Ultrasonic Myocardial Tissue Characterization Research Articles

Myocardial ultrasonic tissue characterization in patients with thyroid dysfunction

BackgroundStructural myocardial abnormalities have been extensively documented in hypothyroidism. Experimental studies in animal models have also shown involvement of thyroid hormones in gene expression of myocardial collagen. This study was planned to investigate the ability of ultrasonic tissue characterization, as evaluated by integrated backscatter (IBS), to early identify myocardial involvement in thyroid dysfunction.Patients and MethodsWe studied 15 patients with hyperthyroidism (HYPER), 8 patients with hypothyroidism (HYPO), 14 patients with subclinical hypothyroidism (SCH) and 19 normal (N) subjects, who had normal LV systolic function. After treatment, 10 HYPER, 6 HYPO, and 8 SCH patients were reevaluated. IBS images were obtained and analyzed in parasternal short axis (papillary muscle level) view, at left ventricular (LV) posterior wall. The following IBS variables were analyzed: 1) the corrected coefficient (CC) of IBS, obtained by dividing IBS intensity by IBS intensity measured in a rubber phantom, using the same equipment adjustments, at the same depth; 2) cardiac cyclic variation (CV) of IBS - peak-to-peak difference between maximal and minimal values of IBS during cardiac cycle; 3) cardiac cyclic variation index (CVI) of IBS - percentual relationship between the cyclic variation (CV) and the mean value of IBS intensity.ResultsCC of IBS was significantly larger (p < 0.05) in HYPER (1.57 ± 0.6) and HYPO (1.53 ± 0.3) as compared to SCH (1.32 ± 0.3) or N (1.15 ± 0.27). The CV (dB) (HYPO: 7.5 ± 2.4; SCH: 8.2 ± 3.1; HYPER: 8.2 ± 2.0) and the CVI (HYPO: 35.6 ± 19.7%; SCH: 34.7 ± 17.5%; HYPER: 37.8 ± 11.6%) were not significantly different in patients with thyroid dysfunction as compared to N (7.0 ± 2.0 and 44.5 ± 15.1%).ConclusionsCC of IBS was able to differentiate cardiac involvement in patients with overt HYPO and HYPER who had normal LV systolic function. These early myocardial structural abnormalities were partially reversed by drug therapy in HYPER group. On the other hand, although mean IBS intensity tended to be slightly larger in patients with SCH as compared to N, this difference was not statistical significant.

437 Ultrasonic myocardial tissue characterization by cyclic variation of integrated backscatter in patients with aortic stenosis

s S63 Eur J Echocardiography Abstracts Supplement, December 2006 437 Ultrasonic myocardial tissue characterization by cyclic variation of integrated backscatter in patients with aortic stenosis M. Fijalkowski 1 ; A. Koprowski 1 ; R. Galaska 1 ; W. Dubaniewicz 1 ; J. Rogowski 1 ; A. Rynkiewicz 1 1Medical University Of Gdansk, 1St Department Of Cardiology, Gdansk, Poland Background: Ultrasonic myocardial tissue characterization by cyclic variation of integrated backscatter (CVIBS) has been successfully used for the differentiation of various myopathies from normal myocardium. Aim: The aim of the study was ultrasonic myocardial tissue characterization in patients with aortic stenosis (AS) by cyclic variation of integrated backscatter. Methods: The study population consisted of 128 patients (42 women; mean age 65±10 years). In the parasternal long-axis view two regions of interest were chosen to estimate CVIBS: the mid-septum and the mid-posterior wall. Types of left ventricular remodeling in our group were classified according to left ventricular mass index (LVMI) and relative wall thickness (RWT): normal LV (N), LV concentric remodeling (CR), LV concentric hypertrophy (CH) and LV excentric hypertrophy (EH). Results: The mean echocardiographic parameters were: the aortic valve area (AVA) 0.8±0.3 cm2, maximal pressure gradient (PG max) 86±29 mm Hg and mean pressure gradient (PG mean) 54±20 mm Hg, LVEF 71±14%, fractional shortening (FS) 35±10%, left LVMI 146±47 mg, circumferential end-systolic wall stress (cESS) 102±48 kdynes/cm2; CVIBS septum 5.6±2.3 db, CVIBS posterior wall 5.4±2.0 dB. We found inverse correlation between mean CVIBS and LVMI (r=-0.29; r=-24; p<0.05; for septum and posterior wall respectively) and cESS (r=-0.28; r=-32; p<0.05; for septum and posterior wall respectively) and direct correlation between mean CVIBS and LVEF (r=0.28; r=-25; p<0.05; for septum and posterior wall respectively) and FS (r=0.26; r=-22 p<0.05; for septum and posterior wall respectively). In addition mean CVIBS for both septum and posterior wall was significantly lower in group with LV excentric hypertrophy compared to patients with LV concentric remodeling and LV concentric hypertrophy (Table 1). There were no significant correlations between mean CVIBS and NYHA, AVA, PG max, PG mean and diastolic function indices. Conclusion: The severity of myocardial dysfunction and left ventricle remodeling in patients with aortic stenosis are associated with alterations in myocardial ultrasonic reflectivity detected by integrated backscatter analysis.

