Biomechanical changes of the common carotid artery and internal jugular vein in patients with multiple sclerosis

Purpose@#Investigations of the hemodynamic changes of the venous system in patients with multiple sclerosis (MS) have shown contradictory results. Herein, the biomechanical parameters of the internal jugular vein (IJV) and common carotid artery (CCA) of MS patients were extracted and compared to healthy individuals. @*Methods@#B-mode and Doppler sequential ultrasound images of 64 IJVs and CCAs of women including 22 healthy individuals, 22 relapsing-remitting multiple sclerosis (RRMS) patients, and 20 primary-progressive multiple sclerosis (PPMS) patients were recorded and processed. The biomechanical parameters of the IJV and the CCA walls during three cardiac cycles were calculated. @*Results@#The IJV maximum and minimum pressures were higher in the MS patients than in the healthy subjects, by 31% and 19% in RRMS patients and 39% and 24% in PPMS patients. The venous wall thicknesses in RRMS and PPMS patients were 51% and 60% higher than in healthy subjects, respectively. IJV distensibility in RRMS and PPMS patients was 70% and 75% lower, and compliance was 40% and 59% lower than in healthy subjects. The maximum intima-media thicknesses of the CCAs were 38% and 24%, and the minimum intima-media thicknesses were 27% and 23% higher in RRMS and PPMS patients than in healthy individuals, respectively. The shear modulus of CCA walls in RRMS and PPMS patients was 17% and 31%, and the radial elastic moduli were 47% and 9% higher than in healthy individuals. @*Conclusion@#Some physical and biomechanical parameters of the CCA and IJV showed significant differences between MS patients and healthy individuals.

Assessing the short-term effects of radiotherapy on the shear modulus of the common carotid artery as a new biomarker of radiation-induced atherosclerosis

Purpose@#The purpose of this study was to investigate the incidence of short-term atherosclerosis in the common carotid arteries following radiotherapy. @*Methods@#The mean radiation dose to the arteries was 49.30±15.83 Gy. A computational ultrasound method was introduced to investigate the elastic modulus. Ultrasonography was performed 2-3 cm inferior to the bifurcation region before and after radiotherapy, and sequential images were extracted from a video of each artery. Instantaneous movement of the arterial wall in the radial and longitudinal directions was extracted by implementing the maximum gradient and block matching algorithms, respectively. @*Results@#There was a significant change in systolic blood pressure after radiotherapy (P=0.008). Irradiated arteries had significantly smaller systolic and end-diastolic diameters than non-irradiated arteries (P<0.001). The shear modulus was significantly different between irradiated and non-irradiated arteries (3.10±2.03 kPa vs. 1.38±0.98 kPa, P<0.001). The shear and Young moduli of radiation-induced arteries were 2.25±1.50 and 1.57±0.59 times higher than those of the pre-irradiation arteries. @*Conclusion@#The arterial shear modulus can be considered as a new biomarker of radiationinduced atherosclerosis in the common carotid artery.

Stress distribution analysis in healthy and stenosed carotid artery models reconstructed from in vivo ultrasonography

Purpose@#This study investigated the accuracy of models reconstructed from ultrasound image processing by comparing the radial displacement waveforms of a subject-specific artery model and evaluated stress changes in the proximal shoulder, throat, and distal shoulder of the plaques depending on the degree of carotid artery stenosis. @*Methods@#Three groups of subjects (healthy and with less than 50% or more carotid stenosis) were evaluated with ultrasonography. Two-dimensional transverse imaging of the common carotid artery was performed to reconstruct the geometry. A longitudinal view of the same region was recorded to extract the Kelvin viscoelastic model parameters. The pulse pressure waveform and the effective pressure of perivascular tissue were loaded onto the internal and external walls of the model. Effective, circumferential, and principal stresses applied to the plaque throat, proximal shoulder, and distal shoulder in the transverse planes were extracted. @*Results@#The radial displacement waveforms of the model were closely correlated with those of image processing in all three groups. The mean of the effective, circumferential, and principal stresses of the healthy arteries were 15.01±4.93, 12.97±5.07, and 12.39±2.86 kPa, respectively. As stenosis increased from mild to significant, the mean values of the effective, circumferential, and first principal stresses increased significantly (97%, 74%, and 103% at the plaque throat, respectively) (P<0.05). The minimum effective stress was at the lipid pool. The effective stress in calcified areas was higher than in other parts of the artery wall. @*Conclusion@#This model can discriminate differences in stresses applied to mildly and severely stenotic plaques.

