Linear Transducer Research Articles

Absolute temperature estimation using thermal strain imaging

The objective of this study is to present a new thermometry method, based on thermal strain imaging, to estimate the absolute temperature using ultrasound. Unlike the conventional method presented in previous studies, this method does not require knowledge of the initial temperature or of speed of sound. The method was tested in simulations and experimentally. Simulations were performed at different temperatures (from 20 to 90 °C), using k-wave. Then, experimental measurements were performed in Zerdine phantom samples at different temperature (from 23 to 88 °C). A linear array transducer, with a 12-angle plane wave imaging sequence, was used to acquire the thermal strain images and to derive the temperature at the focus. To control the temperature during the measurements, a thermocouple was used. Both simulations and experiments showed a good estimation of the temperatures. The new ultrasound-based method is a promising technique to estimate and monitor temperature during thermal ablation.

The effect of a single cycle of ischemia on bar velocity during bench press exercise

Introduction: The main goal of this study was to investigate the effects of a single cycle of ischemia applied before the bench press exercise on acute bar velocity changes. Materials and Methods: Twelve physically active males participated in the study. The experiment followed a randomized, cross-over design under two testing conditions. The experimental condition involved the application of a single cycle of ischemia (5 minutes; 80% arterial occlusion pressure [AOP]) before the first set of bench press exercise (2 sets at 60% 1RM). The control condition did not use ischemia. The peak and mean bar velocities were measured using a linear position transducer. Results: Two-way repeated measures ANOVA revealed no statistically significant differences in the peak or mean bar velocity between the ischemia and control conditions both during the first and the second set of the bench press exercise. Conclusions: The results of this study indicate that a single cycle of ischemia applied before the bench press exercise did not influence changes in peak or mean bar velocity.

Active targeting of nanotherapeutics using power cavitation imaging with a linear array transducer

Power cavitation imaging (PCI) is an emerging strategy for monitoring blood–brain barrier (BBB) opening, enabling spatial discrimination of cavitation intensity through power Doppler-analogous processing of passive cavitation images. Single-element cavitation detectors, while beneficial in signal monitoring for cavitation controllers, provide limited spatial information, conferring the need for an image-guided approach to ensure accurate cavitation localization and regulation. This study aims to evaluate the capability of PCI to spatially correlate real-time acoustic cavitation emissions with mechanical bioeffects as a predictor of P-selectin-targeted nanocarrier delivery. Preliminary sonoporation experiments were performed in vitro with brain tissue derived mouse endothelial cells and 3 kDa tetramethylrhodamine (TMR)-dextran. A focused ultrasound transducer (0.5 MHz, 5000 cycles/pulse, 5 Hz PRF, 30 second treatment duration) was used to sonicate cells in small volume (25 μl) cell suspension. Homogenous distribution of TMR-dextran in the cytosol and nucleus was observed via fluorescence microscopy at lower pressures (7% ± 2% fluorescent cells), while higher pressures had no significant differences above control (3% ± 2% vs 1% nontreated) due to microbubble destruction. Future experiments will correlate sonoporation with P-selectin expression and validate a linear array PCI system against contrast-enhanced MRI as a guide for P-selectin-targeted nanocarrier delivery in mouse models of medulloblastoma.

The Validity of Perceptual Recovery Status on Monitoring Recovery During a High-Intensity Back-Squat Session.

