M-mode Imaging Research Articles

Reference values for 2-dimensional and M-mode echocardiography in Friesian and Warmblood horses.

BackgroundEchocardiographic reference intervals for Friesian horses are poorly described.ObjectivesTo obtain reference intervals for echocardiographic measurements in Friesians and compare these with Warmbloods.AnimalsOne hundred healthy adult Friesians and 100 healthy adult Warmblood horses.MethodsCross‐sectional study. Two‐dimensional and M‐mode echocardiographic images were obtained. Echocardiographic measurements, including size, area, and volumetric measurements of left atrium, left and right ventricle, aorta, and pulmonary artery, were performed. Measurements were compared between the 2 breeds using an independent samples t test with Bonferroni correction for multiple comparisons.ResultsReference ranges for standard echocardiographic measurements in Friesians were obtained. Several left ventricular measurements were significantly smaller in Friesians compared to Warmbloods, such as the left ventricular end‐diastolic volume using the 4‐chamber modified Simpsons' method (99.85% confidence interval for the difference [CI] = −245 to −63). Also the right ventricular end‐diastolic and peak‐systolic internal diameter were smaller in Friesians (99.85% CI = −1.33 to −0.6 and 99.85% CI = −1.54 to −0.76, respectively). Fractional shortening (99.85% CI = 0.61‐6) and ejection fraction (99.85% CI = 0.21‐4.6) were significantly larger. No structural effects of systemic hypertension, such as concentric hypertrophy, were detected.Conclusions and Clinical ImportanceOur study provides reference intervals for echocardiographic measurements in Friesians useful in a clinical setting. In general, the left ventricular dimensions in Friesians were significantly smaller compared to Warmbloods, emphasizing the need for breed‐specific reference intervals.

Aortic adventitial thickness as a marker of aortic atherosclerosis, vascular stiffness, and vessel remodeling in systemic lupus erythematosus.

There is limited human imaging data on the association of adventitial thickness (AT) with arterial disease. Systemic lupus erythematosus (SLE) is a prototypical disease model for studying markers of premature arterial disease. To determine if increased aortic AT is associated with aortic atherosclerosis [increased intima media thickness (IMT) or plaques], stiffness [increased pressure-strain elastic modulus (PSEM)], and vessel remodeling. In total, 70 SLE patients and 26 age- and sex-matched controls underwent transesophageal echocardiography (TEE). Two-dimensional guided M-mode images were obtained to assess AT, IMT, and plaques, and PSEM at the proximal, mid, and distal thoracic aorta. Images were interpreted by 3 observers unaware of the subjects' clinical data and each other's measurements. Abnormal aortic AT, IMT, and PSEM were defined as > 2SD above the overall mean values in controls and corresponded to > 1 mm, > 1 mm, and > 10.6 Pascal units, respectively. Plaques were defined as focal-protruding IMT > 50% of the surrounding vessel wall. Abnormal aortic AT, atherosclerosis, and abnormal stiffness were more frequent in SLE patients than in controls (all p ≤ 0.02). In SLE patients, abnormal AT combined with atherosclerosis was associated with larger aortic end-diastolic diameters than in controls (p ≤ 0.05). In SLE patients, aortic AT was greater in patients with atherosclerosis and in those with abnormal stiffness than in patients without these abnormalities (all p ≤ 0.02). In patients with abnormal AT, the degree of aortic stiffness was similar to those with atherosclerosis (p = 0.22). In patients with SLE, increased aortic AT is associated with aortic atherosclerosis, abnormal stiffness, and eccentric vessel remodeling. Key Points • In patients with SLE, abnormal aortic adventitial thickness is associated with aortic atherosclerosis, abnormal stiffness, and eccentric vessel remodeling. • In patients with SLE, aortic adventitial thickening may contribute to the extent of aortic atherosclerosis, abnormal aortic stiffness, and vessel remodeling. • To our knowledge, this is the first human imaging study to characterize the aortic adventitial layer and delineate its association with aortic disease.

Feasibility and Reliability of Automatic Quantitative Analyses of Mitral Annular Plane Systolic Excursion by Handheld Ultrasound Devices: A Pilot Study.

