Diagnostic Ultrasound System Research Articles

Using laparoscopic ultrasound to delineate dangerous anatomy during difficult laparoscopic cholecystectomies.

Bile duct injury (BDI) during laparoscopic cholecystectomy (LC) is not as common now as in the past, but it is still a very debilitating complication. Therefore, there is a very strong need for a method that lowers the number of complications during LC without any additional risks for the patient and the operating team. Laparoscopic ultrasound (LUS), which serves to delineate anatomy, appears to be a very effective and safe technique. The aim of this study was to explore the advantages of performing LUS during difficult LC. The study group consisted of 126 patients who underwent surgery between January 2014 and February 2016. All the patients had difficult intraoperative anatomical conditions due to chronic inflammation, previous upper abdominal surgery or biliary pancreatitis in the past. We used a Toshiba PEF-704 LA laparoscopic probe and the Toshiba NemioMX SSA-590A diagnostic ultrasound system (Toshiba Corp., Tokyo, Japan). Doppler sonography was used to differentiate between vascular and biliary structures. Laparoscopic ultrasound ensured a safe plane of dissection and no biliary or vascular complications were observed. Stent insertion into the common bile duct before the operation undoubtedly made the identification of anatomical structures easier. Conversion to an open procedure was deemed necessary in only 6 patients (4.8%). Laparoscopic ultrasound facilitates the successful performance of LCs. It can be used at any time during the operation; it is noninvasive; and there is no need to use X-rays or contrast dye, or to cannulate the cystic duct. The most important advantage of LUS is that it leads to a lower number of conversions and intraoperative complications by identifying anatomical relationships in the plane of dissection.

Spatial Resolution and Measurement Accuracy of the Ultrasound Diagnostic System at Acoustic Remote Palpation Using High Intensity Focusing Ultrasound

In this work the spatial resolution and measurement accuracy of the ultrasound diagnostic system at acoustic remote palpation (ARP) using high-intensity focusing ultrasound (HIFU) are studied theoretically and experimentally. A physical model is proposed, which describes the specific features of ARP taking into account the remote nature of ultrasound Doppler probing of the soft tissues local movements, which are caused by the radiation pressure of HIFU pulse. Taking into account the accepted simplifying assumptions it is shown that the model conclusions are in a good agreement with the results of the experiments on measuring the value of displacements under the influence of HIFU. In particular, the nontrivial dependence of the value of displacements, measured by the Doppler method, on the probing depth and focusing degree of the incident and scattered wave beams, is proved. An experimental study was performed on the transverse resolution at ARP in the case of probing of the medium with Young's modulus irregularity, as well as on the influence of noise and interference on the measurement accuracy and resolution. It is concluded, that the transverse resolution at ARP is determined by the parameters of the local area of the movement, and can be significantly higher than the transverse intrinsic resolution of the ultrasound system at B-mode of diagnostics. The obtained results indicate that ARP is a promising method for monitoring the process of the soft tissues thermal ablation, when HIFU is used.

Increased Excitability Induced in the Primary Motor Cortex by Transcranial Ultrasound Stimulation.

