Diagnostic Ultrasound Imaging System Research Articles

Rib detection using pitch-catch ultrasound and classification algorithms for a novel ultrasound therapy device

BackgroundNoninvasive ultrasound (US) has been used therapeutically for decades, with applications in tissue ablation, lithotripsy, and physical therapy. There is increasing evidence that low intensity US stimulation of organs can alter physiological and clinical outcomes for treatment of health disorders including rheumatoid arthritis and diabetes. One major translational challenge is designing portable and reliable US devices that can be used by patients in their homes, with automated features to detect rib location and aid in efficient transmission of energy to organs of interest. This feasibility study aimed to assess efficacy in rib bone detection without conventional imaging, using a single channel US pitch-catch technique integrated into an US therapy device to detect pulsed US reflections from ribs.MethodsIn 20 healthy volunteers, the location of the ribs and spleen were identified using a diagnostic US imaging system. Reflected ultrasound signals were recorded at five positions over the spleen and adjacent ribs using the therapy device. Signals were classified as between ribs (intercostal), partially over a rib, or fully over a rib using four models: threshold-based time domain classification, threshold-based frequency domain classification, logistic regression, and support vector machine (SVM).ResultsSVM performed best overall on the All Participants cohort with accuracy up to 96.25%. All models’ accuracies were improved by separating participants into two cohorts based on Body Mass Index (BMI) and re-fitting each model. After separation into Low BMI and High BMI cohorts, a simple time-thresholding approach achieved accuracies up to 100% and 93.75%, respectively.ConclusionThese results demonstrate that US reflection signal classification can accurately provide low complexity, real-time automated onboard rib detection and user feedback to advance at-home therapeutic US delivery.

Focused ultrasound neuromodulation of the spleen activates an anti-inflammatory response in humans

Focused ultrasound stimulation (FUS) activates mechanosensitive ion channels and is emerging as a method of noninvasive neuromodulation. In preclinical studies, FUS of the spleen (sFUS) activates an anti-inflammatory neural pathway which suppresses acute and chronic inflammation. However, the relevance of sFUS for regulating inflammatory responses in humans is unknown. Here, we used a modified diagnostic ultrasound imaging system to target the spleen of healthy human subjects with 3 min of continuously swept or stationary focused pulsed ultrasound, delivered at three different energy levels within allowable safety exposure limits. Potential anti-inflammatory effects of sFUS were assessed by measuring sFUS-elicited changes in endotoxin-induced tumor necrosis factor (TNF) production in whole blood samples from insonified subjects. We found that stimulation with either continuously swept or focused pulsed ultrasound has an anti-inflammatory effect: sFUS lowers TNF production for >2 h, with TNF returning to baseline by 24 h following sFUS. This response is independent of anatomical target (i.e., spleen hilum or parenchyma) or ultrasound energy level. No clinical, biochemical, or hematological parameters are adversely impacted. This is the first demonstration that sFUS suppresses the normal inflammatory response in humans, with potential implications for noninvasive bioelectronic therapy of inflammatory disorders.

Imaging-guided gene delivery: seeing is delivering

Imaging-guided gene delivery: seeing is delivering

Imaging three dimensional objects with ultrasound

The ultrasound imaging laboratory provided students with the opportunity of determining what an unknown three dimensional object was from two-dimensional images. Armed with a portable diagnostic ultrasound imaging system, and internal calipers for quantification, students were given unknown objects from the creepy crawly collection. Each object was immersed in a small tub of opaque fluid. Students could adjust the imaging system to give different cross-sections or cut planes through the object. From this information and linear calipers, they were to determine what the object was and provide a quantitative three dimensional sketch. This experience gave them a taste of the chief difficulty in diagnostic imaging of the body: deciphering and recognizing tissue structures and organs from partial views. Other imaging exercises included the use of imaging phantoms to measure spatial and temporal resolution as a function of depth and other controls.

Effect of Insole Use on the Brightness of the Abductor Hallucis: Measurement Using a Diagnostic Ultrasound Imaging System

Effect of Insole Use on the Brightness of the Abductor Hallucis: Measurement Using a Diagnostic Ultrasound Imaging System

Sonothrombolysis of embolic carotid artery, using pesda microbubbles- mediated B-mode ultrasound- guided extracorporeal pulsed low- level focused confocal dual frequency ultrasound accompanied by streptokinase administration

Background and Aims: Therapeutic ultrasound was found to selectively lyse thrombi with a wide margin of safety. Ultrasound effects sonothrombolysis by selective disruption of the fibrin matrix of the thrombus. In this study, we developed an experimental sonothrombolysis system, and investigated its effectiveness on carotid artery recanalization, accompanied by intravenous streptokinase and PESDA (perfluorocarbon exposed sonicated dextrose albumin) microbubbles administration, wherein diagnostic ultrasound imaging system is combined with the therapy system, with a goal of increased safety.