Handheld ultrasound devices (HUDs) have previously been limited to grayscale imaging without options for left ventricle (LV) quantification. We aimed to study the feasibility and reliability of automatic measurements of mitral annular plane systolic excursion (MAPSE) by HUDs. An algorithm that automatically measured MAPSE from live grayscale recordings was implemented in a HUD. Twenty patients at a university hospital were examined by either a cardiologist or a sonographer. Standard echocardiography using a high-end scanner was performed. The apical 4-chamber view was recorded 4 times by both echocardiography and the HUD. MAPSE was measured by M-mode and color tissue Doppler (cTD) during echocardiography and automatically by the HUD. The automatic method underestimated mean MAPSE ± SD versus M-mode (9.6 ± 2.2 versus 10.9 ± 2.6 mm; difference, 1.2 ± 1.4 mm, P < .005). The difference between the automatic and cTD measurements was not significant (0.8 ± 1.8 mm; P = .073). The intraclass correlation coefficients (ICCs) between automatic and M-mode measurements was 0.85, and 0.81 for cTD measurements. There was good agreement between the methods, and the intra- and inter-rater ICCs were excellent for all methods (≥0.86). In this novel study evaluating automatic quantification of LV longitudinal function by HUD, we showed the high feasibility and reliability of the method. Compared to M-mode imaging, the automatic method underestimated MAPSE by 8% to 10%, but the difference with cTD imaging was nonsignificant. We conclude that this study's method for automatic quantitative assessment of LV function can be integrated in HUDs.

M-mode Ultrasound Detects Changes In Lumbopelvic-hip Muscle Activity Using Body Mass Normalization Technique

M-mode or motion mode allows for non-invasive assessment of contractile tissue movement from echogenicity changes. This method has been used in muscles surrounding the lumbopelvic-hip complex, including the gluteals, however this measurement has not been explored to our knowledge in the rectus abdominis, external oblique, or erector spinae. A normalization technique has not been utilized for M-mode to ensure proper comparison within and between groups as normalization strategies have been applied with other musculoskeletal ultrasound techniques, such as B-mode imaging. PURPOSE: To determine activity ratio and timing of rectus abdominis (RA), external oblique (EO), erector spinae (ES), gluteus maximus (Gmax), and gluteus medius (Gmed) with a body mass normalization technique. METHODS: Ten healthy, physically active individuals with no history of low back or lower extremity injury (21.1±0.7yrs, 67.1±14.8kg, 168.1±6.9cm, 5F) participated in this study. B-mode ultrasound images were collected at rest and during contraction: supine, hook-lying for RA and EO; prone for ES; and side-lying for Gmax and Gmed. Thickness from B- and M-mode images were normalized to body mass (kg) and timing of M-mode was measured in seconds (s). Contracted muscle thickness was divided by rested muscle thickness to calculate activity ratios from B-mode images. Paired t-tests were used to compare activity ratios and contraction timing (cm-s/kg) between muscles. RESULTS: There were no significant differences (p>.05) between activity ratios, although the EO had the largest activity (1.66±0.72). The RA followed with the second highest activity ratio (1.48±0.38), then ES (1.34±0.43), Gmed (1.30±0.51), and finally Gmax (1.06±0.27). ES exhibited the greatest output from the M-mode normalization technique (0.019± 0.004cm-s/kg) and EO had the least at 0.0053±0.002cm-s/kg (p<.001). CONCLUSIONS: The anterior musculature assessed, EO and RA, generated the largest activity ratios, while ES and EO had the greatest disparity detected during motion. The balance of activity between anterior and posterior muscles of the lumbopelvic-hip complex should be noted especially with M-mode activity with this body mass normalization application as the variance in size of muscle plays a major role in how ultrasound data may be interpreted.

Rapid, Single-View Speckle-Tracking-Based Method for Examining Left Ventricular Systolic and Diastolic Function in Point of Care Ultrasound.