Background: Transcranial Ultrasound Stimulation (tUS) is an emerging technique that uses ultrasonic waves to noninvasively modulate brain activity. As with other forms of non-invasive brain stimulation (NIBS), tUS may be useful for altering cortical excitability and neuroplasticity for a variety of research and clinical applications. The effects of tUS on cortical excitability are still unclear, and further complications arise from the wide parameter space offered by various types of devices, transducer arrangements, and stimulation protocols. Diagnostic ultrasound imaging devices are safe, commonly available systems that may be useful for tUS. However, the feasibility of modifying brain activity with diagnostic tUS is currently unknown.Objective: We aimed to examine the effects of a commercial diagnostic tUS device using an imaging protocol on cortical excitability. We hypothesized that imaging tUS applied to motor cortex could induce changes in cortical excitability as measured using a transcranial magnetic stimulation (TMS) motor evoked potential (MEP) paradigm.Methods: Forty-three subjects were assigned to receive either verum (n = 21) or sham (n = 22) diagnostic tUS in a single-blind design. Baseline motor cortex excitability was measured using MEPs elicited by TMS. Diagnostic tUS was subsequently administered to the same cortical area for 2 min, immediately followed by repeated post-stimulation MEPs recorded up to 16 min post-stimulation.Results: Verum tUS increased excitability in the motor cortex (from baseline) by 33.7% immediately following tUS (p = 0.009), and 32.4% (p = 0.047) 6 min later, with excitability no longer significantly different from baseline by 11 min post-stimulation. By contrast, subjects receiving sham tUS showed no significant changes in MEP amplitude.Conclusion: These findings demonstrate that tUS delivered via a commercially available diagnostic imaging ultrasound system transiently increases excitability in the motor cortex as measured by MEPs. Diagnostic tUS devices are currently used for internal imaging in many health care settings, and the present results suggest that these same devices may also offer a promising tool for noninvasively modulating activity in the central nervous system. Further studies exploring the use of diagnostic imaging devices for neuromodulation are warranted.

A universal ultrasound diagnostic system developed to support urology and coloproctological applications.

In this study, we sought to describe a novel imaging apparatus that is lightweight, inexpensive, and highly effective for use in colorectal diagnostic and treatment settings. Typical probes for use in colorectal ultrasonic imaging applications are developed for surgeons to diagnose and stage rectal tumors and image the rectum and anus. Here we outline a new technique and use it for colorectal imaging in an animal. This technique involves use of an ultrasound array module positioned along the axis of rotation such that improved rotation is possible. This module is in the shape of a linear rod with a rotary linear component that allows for emission of focused ultrasonic echo signals from a linear section of the probe. The usability of the transducer and rectal image quality are satisfactory in a porcine model with the technique proposed here, axial/lateral resolution as 0.96/2.24mm with 6dB applied through the contour map using the point spread function. When compared to currently available methods, this technique provides superior diagnostic 3D volumetric image quality with reduced acquisition time. Given this, the ultrasound device proposed here may prove a viable and preferable method to those currently available for urology and colorectal imaging applications.

ScAlN Thick-Film Ultrasonic Transducer in 40-80 MHz.

A medical ultrasound diagnostic system and an ultrasonic microscope are generally used in the frequency range of 1-20 MHz and 100 MHz-2 GHz, respectively. Ultrasonic transducers in the frequency range of 20-100 MHz are, therefore, not well developed because of less application into ultrasonic imaging or suitable piezoelectric materials with this frequency range. Polyvinylidene difluoride (PVDF) is usually used for ultrasonic transducers in the 10-50-MHz ranges. However, their electromechanical coupling coefficient of 4% is not enough for the practical uses. In order to excite the ultrasonic wave in the 20-100 MHz range, a 125-25- -thick piezoelectric film is required when the longitudinal velocity of the material is assumed to be 5000 m/s. However, it is difficult to grow such a thick piezoelectric film without a crack being caused by the internal stress during the dry deposition technique. We achieved a stress-free film growth by employing the unique hot target sputtering technique without heating the substrate. High-efficient 81- ( .5%) and 43-MHz ( %) ultrasonic generation by using the 43- and 90- extremely thick ScAlN (Sc: 39%) films were demonstrated, respectively. We discussed the advantage of ScAlN thick-film transducers by comparing them with the conventional PVDF transducer for the water medium.

OR-032 Effects of Protein Supplement Timing during 4-Week Resistance Training on Muscle Hypertrophy in Males

OR-032 Effects of Protein Supplement Timing during 4-Week Resistance Training on Muscle Hypertrophy in Males

