Ultrasound in Medicine and Biology

Masthead

2012-03-01

Editorial Advisory Board

2012-03-01

Clinical Integrated Ultrasound of the Thorax Including Causes of Shock in Nontraumatic Critically Ill Patients. A Practical Approach

Roberto Copetti, Paolo Copetti, Angelika Reissig — 2012-01-24

Abstract: A rapid identification of the causes of hemodynamic instability or cardiac arrest is crucial for correct treatment. In a critical care setting, ultrasound seems to be an ideal tool for a rapid diagnosis. A multiple-goal problem-based approach represents the main peculiarity of emergency ultrasound and may be considered an extension of physical examination. The integration of data that can rapidly be obtained from the heart, lung, inferior vena cava, abdomen and leg vein examination are often essential for the diagnosis and treatment in critically ill patients. The role and potentiality of integrated ultrasound in cardiac arrest, shock/hypotension and severe dyspnea are considered in this article.

The Effect of Vasospasm on Cerebral Perfusion: A Colour Duplex Study of the Extra- and Intracranial Cerebral Arteries

2012-01-24

Abstract: To assess whether middle cerebral artery (MCA) vasospasm reduces the flow volume in the corresponding extracranial internal carotid artery (ICA) or global cerebral blood flow volume (CBFV) in subarachnoid haemorrhage (SAH) patients, a colour duplex ultrasound study of the intra- and extracranial cerebral arteries was performed. MCA vasospasm was defined as a time-averaged maximum flow velocity (TAMX) exceeding 120 cm/s. ICA flow volumes and CBFV, were compared in each patient at maximum TAMX recorded in one MCA (“maximum-vasospasm”) and when TAMX in the same vessel was closest to mean reference values (“no-vasospasm”). Additionally, the CBFV course during the first 3 weeks after SAH was evaluated longitudinally. Data from age- and gender-matched healthy test persons served as control. In 28 patients with MCA vasospasm, 337 measurements were completed. Global CBFV was significantly reduced starting from day 3 after SAH. ICA flow volumes and CBFV were not different when comparing at “maximum-vasospasm” and “no-vasospasm”. Compared with the control group, both were lower at either condition. Thus, in SAH patients, vasospasm even severe, in general does not further diminish ICA flow volumes and global CBFV, which are reduced already before the onset of vasospasm.

Ultrasound Is a Reliable Measure of Muscle Thickness in Acute Stroke Patients, for Some, but Not All Anatomical Sites: A Study of the Intra-Rater Reliability of Muscle Thickness Measures in Acute Stroke Patients

2012-01-24

Abstract: This prospective, blinded study investigates the test retest reliability of measures of muscle thickness made by one sonographer across two cohort groups (n = 29) of people hospitalised with acute stroke. Reliability was assessed in cohort one (n = 14) for measurements made bilaterally at the anterior and posterior upper arms, the anterior and posterior thighs (total of eight measurements) and in cohort two (n = 15), for measurements made bilaterally at the lateral forearms, the anterior abdominal wall and the anterior and lower legs (total of eight measurements). Reliability estimates varied between measurement sites; intraclass correlation coefficients (ICCs) ranged from –0.26 (lateral forearm, paretic side) to 0.95 (anterior thigh, nonparetic side), percent mean differences ranged from 0.42% (posterior upper arm, nonparetic side) to 14.68% (anterior lower limb, nonparetic side) and method error ranged from 1.08 (abdomen, nonparetic side) to 9.69 mm (posterior lower limb, nonparetic side). Only four measurement sites (anterior upper arm, posterior upper arm, abdomen and anterior thigh) were within the acceptable ranges (ICC 0.60 to 1.00, mean percent difference range 0%–5% and method error range 0–5 mm) and considered reliable to use for measures of muscle thickness in people hospitalised with acute stroke.