A rapid, reliable quantitative assessment of left ventricular systolic and diastolic function is important for patient treatment in urgent and dynamic settings. Quantification of annular velocities based on a single 2-dimensional image loop, rather than on Doppler velocities, could be useful in point-of-care or focused cardiac ultrasound. We hypothesized that novel speckle-tracking-based mitral annular velocities would correlate with reference standard tissue Doppler imaging (TDI) velocities in a focused cardiac ultrasound-esque setting. Two echocardiographers each performed transthoracic echocardiographic measurements before and after induction of anesthesia in supine patients undergoing cardiac surgery. Speckle-tracking echocardiography (STE)-based systolic (S'STE ) and diastolic (E'STE and A'STE ) velocities were compared to TDI and global longitudinal strain/strain rate. We also compared mitral annular displacement by speckle tracking with M-mode imaging. Twenty-five patients were included and examined in both preinduction and postinduction states. Speckle-tracking-based velocities correlated with TDI measurements in both states (S', r = 0.73 and 0.76; E', r = 0.87 and 0.65; and A', r = 0.65 and 0.73), showing a mean bias of 25% to 30% of the reference standard measurement. The correlation of S'STE with strain and the strain rate (S-wave) and E'STE with the strain rate (E-wave) was good in awake, spontaneously breathing patients but was less strong in the ventilated state. Similarly, displacement by speckle tracking correlated with M-mode measurements in both states (r = 0.91 and 0.84). Measurements required medians of 31 and 34 seconds; reproducibility was acceptable for S'STE and E'STE . Speckle-tracking-based mitral annular velocities and displacement correlate well with conventional measures as well as with deformation imaging. They may be clinically useful in rapidly assessing both systolic and diastolic function from a single 2-dimensional image loop.

Lung Ultrasound for Cardiologists in the Time of COVID-19

Lung ultrasound (LUS) is a point-of-care ultrasound technique used for its portability, widespread availability, and ability to provide real-time diagnostic information and procedural guidance. LUS outperforms lung auscultation and chest X-ray, and it is an alternative to chest computed tomography in selected cases. Cardiologists may enhance their physical and echocardiographic examination with the addition of LUS. We present a practical guide to LUS, including device selection, scanning, findings, and interpretation. We outline a 3-point scanning protocol using 2-dimensional and M-mode imaging to evaluate the pleural line, pleural space, and parenchyma. We describe LUS findings and interpretation for common causes of respiratory failure. We provide guidance specific of COVID-19, which at the time of writing is a global pandemic. In this context, LUS emerges as a particularly useful tool for the diagnosis and management of patients with cardiopulmonary disease.

Ultrasound diaphragmatic manual and semi-automated motion measurements: Application in simulated and in vivo data of critically ill subjects

Background and ObjectiveUltrasound diaphragmatic muscle motion characteristics may provide useful information about normal or abnormal diaphragmatic function and indicate diaphragmatic weakness, or paralysis. In the present work we propose and evaluate an integrated semi-automated analysis system for the quantitative analysis of ultrasonic motion from ultrasound diaphragmatic videos. MethodsThe proposed system was evaluated in simulated videos and in 13 patients, four of whom patients were mechanically ventilated. The major steps of the methodology were as follows: video normalization, despeckle filtering, generation of an M-Mode image, snakes segmentation, and motion measurements. ResultsThe following manual (-/) vs semi-automated (/-), (median±IQR) measurements, which are routinely carried out by the experts, for assessing the severity of the disease, were computed. For the simulated videos the diaphragmatic excursion was 1.80±0.00 cm / 1.76±0.03 cm. For all the real ultrasound videos investigated in this study the following measurements were computed: (i) diaphragmatic excursion: 0.84±0.15 cm / 0.83±0.14 cm, (ii) inspiration time (Tinsp): 0.71±0.18 sec / 0.70±0.15 sec, (iii) total breathing time for one cycle (Ttot): 1.71±0.37 sec / 1.67±0.37 sec, (iv) diaphragmatic curve slope: 1.29±0.36 cm/sec / 1.27±0.36 cm/sec, and (v) relaxation rate (RR): 0.82±0.17 cm/sec / 0.82±0.18 cm/sec. ConclusionsManual and semi-automated measurements were very close with non-statistical significant differences and strong correlations between them. It is anticipated that the proposed system might be useful in the clinical practice in the assessment and follow up of patients with diaphragmatic weakness or paralysis and aid in the separation of normal and abnormal diaphragmatic motion. Further validation and additional experimentation in a larger sample of videos and different patient groups is required.