INFLUENCE OF GEOMETRIC PROPERTIES OF SENSITIVE ELEMENTS ON CHARACTERISTICS OF PIEZOELECTRIC SENSORS

Introduction. The article is devoted to the actual problem of creating piezoelectric sensors in order to improve their characteristics, which contribute to increasing the resolution of the system. It is noted that the quality of the received information signal of the ultrasound diagnostic system depends on the characteristics of the primary sensing elements of the sensors.Modelling of a sensitive element and studying its characteristics. Choosing and substantiating the material and geometric shape of piezoelectric crystals affects the radiation range, the shape of the radiation signal, resolution, etc., which generally affects the accuracy of the information signal. That is why the choice and justification of the parameters of the sensing element and the method of constructing the sensor is a very important parameter for the ultrasound diagnostic system.A model of a primary sensing element is proposed, which, as a result of using a geometric shape, provides an extension of the frequency range of the converter. Thus, such a model increases the reliability of the information signal, which displays the parameters of the inhomogeneous medium of the object of investigation. This gives new possibilities when using such radiators for different types of diagnostic signals.If we analyze the numerical values of the absolute and relative bandwidths that we define for the standard and modified sensitive elements, we obtain the following: the bandwidth of the modified sensing element expands in comparison with the bandwidth of the plane disk sensitive element. This provides new opportunities for the application of similar emitters for different types of diagnostic signals. At the same time, the obtained characteristics should be selected, taking into account the dependencies between the quality factor and the frequency range of a particular sensor.Conclusion. Proposed model of the modified converter is suitable for use in the practice of ultrasound diagnostics of various objects.In further research it is necessary to analyze the character of the distribution of acoustic pressure in the radiation field, taking into account the zonal form of the proposed modified radiator

Utility of a High-Resolution Superficial Diagnostic Ultrasound System for Assessing Skin Thickness: A Cross-Sectional Study.

Compared with other imaging modalities, ultrasound is relatively deeply penetrating and can be used to evaluate deep dermal and subcutaneous structures. Image skin thickness of the face and neck using high-frequency diagnostic ultrasound devices. Skin overlying 20 different predesignated face and neck anatomic sites in 32 individuals was imaged using 2 commercially available high-frequency diagnostic ultrasound devices, a dedicated imaging device and a diagnostic device bundled with a therapeutic device. At each site, the subcutaneous and combined epidermal and dermal layer thicknesses were assessed by blinded expert raters. Similar skin thickness measurements were obtained. Notably, subcutaneous fat depth was measured to be 0.2 cm at the forehead; 0.5 cm at the mental eminence; and 0.6 cm at the submental, supraglenoid, and temporal regions. The combined epidermal and dermal thickness was approximately 0.1 cm at the zygomatic process, suborbital area, inferior malar region, gonion, supraglenoid area, and nasolabial-buccal, and nasolabial fold regions. This is the first study using high-resolution superficial diagnostic ultrasound to map skin thickness of the face and neck at standard anatomic locations. Ultrasound is an inexpensive, noninvasive, and convenient means to monitor dermatologic conditions and guide their treatment.

Change of heart dimensions and function during pregnancy in goats

The study aimed to evaluate the effect of pregnancy on heart diameters and function in goats. Transthoracic echocardiography of 12 female dairy goats of two Polish regional breeds was performed. A Mindray M7 diagnostic ultrasound system with Phased Array transducer was used. Simultaneously, electrocardiography was recorded. All animals were examined four times – at mating season, at the end of the first trimester, at the end of the second trimester and just before kidding. Eleven measurements were taken each time: aortic and left atrial diameter (AoD and LAD), right and left ventricular internal diameter in diastole (RVIDd and LVIDd), left ventricular internal diameter in systole (LVIDs), inter-ventricular septum thickness in diastole and systole (IVSd and IVSd) and left ventricular posterior wall in diastole and systole (LVPWd and LVPWs), maximum left and right ventricular outflow tract velocity (RVOT Vmax and LVOT Vmax). Nine consecutive measurements were derived: the ratio of the left atrial diameter to the aortic diameter (AoD/LAD), left ventricular fractional shortening (FS%), left ventricular ejection fraction (EF%), maximum outflow tract pressure gradients (RVOT PGmax and LVOT PGmax), left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV), stroke volume (SV) and cardiac output (CO). HR, LAD, LVPWs, IVSs increased significantly in the first trimester. AoD and RVIDd were significantly higher around parturition. LVIDd, FS%, EF%, SV and CO rose both in the first and third trimester. No measurement decreased during pregnancy. The study confirms that pregnancy causes changes in the heart size and functioning.