Detection of Hepatocellular Carcinoma and Liver Metastases with BR14: A Multicenter Phase IIA Study

2012-01-20

Abstract: The study was designed primarily to find the optimal dosage range of BR14 contrast-enhanced ultrasonography (CEUS) to detect malignant focal liver lesions. Secondary objectives were the evaluation of the safety profile and comparison with contrast-enhanced MRI (CE MRI). We studied 25 patients (9 females, 16 males, mean age, 66 years) with known hepatocellular carcinoma or liver metastases at 3 centers over a 3-month period. Each patient underwent a baseline examination and at least 3 CEUS examinations with ascending dose levels (0.25 mL; 1.0 mL; 4.0 mL) of BR14. CE MRI was performed 4 weeks before or after the CEUS examination. Dedicated liver maps were used to record the location, size, and type of detected lesions. Examination quality was documented and safety parameters were assessed. The number of lesions detected by BR14 CEUS increased with dosage, whereas the number of missed lesions and the lesion sizes decreased. Despite the increasing contrast enhancement, substantial differences among dosages were not seen for other image quality parameters. No significant changes were noted in safety parameters and no serious adverse events were reported. We conclude that the recommended dose level of BR14 is between 1 mL and 4 mL; at this dosage, lesion detection is comparable to that of CE MRI.

Heterogeneity of Microbubble Accumulation: A Novel Approach to Discriminate Between Well-Differentiated Hepatocellular Carcinomas and Regenerative Nodules

2012-01-20

Abstract: This prospective study aimed to elucidate the possibility of differentiating well-differentiated hepatocellular carcinoma (wHCC) from regenerative nodule (RN) on the basis of the heterogeneity of microbubble accumulation. Intensity analysis was conducted on early-phase and late-phase (60 s and 900 s post-injection; perflubutane microbubble) harmonic sonograms in 33 focal hepatic lesions (≤15 mm; 30 patients with chronic liver disease) that were histologically proven as wHCC or RN. Heterogeneity of enhancement, an average of standard deviation of late-phase enhancement in three different sections in the lesions with late-phase iso-enhancement, was examined with respect to the histologic findings. Heterogeneity of enhancement was higher in wHCC (28.7 ± 3.8) than RN (19.8 ± 2.1, p = 0.0213) in the 29 late-phase iso-enhancement lesions. The best cut-off value of the heterogeneity for the diagnosis of wHCC was 25.58, and the sensitivity and specificity were 77.8% and 100%, respectively. A novel parameter, heterogeneity of microbubble accumulation, facilitates differentiation between wHCC and RN showing a late-phase, iso-enhancement appearance.

Real-Time Tissue Elastography for the Diagnosis of Lymph Node Metastasis in Oral Squamous Cell Carcinoma

2012-01-24

Abstract: We compared conventional ultrasound (US) B-mode, color Doppler and elastographic assessment of lymph node (LN) stiffness against pathological findings from surgical samples, to determine the most useful factors for identifying LN metastases. Seventy-one LNs in 19 patients with oral squamous cell carcinoma (OSCC) were examined. Using our new system, elastography images were scored from 1–5. The score 1–4 were correlated with the blue area of each LN, which indicated increased stiffness: (1) none; (2) <50%; (3) 50%; or (4) >50%. A score 5 indicated central necrosis and did not correlate with the blue area. We found significant differences in minimal diameter, shape index, margin, internal structure, hilus presence or absence, elastography score and percentage of blue area between metastatic and nonmetastatic LNs. Stepwise regression analysis identified elastography score 3–5 as an independent significant LN metastatic factor, suggesting that our scoring system may be useful for accurately diagnosing metastatic LNs.