Computer simulation model on ultrasonic myocardial backscatter

Myocardial ultrasonic tissue characterization with integrated backscatter (IB) has been studied in recent years. To evaluate the dynamic characters of the myocardium, dynamic tracing of each unit volume of myocardium is a key point. Thus, a 2D CVIB imaging algorithm based on an auto-tracing method was developed in our previous work. Where, an auto-tracking method was used in CVIB-weighted images so that the POI in each frame throughout the cardiac cycle is automatically traced to reflect the real myocardial tissue movement. It is necessary to validate the auto-tracing method. However, at present there are no appropriate models to support the process. In order to validate the auto-tracing method, two myocardium models have been established to simulate the short and long axis view of echocardiography. The motions of partially ischemic myocardium have been simulated. The models have been used to validate the 2D CVIB imaging methods in the detection of myocardial ischemia. The simulation results show that the auto-tracing algorithm is effective. The model developed in this work provides a tool for studying and developing technologies in myocardial behavior.

Serum markers of angiogenesis and myocardial ultrasonic tissue characterization in patients with dilated cardiomyopathy

It has been proven that a disturbance in angiogenesis contributes to the progression of myocardial interstitial fibrosis in idiopathic dilated cardiomyopathy (DCM). This study was designed to evaluate the relationship between serum activity of angiogenic factors and myocardial ultrasonic tissue characterization in patients with DCM. We studied 30 patients with DCM and 15 healthy control subjects. Serum levels of vascular endothelial growth factor (VEGF), interleukin (IL)-4 and IL-13 were measured using enzyme-linked immunosorbent assay. We determined calibrated myocardial integrated backscatter (IB) as the value of myocardial interstitial fibrosis using ultrasonic tissue characterization and also quantified the magnitude of cyclic variations in IB (CV-IB). Serum levels of VEGF and IL-13 were significantly higher in patients with DCM than in control subjects (both P<0.05). Calibrated IB was significantly higher and CV-IB was markedly lower in patients with DCM than in control subjects (both P<0.01). In patients with DCM, the levels of IL-13 significantly correlated with calibrated IB (r=0.520, P=0.018). In addition, there was a significant negative correlation between levels of VEGF and CV-IB (r=-0.611, P=0.007). The increase in serum VEGF and IL-13 may be closely related to alterations in myocardial texture in DCM.

102 Dipyridamole stress echocardiography and ultrasonic myocardial tissue characterization in predicting myocardial ischemia, in comparison with dipyridamole stress Tc-99m MIBI SPECT myocardial imaging

102 Dipyridamole stress echocardiography and ultrasonic myocardial tissue characterization in predicting myocardial ischemia, in comparison with dipyridamole stress Tc-99m MIBI SPECT myocardial imaging

101 Prediction of mortality by modified myocardial jeopardy score: a strategy for combination with stress echocardiography

of significantly stenosed coronary vessel (scored from 3-5), and (3) weighting flow factor for particular localisation. Results: Among clinical, demographical, stress echocardiographic and angiographycal variables, factors strongly associated with high mortality rates were: myocardial jeopardy score >7 (p=0.0003), positive DobAtro (p=0.016), positive DipAtro (p=0.0215) and the number of diseased vessels (p=0.005), while other variables and the results ox Ex stress echocardiography didn’t show significant influence on long-term risk of cardiac death (p=ns). Variable most strongly associated with cardiac death was myocardial jeopardy score (RR 1.05; p=0.00054). Conclusion: Patients with high amount of potentially ischemic myocardium and positive DipAtro and DobAtro stress echocardiography are at high risk for subsequent cardiac death. Myocardial jeopardy score is the strongest predictor of longterm outcome in patents with stress induced myocardial ischemia. 102 Dipyridamole stress echocardiography and ultrasonic myocardial tissue characterization in predicting myocardial ischemia, in comparison with dipyridamole stress Tc-99m MIBI SPECT myocardial imaging.