Hemodynamic analysis of radiation-induced damage in common carotid arteries by using color Doppler ultrasonography

PURPOSE: The aim of this study was to assess vascular changes and blood flow abnormalities in the common carotid arteries of patients with head and neck cancers after external radiotherapy, using color Doppler ultrasonography. METHODS: We studied 24 patients treated with external radiotherapy for various head and neck cancers. In order to study the acute effects of irradiation on common carotid blood flow and arterial diameter changes, color Doppler ultrasonography parameters such as peak systolic velocity, end diastolic velocity, mean velocity, systolic-to-diastolic velocity (S/D) ratio, pulsatility index (PI), resistive index (RI), and instantaneous diameter changes were evaluated before and after external radiotherapy. Additionally, the blood volume flow (VF) values in the peak systolic and end diastolic phases, as well as mean velocity, were evaluated throughout three cardiac cycles using B-mode ultrasonic image processing. RESULTS: The findings showed significant changes in the S/D ratio, PI, and RI of the common carotid arteries before and after external radiotherapy (P < 0.05). Moreover, a significant decrease in artery diameter and blood VF was observed after radiotherapy relative to the pretreatment values. A significant correlation was found between the blood VF values estimated using ultrasonic measurements and mathematical methods throughout three cardiac cycles. CONCLUSION: The hemodynamic parameters of the common carotid arteries changed during radiotherapy. These arterial changes may lead to late adverse effects of radiotherapy, such as ischemic strokes and ischemic attacks.

Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

PURPOSE: The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. METHODS: Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. RESULTS: A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was −1.333±6.548 mm Hg. CONCLUSION: The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes.

Estimating the Myocardium's Angle of Three-Dimensional Trajectory, Using the Tracking of Sequential Two-Dimensional Echocardiography Images

BACKGROUND: In this study, the angle of the myocardium's trajectory in three dimensions (small ef, Cyrillic) was estimated by simultaneous use of long-axis and short-axis views of left ventricle septum two-dimensional images. Then correlation of three-dimensional trajectory's angle with the rotation angle from the long (chi) and short (theta) axis views was estimated and compared at the three levels of base, mid and apex of the interventricular septum wall. METHODS: Two-dimensional echocardiography images of long- and short-axis views of 19 healthy men were recorded and analyzed. Using an electrocardiogram of each individual, the images of the two views were synchronized. The interventricular septum wall motion at the three levels of base, mid and apex were estimated, using a block matching algorithm throughout three cardiac cycles. Considering the defined system of coordinates and the position vectors in long and short-axis views, the 3-dimensional angle of the trajectory was calculated. RESULTS: Maxima of the small ef, Cyrillic, theta, and chi angles were extracted at 16.33 +/- 3.01, 10.61 +/- 3.38, and 15.11 +/- 3.30 degrees at base level, 22.77 +/- 4.95, 7.78 +/- 2.96, and 16.72 +/- 2.66 degrees at mid level and 14.60 +/- 5.81, 10.37 +/- 5.48, and 8.79 +/- 3.32 degrees at apex level, respectively, of the septum wall, respectively. This study shows significant correlation between the angle of 3-dimensional trajectory (small ef, Cyrillic) with the angle in short axis view (theta) of the septum wall at the apex level; and also with the angle in long axis view (chi) of the septum wall at base and mid levels. CONCLUSION: Due to the motion of the wall of the left ventricle in three dimensions, and the non-isotropic structure of myofibers, the angle of 3-dimensional trajectory was estimated using the speckle tracking method of 2-dimentional echocardiography images.