Transvaginal 3-D Power Doppler Ultrasound Evaluation of the Fetal Brain at 10–13 Weeks’ Gestation

Toshiyuki Hata, Hirokazu Tanaka, Junko Noguchi — 2012-01-20

Abstract: The objective of this study was to measure the fetal brain volume (FBV) and vascularization and blood flow using transvaginal 3-D power Doppler (3DPD) ultrasound late in the first trimester of pregnancy. 3DPD ultrasound examinations with the VOCAL imaging analysis program were performed on 36 normal fetuses from 10–13 weeks’ gestation. FBV and 3DPD indices related to the fetal brain vascularization (vascularization index [VI], flow index [FI] and vascularization flow index [VFI]) were calculated in each fetus. Intra- and interclass correlation coefficients and intra- and interobserver agreements of measurements were assessed. FBV was curvilinearly correlated well with the gestational age (R2 = 0.861, p < 0.0001). All 3-D power Doppler indices (VI, FI and VFI) showed no change at 10–13 weeks’ gestation. FBV and all 3-D power Doppler indices (VI, FI and VFI) showed a correlation >0.82, with good intra- and interobserver agreement. Our findings suggest that 3-D ultrasound is a superior means of evaluating the FBV in utero, and that 3-D power Doppler ultrasound histogram analysis may provide new information on the assessment of fetal brain perfusion.

Measurement of Articular Cartilage Thickness Using a Three-Dimensional Image Reconstructed from B-Mode Ultrasonography Mechanical Scans Feasibility Study by Comparison with MRI-Derived Data

2012-01-20

Abstract: The present study aimed to develop a method to measure three-dimensional (3-D) thickness of cartilage (Tc) at the femoral condyle using B-mode ultrasonography (US) and to clarify the feasibility of US in clinical evaluations of articular cartilage by comparing the results with 3-D measurement values using magnetic resonance imaging (MRI) and assessing repeatability. The medial surface of the right knees of two healthy male volunteers (age, 37 and 59 years) and the knees on affected side of three male patients with osteoarthritis (OA) (age, 73, 81 and 83 years) were scanned using B-mode US with the knee flexed at 120°. The range of the angle of probe rotation for the arm was 0-80° and B-mode images (total, 101 images) were acquired every 0.8°. MRI of the knees was also performed using the double echo steady-state sequence. Both US and MRI images were used to create 3-D models of medial femoral condyle articular cartilage. Tc was determined at points 1 mm apart from one another in the US model (Tc-US) and MRI model (Tc-MRI). Tc-US was compared with Tc-MRI and the repeatability of Tc-US was assessed by mean Tc in the specific region of interest of the femoral condyle. Tc-US correlated significantly with Tc-MRI both in volunteers and in OA patients (p < 0.0001 each) and coefficients of correlation were 0.976 and 0.964 for volunteers and OA patients, respectively. The coefficient of variance for mean Tc-US was 4.90%. Our results show that 3-D US measurements of femoral cartilage are reproducible and correlate strongly with MRI measurements.

Ultrasonographic Evidence of Intra-Abdominal Umbilical Vein Dilatation: Is It a True Varix?

Yoni Cohen, Joseph Har-Tov, Gideon Fait, Igal Wolman, Ariel Jaffa — 2012-01-20

Abstract: Fetal intraabdominal umbilical vein (FIUV) dilatation, or varix, is a rare ultrasonographic (US) finding of focal dilatation of the umbilical vein. This article describes FIUV tortuosity in cases with suspected varix and provides ultrasonographic criteria for its diagnosis. Cases of suspected FIUV varix referred to our unit for final diagnosis and follow-up were studied. Each woman underwent comprehensive US evaluations that included basic grayscale scan and color Doppler scan. In 12 singleton pregnancies, primary grayscale scan confirmed FIUV dilatation. Supplementary color Doppler scans, however, revealed linear bidirectional blood flow and FIUV tortuosity in all cases. Color Doppler scans did not depict true FIUV dilatations or varix but rather a tortuous course of the vein. A normal pregnancy outcome can be expected in these cases.

