Ultrasonic Diagnostic Imaging Research Articles

ULTRASONIC DIAGNOSIS OF MYOCARDIAL SYNCHRONIZATION

An ultrasonic diagnostic imaging method and system are described for detecting abnormalities in the synchronicity of heart wall stimulation. Points on opposite sides of a chamber of the heart are identified in a starting ultrasound image, then tracked through at least a portion of the heart cycle. The changing positions of lines extending between pairs of the points are accumulated and displayed in a color kinesis display in which each color depicts the location of a line at a particular point in the cardiac cycle. In an illustrated example the points are tracked through the cardiac cycle by speckle tracking of the speckle pattern of the adjacent myocardial tissue, tracking specific anatomy, or tracking tissue texture.

LINEAR ARRAY ULTRASOUND TRANSDUCER WITH VARIABLE PATCH BOUNDARIES

An ultrasonic diagnostic imaging system has a two dimensional array arranged in multiple patches of multiple transducer elements. Each patch of transducer elements is coupled to a group of microbeamformer delay lines having outputs which can be coupled to a selected channel of a system beamformer, which beamforms the partially summed beams of each patch into a final beamformed signal. The ability to direct a delayed signal from a transducer element to a selected beamformer channel enables the patch boundaries to be changed as the aperture is translated across the array.

Contrast sensitivity function and extraocular muscles thickness in patients with early stage Graves’ ophthalmopathy

The aim of this study was to determine the value of the ultrasonography measurements of extraocular muscles in early stage Graves' ophthalmopathy (GO) and compare the contrast sensitivity function in patients and healthy control eyes. We examined 25-65 years old patients with early stage GO (20 eyes) and age matched healthy subjects (16 eyes). All participants underwent complete ophthalmic examination. The measurements of rectus extraocular muscles were performed by A/B mode MentorTM Advent ultrasonic diagnostic imaging system. We evaluated thickness (mm) of each extraocular muscle, compared with normal values, calculated the sum of the muscles thickness in a given eye. Contrast sensitivity (CS) was assessed by a Ginsburg Functional Acuity Contrast Test (FACT, Vision Sciences Research Corp.) chart, under day and night lighting conditions at five spatial frequencies (cpd). Inferior rectus muscle enlargement (thickness ≥ 3,6 mm) was found in 14 eyes (70 percent) of patients, p=0.008. Patients CS results differ significantly  from those of the control group (p<0.05; power 0.65-0.87), except the 6 cpd range under night lighting conditions (p=NS). The relation between the sum of the muscles thickness and CS thresholds are pronounced for the medium (6cpd) and high (12cpd) spatial frequency ranges (Spearman correlation coefficient 0.6, p=0.032 and 0.7; p=0.012, respectively). Even if visual acuity was intact and proptosis was not pronounced, CS impairment and extraocular muscles enlargement were detected in patients with early stage of GOhttp://dx.doi.org/10.5755/j01.u.66.3.658

Guidance Of Invasive Medical Devices By Three Dimensional Ultrasonic Imaging

A three dimensional ultrasonic diagnostic imaging system is operated to guide or observe the operation of an invasive medical device (30) in three dimensions. An interventional system (20) is used to operate the invasive medical device (30) and produces spatially-based information relating to the activity of the invasive medical device (30). The spatially-based information from the interventional system (20) is merged into the three dimensional ultrasonic image data to produce a live three dimensional image of the invasive medical device (30) or its activity. In one embodiment the locations where the activity of the invasive medical device (30) is performed is recorded and displayed in the three dimensional ultrasonic image. The three dimensional ultrasonic image may be shown as an anatomical volume rendered image or as a wire frame model (130) of the anatomy. In another embodiment an integrated three dimensional ultrasonic imaging and invasive device system is described.