Assessment of left ventricular torsion in short axis view between healthy subjects and significant coronary artery disease patients

Coronary artery disease causes changes in biomechanical parameters and function of myocardial. Recently, torsion angle is one of the most important mechanical parameters. Therefore in this study, torsion angle in healthy subjects and LAD significant coronary artery disease patients, using echo tracking method in short axis view, was evaluated. In cross sectional study, 14 healthy subjects and 10 patients with significant stenosis of LAD were evaluated. Two dimensional echocardiography images were scanned in apical and basal parasternal short axis view were recorded. Successive ultrasonic images were processed by echo tracking under block matching algorithm and peak torsion angle were estimated. Difference between healthy group and patient group were extracted by using peak torsion angle by the confidence level of 95%. In this study, basal rotation angle, apical rotation angle and torsion angle in short axis view in significant coronary artery disease patients significantly decreased 33%, 44% and 38% relative to healthy subjects, respectively. Also time to reach peak torsion angle in LAD coronary artery stenosis patients increased 19% relative to healthy group. It seems, torsion angle in short axis view, can diagnose LAD coronary artery stenosis patients reative to healthy subject

Preparation of methylene blue-containing nanoliposomes and determination of stability, biological distribution and drug release after sonication by 1 MHZ ultrasound waves

In order to overcome the limitation of systemic administration of methylene blue, this study investigated the encapsulation of methylene blue in polymeric liposomes and drug release following sonication. We encapsulated methylene blue into nanoliposomes. The dynamic light scattering [DLS] method was used to measure the size distribution of the liposomes. After loading methylene blue into these liposomes, both drug encapsulation efficiency and stability were fluorometrically determined. Biodistribution of drug was studied in vivo in a mouse model of adenocarcinoma tumor cells. The amount of drug released upon 1 MHz sonication at an intensity of 2 W/cm2 was fluorometrically verified in vitro. DLS studies showed that the synthesized liposomes had an average size of 66.19 +/- 4.49 nm. Methylene blue was efficiently encapsulated in nanoparticles at an average of 65.21 +/- 3.47%. Stability of the generated liposomes decreased with time. Biodistribution study revealed that the drug content in the group that received liposomal drugs in their tumor tissue was significantly higher than in the group that received methylene blue in its free form and in the heart was inverse [P<0.05]. The results indicated that a 5 min application of 1 MHz ultrasound caused a methylene blue release of approximately 51.8 +/- 8.3% from the nanoparticles. This study has shown that fabricated liposomes are suitable for the encapsulation and delivery of hydrophilic photosensitizers such as methylene blue. Ultrasound-triggered release was achieved by the use of a 1 MHz ultrasound

Endothelial dysfunction in experimental atherosclerosis in the rabbit with extraction of instantaneous changes in the arterial wall

In this study, we used a new computerized analytical method for the measurement of the endothelial function in sequential ultrasound images and compared it with histological studies, using the abdominal aorta in normal and atherosclerotic rabbits. Six rabbits received a standard rabbit chow as the normal group and the other 6 rabbits were fed a high cholesterol diet for four weeks as the atherosclerotic group. B-mode images of the abdominal aorta with 46 frames per second were saved over three cardiac cycles at baseline and during acetylcholine or nitroglycerin drug infusion in the normal and atherosclerotic rabbits. In order to evaluate endothelial-dependent relaxation, acetylcholine-mediated dilation [AMD] was measured during the infusion of acetylcholine at a rate of 0.5 microg/kg/min and endothelial-independent relaxation was evaluated by measuring nitroglycerine-mediated dilation [NMD] during the infusion of nitroglycerin at a rate of 5 microg/kg/min. In addition, the ultrasonic evaluation was confirmed by histopathological evaluation of the abdominal aorta. Significant differences in AMD were detected between the normal and the four-week cholesterol-fed rabbits [p value < 0.05], whereas there were no significant differences in NMD between the two groups [p value > 0.05]. No microscopic intimal lesions were seen in the normal rabbits, but intimal thickening was observed in the histological studies in the four week cholesterol-fed rabbits. Additionally, the total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high density lipoprotein cholesterol levels were remarkably increased in the sera of the four-week cholesterol-fed rabbits [p value < 0.05]. A new automatic method can help accurately evaluate the endothelial function in normal and hypercholesterolemic rabbits.