Ultrasound Markers that Describe Plaques Are More Sensitive than Mean Intima-Media Thickness in Patients with Familial Hypercholesterolemia

2012-01-20

Abstract: A widely adopted ultrasound surrogate marker for predicting cardiovascular risk is mean intima-medial thickness (mean-IMT). There are, however, certain limitations to this methodology. We compared the severity of carotid atherosclerosis in adult patients with high cardiovascular risk (patients with familial hypercholesterolemia [FH] and without previous statin treatment) and in their adult FH-free first-degree relatives using not only mean-IMT, but also maximum-IMT, plaque number, plaque score and percent area stenosis. Mean-IMT has not differed in both groups (0.64 ± 0.18 mm vs. 0.58 ± 0.13 mm in the control group, p = 0.349). Maximum-IMT (0.99 ± 0.35 vs. 0.76 ± 0.19, p = 0.0057), plaque number (3 ± 3 vs. 1 ± 2, p = 0.0009), plaque score (5.14 ± 4.97 mm vs. 1.58 ± 3.09 mm, p = 0.0009) and percent area stenosis (38% ± 22% vs. 12% ± 20%, p = 0.0004) were significantly higher for FH patients than for their relatives. We have demonstrated that plaque number, plaque score and percent area stenosis markers were more sensitive than mean-IMT for cardiovascular risk estimation in patients with familial hypercholesterolemia.

High-Frequency Ultrasound in the Evaluation of Cerebral Intraventricular Haemorrhage in Preterm Rabbit Pups

Snjolaug Sveinsdottir, Magnus Cinthio, David Ley — 2012-03-01

Abstract: Cerebral intraventricular haemorrhage (IVH) is the most common cause of severe neurologic impairment following preterm birth in human infants. Ideally, an animal model for cerebral IVH should allow for reliable noninvasive evaluation of haemorrhagic extension and of subsequent development of posthaemorrhagic ventricular dilatation (PHVD). The aim of this study was to evaluate the use of high-frequency ultrasound (HFU) in premature rabbit pups with cerebral IVH induced by IP glycerol injection. Serial examinations using HFU enabled an accurate description of haemorrhagic extension and measurement of progressive PHVD over 72 h. The coefficient of variation for inter- and intraobserver variability in two measurements of ventricular size was less than 8.8% and 9.3%, respectively. Repeated ultrasound-guided intraventricular injection and sampling could be performed in vivo excluding requirement of stereotactic procedures and sedation. Application of HFU is a powerful tool for the evaluation of mechanisms involved in cerebral IVH and PHVD in the preterm rabbit pup model.

High-Frequency Ultrasound for In Vivo Measurement of Colon Wall Thickness in Mice

2012-01-24

Abstract: Mouse models are becoming increasingly important in the study of molecular mechanisms of colorectal disease and in the development of novel therapeutics. To enhance this phase of preclinical research, cost-effective, easy to use noninvasive imaging is required to detect and monitor changes in the colon wall associated with disease pathology. This study investigated the feasibility of using 40-MHz (high frequency) B-mode ultrasound (HF-US) to image the normal mouse colon and measure its thickness in vivo by establishing a robust imaging protocol and conducting a blinded comparison of colon wall thickness (CWT) measurement between and within operators. The in vivo and ex vivo appearance of mouse colon under HF-US revealed distinct patterns. Colon wall thickness was reproducibly and accurately measured using HF-US compared with histology measurement. The technique was more sensitive in detecting changes in CWT in distal than proximal colon as it showed the highest level of inter- and intraoperator reproducibility. Using the protocol described, it is possible to detect changes in thickness of 0.09 mm and 0.25 mm in distal and proximal colon, respectively. In conclusion, HF-US provides an easy to use and noninvasive method to perform anatomical investigations of mouse colon and to monitor changes in CWT.

