquired in nine patients. Prosthetic-driven surgical guides were planned and fabricated based on ultrasound images and intraoral scans. Implants were then placed. Postoperative implant position was obtained intra-surgically by intraoral scan. Aside from the ultrasound-based plan, conventional implant planning was performed by the same operator on a pre-surgical CBCT for comparison. Linear deviations between ultrasound and CBCT-planned implant positions were measured and compared with the intra-surgical implant position, and the position deviations between two consecutive plannings were performed on the same CBCT by the same operator. The linear deviation between the 3D scan surface of the edentulous region and the ultrasonographic soft tissue profile segmentation was also assessed with reverse-engineering software. Means, standard deviations, and root mean square differences (RMSD) were calculated for every variable. All the ultrasound-planned implants were successfully placed, and no complications were recorded. The mean deviations in angles, shoulders, and apexes were 5.27 ± 1.75° (RMSD: 5.53°), 0.92 ± 0.26 mm (RMSD: 0.95 mm), and 1.41 ± 0.61 mm (RMSD: 1.53 mm), respectively, between the US and CBCT-planned implants; 2.63 ± 0.43° (RMSD: 2.66°), 1.16 ± 0.30 mm (RMSD: 1.19 mm), and 1.26 ± 0.27 mm (RMSD: 1.28 mm) between the planned implant and intra-surgically recorded positions; and 2.90 ± 1.36° (RMSD: 3.18°), 0.65 ± 0.27 mm (RMSD: 0.70 mm), and 0.99 ± 0.37 mm (RMSD: 1.05 mm) between two consecutive CBCTs planning performed by the same operator. The mean deviation between the 3D surfaces of model scans and ultrasound-derived soft tissue profile in the edentulous area was 0.19 ± 0.08 mm. Ultrasound-guided implant surgery represents a feasible non-ionizing alternative to conventional static guided implant surgical protocols for implant placement in sites with favorable characteristics.

Strain Patterns With Ultrasound for Assessment of Abdominal Aortic Aneurysm Vessel Wall Biomechanics

BackgroundAbdominal aortic aneurysms (AAAs) are an important cause of death. Small AAAs are surveyed with ultrasound (US) until a defined diameter threshold, often triggering a computer tomography scan and surgical repair. Nevertheless, 5%–10% of AAA ruptures are below threshold, and some large AAAs never rupture. AAA wall biomechanics may reveal vessel wall degradation with potential for patient-centred risk assessment. This clinical study investigated AAA vessel wall biomechanics and deformation patterns, including reproducibility. MethodsIn 50 patients with AAA, 183 video clips were recorded by two sonographers. Prototype software extracted AAA vessel wall principal strain characteristics and patterns. Functional principal component analysis (FPCA) derived strain pattern statistics. ResultsStrain patterns demonstrated reduced AAA wall strains close to the spine. The strain pattern “topography” (i.e., curve phases or “peaks” and “valleys”) had a 3.9 times lower variance than simple numeric assessment of strain amplitudes, which allowed for clustering in two groups with FPCA. A high mean reproducibility of these clusters of 87.6% was found. Median pulse pressure-normalised mean principal strain (PPPS) was 0.038%/mm Hg (interquartile range: 0.029–0.051%/mm Hg) with no correlation to AAA size (Spearman's ρ = 0.02, false discovery rate-p = 0.15). Inter-operator reproducibility of PPPS was poor (limits of agreement: ±0.031%/mm Hg). DiscussionStrain patterns challenge previous numeric stiffness measures based on anterior-posterior-diameter and are reproducible for clustering. This study's PPPS aligned with prior findings, although clinical reproducibility was poor. In contrast, US-based strain patterns hold promising potential to enhance AAA risk assessment beyond traditional diameter-based metrics.