P1111 The assessment of cardiac toxicity of high-dose continuous infusion 5-fluorouracil with ultrasonic myocardial tissue characterization

P1111 The assessment of cardiac toxicity of high-dose continuous infusion 5-fluorouracil with ultrasonic myocardial tissue characterization

Myocardial Ultrasonic Tissue Characterization In A Case Of Myocardial Contusion

Myocardial ultrasonic tissue characterization has been used recently for evaluating myocardial disease. However, it has been unknown whether myocardial ultrasonic tissue characterization is useful for detection of myocardial cotusion. We treated a patient with myocardial contusion in whom we observed changes in cyclic variation of myocardial ultrasonic integrated backscatter. A 61-year-old male was transported to Osaka Prefectural Nakakawachi Medical Center of Acute Medicine after suffering blunt anterior chest trauma due to motor vehicle accident. Second hospital day after the trauma, myocardial contusion showing diffuse left ventricular hypokinesia was diagnosed by electrocardiogram and echocardiogram. After diagnosing myocardial contusion, we evaluated the myocardial ultrasonic tissue characterization with an integrated backscatter imaging system. We analyzed cyclic variation of the integrated backscatter. Cyclic variation was measured in both the anterior and posterior myocardium at the left ventricle. The values of cyclic variation were consistent with recovery of left ventricular function. Thus, we conclude that integrated backscatter examination is a new technique that may be useful in the evaluating myocardial contusion.

Feasibility and usefulness of right ventricular ultrasonic tissue characterization with integrated backscatter in patients with unsuccessfully operatively “repaired” tetralogy of Fallot

Feasibility and usefulness of right ventricular ultrasonic tissue characterization with integrated backscatter in patients with unsuccessfully operatively “repaired” tetralogy of Fallot

Prognostic implications derived from ultrasonic tissue characterization with myocardial integrated backscatter in patients with dilated cardiomyopathy

Background: Various clinical parameters have been reported to predict survival in patients with dilated cardiomyopathy (DCM). Myocardial ultrasonic integrated backscatter (IB) imaging has a potential to perform in vivo tissue characterization. The present study was performed to examine whether myocardial IB analysis can predict the prognosis of DCM patients. Methods and results: We prospectively carried out echocardiographic examinations with IB analysis in 43 patients with DCM (31 males, 12 females) under the standard treatment. IB analysis was performed in the left ventricular wall and the calibrated (subtracting pericardial data) myocardial IB intensity (IBI) was obtained from the interventricular septum and the left ventricular posterior wall. After the follow-up (8–39 months), 31 followed a good clinical course, but eight had cardiac death, one had partial left ventriculectomy for uncontrolled heart failure and three were hospitalized for worsening heart failure. β-Blocker responded in 27 (87%) of the 31 with good clinical course, but it did not respond in 11 among the 12 with poor course. In these 12 DCM, left ventricular fractional shortening (LVFS) was lower (good: 18±5%, poor: 14±4, P<0.03) and calibrated IBI was higher in both the septum (good: −16.4±5.6 dB, poor: −11.1±4.2 dB, P<0.006) and the posterior wall (good: −19.5±3.6 dB, poor: −13.8±5.6 dB, P<0.004). On the Cox proportional hazard model analysis, only calibrated IBI in the septum >−17 dB, the cut-off score of calibrated IBI discriminating non-responders to β-blocker therapy in our previous report, was related to the poor outcome ( χ 2=4.43, P=0.035). The stepwise multivariate analysis revealed that both calibrated IBI in the septum>−17 dB ( χ 2=4.43, P=0.035) and LVFS<15% ( χ 2=3.89, P=0.049) were useful to predict the poor clinical outcome. The event free rate assessed by the Kaplan–Meier method was also significantly reduced in patients with calibrated IBI in the septum >−17 dB ( χ 2=6.594, P=0.01) and calibrated IBI in the posterior wall>−17 dB ( χ 2=4.215, P=0.04). However, LVFS<15% ( χ 2=3.576, not significant) did not contribute to discriminating the event free rate in the clinical course. Conclusions: The present study demonstrated that myocardial IB intensity was higher in DCM patients who followed a poor clinical course rather than in those with a good outcome. Therefore, it is clarified that myocardial ultrasonic tissue characterization in DCM patients is useful for assessing their clinical outcome after receiving not only the standard treatment but also β-blocker therapy.