Differentiation of Benign Periablational Enhancement from Residual Tumor Following Radio-Frequency Ablation Using Contrast-Enhanced Ultrasonography in a Rat Subcutaneous Colon Cancer Model

2012-01-24

Abstract: Benign periablational enhancement (BPE) response to thermal injury is a barrier to early detection of residual tumor in contrast enhanced imaging after radio-frequency (RF) ablation. The objective of this study was to evaluate the role of quantitative of contrast-enhanced ultrasound (CEUS) in early differentiation of BPE from residual tumor in a BD-IX rat subcutaneous colon cancer model. A phantom study was first performed to test the validity of the perfusion parameters in predicting blood flow of two US contrast imaging modes—contrast harmonic imaging (CHI) and microflow imaging (MFI). To create a simple model of BPE, a peripheral portion of the tumor was ablated along with surrounding normal tissue, leaving part of the tumor untreated. First-pass dynamic enhancement (FPDE) and MFI scans of CEUS were performed before ablation and immediately, 1, 4 and 7 days after ablation. Time-intensity-curves in regions of BPE and residual tumor were fitted to the function , in which A, β, t0 and C represent blood volume, flow speed, time to start and baseline intensity, respectively. In the phantom study, positive linear correlations were noted between A, β, Aβ and contrast concentration, speed and flow rate, respectively, in both CHI and MFI. On CEUS images of the in vivo study, the unenhanced ablated zone was surrounded by BPE and irregular peripheral enhancement consistent with residual tumor. On days 0, 4 and 7, blood volume (A) in BPE was significantly higher than that in residual tumor in both FPDE imaging and MFI. Significantly greater blood flow (Aβ) was seen in BPE compared with residual tumor tissue in FPDE on day 7 and in MFI on day 4. The results of this study demonstrate that qualitative CEUS can be potentially used for early detection of viable tumor in post-ablation assessment.

New Microembolus Size Estimator for Peripheral Blood Vessels

Jakub Zmigrodzki, Krzysztof Kaluzynski — 2012-03-01

Abstract: Several factors affecting the power of Doppler scattered signal and, consequently, microembolus size estimation, may be eliminated when assessing the microembolus size via multiple measurements. A new microembolus size estimator is proposed based on the ratio of microembolus scattering cross-section in two directions and for two emission frequencies. Theoretical considerations indicate that the estimation of size of microembolic elements should be independent of the spatial distribution of the wave intensity, tissue attenuation and hardware factors. The simulation results indicate that this estimation only slightly depends on the material of the microembolus and acoustic properties of blood. The experimental results indicate that the accuracy of median size estimation increases with microembolus size. The measurement error is less than 27% for microemboli with median diameter larger than 360 μm. The method is constrained to the estimation of microembolus size in the vessels of extremities.

Simultaneous Measurement of Red Blood Cell Aggregation and Whole Blood Coagulation Using High-Frequency Ultrasound

Kweon-Ho Nam, Eunseop Yeom, Hojin Ha, Sang Joon Lee — 2012-01-24

Abstract: This study aims to investigate the feasibility of using high-frequency ultrasound (HFUS) for simultaneous monitoring of blood coagulation and red blood cell (RBC) aggregation. Using a 35-MHz ultrasound scanner, ultrasound speckle data were acquired from whole blood samples of three experimental groups of rats, including 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS)-treated, noncoagulation and normal control groups. The variations of blood echogenicity, the shape parameters of probability distribution of speckle intensity (skewness and kurtosis) and the correlation coefficient between two consecutive speckle data were calculated as a function of time starting from immediately after taking blood. The blood echogenicity increases rapidly to plateaus at the early stage of measurement for all the experimental groups caused by the formation of RBC aggregates. The DIDS-treated group exhibits the lowest echogenicity level due to the inhibitory effect of DIDS on RBC aggregation. The correlation analysis between consecutive speckle patterns seems to be useful to examine the variation of blood fluidity and the progress of clot formation. Whole blood coagulation is observed to be accelerated by DIDS treatment. In addition, the results of skewness and kurtosis analysis indicated that RBC aggregates may be disrupted during blood coagulation. The present study suggests that HFUS has good potential for simultaneous monitoring of RBC aggregation and blood coagulation to examine the relationship between them.