A clinical controlled trial of two different PICC catheter positioning methods

Objective To compare the consistency of two different peripherally inserted central catheters (PICC) catheter tip positioning methods of the chest X-ray and full digital color cardiovascular ultrasound diagnostic system in PICC patients. Methods A total of 157 cases of patients who underwent PICC catheterization in Tianjin Medical University General Hospital from 1st March to 31st December 2015 were selected. Self-control trial was applied, using full digital color cardiovascular ultrasound diagnostic system to determine the position of the catheter tip when implanting and using chest X-ray to reconfirm after catheterization. Results All 157 cases of patients were catheterized successfully. The correlation between the two methods of localization was tested, Spearman correlation coefficient rs=0.450 (P<0.001) , Pearson serial number r=0.710 (P<0.001) , showed that the two localization methods had certain relevance. The consistency test results showed that Kappa value was 0.390 (P<0.001) in the three classification method, and Kappa value was 0.707 (P<0.001) in the two classification method, and the two localization methods had certain consistency. The sensitivity of the cardiovascular ultrasound method was 98.6%, and the area under the ROC curve (AUC) was 0.917 (P<0.001) , which showed a higher accuracy in cardiovascular ultrasound method. Conclusions Cardiovascular ultrasound can be used as another clinical method to determine the position of the PICC catheter tip, and it is worthy of promotion in clinical practice. Key words: Cardiovascular ultrasound; Peripherally inserted central catheters; Catheter tip position

Real-time ultrasound imaging of complex skeletal defects and fractures Preliminary results

We report preliminary results on the use of ultrasound imaging techniques for real-time assessment of intact bones and bones with different types of fractures in animal samples ex vivo. Methods: Twenty-three cases of intact tibias and sixteen cases of fractured tibias obtained from rabbit, chicken and sheep samples were 2D and 3D scanned using a Sonix RP diagnostic ultrasound system and the results were statistically analyzed. Results: We report representative 2D and 3D results obtained for intact and fractured tibias in selected ex vivo rabbit, chicken and sheep animal samples. In selected cases, X-rays and CT data are also reported for a visual comparison with the ultrasound images. These preliminary results suggest that 2D and 3D real-time ultrasound imaging techniques have the potential to provide non-invasive and fast visualization of cortical defects in different types of bones. Conclusion: This study indicates that ultrasound imaging techniques can be used for a prompt assessment of bone defects including fractures and controlled defects. Off-line, more advanced image processing and analysis techniques can be used to further refine and improve the quality of the 3D ultrasound images especially in the case of bones located in deep tissues.

Correlation of IVC Diameter and Collapsibility Index With Central Venous Pressure in the Assessment of Intravascular Volume in Critically Ill Patients.

ObjectiveThe objective of our study is to assess the correlation between inferior vena cava (IVC) diameters, central venous pressure (CVP) and the IVC collapsibility index for estimating the volume status in critically ill patients.MethodsThis cross-sectional study used the convenient sampling of 100 adult medical intensive care unit (ICU) patients for a period of three months. Patients ≥ 18 years of age with an intrathoracic central venous catheter terminating in the distal superior vena cava connected to the transducer to produce a CVP waveform were included in the study. A Mindray diagnostic ultrasound system model Z6 ultrasound machine (Mindray, NJ, USA) was used for all examinations. An Ultrasonic Transducer model 3C5P (Mindray, NJ, USA) for IVC imaging was utilized. A paired sampled t-test was used to compute the p-values.ResultsA total of 32/100 (32%) females and 68/100 (68%) males were included in the study with a mean age of 50.4 ± 19.3 years. The mean central venous pressure maintained was 10.38 ± 4.14 cmH2O with an inferior vena cava collapsibility index of 30.68 ± 10.93. There was a statistically significant relation among the mean CVP pressure, the IVC collapsibility index, the mean maximum and minimum IVC between groups as determined by one-way analysis of variance (ANOVA) (p < 0.001). There was a strong negative correlation between CVP and IVC collapsibility index (%), which was statistically significant (r = -0.827, n = 100, p < 0.0005). A strong positive correlation between CVP and maximum IVC diameter (r = 0.371, n = 100, p < 0.0005) and minimum IVC diameter (r = 0.572, n = 100, p < 0.0005) was found.ConclusionThere is a positive relationship of CVP with minimum and maximum IVC diameters but an inverse relationship with the IVC collapsibility index.