Ultrasonic myocardial tissue characterization in normal and abnormal right ventricle

Ultrasonic myocardial tissue characterization in normal and abnormal right ventricle

Ultrasonic myocardial tissue characterization in patients with hypertrophic cardiomyopathy and pressure-overloaded hypertrophy by backscattered energy temporal analysis.

This study measured integrated backscatter (IB) values in the subendocardium and subepicardium of patients with hypertrophy using the newly developed Backscattered Energy Temporal Analysis (BETA) system, and evaluated the differences of acoustic properties according to etiology. Twenty-one patients with hypertrophic cardiomyopathy (HCM), 16 with pressure-overloaded hypertrophy (POH), and 21 controls were studied. M-mode formatted IB images were obtained using BETA and the region of interest (ROI), automatically divided into epicardial and endocardial halves of the myocardium, was placed in the ventricular septum and posterior wall. Values for the cyclic variation of IB (CVIB) in the entire ROI and in each half of the ROI were obtained. CVIB significantly decreased in the ventricular septum in HCM and POH compared with normal subjects, but there were no significant differences between HCM and POH. In the posterior wall, the CVIB was less in the subendocardium than in the epicardium in POH, and was also less than in normal subjects (7.0+/-1.7 dB vs 8.6+/-1.9 dB and 8.8+/-2.1 dB, p<0.05, respectively). Separate ultrasonic tissue characterization of the subendocardium and subepicardium provides further etiological information of various heart diseases.

Myocardial Ultrasonic Tissue Characterization for Estimating Histological Abnormalities in Hypertrophic Cardiomyopathy: Comparison with Endomyocardial Biopsy Findings

Aims: In this study, we investigated the clinical usefulness of ultrasonic tissue characterization with integrated backscatter for the evaluation of myocardial histological abnormalities in comparison with endomyocardial biopsy findings in patients with hypertrophic cardiomyopathy. Methods: Twenty patients with hypertrophic cardiomyopathy and 20 normal subjects were enrolled in this study. We measured two parameters for the ultrasonic tissue characterization with integrated backscatter: the magnitude of the cardiac-cycle-dependent variation in integrated backscatter signals (cdv-IB) and the mean value of integrated backscatter signals calibrated by the pericardium (cal-IB). These parameters were measured at both the interventricular septum and the left ventricular posterior wall. Histological findings of right ventricular endomyocardial biopsy specimens were analyzed by computer image analyzer. Results: cdv-IB was significantly lower and cal-IB significantly higher in both the interventricular septum and the left ventricular posterior wall in patients with hypertrophic cardiomyopathy compared with normal subjects. In patients with hypertrophic cardiomyopathy, the degree of myocardial disarray, interstitial fibrosis, and nonhomogeneity of myocyte size showed positive correlations with cal-IB and negative correlations with cdv-IB. Conclusions: Ultrasonic tissue characterization with IB enables the noninvasive evaluation of myocardial histological abnormalities in patients with hypertrophic cardiomyopathy.