Flow Spectrograms Synthesized From Ultrasonic Flow Color Doppler Information

An ultrasonic diagnostic imaging system and method are described by which a user can delineate a region of interest ( 122, 128 ) in a colorflow Doppler image. The ultrasound system processes the Doppler pixel information of the region of interest ( 122, 128 ) to produce a spectrogram illustrating motion at the region of interest ( 122, 128 ) as a function of time. In a preferred embodiment the Doppler pixel information is processed by histograms to produce the spectrogram data.

Medical Diagnostic Ultrasonic Imaging Method And System For Displaying Multi-Phase, Multi-Frame Images

A medical diagnostic ultrasonic imaging system acquires image data for at least two frames at each of multiple positions, each frame identified with a respective phase of a physiological cycle. A multiphase 3-D or extended field of view data set is constructed from the image data. Then a plurality of images are generated from the multiphase data set. Each image is associated with a respective phase of the physiological cycle, and these images are displayed in sequence to a user.

Colorflow biplane ultrasonic imaging system and method

An ultrasonic diagnostic imaging system is described in which two planes of a volumetric region which are in different elevation planes are scanned in real time. In one embodiment the two planes are scanned with less than the maximum number of scanlines which the transducer can transmit in a single plane. A user control enables the two planes to be moved laterally without moving the transducer probe. In another embodiment each image plane contains a color box depicting flow or motion in the same respective position in the image. The color boxes of the two images can be sized and positioned in tandem so that both are in the same corresponding area of the two images.

Development and Significance of a Fetal Electrocardiogram Recorded by Signal-Averaged High-Amplification Electrocardiography

Although ultrasonic diagnostic imaging and fetal heart monitors have undergone great technological improvements, the development and use of fetal electrocardiograms to evaluate fetal arrhythmias and autonomic nervous activity have not been fully established. We verified the clinical significance of the novel signal-averaged vector-projected high amplification ECG (SAVP-ECG) method in fetuses from 48 gravidas at 32-41 weeks of gestation and in 34 neonates. SAVP-ECGs from fetuses and newborns were recorded using a modified XYZ-leads system. Once noise and maternal QRS waves were removed, the P, QRS, and T wave intervals were measured from the signal-averaged fetal ECGs. We also compared fetal and neonatal heart rates (HRs), coefficients of variation of heart rate variability (CV) as a parasympathetic nervous activity, and the ratio of low to high frequency (LF/HF ratio) as a sympathetic nervous activity. The rate of detection of a fetal ECG by SAVP-ECG was 72.9%, and the fetal and neonatal QRS and QTc intervals were not significantly different. The neonatal CVs and LF/HF ratios were significantly increased compared with those in the fetus. In conclusion, we have developed a fetal ECG recording method using the SAVP-ECG system, which we used to evaluate autonomic nervous system development.

Automatic liquid injection system and method

A power assisted method and injector device for controllably delivering to patients a dispersion medicament or diagnostically active agent, the homogeneity of which is preserved throughout delivery. Diagnostically active agents disclosed are gas microbubble suspensions useful in ultrasonic diagnostic imaging and liposomal formulations in which liposome vesicles are loaded with iodinated compounds.

Guidance of invasive medical devices by wide view three dimensional ultrasonic imaging

A three dimensional ultrasonic diagnostic imaging system is operated to guide or observe the operation of an invasive medical device (30) in three dimensions. The invasive medical device (30) is shown in a detailed ultrasonic image and the balance of the volumetric region (120) in which the device is located is shown in a wide field of view. The detailed and wide fields of view may be displayed separately or overlapping in spatial alignment on an image display (18). The wide field of view may be shown in two or three dimensions. A quantified display may be shown together with the wide and detailed anatomical displays. The detailed view may also be shown in an enlarged or zoomed format.

Ultrasonic spatial compounding with multiple simultaneous beam transmission

An ultrasonic diagnostic imaging system and method are described in which spatially compounded images are produced by transmitting ultrasound beams in different directions during a common transmit-receive interval. Echoes are received from the different beam directions and are beamformed by a multiline beamformer to produce differently steered beams of coherent echo signals. The echoes are combined on a spatial basis with echoes from different look directions which correspond to the same spatial location being combined. The resulting spatially compounded image is displayed.