[Radial motion of the carotid artery wall: a block matching algorithm approach]

During recent years, evaluating the relation between mechanical properties of the arterial wall and cardiovascular diseases has been of great importance. On the other hand, motion estimation of the arterial wall using a sequence of noninvasive ultrasonic images and convenient processing methods might provide useful information related to biomechanical indexes and elastic properties of the arteries and assist doctors to discriminate between healthy and diseased arteries. In the present study, a block matching based algorithm was introduced to extract radial motion of the carotid artery wall during cardiac cycles. The program was implemented to the consecutive ultrasonic images of the common carotid artery of 10 healthy men and maximum and mean radial movement of the posterior wall of the artery was extracted. Manual measurements were carried out to validate the automatic method and results of two methods were compared. Paired t-test analysis showed no significant differences between the automatic and manual methods [P>0.05]. There was significant correlation between the changes in the instantaneous radial movement of the common carotid artery measured with the manual and automatic methods [with correlation coefficient 0.935 and P<0.05]. Results of the present study showed that by using a semi automated computer analysis method, with minimizing the user interfere and no attention to the user experience or skill, arterial wall motion in the radial direction can be extracted from consecutive ultrasonic frames.

Carotid artery wall motion estimation from consecutive ultrasonic images: comparison between block-matching and maximum-gradient algorithms

Radial movement of the arterial wall is a well-known indicator of the mechanical properties of arteries in arterial disease examinations. In the present study, two different motion estimation methods, based on the block-matching and maximum-gradient algorithms, were examined to extract the radial displacement of the carotid artery wall. Each program was separately implemented to the same axial consecutive ultrasound images of the carotid artery of 10 healthy men, and the radial displacement waveform of this artery was extracted during two cardiac cycles. The results of the two methods were compared using the linear regression and Bland-Altman statistical analyses. The maximum and mean displacements traced by the block-matching algorithm were compared with the same parameters traced by the maximum-gradient algorithm. The frame numbers in which the maximum displacement of the wall occurred were compared too. There were no significant differences between the maximum and the mean displacements traced by the block-matching algorithm and the same parameters traced by the maximum-gradient algorithm according to the pair t-test analysis [p value > 0.05]. There was a significant correlation between the radial movement of the common carotid artery measured with the block-matching and maximum-gradient methods [with a correlation coefficient of 0.89 and p value < 0.05]. The Bland-Altman analysis results confirmed a good agreement between the two methods in measuring the radial movement, with a mean difference and limits of agreement of 0.044 +/- 0.038. The results showed that both methods found the maximum displacement occurring in the same frame. Both block-matching and maximum-gradient algorithms can be used to extract the radial displacement of the carotid artery wall and in addition, with respect to the pixel size as error, the same results can be obtained

Non invasive estimation of left ventricular normalized torsion angle in healthy persons by echo tracking algorithm: short axis view

Left ventricular [LV] torsion angle is a key parameter of cardiac performance but is difficult to measure. The purpose of this study is to describe a noninvasive imaging method for the assessment of these complex cardiac motions. In this study, left ventricular torsion angle and normalized torsion angle were estimated in the short axis view for healthy persons. We acquired basal and apical short axis left ventricular LV images in the short axis view for 14 healthy men to estimate LV torsion angle by echo tracking under a block-matching [BM] algorithm. By extracting the instantaneous changes in total displacement vector in the short axis view throughout a cardiac cycle, we calculated the instantaneous rotation and torsion angles in the short axis view. To account for differences in heart size, normalized torsion was calculated based on the radius of both the apical and basal slices in the end diastolic frame. Apical and basal rotation was measured from short axis images by automatic frame-to-frame tracking of grayscale echo patterns. The vertical and horizontal displacements of the apical level were more than those of the basal level. All data are expressed as mean +/- standard deviation [SD]. Data was tested for normal distribution and homogeneity of variance by the Kolmogorov-Smirnov test [K-S] and Levene's test respectively. The peak rotation angles of the basal and apical levels and LV torsion angle in the short axis view were 8.0 +/- 1.6°, 9.5 +/- 1.8°, and 17.3 +/- 2.5°, respectively. The normalized torsion was calculated as 7.8 +/- 1.3°, based on the basal maximum radius, the apical maximum radius, and the distance between the apical and basal levels. We conclude that the normalized torsion angle is an important biome-chanical parameter, because it is independent of heart size and distorted geometries in pathological ventricles