Alterations of myocardial ultrasonic tissue characterization by coronary angioplasty in patients with chronic stable coronary artery disease

We conducted a study to delineate the alterations in the cyclic changes of myocardial ultrasonic integrated backscatter (IBS) in patients receiving angioplasty for chronic coronary artery disease. Ultrasonic tissue characterization (UTC) and dobutamine stress echocardiography were performed in 43 patients before and 24 h after angioplasty, as well as before the follow-up angiography 3 months later. For segments being normokinetic with ischemic burden, the blunted amplitude and increased nadir deviation of IBS cyclic modulation recovered soon after angioplasty. For dyssynergic segments with contractile reserve, the angioplasty rebuilt the amplitude before the wall motion recovered, but corrected the nadir deviation tardily. In both circumstances, the coronary restenosis abolished the initial restoration. Those nonviable segments persistently revealed large deviations and small weighted amplitudes irrelevant to coronary lesions. The progress of myocardial ischemia, the development of wall motion dyssynergy and, then, the loss of viability, show different patterns of alterations in UTC after alleviating coronary obstructions. (E-mail: ytlee@ha.mc.ntu.edu.tw)

Dipyridamole stress ultrasonic myocardial tissue characterization in patients with Kawasaki disease

Dipyridamole stress integrated backscatter (IBS) was used for evaluation of myocardial ischemia or damage in 31 children with coronary artery lesions caused by Kawasaki disease, in comparison with thallium-201 myocardial imaging. All patients underwent echocardiography at rest and after dipyridamole stress at the anterior interventricular septum, posterior wall (PW), and inferior wall (INF). At rest, no significant difference was seen in cyclic variation (CV) of IBS in the regions with normal or abnormal distribution on Tl-201 imaging. But in the regions showing abnormal distribution after stress, CV decreased significantly. A delayed study after stress showed the recovery of CV to the level at rest in all patients. Sensitivity of abnormal cyclic variation integrated backscatter was 75% in the PW and 91% in the INF, and specificity was 91% in the PW and 90% in the INF, compared with the results of thallium-201 imaging. Dipyridamole stress IBS can provide sensitive detection of myocardial ischemia or damage in Kawasaki disease. (J Am Soc Echocardiogr 2001;14:682-90.)

Ultrasonic myocardial tissue characterization in patients with primary amyloidosis Jun Koyama, Patricia A. Ray, Rodney H. Falk. Boston Medical Center, Boston, MA

Ultrasonic myocardial tissue characterization in patients with primary amyloidosis Jun Koyama, Patricia A. Ray, Rodney H. Falk. Boston Medical Center, Boston, MA

Normal Values in Children for Myocardial Ultrasonic Tissue Characterization by Integrated Backscatter.

Normal values in adults for ultrasonic tissue characterization by integrated backscatter have been reported previously and subsequently applied to patients with specific diseases. Factors influencing integrated backscatter values in a pediatric population are not clearly defined. To obtain normal values for myocardial ultrasonic integrated backscatter in a pediatric population, we studied 72 children with normal cardiac anatomy using an ultrasonic integrated backscatter imaging system. The parameters measured were at peak, nadir, and end-diastole in eight different regions with two different settings: fixed and variable. We subsequently calculated cyclic variation, the ratios of cyclic variation to end-diastole and to peak. Age ranged from 1 day to 17.4 years (median 4.4 years). More than 90% of data curves from the two regions in the left ventricular posterior wall in long-axis view had normal patterns, whereas more than 50% of curves for the other regions had abnormal patterns. Comparing the two posterior wall positions, there were no differences in cyclic variation between the two regions, with little effect of setting. Less effect of regions and settings was noted for the ratios of cyclic variation to end-diastole or peak. There was no relation between backscatter variables and age, gender, or height, and some variables correlated weakly with body surface area. The assessment of integrated backscatter in children is optimal with interrogation of the left ventricular posterior wall imaged in the long-axis view. More stable estimates are obtained when the cyclic variation is related to the peak or end-diastolic value.

Myocardial ultrasonic tissue characterization in patients with different types of left ventricular hypertrophy: A videodensitometric approach