Effect of pimobendan on left atrial function: an echocardiographic pilot study in 11 healthy cats

Objectives– To evaluate the effect of a single dose of pimobendan on left atrial (LA) function in healthy cats. Animals– Eleven client owned healthy cats. Material and methods– Standardized and repeated echocardiographic examinations were performed on healthy and conscious cats before and after a single dose of orally administered pimobendan (1.25 mg/cat). Left atrial systolic functional parameters were assessed. Results– Some of the tested parameters of LA function showed significant improvement after pimobendan administration, whereas no significant effect on left ventricular function was observed. In particular, LA minimal diameters obtained from M-mode images in short (p=0.018) and long (p=0.009) axis reduced after pimobendan administration, whereas LA fractional shortening from short (p=0.027) and long (p=0.042) axis and LA appendage emptying velocity (p<0.001) significantly increased. A mild increase in heart rate (p=0.001), and a transient increase on the peak systolic wave pulmonary vein velocity (p=0.008) were also recorded as a possible effect. Conclusions– A single dose of pimobendan appears to impact LA function in healthy cats. However, because of the small number of cats included, and the absence of a placebo group, these results cannot be definitively separated from the effect of time. Additional studies are needed to understand if similar effects are observed in cats with cardiomyopathy and LA dilatation.

Motion Mode and Two-Dimensional Echocardiographic Measurements of Cardiac Dimensions in Local Dogs in Malaysia

Echocardiographic measurements of the dog’s heart are known to be breed-specific. The establishment of normal echocardiographic measurements for each breed of dog increases the accuracy of echocardiographic examination. The purpose of this preliminary study was to determine the value of normal echocardiographic measurements of local dogs from Malaysia. A total of 20 clinically healthy client-owned pet dogs were recruited, in accordance to the pre-determined inclusion criteria of the study. Two dimensional and M-mode echocardiograms image of both long and short axis of the left ventricle were obtained in accordance to recommendation by the American Society of Echocardiography. From this study, the reference echocardiographic measurements of local dogs in Malaysia were established. The measurements of intra-cardiac dimensions, wall thickness, and contractility varied from the Indonesian mongrel dogs, as well as the general population of dogs that have the same average body weight. There is no association between echocardiographic measurements with gender and bodyweight of local dogs in Malaysia.

Effects of Habit-Breaking Appliances on Tongue Movements during Deglutition in Children with Tongue Thrust Swallowing using Ultrasonography - A Pilot Study.

Objective:The aim of this study is to evaluate and compare the duration and range of tongue movements in tongue thrust swallow patterns with and without habit-breaking appliances using computer-aided M-mode ultrasound images. Also to record the corresponding position of the tongue associated with normal and tongue thrust swallowing pattern using B-mode ultrasound images.Methodology:Ten patients with mature swallow pattern, ten subjects with anterior tongue thrust (ATT) and ten patients with lateral tongue thrust (LTT) swallowing habit were analyzed for the duration and range of tongue movement using two-dimensional ultrasound M-mode images before and after insertion of three habit-breaking appliances (anterior tongue crib [ATC], double oral screen [DOS] and DeLuke oral trainer [DOT]). Further, B-mode images were examined for the tongue positions in different swallow patterns with and without appliances.Results:Duration and range of tongue movement for the entire swallowing phase did not show a statistically significant difference for mature, ATT and LTT. Statistical significant difference existed in the duration between ATC and DOS with DOT for ATT patient (P ≤ 0.05). Furthermore, a significant difference existed in the range of tongue movement between DOS and DOT in LTT patients (P ≤ 0.05).Conclusion:Remarkable changes in the tongue position were observed postinsertion of DOT in both anterior and LTT swallow patterns where the tongue tip and anterior tongue dorsum shifted upward toward the anterior palate resembling that of a mature swallow pattern.

Smartphone interfaced handheld echocardiography for focused assessment of ventricular function and structure in children: A pilot study.

Miniaturized echocardiographic machines improve availability and portability and can be particularly useful for underserved and resource-limited settings. The goal of this study was to compare left ventricular fractional shortening (FS) and left ventricular ejection fraction (LVEF) obtained by a newer handheld echo (HHE) machine to standard transthoracic echocardiogram (TTE) in children. Pediatric outpatients (Birth-18years) undergoing TTE were prospectively enrolled. HHE protocol included 2D and M-mode images from the parasternal long, short, and apical-4 chamber views. HHE and TTE measurements were reviewed for agreement. Kappa statistic was used to analyze qualitative indices while FS and LVEF were analyzed with Lin's concordance correlation coefficient (CCC) and Bland-Altman limits of agreement (loa). Sixty children were enrolled; 55 were included in the quantitative analysis. Mean age was 7.5±5.5years; 67% males; median HHE image acquisition duration was 2.3(1-5) minutes. Fractional shortening and EF by HHE showed good agreement with TTE [CCC=0.82, 95%CI (0.73,0.90), mean bias -3.18%, loa (-7.00,6.44%) vs CCC=0.81 (0.72,0.90), mean bias -0.87%, loa (-6.94,5.17%], respectively. In children ≤5years, HHE FS (n=20) and EF (n=21) agreed with TTE measurement [0.59 (0.31, 0.88), mean bias 0.30%, loa (-8.5, 9.1%); 0.79 (0.63, 0.96), mean bias 0.10%, loa (-5.99, 6.14)]. Kappa values for RV size, function, and LV function were 1.00 (P<.05); 0.75 for LV size (P<.05) and 0.66 for pericardial effusion (P<.05). Handheld echo demonstrates good correlation with standard TTE for focused assessment of ventricular chamber sizes and function in children.