Effect of Ultrasound Parameters on the Release of Liposomal Calcein

2012-01-24

Abstract: The ultrasound exposure parameters that maximize drug release from dierucoyl-phosphatidylcholine (DEPC)-based liposomes were studied using two transducers operating at 300 kHz and 1 MHz. Fluorescent calcein was used as a model drug, and the release from liposomes in solution was measured using a spectrophotometer. The release of calcein was more efficient at 300 kHz than at 1 MHz, with thresholds of peak negative pressures of 0.9 MPa and 1.9 MPa, respectively. Above this threshold, the release increased with increasing peak negative pressure, mechanical index (MI), and duty cycle. The amount of drug released followed first-order kinetics and increased with exposure time to a maximal release. To increase the release further, the MI had to be increased. The results demonstrate that the MI and the overall exposure time are the major parameters that determine the drug’s release. The drug’s release is probably due to mechanical (cavitation) rather than thermal effects, and that was also confirmed by the detection of hydroxide radicals.

The Relation Between Carotid Plaque Echogenicity and Oxidative Stress Marker 8-iso-Prostaglandin F2α

2012-01-20

Abstract: Echolucent plaques are associated with high risk of ischemic cerebrovascular events. Oxidative stress has been implicated in the process of atherosclerotic plaque development from initiation to progression. We assessed the relation between carotid plaque echogenicity and urinary 8-iso-prostaglandin F2α, as an index of oxidative stress. This cross-sectional study was conducted prospectively on 290 consecutive outpatients. Each patient was evaluated for carotid plaque echogenicity using the gray-scale median at the maximal thickness plaque and urinary 8-iso-prostaglandin F2α using enzyme linked immunosorbent assay. By Pearson correlation analysis, we found significant negative linear relation between gray-scale median values and the urinary 8-iso-prostaglandin F2α levels (r = −0.133, p = 0.023). This correlation remained significant after adjustment for atherosclerotic risk factors, thickness of the maximal plaque and medication use (β = −0.137, p = 0.031). We herein show that higher levels of urinary 8-iso-prostaglandin F2α is associated with lower plaque echogenicity.

Effect of Surface Architecture on In Vivo Ultrasound Contrast Persistence of Targeted Size-Selected Microbubbles

Cherry C. Chen, Shashank R. Sirsi, Shunichi Homma, Mark A. Borden — 2012-03-01

Abstract: Ultrasound molecular imaging is a powerful diagnostic modality using microbubbles coated with targeting ligands specific for endothelial biomarkers. The circulation persistence of ligand-bearing contrast agents is a key determinant in their contrast enhancement and targeting capability. Prior studies have shown that targeted microbubbles with ligands attached to the shell using the conventional exposed-ligand architecture (ELA) could trigger undesired ligand-induced complement activation and decreased circulation time. Microbubbles with the buried-ligand architecture (BLA), however, were found to inhibit complement activation and prolong circulation time. In the present study, we extended the stealth BLA microbubble design to size-selected (4 to 5-μm diameter) microbubbles targeted with cyclic RGD peptide using the postlabeling technique. Microbubble circulation persistence was measured in the healthy mouse kidney using a Visualsonics Vevo 770 scanner operating at 40 MHz in fundamental mode. The circulation persistence for targeted BLA microbubbles was significantly longer compared with their ELA counterparts and similar to no-ligand controls. Use of the BLA instead of the ELA increased the circulation half-life approximately two-fold. Analysis of the time-intensity and time-fluctuation curves with a two-compartment pharmacokinetic model showed a minimal degree of nonspecific vascular adhesion for any group. These results demonstrate the importance of surface architecture in the design of targeted microbubbles for ultrasound molecular imaging.