The aim of this study was to assess the validity of PRS on monitoring recovery during a high-intensity back-squat session. Ten healthy men participated in the 2-session study (separated by at least 48h). Session 1 included anthropometrics, PRS familiarization, and a 1-repetition-maximum back squat. Session 2 included a high-intensity protocol (5 sets of 5 repetitions; 5-min interset recovery; 85% of 1-repetition maximum). PRS was obtained before the first set and during the last 30seconds of each 5-minute recovery; rating of perceived exertion (RPE) was also collected. A linear position transducer collected mean barbell velocity (MBV). Repeated-measures correlations assessed the common intraindividual relationships of PRS scores to intraset MBV and RPE, respectively. A very large, positive correlation appeared between PRS and MBV (r [95% CI] = .778 [.613 to .878]; P < .0001). A large, negative correlation emerged between PRS and RPE (r [95% CI] = -.549 [-.737 to -.282]; P < .001). Results indicate that PRS can be a means for practitioners to monitor individualized recovery. PRS tracked well with RPE, strengthening its utility in a practitioner-based setting. Findings provide insight into the practicality of PRS for recovery monitoring. It could be used alongside other measures (eg,MBV and countermovement jump) to individually program and maintain performance.

An Enhanced Nonlinear Energy Sink for Hybrid Bifurcation Passive Mitigation and Energy Harvesting From Aeroelastic Galloping Phenomena

Abstract Galloping is a self-excited vibration problem that structures immersed in fluid flow can experience. Due to its essential nonlinear phenomena, the structure exhibits limit cycle oscillations (LCOs), which, at high levels, can lead to failure of the systems. This work proposes an investigation of electromagnetic-enhanced nonlinear energy sinks (NES-EH) for the hybrid mitigation of aeroelastic LCOs and energy harvesting. The study focuses on a prismatic bluff body with a linear suspension immersed in the airflow, using classical steady nonlinear modeling for aerodynamic loads. The conventional NES approach is adopted, employing cubic stiffness and linear damping. Additionally, a linear electromagnetic transducer is included in the assembly for the energy harvesting process. By combining the method of multiple scales with the Harmonic Balance Method, analytical solutions are derived to characterize the system's dynamics under the influence of the device. The different response domains and their respective boundaries induced by the NES-EH are characterized based on the bifurcation diagrams. Furthermore, a slow invariant manifold (SIM) characterization is presented for each induced response domain, and its significant features are discussed. Parametric studies are carried out based on bifurcation analyses to assess the effect of NES-EH parameters on the galloping system dynamics, which allows for designing the absorber parameters. The electrical resistance is optimized to maximize the harvested power. The optimal design of NES-EH is then compared with classical energy harvesting solutions for the galloping problem. Additionally, a thorough analysis of the Target Energy Transfer phenomenon is performed.

First assessment of flow phenomena of acute and chronic thrombosis in the jugular veins using new ultrasound vector-flow imaging.

First assessment of flow changes in the jugular veins using high resolution ultrasound vector flow. 15 patients (8 males, 7 females) with an age range of 35 to 82 years (mean age 58.53±12.26 years) were examined by an experienced examiner using high power ultrasound equipment (Resona R9, Mindray) with probe technology (Mindray L9-3U Linear Array transducer, 2.5 to 9.0 MHz). This group was compared with five healthy subjects (mean age 35.4±13.79 years) as a reference. To assess flow changes, the color-coded duplex sonography and the novel vector flow technique were used. The evaluation was performed of vector morphology changes, turbulence, and wall resistance measurements. There were changes after acute and chronic thrombosis in 9 cases, and venous compression in 7 cases. Turbulence was measurable from 0.01 % to 64.44 %, the average turbulence was 19.73±22.06 %. Wall resistance measurement showed values from 0.01 Pa to 3.14 Pa, depending on the age of the thrombosis or compression. The reference veins showed turbulence of 0.94±1.5 % and a mean wall resistance of 0.05±0.05 Pa. There are statistically significant differences between normal and thrombotic or compressed veins in terms of maximum wall stress (p = 0.006) and mean degree of turbulence (p = 0.012), while the difference in mean wall stress is not statistically significant (p = 0.058). Despite still existing technical limitations, the combination of V-flow and wall stress measurements in jugular vein changes suggests a high diagnostic potential.

A Novel Method for the Measurement of the Vaginal Wall Thickness by Transvaginal Ultrasound: A Study of Inter- and Intra-Observer Reliability.