Pulmonary vein to pulmonary artery ratio in healthy and cardiomyopathic cats

Introduction/objectivesRecognition of congestive heart failure (CHF) in dyspnoeic cats is crucial for correct intervention. The pulmonary vein (PV) to pulmonary artery (PA) ratio (PV/PA) has been proposed as an index that might help discriminate dogs suffering from CHF but has never been studied in cats. We sought to determine reference intervals for various PV and PA variables in healthy cats. We then examined these variables in cats with subclinical and clinical cardiomyopathies to determine their diagnostic utility in identifying CHF. Animals, materials and methodsWe took a sample of 114 cats: 51 healthy cats, 32 subclinical cardiomyopathy affected cats and 31 cardiomyopathic cats with CHF.PV and PA were measured at the minimal and maximal diameters using M-mode images obtained from a modified right parasternal long axis view. The aorta (Ao) and left atrium were measured using two-dimensional imaging employing the right parasternal short axis view. Resultsmedian PVmin/PAmin value in healthy cats was approximately 0.51 and the PVmax/PAmax value was 0.67. The median distensibility value of the vessels was 23% for ΔPA and 41% for ΔPV. Cats with CHF had higher PVmin/PAmin, PVmax/PAmax, PVmin/Ao, PVmax/Ao values and a smaller ΔPV value compared to subclinical and healthy cats (p < 0.0001). When evaluating the diagnostic performance of these variables (in cardiomyopathic cats), PVmin/PAmin and PVmin/Ao values had higher accuracy compared to the LA:Ao value when identifying cats with CHF. ConclusionsOur study provides reference values for PV and PA variables in cats. Moreover, PV/PA variables were better factors than LA:Ao for discriminating cardiomyopathic cats with and without CHF.

Aortic, common carotid and external iliac artery arterial wall stiffness parameters in horses: Inter-day and inter-observer and intra-observer measurement variability.

In human medicine, local and regional arterial wall stiffness (AWS) parameters are routinely used to assess the vascular health. In horses, information regarding reproducibility of ultrasonographically derived AWS parameters is lacking. To evaluate the inter-day and inter-observer and intra-observer measurement variability of both local and regional AWS parameters in horses. Experimental study. In 10 healthy, adult Warmblood horses, B-, M-mode and pulsed-wave Doppler ultrasound images were collected on two different days from aorta, cranial and caudal common carotid arteries and external iliac artery. Heart rate and noninvasive blood pressure were recorded simultaneously. From blinded data, diastolic and systolic vessel lumen areas and diameters were measured from B/M-mode images and the velocity of the pressure wave was determined by pulsed-wave Doppler spectra. From each horse, one examination was measured again by the same observer and by a second, independent observer. Local and regional AWS parameters were calculated and inter-day and inter-observer and intra-observer measurement coefficient of variation (CV) were assessed. Low CV was found for both arterial diameter and lumen area measurements. Moderate to high CV was found for local AWS parameters, while regional AWS parameters had low CV. The number of horses investigated was too low to obtain reference values. The inter-operator variability was not evaluated. Our results show good reproducibility of aortic, carotid and external iliac artery diameter and area measurements using both B- and M-mode ultrasonography. Nevertheless, the variability of the derived local AWS parameters was relatively high. Therefore, local AWS parameters might be less suitable for follow-up studies, although they might be useful for population studies. On the other hand, regional AWS parameters showed low CV, making them valuable for both follow-up and population studies.

Enhanced Instantaneous Elastography in Tissues and Hard Materials Using Bulk Modulus and Density Determined Without Externally Applied Material Deformation.