Microbubble Contrast Imaging of the Cardiovascular System of the Chick Embyro

Michael A. Schellpfeffer, Gary L. Kolesari — 2012-01-24

Abstract: Ultrasound imaging of the chick embryo cardiovascular system is limited to B-scan and Doppler technologies. This study demonstrates microbubble contrast imaging of the embryonic cardiovascular anatomy and physiology. Day 8–19 (Hamburger & Hamilton Stage 34–43) chick embryos are examined in ovo using high-frequency ultrasound imaging through an opening in the blunt end (air cell) of the egg. A chorioallantoic vein is cannulated, and small boluses of octofluoropropane lipid microspheres (Definity®) are injected to visualize the chick embryo cardiovascular system. The entire chick embryo cardiovascular system including the two embryologic arteriovenous (AV) shunts can be visualized. More accurate physiologic measurements of ejection fractions and cardiac output measurements can be obtained using this technology. Microbubble contrast ultrasound imaging in the chick embryo greatly expands the ability to study cardiovascular development. Also, the two natural embryonic A-V shunts provide an excellent model to study the bioeffects of microbubbles in the arterial system.

A New Nonlinear Parameter in the Developed Strain-to-Applied Strain of the Soft Tissues and Its Application in Ultrasound Elasticity Imaging

2012-01-24

Abstract: Strain developed under quasi-static deformation has been mostly used in ultrasound elasticity imaging (UEI) to determine the stiffness change of tissues. However, the strain measure in UEI is often less sensitive to a subtle change of stiffness. This is particularly true for Crohn’s disease where we have applied strain imaging to the differentiation of acutely inflamed bowel from chronically fibrotic bowel. In this study, a new nonlinear elastic parameter of the soft tissues is proposed to overcome this limit. The purpose of this study is to evaluate the newly proposed method and demonstrate its feasibility in the UEI. A nonlinear characteristic of soft tissues over a relatively large dynamic range of strain was investigated. A simplified tissue model based on a finite element (FE) analysis was integrated with a laboratory developed ultrasound radio-frequency (RF) signal synthesis program. Two-dimensional speckle tracking was applied to this model to simulate the nonlinear behavior of the strain developed in a target inclusion over the applied average strain to the surrounding tissues. A nonlinear empirical equation was formulated and optimized to best match the developed strain-to-applied strain relation obtained from the FE simulation. The proposed nonlinear equation was applied to in vivo measurements and nonlinear parameters were further empirically optimized. For an animal model, acute and chronic inflammatory bowel disease was induced in Lewis rats with trinitrobenzene sulfonic acid (TNBS)-ethanol treatments. After UEI, histopathology and direct mechanical measurements were performed on the excised tissues. The extracted nonlinear parameter from the developed strain-to-applied strain relation differentiated the three different tissue types with 1.96 ± 0.12 for normal, 1.50 ± 0.09 for the acutely inflamed and 1.03 ± 0.08 for the chronically fibrotic tissue. T-tests determined that the nonlinear parameters between normal, acutely inflamed and fibrotic tissue types were statistically significantly different (normal/ fibrotic [p = 0.0000185], normal/acutely inflamed [p = 0.0013] and fibrotic/acutely inflamed [p = 0.0029]). This technique may provide a sensitive and robust tool to assess subtle stiffness changes in tissues such as in acutely inflamed bowel wall.

A Texture Matching Method Considering Geometric Transformations in Noninvasive Ultrasonic Measurement of Arterial Elasticity

Lili Niu, Ming Qian, Ruibo Song, Long Meng, Xin Liu, Hairong Zheng — 2012-01-24

Abstract: Measurement of arterial elasticity can provide an important reference for understanding arterial wall changes that may occur in the early stages of atherosclerosis. Conventional correlation-based methods for evaluating arterial wall movements consider only the translation, ignoring the rotation and deformation, which limits the accuracy of measurement of arterial displacement and its biomechanical properties. This article proposes a novel texture matching method based on ultrasonic B-mode image considering geometric transformations to accurately measure arterial displacement and acquire arterial elasticity noninvasively. The method was validated by simulated images with rotation and deformation and further by measurements in vitro arterial phantom and in vivo common carotid arteries of 20 healthy volunteers. Simulation results demonstrate that the method can improve the accuracy of measurement of arterial displacement. Experimental results show that the elastic modulus of the arterial phantom agrees well with the results obtained from mechanical tests, deviating only 4.1%. The mean elastic modulus of the common carotid arteries is 361.7 ± 93.5 kPa. The texture matching method was shown to be able to measure the displacement and elasticity of the arterial wall with complex geometric transformations and may be clinically useful for early detecting and monitoring atherosclerosis.