306 超音波エラストグラフィの現状(OS3-(2) バイオメカニクスにおける新分野の開拓 : 組織粘弾性の無侵襲計測,オーガナイズドセッション)

This paper reviews a current progress of ultrasonic elastography and discusses the point of difference and common point between magnetic resonance elastography (MRE) under development and the ultrasonic elastography, with the aim of exploring a possibility of complementary coexistence between the MRE and the ultrasonic elastography. The ultrasonic elastography has already been put to practical use and its clinical effectiveness is gradually being verified. On the other hand, if the MRE technology put to practical use, the MRE might become used as a complementary approach of the ultrasonic elastography to the diagnosis and so on, as analogized from the complementary relationship between conventional diagnostic ultrasonic imaging and MRI.

End-element anomalies in medical ultrasonic piezo-composite arrays

Piezoelectric composites are commonly used in medical diagnostic ultrasonic imaging arrays. The performance of the array elements at either end of the array can differ from that of array elements away from the ends. There is some general understanding about the origin of these effects (such as different acoustic impedance), and some standard compensatory designs exist (such as adding unused array elements further on the end than the last used array element). This work seeks to elucidate the origins of these end-element anomalies and to propose corresponding design changes. A commercially produced array with notable end-element anomalies is examined as a case study. Results from experiments and finite element analysis indicate that, in the presence of a stiffness discontinuity within the composite (such as poled elements adjacent to unpoled ones), a secondary wave that propagates laterally through the composite may be generated during the receive transduction. This wave appears to cause the anomalous behavior observed in the signals and metrics of the end elements. Changing the electrical loading of an element and poling the unused, previously unpoled elements are explored as anomaly-mitigating design alterations. The latter of these 2 initially appears to be the more effective solution.

Ultrasonic diagnostic imaging with steered image plane

A two-dimensional array transducer probe is used to image regions of the body that are acoustically obstructed from conventional view by objects such as the lungs or ribs. The probe is located against the body at an acoustic window which provides acceptable ultrasonic transmissivity between the transducer array and the body. While maintaining the probe at its acoustic window, an image plane location is manipulated by adjusting the beam steering directions. The image plane can be tilted in the elevation direction, moved laterally, and/or rotated about a center axis to position the image plane so that the obstructed anatomy is effectively imaged for diagnosis.

Whole-Body Bioluminescent Imaging of Human Uveal Melanoma in a New Mouse Model of Local Tumor Growth and Metastasis

Human uveal melanoma develops in one of the most capillary-rich tissues of the body and has a pure hematogenous dissemination. Radiodiagnostic examinations, such as ultrasonic diagnostic resonance imaging and chest radiographs plus liver enzyme studies in blood, are methods used to detect liver and other distant metastases in patients. Nevertheless, the mortality rate is high, because of the frequent occurrence of metastases and the lack of systemic therapy. Therefore, the development of novel anticancer strategies is urgent, and more sensitive and less invasive methods of detecting and monitoring in vivo tumor growth and metastatic disease in cancer models are needed. A luciferase (Luc)-positive human uveal melanoma cell line (OCM-1 FRT/luc) was established. Tumor cells were inoculated into the anterior chamber of murine eyes for induction of orthotopic growth or into the left heart ventricle to mimic hematogenous micrometastatic spread. Development of metastases and tumor growth was monitored weekly by whole-body bioluminescent reporter imaging (BLI). Injection of cancer cells into the anterior chamber of the eye of mice closely mimicked orthotopic tumor growth of uveal melanoma. Tumor progression could be quantitatively monitored 3 weeks after inoculation of 10(5) OCM-1 FRT/luc cells. Of the mice injected, 83% exhibited a detectable tumor within 5 weeks. Intracardiac injection of tumor cells resulted in metastatic growth, especially in bone. Mice had bone (maxillofacial region and femora) and visceral (lung and mediastinum) metastases after 4 to 6 weeks. OCM-1 FRT/luc cells may also have a propensity to colonize the eye after intracardiac inoculation. BLI enables continuous quantitative monitoring in the same animal of growth kinetics for each tumor and its metastases. This model will accelerate the understanding of the pathogenesis and treatment of uveal melanoma and metastasis.