Ultrasound is a continually developing technology that is broadly used for fast, non-destructive mechanical property detection of hard and soft materials in applications ranging from manufacturing to biomedical. In this study, a novel monostatic longitudinal ultrasonic pulsing elastography imaging method is introduced. The existing elastography methods require an acoustic radiational or dynamic compressive externally applied force to determine the effective bulk modulus or density. This new, passive M-mode imaging technique does not require an external stress and can be effectively used for both soft and hard materials. Strain map imaging and shear wave elastography are two current categories of M-mode imaging that show both relative and absolute elasticity information. The new technique is applied to hard materials and soft material tissue phantoms for demonstrating effective bulk modulus and effective density mapping. When compared with standard techniques, the effective parameters fall within 10% of standard characterization methods for both hard and soft materials. As neither the standard A-mode imaging technique nor the presented technique require an external applied force, the techniques are applied to composite heterostructures and the findings presented for comparison. The presented passive M-mode technique is found to have enhanced resolution over standard A-mode modalities.

Caval-aortic ratio and caudal vena cava diameter in dogs before and after blood donation.

To investigate whether the donation of 1 unit of blood results in a significant decrease in the caudal vena cava diameter (CVCd) and the caudal vena cava diameter to aortic diameter (CVCd:Aod) ratio measured at the iliac location. Eight healthy client-owned Greyhounds underwent ultrasound of their caudal vena cava and aorta before and after blood donation. The principal investigator obtained M-mode images of the blood vessels from all dogs and a secondary investigator measured the CVCd and aortic diameter in a blinded manner from stored images. The ratio of CVCd:Aod was then calculated. After assessing for normality, paired-sample t-tests were performed to compare mean values before and after donation. The mean (±SD) CVCd before and after blood donation were 15.84 mm (±5.06 mm) and 15.82 mm (±5.42 mm) and the CVCd:Aod ratios were 0.93 (±0.23) and 1.00 (±0.27), respectively. There was no statistical difference between pre- and postdonation values for CVCd (P=0.99) or CVCd:Aod (P=0.34). The measurement of CVCd and CVCd:Aod ratio with ultrasound at the iliac location failed to detect mild-to-moderate blood loss produced by the donation of 1 unit of blood in Greyhounds.

P2476Non-invasive left ventricular stiffness measurements for assessing diastolic myocardial properties after orthotopic heart transplantation

Abstract Background After orthotopic heart transplantation (HTx), allografts undergo characteristic alterations including myocardial fibrosis. These histologic changes contribute to functional impairment, especially to increased passive myocardial stiffness (MS), which is an important pathophysiological determinant of left ventricular diastolic dysfunction (DF). However, the transplanted heart is affected by many factors that make the interpretation of diastolic echocardiographic parameters difficult. Echocardiographic shear wave (SW) elastography is an emerging approach for measuring MS in vivo. Natural SWs occur after mechanical excitation of the myocardium, e.g. after mitral (MVC), and their propagation velocity is directly related to MS, thus providing an opportunity to assess stiffness at end-diastole (ED). Purpose The aim was to evaluate the relationship between MS and diffuse myocardial fibrosis as mechanism of DF in HTx patients. Methods We prospectively enrolled 33 patients (10.3±6.3 years after HTx) that underwent right heart catheterization (all) and CMR (n=18) during their annual check-up. We performed SW elastography in parasternal long axis views of the LV using a fully programmable experimental scanner (HD-PULSE) equipped with a clinical phased array transducer (Samsung Medison P2–5AC) at 1100±250 frames per second. Tissue acceleration maps were extracted from an anatomical M-mode line along the midline of the LV septum. The ED SW propagation velocity was measured as the slope in the M-mode image (Figure A). Right heart catheterization was performed on the same day. HTx patients were assumed to have diastolic dysfunction (DDF) if the pulmonary capillary wedge pressure (PCWP) exceeded 18mmHg (n=9). All other patients were assumed to have normal diastolic function (NDF, n=24). Native T1 and extracellular volume (ECV) were measured to evaluate diffuse myocardial fibrosis. Results Positive correlations were found between SW velocities at ED and PCWP (r=0.61, p&lt;0.001; Figure B), between SW velocities at ED and T1 (r=0.80, p&lt;0.001; Figure D), and between SW velocities at ED and ECV (r=0.66, p=0.004). SW propagation velocities at ED were significantly higher in DDF than in NDF (8.05±1.85 vs. 3.77±1.02 m/s; p&lt;0.001; Figure C), and corresponded to the T1 values (as illustrated in Figure D). Conclusions End-diastolic shear wave velocity – as a measurement of passive myocardial stiffness – showed a good correlation with CMR defined myocardial fibrosis. High PCWPs were consistent with the increase in SW velocities, reflecting the fibrous changes in the ventricle. These findings thus suggest that cardiac shear wave elastography has the potential to become a powerful tool for the assessment of diastolic myocardial properties in cardiac transplant recipients.