Although analysis of the radio frequency signal is the most accurate approach to myocardial tissue characterization, clinical diffusion has been limited because of the complex technology required. Much easier to perform, videodensitometric analysis could represent a valuable alternative. Previous works carried out on radio frequency data have shown that the absolute value of ultrasonic back scatter increases while its diastole-to-systole variation decreases in the hypertrophied myocardium. This study was aimed at clarifying whether alterations in characterization indexes of ultrasonic tissue can be detected by means of a videodensitometric approach, whether a specific type of left ventricular (LV) hypertrophy can be identified with this method, and finally what possible relationships exist between parameters of contractile function and tissue characterization indexes. Myocardial echo intensity (MEI), its cyclic variation (CV), and the dynamic relationship between myocardial signal and wall thickness variations during the cardiac cycle were assessed in 20 healthy subjects, 11 patients with essential hypertension and LV hypertrophy, 15 patients with hypertrophic cardiomyopathy, and 4 patients with primary amyloidosis. The CV was lower in the interventricular septum of patients with cardiac hypertrophy as a group, compared with that of control subjects (13.0% +/- 5.6% versus 18.8% +/- 5.5%, p < 0.001), but it was similar among patients with different types of hypertrophy. In control subjects, a significant inverse correlation was found between the progressive decrease of the myocardial signal and the parallel increase in wall thickness during systole; this correlation was lost in 60% of patients with hypertrophic cardiomyopathy and 50% of those with amyloidosis, but only in 9% of patients with essential hypertension (chi square analysis 12.68, p < 0.01). The CV was associated with systolic wall thickening (r = 0.53, p = 0.0001) and fractional shortening (r = 0.44, p = 0.0014). MEI and its CV per se cannot distinguish among different types of LV hypertrophy; however, the loss of an inverse relationship between the myocardial signal and wall thickness may suggest abnormal myocardial conditions in individual patients with the same disease or comparable wall thickness.

Myocardial ultrasonic tissue characterization in pediatric and adult patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) has different clinical and prognostic aspects in young than in adult patients. This study was undertaken to determine whether these reported differences are reflected by changes in ultrasonic backscatter parameters and whether oral treatment with verapamil modifies backscatter variables in children with HCM. Sixty-eight subjects underwent backscatter analysis to assess the ultrasonic myocardial reflectivity and the amplitude of the cardiac cycle-dependent variation of the backscatter power curve. Subjects were divided into four groups: 10 HCM and 23 normal subjects < 10 years old and 17 HCM and 18 normal adults. Myocardial reflectivity and amplitude of the cyclic variation were assessed in the septum and in the posterior wall of all subjects. The children with HCM were restudied after long-term oral administration of verapamil. Both children and adult patients, compared with the normal control groups, showed a significant reduction in the amplitude of the cyclic variation both in the septum and in the posterior wall. In contrast, myocardial reflectivity, although significantly increased in adult HCM patients, was unchanged in the young HCM group. Verapamil administration did not significantly alter the results in the children with HCM. These data demonstrate that in young HCM patients, the ultrasonic myocardial reflectivity is normal, in contrast to the significant increase observed in adult patients affected by the same disease. This observation is in accord with the different clinical manifestations reported in young HCM patients and indicates an age-dependent difference in the echogenic structure of the hypertrophied myocardium in HCM.

Dobutamine stress ultrasonic myocardial tissue characterization in patients with dilated cardiomyopathy

Although acoustic properties of the myocardium are different between patients with cardiomyopathy and normal subjects, the frequency of the abnormal properties in patients with cardiomyopathy is unknown. We assessed the frequency of abnormal acoustic properties of the myocardium detectable with integrated backscatter in patients with cardiomyopathy and attempted more sensitive ultrasonic tissue characterization by combining dobutamine stress testing in patients with cardiomyopathy with apparently normal acoustic properties of the myocardium at rest. The magnitude of cyclic variation of integrated backscatter and calibrated myocardial integrated backscatter at end diastole were measured in 36 normal subjects and 40 patients with dilated cardiomyopathy. Either one of the integrated backscatter parameters was abnormal in 30 of 40 patients with cardiomyopathy. Dobutamine stress ultrasonic tissue characterization was performed in 10 patients with cardiomyopathy with normal values of both integrated backscatter parameters and 10 normal subjects. Calibrated myocardial integrated backscatter did not change during dobutamine infusion in any subject. The magnitude of cyclic variation in integrated backscatter increased in normal subjects but did not change in patients with cardiomyopathy despite a comparative associated increase in the systolic wall thickening during dobutamine infusion. Abnormal acoustic properties are detectable at rest with myocardial integrated backscatter about in three quarters of patients with cardiomyopathy. A combination of dobutamine stress testing would provide more sensitive ultrasonic myocardial tissue characterization and may make it possible to detect subtle changes in the acoustic properties of the myocardium in patients with dilated cardiomyopathy. Therefore dobutamine stress ultrasonic tissue characterization may detect mild dilated cardiomyopathy.