Fetal Echocardiography, 2nd Edition

Christine S. Sahn, David J. Sahn — 2012-01-20

The second edition of the textbook Fetal Echocardiography, by Julia Drose, includes many of the same contributors as the first edition, published in 1998, but represents a substantial improvement as it has been brought up to date with many expanded features. The new text is well-organized, with chapters dedicated to defining normal anatomy, as well as chapters dedicated to every type of major fetal heart malformation. Each chapter has been updated and many images that were in gray-scale in the first edition have been changed to color with enhanced resolution. Additionally, the line art has been redrawn in full color.

Calendar

2012-03-01

Ultrasound in Medicine and Biology

Masthead

Editorial Advisory Board

Contents

Clinical Integrated Ultrasound of the Thorax Including Causes of Shock in Nontraumatic Critically Ill Patients. A Practical Approach

The Effect of Vasospasm on Cerebral Perfusion: A Colour Duplex Study of the Extra- and Intracranial Cerebral Arteries

Ultrasound Is a Reliable Measure of Muscle Thickness in Acute Stroke Patients, for Some, but Not All Anatomical Sites: A Study of the Intra-Rater Reliability of Muscle Thickness Measures in Acute Stroke Patients

Detection of Hepatocellular Carcinoma and Liver Metastases with BR14: A Multicenter Phase IIA Study

Heterogeneity of Microbubble Accumulation: A Novel Approach to Discriminate Between Well-Differentiated Hepatocellular Carcinomas and Regenerative Nodules

Real-Time Tissue Elastography for the Diagnosis of Lymph Node Metastasis in Oral Squamous Cell Carcinoma

Transvaginal 3-D Power Doppler Ultrasound Evaluation of the Fetal Brain at 10–13 Weeks’ Gestation

Measurement of Articular Cartilage Thickness Using a Three-Dimensional Image Reconstructed from B-Mode Ultrasonography Mechanical Scans Feasibility Study by Comparison with MRI-Derived Data

Ultrasonographic Evidence of Intra-Abdominal Umbilical Vein Dilatation: Is It a True Varix?

Ultrasound Markers that Describe Plaques Are More Sensitive than Mean Intima-Media Thickness in Patients with Familial Hypercholesterolemia

High-Frequency Ultrasound in the Evaluation of Cerebral Intraventricular Haemorrhage in Preterm Rabbit Pups

High-Frequency Ultrasound for In Vivo Measurement of Colon Wall Thickness in Mice

Differentiation of Benign Periablational Enhancement from Residual Tumor Following Radio-Frequency Ablation Using Contrast-Enhanced Ultrasonography in a Rat Subcutaneous Colon Cancer Model

New Microembolus Size Estimator for Peripheral Blood Vessels

Simultaneous Measurement of Red Blood Cell Aggregation and Whole Blood Coagulation Using High-Frequency Ultrasound

Effect of Ultrasound Parameters on the Release of Liposomal Calcein

The Relation Between Carotid Plaque Echogenicity and Oxidative Stress Marker 8-iso-Prostaglandin F2α

Effect of Surface Architecture on In Vivo Ultrasound Contrast Persistence of Targeted Size-Selected Microbubbles

Microbubble Contrast Imaging of the Cardiovascular System of the Chick Embyro

A New Nonlinear Parameter in the Developed Strain-to-Applied Strain of the Soft Tissues and Its Application in Ultrasound Elasticity Imaging

A Texture Matching Method Considering Geometric Transformations in Noninvasive Ultrasonic Measurement of Arterial Elasticity

Fetal Echocardiography, 2nd Edition

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