Background and Objectives: A consensus regarding the optimal sonographic technique for measuring vaginal wall thickness (VWT) is still absent in the literature. This study aims to validate a new method for measuring VWT using a biplanar transvaginal ultrasound probe and assess both its intra-operator and inter-operator reproducibility. Material and Methods: This prospective study included patients with genitourinary syndrome of menopause-related symptoms. Women were scanned using a BK Medical Flex Focus 400 with the 65 × 5.5 mm linear longitudinal transducer of an endovaginal biplanar probe (BK Medical probe 8848, BK Ultrasound, Peabody, MA, USA). Vaginal wall thickness (VWT) measurements were acquired from the anterior and posterior vaginal wall at three levels. Results: An inter-observer analysis revealed good consistency between operators at every anatomical site, and the intra-class coefficient ranged from 0.931 to 0.987, indicating high reliability. An intra-observer analysis demonstrated robust consistency in vaginal wall thickness measurements, with an intra-class coefficient exceeding 0.9 for all anatomical sites. Conclusions: The measurement of vaginal wall thickness performed by transvaginal biplanar ultrasound was easy and demonstrated good intra- and inter-operator reliability.

Digital postprocessing analysis of prostatic perfusion in neutered dogs.

B-mode ultrasound is routinely performed to evaluate the prostate gland in neutered dogs, although, the detection of malignancies may be challenging. Contrast-enhanced ultrasound (CEUS) has shown to be useful for the assessment of prostatic perfusion in normal and diseased dogs, although the interpretation of contrast ultrasonographic features may still be subjective. A quantitative tool for evaluating prostatic perfusion might improve the reliability of the results in terms of early detection of prostate neoplasia in neutered dogs. The present study aimed to evaluate the applicability of a postprocessing analysis tool to CEUS of the prostate in healthy neutered dogs, to provide quantitative measurements, and to study the influence of individual characteristics on prostatic regression. Twenty-three neutered dogs underwent a B-mode and CEUS examination of the prostate to acquire data about prostatic morphology and microcirculation. The prostate was imaged using a 5-7.5MHz linear transducer and contrast was administered intravenously. Videoclips were analyzed by using Qontrast software and a postprocessing digital analysis tool (ImageJ) to measure perfusion peak intensity, time to peak, and vascularization ratio at the moment of the peak, which were then related to body weight, age, and time elapsed since orchiectomy. Correlation tests revealed higher vascularization in younger compared with older dogs (P<.05) and in smaller compared with larger dogs (P<.05). Time elapsed since orchiectomy (P>.05) did not affect prostatic perfusion. Contrast-enhanced ultrasound and the postprocessing analysis tool ImageJ allowed analysis of vascular perfusion in all dogs and have the potential to improve the diagnostic possibilities for andrological examination.

Isohydric stomatal behaviour alters fruit vascular flows and minimizes fruit size reductions in drought-stressed 'Hass' avocado (Persea americana Mill.).

Plant water status is important for fruit development, because many fleshy fruits contain large amounts of water. However, there is no information on vascular flows of Persea americana 'Hass' avocado. The aims of this research were to explore the impact of drought stress on the water relationships of the 'Hass' avocado plant and its fruit growth. Well-watered and water-stressed 'Hass' avocado plants were compared. Over 4 weeks, water flows through the shoot and fruit pedicel were monitored using external sap flow gauges. Fruit diameter was monitored using linear transducers, and stomatal conductance (gs), photosynthesis (A) and leaf and stem water potentials (Ѱleaf and Ѱstem) were measured to assess the response of the plants to water supply. In well-watered conditions, the average water inflow to the shoot was 72 g day-1. Fruit water inflow was 2.72 g day-1, but there was water loss of 0.37 g day-1 caused by the outflow (loss back into the tree) through the vascular tissues and 1.06 g day-1 from the fruit skin. Overall, fruit volume increased by 1.4 cm3 day-1. In contrast, water flow into fruit of water-stressed plants decreased to 1.88 g day-1, with the outflow increasing to 0.61 g day-1. As a result, increases in fruit volume were reduced to 0.4 cm3 day-1. The values of A, gs and sap flow to shoots were also reduced during drought conditions. Changes in the hourly time-courses of pedicel sap flow, fruit volume and stem water potential during drought suggest that the stomatal response prevented larger increases in outflow from the fruit. Following re-watering, a substantial recovery in growth rate was observed. In summary, a reduction in growth of avocado fruit was observed with induced water deficit, but the isohydric stomatal behaviour of the leaves helped to minimize negative changes in water balance. Also, there was substantial recovery after re-watering, hence the short-term water stress did not decrease avocado fruit size. Negative impacts might appear if the drought treatment were prolonged.