Intermediate stage atherosclerosis regression, using protoporphyrin ІX-loaded pesda microbubbles- mediated B-mode ultrasound- guided extracorporeal focused low- level confocal dual pulse electrohydraulic shock wave sonodynamic therapy

Background and Aims: In this study, we aimed to investigate the effect of confocal dual pulse shock wave- mediated sonodynamic therapy on intermediate stage atherosclerosis regression, wherein diagnostic ultrasound imaging system is combined with the therapy system, with a goal of increased safety.

Effect of high- dose atorvastatin- loaded pesda microbubbles- mediated b-mode ultrasound- guided extracorporeal pulsed low- level focused confocal dual frequency insonation on intermediate stage atherosclerosis

Background and Aims: Intermediate stage atherosclerosis is highlighted by infiltration of oxidized low-density lipoprotein LDL and foam cell formation, resulting in the thickening of arterial walls. In this study, we aimed to investigate the effect of sonoporation- based atorvastatin therapy on intermediate stage atherosclerosis regression, wherein diagnostic ultrasound imaging system is combined with the therapy system, with a goal of increased safety.

Effect of optison microbubbles- mediated B-mode ultrasound- guided focused low- level confocal dual pulse electrohydraulic shock wave- assisted streptokinase thrombolysis on embolic carotid artery

Background and Aims: In this study, we developed an experimental focused low- level confocal dual pulse electrohydraulic shock wave thrombolytic therapy system, and investigated its effectiveness on common carotid artery recanalization, accompanied by intravenous streptokinase and Optison microbubbles administration, wherein diagnostic ultrasound imaging system is combined with the therapy system, with a goal of increased safety.

Reliability of the rectus abdominis muscle confirmation technique using a diagnostic ultrasound imaging system for stoma site marking by nursing students

Reliability of the rectus abdominis muscle confirmation technique using a diagnostic ultrasound imaging system for stoma site marking by nursing students

High-Accuracy Ultrasound Contrast Agent Detection Method for Diagnostic Ultrasound Imaging Systems

An accurate method for detecting contrast agents using diagnostic ultrasound imaging systems is proposed. Contrast agents, such as microbubbles, passing through a blood vessel during ultrasound imaging are detected as blinking signals in the temporal axis, because their intensity value is constantly in motion. Ultrasound contrast agents are detected by evaluating the intensity variation of a pixel in the temporal axis. Conventional methods are based on simple subtraction of ultrasound images to detect ultrasound contrast agents. Even if the subject moves only slightly, a conventional detection method will introduce significant error. In contrast, the proposed technique employs spatiotemporal analysis of the pixel intensity variation over several frames. Experiments visualizing blood vessels in the mouse tail illustrated that the proposed method performs efficiently compared with conventional approaches. We also report that the new technique is useful for observing temporal changes in microvessel density in subiliac lymph nodes containing tumors. The results are compared with those of contrast-enhanced computed tomography.

A fast minimum variance beamforming method using principal component analysis.

Minimum variance (MV) beamforming has been studied for improving the performance of a diagnostic ultrasound imaging system. However, it is not easy for the MV beamforming to be implemented in a real-time ultrasound imaging system because of the enormous amount of computation time associated with the covariance matrix inversion. In this paper, to address this problem, we propose a new fast MV beamforming method that almost optimally approximates the MV beamforming while reducing the computational complexity greatly through dimensionality reduction using principal component analysis (PCA). The principal components are estimated offline from pre-calculated conventional MV weights. Thus, the proposed method does not directly calculate the MV weights but approximates them by a linear combination of a few selected dominant principal components. The combinational weights are calculated in almost the same way as in MV beamforming, but in the transformed domain of beamformer input signal by the PCA, where the dimension of the transformed covariance matrix is identical to the number of some selected principal component vectors. Both computer simulation and experiment were carried out to verify the effectiveness of the proposed method with echo signals from simulation as well as phantom and in vivo experiments. It is confirmed that our method can reduce the dimension of the covariance matrix down to as low as 2 × 2 while maintaining the good image quality of MV beamforming.

Quantitative Assessment of Shockwave Lithotripsy Accuracy and the Effect of Respiratory Motion

Effective stone comminution during shockwave lithotripsy (SWL) is dependent on precise three-dimensional targeting of the shockwave. Respiratory motion, imprecise targeting or shockwave alignment, and stone movement may compromise treatment efficacy. The purpose of this study was to evaluate the accuracy of shockwave targeting during SWL treatment and the effect of motion from respiration. Ten patients underwent SWL for the treatment of 13 renal stones. Stones were targeted fluoroscopically using a Healthtronics Lithotron (five cases) or Dornier Compact Delta II (five cases) shockwave lithotripter. Shocks were delivered at a rate of 1 to 2 Hz with ramping shockwave energy settings of 14 to 26 kV or level 1 to 5. After the low energy pretreatment and protective pause, a commercial diagnostic ultrasound (US) imaging system was used to record images of the stone during active SWL treatment. Shockwave accuracy, defined as the proportion of shockwaves that resulted in stone motion with shockwave delivery, and respiratory stone motion were determined by two independent observers who reviewed the ultrasonographic videos. Mean age was 51 ± 15 years with 60% men, and mean stone size was 10.5 ± 3.7 mm (range 5-18 mm). A mean of 2675 ± 303 shocks was delivered. Shockwave-induced stone motion was observed with every stone. Accurate targeting of the stone occurred in 60% ± 15% of shockwaves. US imaging during SWL revealed that 40% of shockwaves miss the stone and contribute solely to tissue injury, primarily from movement with respiration. These data support the need for a device to deliver shockwaves only when the stone is in target. US imaging provides real-time assessment of stone targeting and accuracy of shockwave delivery.