A multimode sonic and ultrasonic diagnostic imaging system with application to peripheral vascular characterization

Ultrasound (US) medical imaging technology is enhanced by integrating a simultaneous noninvasive audible frequency measurement of biological sounds that could be indicative of pathology. Measurement of naturally-occurring biological acoustic phenomena can augment conventional imaging technology by providing unique information about material structure and system function. Sonic phenomena of diagnostic value are associated with a wide range of biological functions, such as breath sounds, bowel sounds, and vascular bruits. The initial focus of this multimode technology was to provide an improved diagnostic tool for common peripheral vascular complications that result in transitional or turbulent blood flow, such as associated with arteriovenous (AV) grafts and stenoses in common carotid and other arteries due to plaque buildup. We review: (1) the development the multimode system by combining a commercial US system with a novel sonic sensor array and associated instrumentation, and (2) the evaluation of its capability via controlled phantom models of basic subsurface sound sources/structures, as well as simulations of constricted peripheral blood vessels. [Work supported by NIH EB002511 and HL55296, and Whitaker Foundation BME RG 01-0198.]

Synthetically focused ultrasonic diagnostic imaging system for tissue and flow imaging

A synthetic focus ultrasound system is described in which individual transducer elements are activated to insonify the image field and the resultant echoes are received by a plurality of elements of the array. The echo signals are stored and the complete echo set is used to produce motion maps for different velocity vectors over the image field. Various ones of the motion maps are used to produce a wide variety of ultrasound image modes, including grey-scale images, colorflow images, and spectral flow displays.

Modelling of nonlinear effects and the response of ultrasound contrast micro bubbles: simulation and experiment

The propagation of diagnostic ultrasonic imaging pulses in tissue and their interaction with contrast micro bubbles is a very complex physical process, which we assumed to be separable into three stages: pulse propagation in tissue, the interaction of the pulse with the contrast bubble, and the propagation of the scattered echo. The model driven approach is used to gain better knowledge of the complex processes involved. A simplified way of field simulation is chosen due to the complexity of the task and the necessity to estimate comparative contributions of each component of the process. Simulations are targeted at myocardial perfusion estimation. A modified method for spatial superposition of attenuated waves enables simulations of low intensity pulse pressure fields from weakly focused transducers in a nonlinear, attenuating, and liquid-like biological medium. These assumptions enable the use of quasi-linear calculations of the acoustic field. The simulations of acoustic bubble response are carried out with the Rayleigh–Plesset equation with the addition of radiation damping. Theoretical simulations with synthesised and experimentally sampled pulses show that the interaction of the excitation pulses with the contrast bubbles is the main cause of nonlinear scattering, and a 2–3 dB increase of second harmonic amplitude depends on nonlinear distortions of the incident pulse.

Ultrasonic diagnostic imaging with elevation biplane images

An ultrasonic diagnostic imaging system is described in which two planes of a volumetric region which are in different elevation planes are scanned in real time. In one embodiment the two planes are scanned in the sector format with a common apex, causing corresponding depths of the two images to be separated by the same distance in elevation. In another embodiment one image plane has a fixed orientation with respect to the imaging probe and the location of the other image plane can be adjusted by the user.

Ultrasonic diagnostic imaging system for low flow rate contrast agents

An ultrasonic diagnostic imaging system and method are presented to determine low rates of blood flow using contrast agents. Pairs of differently modulated pulses are transmitted in several beam directions to acquire echoes which can be combined to separate harmonic frequencies by pulse inversion. The pulses of each pair are transmitted in rapid succession to minimize motional artifacts. The transmission in the different beam directions is time-interleaved, resulting in the sampling of each beam direction over a long ensemble time for the detection of low rates of flow.