Ultrasound Applications in Ophthalmology: A Review

Ultrasound is a powerful tool in ophthalmology with a wide range of physical effects that can interact with biological tissue. This ranges from low-intensity linear transducers for diagnosis to high-intensity pulsed or continuous focused ultrasound for therapy. Designing devices for ophthalmological applications requires creating fine focal spots, minimizing heating, and accounting for eye movements. Ultrasound is essential for ophthalmologists to provide accurate diagnosis and quantitative information on tissue composition and blood flow. Ultrasound has revolutionized cataract surgery, making it less invasive and in an outpatient basis, while enhancing the safety and predictability of glaucoma treatment using high-intensity focused ultrasound. The article aims to review the complex and multifaceted bioeffects of ultrasound used in ophthalmology, and its current and future applications of ultrasound in ophthalmology, notably regarding cavitation-mediated drug delivery.

The reliability of a linear position transducer for measuring countermovement jump performance in national-level road cyclists.

Jump tests have applications in fatigue monitoring, training intervention evaluations, and talent identification in cycling populations. Due to competitive cycling's inherent travel demands, linear position transducers (LPTs) are suitable for assessing jump performance in this population as they are a mobile and validated technology. Understanding the reliability and sensitivity of LPTs in assessing jump performance in cycling populations is required to support the development of sports science protocols. Using an LPT, this study aimed to determine the reliability and sensitivity of countermovement jump (CMJ) variables in road cyclists. Ten national-level male road cyclists performed three maximal CMJ trials twice per week for two weeks, with an LPT measuring force, power, velocity, repetition rate, vertical distance, and concentric time from each trial. Using the mean and best CMJ results from three trials per testing session, the upper limit 90% confidence interval for the coefficient of variation (CV) and smallest worthwhile change (SWC) determined inter-day and -week reliability (CV ≤ 10%) and sensitivity (acceptable sensitivity = CV ≤ SWC) for CMJ variables. Mean power and force, velocity (mean and peak), vertical distance (VD), and concentric time had acceptable inter-day and -week reliability when using either the mean or best CMJ results (CV upper limit 90% confidence interval range = 3.54-10.13%). Moreover, the CV and SWC were typically lower when based on the mean rather than the best of three CMJ trials. Lastly, poor sensitivity (CV > SWC) was evident for all CMJ variables. CMJ-derived mean power and force, velocity (peak and mean), VD, and concentric time have acceptable inter-day and -week reliability when assessed via an LPT in national-level road cyclists. When using an LPT, sports scientists should consider that, while they typically have poor sensitivity, the reliability of CMJ-derived variables improves when expressed as the mean of three trials in national-level road cyclists.