Clinical assessment of shockwave lithotripsy accuracy.

Kidney stone movement primarily due to patient respiration compromises shock wave lithotripsy (SWL) targeting and efficacy. The objective of this study is to describe the use of B‐mode ultrasound to evaluate the accuracy of targeting during SWL. Patients undergoing electrohydraulic SWL were enrolled into this institutionally approved research study. A commercial diagnostic ultrasound imaging system, either Philips HDI 5000 or iU‐22, was used to intermittently visualize and detect any shockwave‐induced motion of the stone during 1–3 min periods. Four patients (mean age 52.7) underwent treatment of seven renal stones with mean individual stone size of 10.41 ± 4.5 mm. A mean of 2937 shocks (range 2750–3000) were delivered at a rate of 1–2 Hz and charging voltage of 14–26 kV. Stone oscillation or jumping at the exact time of individual shock delivery was visualized with ultrasound: no stones completely failed to move. Accurate alignment, as interpreted by positive stone motion, occurred in a mean of 50 ± 20.4% of shockwaves. Ultrasound imaging represents a method of real‐time assessment of accuracy in SWL and may provide the basis for devices to control targeting so that shockwaves are only delivered when the stone is in focus. [Work supported by NIH DK43881 and DK086371.]

Method For Scalable Manufacturing Of Medical Diagnostic Ultrasound Imaging Systems

A plurality of application specific integrated circuit (ASIC) chips with different functions is provided. Each of the ASICs performs one or more functions along an ultrasound data path. The chips include communications protocols or processes for allowing scaling. For example, ASICs for backend processing include data exchange ports for communicating between other ASICs of the same type. As another example, receive beamformer ASICs cascade for beamformation. By providing ASICs implementing many or most of the ultrasound data path functions, with scalability, the same ASICs may be used for different system designs. A family of systems from high end to low-end using the same types of ASICs, but in different configurations, is provided.

Diagnostic ultrasound imaging method and system with improved frame rate

Diagnostic ultrasound imaging method and system with improved frame rate

Medical diagnostic ultrasound imaging system transmitter control in a modulator transducer system

The preferred embodiments described herein provide medical diagnostic ultrasound imaging system transmitter control in a modular transducer system. With these preferred embodiments, transmitters in a medical diagnostic ultrasound imaging system are enabled only when contacts in a scan head are electrically coupled with contacts in a receptacle assembly of a modular transducer system. This prevents high voltages from developing in the receptacle assembly when the scan head is removed from or is not fully engaged with the receptacle assembly. In one preferred embodiment, a detector is used to detect movement of a member comprising the contacts in the receptacle assembly. Other preferred embodiments are provided, and each of the preferred embodiments described herein can be used alone or in combination with one another.

Medical diagnostic ultrasound imaging methods for extended field of view

A medical diagnostic ultrasound imaging system aligns substantially co-planar two-dimensional images to form an extended field of view using improved compounding methods. Compounding with a finite impulse response is used for more versatile compositing. The compounding is adaptive, such as through adapting the image regions, weighting, or type of compounding as a function of correlation, location within the image, estimated motion or combinations thereof. A user warning is provided as a function of the correlation between images.

Medical diagnostic ultrasound imaging system and method for displaying a portion of an ultrasound image

In one embodiment, a region of interest indictor is positioned over a first portion of an ultrasound image, and the first portion and at least some other portion of the ultrasound image are saved in a post-scan-converted format. The stored ultrasound image is played, and a region of interest indicator is positioned over a second portion of the played ultrasound image. In another embodiment, an ultrasound image is stored in a post-scan-converted format. The ultrasound image is played, and a region of interest indicator is positioned over a portion of the ultrasound image. In yet another embodiment, a user requests storage of a multi-frame ultrasound image for a first length of time. The ultrasound system instead stores the multi-frame ultrasound image for a second length of time, which is longer than the first length of time.

Medical diagnostic ultrasound imaging system and method for constructing a composite ultrasound image

The preferred embodiments described herein provide a medical diagnostic ultrasound imaging system and method for constructing a composite ultrasound image. In one preferred embodiment, visual and audio components of an ultrasound image are separately stored so that a composite image including some or all of the components can later be constructed. The audio component can take the form of Doppler audio or voice data, for example. In another preferred embodiment, stored computer-readable program code is selected to perform an operation on a constructed composite ultrasound image.