Developing a rabbit model of neointimal stenosis and atherosclerotic fibrous plaque rupture

A precise understanding of the mechanism of human neointimal stenoses and atherosclerotic fibrous plaques, which give rise to thromboses in vital arteries, requires a suitable animal model that would mimic the same characteristics well. We developed a rabbit model of neointimal stenosis and fibrotic plaque rupture in the carotid artery to visualize the lesion progress and to characterize the lesion types according to the American Heart Association classification. Twenty-eight healthy male New Zealand white rabbits were randomly divided into two groups: The rabbits in group A [n = 14] consumed a standard chow diet, and those in group B [n = 14] were injured via perivascular cold injury using liquid nitrogen at the right common carotid artery before being fed a high cholesterol diet [1.5%] for eight weeks. Plasma lipid evaluation was performed before the sacrificing of the rabbits. At the end of every week, at least 1 rabbit from group B was sacrificed for an analysis of lesion histopathology and calculation of the area ratios of the intima to media. The plasma lipid level in group B was significantly higher than that in group A [p value < 0.05]. The histopathological results revealed atherosclerosis characteristics such as endothelial layer destruction, fatty streaks and lipid-containing macrophages [foam cells] formation in the intima and media layers, extracellular lipid collections, smooth muscle cells proliferation and migration, neointima formation, intima thickening and deformation, fibrotic plaque formation, and finally plaque rupture. Statistical analysis revealed a significant increase in the intima-to-media ratio at the end of the eighth week [6.41 +/- 0.27, p value < 0.05]. We successfully developed a rabbit model of neointimal stenosis and atherosclerotic fibrous connective tissue plaque rupture, which is not only quickly and easily reproducible and inexpensive but also without mortality. The merits of our model render the evaluation of neointimal stenoses and fibrotic plaques and their treatment strategies more feasible in humans

Estimation of carotid artery pulse wave velocity by doppler ultrasonography

Pulse wave velocity [PWV] is widely used for estimating the stiffness of an artery. Various invasive and non-invasive methods have been developed to determine PWV over the years. In the present research, the non-invasive estimation of the PWV of large arteries was used as an index for arterial stiffness. A dynamic model based on the Navier-Stokes equations coupled to elasticity equations was introduced for the PWV in arteries with elastic walls. This system of equations was completed by clinical information obtained from the Doppler ultrasound images of the carotid artery of 40 healthy male volunteers. For this purpose, the Doppler ultrasound images were recorded and saved in a computer; and subsequently center-line blood velocity, arterial wall thickness, and arterial radius were measured by offline processing. The results from the analytic solution of the completed equations showed that the mean value of PWV for the group of healthy volunteers was 2.35 m/s when the mean arterial radius was used as the neutral radius and 5.00 m/s when the end-diastole radius was used as the neutral radius. It is noteworthy that the latter value closely complies with that reported by other researchers. By applying this method, a non-invasive clinical and local evaluation of the common carotid artery stiffness via a Doppler ultrasound measurement will be possible

Assessment of regional myocardial displacement via spectral tissue doppler compared with color tissue tracking

The recent developments in tissue Doppler imaging [TDI] now more than ever permit the quantification of the myocardial function. In the current systems, tissue tracking or displacement curves are generated from color tissue Doppler data through the instantaneous temporal integral of velocity-time curves. The purpose of the present study was to assess regional myocardial displacement via spectral TDI. Maximum myocardial velocities were extracted from spectral pulsed tissue Doppler images using a developed computer program and were integrated throughout the cardiac cycle. Spectral tissue Doppler echocardiography was performed to evaluate longitudinal and radial functions in 20 healthy men, and the calculated end-systolic displacements were subsequently compared with the displacements measured from the same areas via color tissue tracking. According to the Bland-Altman analysis between spectral tissue tracking and color tissue tracking, the significant arithmetic mean was 7.34 mm with SD mean differences of +/- 2.24 mm in all of the evaluated segments. Despite significant differences [p < 0.001], there was a good significant correlation between the two methods [r=0.79, p < 0.001]. A verification study showed that the proposed approach had the ability to assess regional myocardial displacement using spectral TDI, which can be used in a wider range of equipment than is currently possible