(126) Application of HIFEM Therapy Improves Orgasmic, Urinary and Erectile Function by Stimulation of Pelvic Floor Muscles

Abstract Introduction The weak pelvic floor in men contributes to various urological disorders. Treatment can be accomplished by strengthening the pelvic floor muscles (PFM) through pelvic floor muscle training. Nevertheless, such development of PFM is time-consuming and heavily dependent on the subject's ability to perform selective muscle contractions. An advantageous approach is the targeted stimulation of PFM which can be accomplished via electromagnetic stimulation. Particularly, the pelvic floor muscles can be non-invasively and selectively stimulated via the HIFEM field. This results in the natural development and rehabilitation of PFM, which, among other functions, plays a vital role in facilitating orgasmic, urinary and erectile function. Objective The aim of this study is to assess the safety and efficacy of the HIFEM pelvic procedure for the treatment of erectile dysfunction. Methods In this study, 28 males with a median age of 56 (30-72 years) were enrolled. The treatment was composed of ten weekly 28-minute sessions. Outcome measurements were collected via questionnaires and ultrasound imaging prior to and after the last treatment. To assess changes in erectile and sexual function, and prostate-related symptoms, the International Index of Erectile Function (IIEF) and International Prostate Symptom Score (IPSS) were used. Transverse B-Mode ultrasound video scans were recorded along the long axis of the penile shaft from the tip to the base with the penis in a flaccid state. A linear transducer was used, the depth was set at 2 cm, and the frame rate was approximately 30 frames per second. Separate video recordings of the left and right cavernosum were taken. The ultrasound scans were processed by the Morphometrix cloud-based algorithm. Adverse events were monitored during the study. Results All evaluation methods proved the efficiency of treatment on a statistically significant level. A significant improvement was detected in the majority (4 of 5) of the domains of IIEF, with the overall score improvement from a baseline value of 45.14±2.42 to 48.75±2.86 (+3.61 points). The most exceptional improvement was found in Sexual desire (+18.78%; p=1.06x10-3), Erectile dysfunction (+13.03%; p=5.7x10-4), and Orgasmic function (+10.69%; p=7.04x10-5) domains. The mean difference in the total score of the IPSS questionnaire reached -3.04 points (p=5.1x10-6), exceeding the corresponding minimal clinical difference (MIC=3 points). Overall, subjects, on average, shifted from moderately symptomatic (9.57±1.37 points) to mildly symptomatic (6.54±0.91 points). An increase in vascularity of both cavernosal was measured within 57% of patients who underwent ultrasound examination; specifically, a significant improvement was recorded in tissue segment count (TSC; +104%; p=1.17x10-4) and density (TSD; +81% p=2.20x10-3), pointing to better blood flow and delivery in examined tissues. No adverse event was observed. Conclusions The therapy administering HIFEM technology of the pelvic floor for selective PFM stimulation demonstrated significant improvement of erectile and orgasmic function and urinary symptoms. The questionnaire results corresponded with ultrasound measurements using a novel algorithm, identifying positive changes in the penile vascular system. Overall, the treatment may be considered a safe and a possible first-line solution for male patients suffering from dysfunctions linked to weakened pelvic floor muscles. Further investigation is needed. Disclosure Yes, this is sponsored by industry/sponsor: BTL. Clarification: Industry funding only - investigator initiated and executed study. Any of the authors act as a consultant, employee or shareholder of an industry for: AFFIRM Science.

Finger flexor rigidity in the healthy population

The involvement of the hand flexors in trigger finger is not clear. This study aimed to examine the rigidity of the flexor tendon in the first pulley territory in the hand by using ultrasound in a healthy population, as well as to create a reference scale of rigidity for the flexor tendons to compare those values in trigger fingers. We tested 35 healthy volunteers using a linear ultrasound transducer and the color Doppler method. Rigidity levels below the first pulley were examined and compared between the different fingers of the hand and the relationship between rigidity and sex and the three different age groups was evaluated. In the healthy population, the rigidity of the flexor tendons of the hand in the territory of the first pulley varied between 233.1 and 962.8 kPa, with an average of 486.42 kPa and standard deviation of 114.85. We showed that the flexors in the dominant hand were more rigid, there was a difference between the rigidity of the flexor tendons of the thumb and the other fingers of the same hand, and the ring finger of the dominant hand had stiffer flexor tendons than the fingers of the other hand in the male population. We created a value scale for the rigidity of the flexor tendons of the fingers. This base scale can be compared between different pathologies, including trigger finger. The study and all experimental protocols were approved by the local ethical committee.