Development of Biomodel with Micro particles for Ultrasound Diagnostic System

Development of Biomodel with Micro particles for Ultrasound Diagnostic System

High frame-rate visualization of blood flow with ultrasound contrast agents

Recent breakthroughs in diagnostic ultrasound system architectures have enabled new high frame rate (kHz) capabilities, which are opening new opportunities in blood flow imaging. In order to leverage these increases in temporal resolution broader or unfocused beams are employed. The combination high frame and less focused beams with ultrasound contrast agents introduces both new opportunities and trade-offs. One new opportunity is the ability to combine Doppler based processing to visualize both lower velocity blood flow in the microcirculation and higher velocity flow in larger vasculature not possible with conventional techniques. This can be accomplished by combining nonlinear pulsing sequences to separate microbubble and tissue signals with these less focused beams to separate different microbubble flow velocities. The use of less focused beams to image nonlinear echoes from microbubbles distributes ultrasound energy to microbubbles in temporally and spatially different ways. This work explores the compromises of using these less focused beams to visualize moving microbubbles at higher temporal resolutions. The focus will be on the practical challenges of generating nonlinear signals while balancing microbubble disruption and current system reconstruction capabilities. Both in-vitro and in-vivo results will be presented.

THE INFLUENCE OF THE DYNAMIC CHANGE OF ULTRASOUND SYSTEM SENSITIVITY FUNCTION ON THE SPECTRA OF DOPPLER RESPONSE SIGNALS

The previously developed continuum model of ultrasound wave scattering from inhomogeneities of mass density and compressibility was generalized in the present paper to the case of dynamically changing sensitivity function of ultrasound diagnostic system. The general expression relating the full power spectrum of Doppler response signal from the region of interest to spectral characteristics of scattering inhomogeneities movement and components of the probing ultrasound fields on spatial and temporal harmonics was obtained. The results of the work can be useful for the analysis of spectra obtained by means of modern diagnostic systems with dynamic focusing of transmitted beams by synthetic aperture method.

Therapeutic Uses of Contrast Microbubbles

The potential for non-invasive targeted delivery of therapeutic agents and targeted thrombus dissolution using diagnostic ultrasound (DUS) and intravenous microbubbles or droplets is an emerging technology that will change diagnostic ultrasound systems into therapeutic devices. Targeted ultrasound destruction of microbubbles which carry either DNA or inhibitor RNA sequences have been utilized to both promote microvascular regeneration in ischemic myocardium and skeletal muscle and inhibit vascular growth in murine models of carcinoma. Targeted ultrasound microbubble cavitation has been utilized to improve ischemic limb blood flow via nitric oxide pathways and to induce targeted coronary and microvascular recanalization in large animal models of acute ST segment elevation myocardial infarction (STEMI). Initial clinical trials utilizing DUS and commercially available microbubbles in acute STEMI patients prior to, and after, emergent percutaneous coronary intervention have demonstrated the feasibility and efficacy of this approach in preserving microvascular flow.

WE‐AB‐206‐00: Diagnostic QA/QC Hands‐On Workshop

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands‐on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands‐on environment with live demonstrations and on‐site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirementsJennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.

WE‐AB‐206‐01: Diagnostic Ultrasound Imaging Quality Assurance

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands‐on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands‐on environment with live demonstrations and on‐site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirementsJennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.

WE‐AB‐206‐02: ACR Ultrasound Accreditation: Requirements and Pitfalls

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands‐on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands‐on environment with live demonstrations and on‐site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirementsJennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.

WE‐AB‐206‐03: Workshop

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands‐on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands‐on environment with live demonstrations and on‐site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirementsJennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.