Mechanical Function of Internal Jugular Vein Valve: Post-analysis of M-Mode Imaging under Cardiac Monitoring

Because the internal jugular vein (IJV) valve is the only protective valve between the brain and heart, recent studies have focused on the dynamic behaviour of the valve and its importance in regulating the cerebral blood outflow pathway. However, the mechanism underlying valve opening and closure, as well as the normal opening time, has not been investigated before. The aim of the study described here was to investigate IJV physiology in healthy young adults by means of ultrasound imaging. Twenty-four normal young adults (16 male, 8 female, 21.79 ± 0.79 y of age) were enrolled in this study. Each participant underwent IJV B- and M-mode ultrasound scans of the neck veins in supine position. Data on IJV leaflet movement and IJV blood velocity were extracted from images with the associated electrocardiogram traces to analyze the opening and closure cycles of IJV leaflets. The normal opening time calculated in this study includes 70% of the dynamic valve cycle. The normal opening time of the IJV valve could be a new physiologic metric and serves as a premise for further studies in the field of cerebral venous return.

Growth Differentiation Factor-15 Level and Tissue Doppler Echocardiography as a Tool in Identification of Cardiac Effects in the Children with Type 1 Diabetes Mellitus

The aim of this study was to evaluate the importance of growth-differentiation factor-15 level and tissue Doppler imaging in the detection of cardiomyopathy in children who have type 1 diabetes mellitus. Thirty-eight patients (11 males and 27 females) with type 1 diabetes mellitus were included in this study. The control group consisted of 40 age- and gender-matched healthy volunteers. All children underwent a detailed echocardiography, which contained an m-mode, pulse Doppler and tissue Doppler imaging; and growth-differentiation factor-15 level was measured. In this study, there were significant differences between diastolic function parameters of the heart. The mitral isovolumic contraction time, contraction time, and isovolumic relaxation time values were different in the patients than in the controls (p<0.01, p<0.01, p<0.01, respectively). Also, the tricuspid isovolumic contraction time, contraction time, and isovolumic relaxation time values were different in the patients than in the controls (p<0.01, p=0.01, p<0.01, respectively). No statistically significant difference was found between the other M-mode parameters. Mean plasma growth-differentiation factor-15 level was significantly higher in patients than in healthy controls (p<0.01). The follow-up of children with type 1 diabetes mellitus in terms of cardiomyopathy and the use of tissue Doppler imaging and growth differentiation factor-15 levels may be useful.

Mechanical function of internal jugular vein valve: post analysis of M-mode imaging under cardiac monitoring

Not available

Clutter Filter Wave Imaging

The elastic properties of human tissue can be evaluated through the study of mechanical wave propagation captured using high frame rate ultrasound imaging. Methods such as block-matching or phase-based motion estimation have been used to estimate the displacement induced by the mechanical waves. In this paper, a new method for detecting mechanical wave propagation without motion estimation is presented, where the motion of interest is accentuated by an appropriate clutter filter. Thus, the mechanical wave propagation will directly appear as bands of the attenuated signal moving in the B-mode sequence and corresponding anatomical M-mode images. While only the locality of tissue velocity induced by the mechanical wave is detected, it is shown that the method is more sensitive to subtle tissue displacements when compared to motion estimation techniques. The technique was evaluated for the propagation of the pulse wave in a carotid artery, mechanical waves on the left ventricle, and shear waves induced by radiation force on a tissue-mimicking phantom. The results were compared to tissue Doppler imaging (TDI) and demonstrated that clutter filter wave imaging (CFWI) was able to detect the mechanical wave propagating in tissue with a relative temporal and spatial resolution 30% higher and a relative consistency 40% higher than TDI. The results showed that CFWI was able to detect mechanical waves with a relative frequency content 40% higher than TDI in a shear wave imaging experiment.