Electronic Focus Steering Capabilities of a Diagnostic-Type Linear Ultrasound Array Designed for High Power Therapy and Its Visualization

The focus steering capabilities of a 1 MHz linear phased array transducer (64 rectangular elements, 14.8 × 51.2 mm aperture) intended for drug delivery applications in abdominal organs were assessed and compared with its design-stage computer model. Acoustic fields generated by the transducer and predicted by the models of an ideal array with uniformly vibrating elements and either a plane or a cylindrically focused surface were simulated using the Rayleigh integral and angular spectrum methods. The boundary conditions for the transducer were reconstructed from acoustic holography measurements performed for selected focusing configurations of the array and also synthesized from holography data measured for each of its individual elements. It was shown that the transducer field with electronic focus steering can be accurately synthesized based on the holography data of its elements, which significantly simplified acoustic field characterization. Variability of the power and directivity patterns of the array elements were analyzed. A twofold smaller range of electronic steering in the transverse direction for the transducer compared to its computer model is discussed.

Real-Time Intraoperative Ultrasound Using a Minimally Invasive Transducer During Anterior Cervical Spine Surgery.

Intraoperative ultrasound (IOUS) during anterior cervical surgery is hindered by large transducer size and small operative corridor. We hypothesized that a linear (minimally invasive) transducer designed for transsphenoidal surgery can visualize the spinal cord, nerve roots, and surrounding structures during anterior cervical approaches, facilitating intraoperative assessment of central and foraminal decompression. IOUS was used to evaluate 26 levels in 17 patients (15 anterior cervical discectomy and fusion, 1 corpectomy, 1 arthroplasty) with a linear probe (7 × 6-mm end-fire transducer, 150-mm length, 12-15 MHz). After pin-based distraction, discectomy, and posterior longitudinal ligament resection, IOUS assessed adequacy of cord decompression and, following proximal foraminotomy or uncinectomy, nerve root decompression. If indicated, additional decompression was completed. Criteria for adequate central and foraminal decompression were visualization of subarachnoid space around the cord and cerebrospinal fluid pulsatility along the root sleeve/absence of nerve root compression distal to the root sleeve, respectively. IOUS successfully visualized the cord, nerve roots, and surrounding structures in all 26 levels and influenced management in 11 levels (42.3%). IOUS indicated persistent cord and nerve root compression in 2 and 7 levels, respectively. Planned uncinectomy was aborted in 2 levels after IOUS demonstrated adequate nerve root decompression with intervertebral distraction/proximal foraminotomy alone. IOUS identified persistent nerve root compression after initial proximal foraminotomy in 4 levels and uncinectomy in 2 levels. An unplanned uncinectomy was performed in 1 level after IOUS showed persistent nerve root compression after multiple iterations of proximal foraminotomy. At follow-up (mean 3.1 months), the mean improvement in Numeric Rating Scale neck and arm pain, Neck Disability Index, and modified Japanese Orthopedic Association was 4.0%, 3.2%, 3.7%, and 0.7%, respectively. The neural elements and their relationships to surrounding bone/soft tissue can be visualized using a minimally invasive IOUS transducer during anterior cervical surgery without having to remove pin-based distraction. This allows surgeons to intraoperatively verify the extent of central and foraminal decompression.

Equine desmitis, pelvic disease Desmitis of the wide portion of the sacroiliac ligament in horses