Association between atherosclerosis in carotid artery and elastic modulus of brachial artery

Common carotid arterial stiffness can be assessed during carotid arterial ultrasonography, but its association with brachial stiffness, a well-defined cardiovascular risk factor, has not been clarified. The aim of this study was to examine the relationship between common carotid artery and brachial artery stiffness. The static pressure-strain elastic modulus of the common carotid and brachial arteries were evaluated in 40 men with 15 healthy carotids, 15 mild carotid stenoses, and 10 severe carotid stenoses, by B-mode and Doppler ultrasonography. The local elastic modulus was estimated by the measurement of the arterial strain; the static pressure was also measured based on the peak-systolic and end-diastolic velocity in each artery. The elastic modulus of the right common carotid artery [RCCA] and right brachial artery [RBA] increased linearly with the growth of atherosclerosis from 1772 +/- 566 Pa and 26391096 +/- Pa for the normal subjects to 6168 +/- 1026 Pa and 55871592 +/- Pa for the severe stenosis group, respectively. In the three groups; healthy, mild stenosis, and severe stenosis; there was a significant difference in the elastic modulus of the right common carotid artery between the groups and also for the right brachial artery, separately [p-value<0.05]. The Pearson correlation analysis showed a significant correlation between the elastic modulus of the right common carotid artery and the elastic modulus of the right brachial artery. The brachial artery elastic modulus is associated with the common carotid elastic modulus. This study showed that atherosclerosis was a generalized process that might involve the entire vasculature. An evaluation of the elastic modulus of the RBA, however, showed that there were fundamental differences in the dynamic behavior of the brachial artery when compared to elastic arteries, such as the common carotid artery

[ quality control testing system for real time diagnostic ultrasound]

Background: Current methods of ultrasound [US] imaging quality control involve an observer taking a series of measurements on test object images

Materials and Methods: This process is rapidly becoming more so as the complexity of US scanners increases. We have designed and made a suite of programs to analyze captured US images to estimate a number of performance parameters, including dead zone, axial and lateral markers, axial and lateral resolution, focusing number, uniformity, and sensitivity in real time B-mode scanners. For checking caliper accuracy and other parameters in real time B-mode ultrasound, ultrasound propagation velocity in test object must be equal ultrasound propagation velocity in soft tissue. This is clearly that if ultrasound propagation velocity differs from scanner calibration velocity, its effect on other measurements such as resolution is well known. Therefore, we have used from salt-water, ethylene alcohol, ethylene glycol and tissue mimicking materials, and their velocities were compared and measured

Results: Images of rods were digitally captured and analyzed to obtain US performance parameters at each depth. In the current study, test object and its protocol were designed and proposed to quantitatively determine diagnostic ultrasound parameters

Conclusion: This is study, we have proposed Test object phantom with tissue mimicking materials for evaluation of ultrasound systems easily and performance able

[ quality control testing system for real time diagnostic ultrasound]

Background: Current methods of ultrasound [US] imaging quality control involve an observer taking a series of measurements on test object images

Materials and Methods: This process is rapidly becoming more so as the complexity of US scanners increases. We have designed and made a suite of programs to analyze captured US images to estimate a number of performance parameters, including dead zone, axial and lateral markers, axial and lateral resolution, focusing number, uniformity, and sensitivity in real time B-mode scanners. For checking caliper accuracy and other parameters in real time B-mode ultrasound, ultrasound propagation velocity in test object must be equal ultrasound propagation velocity in soft tissue. This is clearly that if ultrasound propagation velocity differs from scanner calibration velocity, its effect on other measurements such as resolution is well known. Therefore, we have used from salt-water, ethylene alcohol, ethylene glycol and tissue mimicking materials, and their velocities were compared and measured

Results: Images of rods were digitally captured and analyzed to obtain US performance parameters at each depth. In the current study, test object and its protocol were designed and proposed to quantitatively determine diagnostic ultrasound parameters

Conclusion: This is study, we have proposed Test object phantom with tissue mimicking materials for evaluation of ultrasound systems easily and performance able