Two adult horses, a male (6 years old, castrated) half-blooded Quarter Horse and a Mangalarga mare (7 years old) each showed decreased step amplitude and lameness of one of their hind limbs (right and left respectively) after working in handling cattle (both with Grade I, scale from 0 to 5). In addition, the male presented slight atrophy in the musculature of the right superficial gluteus. After clinical examination and screening with thermography (done before the animal worked, at the pen and not exposed to any heat source or solar irradiation or any product on the skin surface) no "hot spot" was found in in the right or left limb of either horse, thus raising suspicion of a "high" lesion, without neurological origin, opting for transrectal pelvic evaluation by ultrasound (6.5 MHz linear rectal transducer) in those animals. Differences were found between the left and right sides in the ligaments, in the images produced by the examination of the wide portions of the sacroiliac ligament, associated with pain on the side corresponding to the change in the image obtained. We can thus conclude, after thermography and clinical and neurological examination which excluded any injuries to the hind limbs, that the cause of lameness in these clinical cases is unilateral desmitis of the wide portions of the sacroiliac ligament, showing the importance of transrectal ultrasound evaluation in cases of pain in the limbs or even high claudication.

Effects of Smoking on Intima-Media Thickness of the Common Carotid Artery Using Ultrasonography

BackgroundCigarette smoking is a causative factor in premature atherosclerosis, but the exact mechanism of smoking-induced damage to the arterial wall and its relationship to the atherosclerotic process are still largely unknown. Carotid ultrasound may help target treatment. The aim of this study was to measure carotid intima-media thickness (IMT) and carotid Doppler parameters in Sudanese smokers compared to non-smokers using ultrasound.MethodsThis was a retrospective, case–control, community-based study conducted between June 2021 and September 2021. The study was conducted on 100 Sudanese subjects (50 smokers as the case group and 50 non-smokers as the control group). The practical part was conducted in Khartoum State at Al Raqi University Hospital using the E-CUBE 8-ALPINION and at Yastbshroon Hospital using the Fukuda Denshi Sefius UF890AG with a high-frequency linear transducer (7–10 MHz). Scanning was performed in the supine position with the neck extended. Pulsed-wave (PW) Doppler spectral and IMT measurements were obtained.ResultsThe mean age was 29.8 ± 4.5 years (range 24–40 years), and the mean IMT in smokers was 0.6 ± 0.06 mm, which was greater than the mean in non-smokers (0.462 ± 0.09 mm) (p = 0.000). Peak systolic velocity (PSV) was increased in smokers (40.0 ± 5.67 cm/s) compared to non-smokers (26.5 ± 5.6 cm/s) (p = 0.000), and end-diastolic velocity (EDV) was decreased in smokers (6.0 ± 1.2 cm/s) compared to non-smokers (9.8 ± 2.2 cm/s) (p = 0.000). In addition, the resistive index (RI) and the systolic-diastolic ratio (S/D) were not significantly different between smokers and non-smokers. The study showed that there was a significant positive correlation between IMT and the number of cigarettes per day in chronic smokers (p < 0.05), whereas peak systolic velocity (PSV) and end-diastolic velocity (EDV) were not affected in chronic smokers.ConclusionsThere was a statistically insignificant difference between the case (smokers) and control (non-smokers) groups in terms of age, body mass index (BMI), resistance index (RI), and systolic–diastolic ratio (S/D). While there were statistically significant differences in intima-media thickness (IMT), peak systolic velocity (PSV), and end-diastolic velocity (EDV), regular follow-up of individuals with a history of smoking is recommended to detect carotid intimal changes earlier.

Development of a wideband medical ultrasonic linear array transducer with a double-sided FPCB

Medical ultrasound transducers are being used to acquire medical image information from a patient. In order to acquire high-quality images, studies have been conducted to improve the performance of the transducer. Among them, the high acoustic impedance de-matching layer is effective in improving the sensitivity and bandwidth of the transducer using the backward reflected wave. First, the performance trend of the transducer according to the thickness of the acoustic de-matching layer was analyzed through theoretical calculation and finite element method. It was confirmed that the sensitivity and bandwidth of the transducer increased by adjusting the time delay of the backward reflected wave according to the thickness of the acoustic de-matching layer. Based on the analyzed results, a new structure of a transducer applied with a double-sided FPCB was devised. The time delay of the backward reflected wave was simply controlled by changing the thickness of the polyimide in the FPCB. The bandwidth of the transducer can be increased by changing the thickness of the polyimide in the FPCB. Also, a prototype of a transducer having a designed structure was manufactured and its performance was measured, and it was confirmed that the designed structure was effective in increasing the bandwidth of the transducer.

Comparison of transrectal and transabdominal transducers for use in fast localized abdominal sonography of horses presenting with colic.

Abdominal ultrasonography is valuable in the diagnosis of equine colic. Fast localized abdominal sonography of horses (FLASH) enables practitioners with limited experience to perform ultrasonography in emergency settings. However, many practitioners only possess rectal format linear array transducers (RFLT). The hypotheses are: (a) A low frequency curvilinear transducer (LFCT) and RFLT will detect free abdominal fluid and abnormal small intestinal loops with similar frequency during FLASH, and (b) there will be a difference between the transducers for detection of gastric abnormalities and nephrosplenic entrapment. The objective is to compare transcutaneous abdominal ultrasonographic detection of abnormalities in horses presenting with colic using a LFCT and RFLT. Twenty-four horses requiring FLASH for investigation of colic were enrolled. Horses that were too painful to undergo transcutaneous abdominal ultrasonographic examination were excluded. A single investigator performed FLASH on all horses using a RFLT, while one of three other clinicians simultaneously performed FLASH using a LFCT. Comparison of abnormal findings between the two transducers was performed using Chi square, Fisher's exact or Wilcoxon tests. The incidence of identification of abnormal findings was similar between the two transducers for all comparisons except the visibility of the left kidney and stomach (kidney LFCT 81.25% vs. RFLT 22.92%, stomach LFCT 87.5% vs. RFLT 62.5%). While there are limitations to using a RFLT to identify nephrosplenic entrapment of the colon and detection of the stomach, it reliably detects other common abnormalities, including peritoneal effusion, lesions of the small intestine, and changes to the wall of the large colon and cecum.

3-D Contrast-Enhanced Fusion Ultrasound for Accurate Volume Assessment of Vessel Lumen and Plaque in Carotid Artery Disease as Compared With Computed Tomography Angiography

ObjectiveThree-dimensional contrast-enhanced fusion ultrasound (3D-CEFUS) of atherosclerotic carotid arteries provides spatial visualisation of the vessel lumen, creating a lumenography. As in 3D computed tomography angiography (3D-CTA), 3D-CEFUS outlines the contrast-filled lumen. Plaque and vessel contours are distinguished in 3D-CEFUS, allowing plaque volume quantification as a valid estimate of carotid plaque burden. 3D-CEFUS is unproven in inter-modality studies, vindicating the assessment of 3D-CEFUS applicability and comparing 3D-CEFUS and 3D-CTA lumenography as a proof-of-concept study. MethodsUsing an ultrasound system with magnetic tracking, a linear array transducer, and SonoVue contrast agent generated 3D-CEFUS acquisitions by spatial stitching of serial 2D images. From 3D-CEFUS and 3D-CTA imaging, the atherosclerotic carotid arteries were reconstructed with lumenography in an offline software programme for lumen and plaque volume quantification. Bland-Altman analysis was used for inter-image-modality agreement. ResultsThe study included 39 carotid arteries. Mean lumen and plaque volume in 3D-CEFUS were 0.63 cm3 (SD 0.26) and 0.62 cm3 (SD 0.26), respectively. Lumen volume differences between 3D-CEFUS and 3D-CTA were non-significant, with mean difference of 0.01 cm3 (SD 0.02, p = .26) and limits of agreement range (LoA-range) of ±0.11 cm3. Mean plaque volume difference was -0.12 cm3 (SD 0.19, p = .006) with LoA-range of ±0.39 cm3. ConclusionStrong agreement in lumenography between 3D-CEFUS and 3D-CTA was found. The inter-image-modality difference in plaque volumes was substantial due to challenging vessel wall definition in 3D-CTA. 3D-CEFUS is viable in quantifying carotid plaque volume burden and can potentially monitor plaque development over time.