[Doppler myocardial velocity gradient as a new diagnostic index for the assessment of myocardial disease]. / Dopplerowski gradient predkosci miesnia serca jako nowy parametr w rozpoznawaniu chorób miesnia serca.

Currently, echocardiography is the technique of choice in the noninvasive assessment of left ventricular (LV) function. Unlike the assessment of LV systolic function, its role is limited in the quantification of LV diastolic function where only global LV filling can be assessed. Tissue Doppler echocardiography (TDE) is a recently introduced imaging technique which allows for direct assessment of LV myocardial contraction and relaxation. Therefore, parameters derived from TDE showed provide a more accurate assessment of LV systolic and diastolic function. Doppler myocardial velocity gradient (MVG) is a new parameter derived from TDE, which enables the measurement of the spatial distribution of transmyocardial velocities over the cardiac cycle. The most studied application of this technique relates to the earlier and more sensitive diagnosis of different forms of cardiomyopathy. Based on the Doppler MVG measurement, patients with ischaemic cardiomyopathy can be differentiated from those with idiopathic dilated cardiomyopathy. In both diseases MVG is reduced in systole, but as opposed to dilated cardiomyopathy, MVG in patients with ischaemic cardiomyopathy is also markedly reduced in early diastole. MVG derived from TDE also provides new diagnostic insights into genetically determined heart muscle diseases. It has been shown that an early diastolic MVG < or = 7 s-1 is characteristic for patients with hypertrophic cardiomyopathy and differentiates this group of patients from 'athletes' heart, independently of the degree of LV hypertrophy. A recent study has also shown that in Friedreich ataxia related cardiomyopathy there is a close relation between the degree of genotype abnormalities and the degree of reduction in the MVG. Also, the assessment of Doppler MVG enables the differentiation of restrictive cardiomyopathy from constrictive pericarditis. Based on available literature it appears that TDE derived MVG enhances the information available from conventional echocardiography and helps to establish an earlier diagnosis in patients with primary and secondary myocardial diseases.

Three-dimensional echocardiography: historical development and current applications.

Three-dimensional (3D) echocardiography facilitates spatial recognition of intracardiac structures, potentially enhancing diagnostic confidence of conventional echocardiography. The accuracy of 3D images has been validated in vitro and in vivo. In vitro, a detail 1.0 mm in dimension and 2 details separated by 1.0 mm can be identified from a volume-rendered 3D image. In vitro 3D volume measurements are underestimated by approximately 4.0 mL. In vivo, left ventricular volume measurements correlate highly with both cineventriculography (limits of agreement +/-18 mL for end diastole and +/-10 mL for end systole) and magnetic resonance imaging, including measurements for patients with functionally single ventricles. Studies on congenital heart lesions have shown good accuracy and good reproducibility of dynamic "surgical" reconstructions of septal defects, aortoseptal continuity, atrioventricular junction, and both left and right ventricular outflow tract morphology. Transthoracic 3D echocardiography was shown feasible in 81% to 96% of patients with congenital heart defects and provided additional information to that available from conventional echocardiography in 36% of patients, mainly in more detailed description of mitral valve morphology, aortoseptal continuity, and atrial septum. In patients with mitral valve insufficiency, 3D echocardiography was shown to be accurate in the quantification of the dynamic mechanism of mitral regurgitation and in the assessment of mitral commissures in patients with mitral stenosis. This includes not only valve tissue reconstruction but also color flow intracardiac jets. Three-dimensional reconstructions of the aortic valve were achieved in 77% of patients, with an accuracy of 90%. In conclusion, the role of 3D echocardiography, which continues to evolve, shows promise in the assessment of congenital and acquired heart disease.

Transthoracic three-dimensional echocardiography in the preoperative assessment of atrioventricular septal defect morphology.

A prospective study of 3-dimensional (3-D) transthoracic echocardiographic definition of atrioventricular septal defect (AVSD) morphology and its dynamic changes during the cardiac cycle was performed. The information obtained from 2-D and 3-D transthoracic echocardiography (TTE) was compared with intraoperative findings in an unselected group of 15 patients with AVSD (median age 22 months). In all study patients, 3-D reconstructions provided anatomic views of the atrioventricular valve(s) en face from either atrial or ventricular perspectives that allowed comprehensive assessment of dynamic valve morphology and the mechanism of valve reflux. Left-sided valve function was correctly assessed by 2-D TTE in 11 of 15 patients (73%) and in 14 of 15 (93%) by 3-D TTE. In 6 of 15 patients (40%), the severity of right-sided valve reflux was described precisely by 2-D TTE and in 12 of 15 patients (80%) by 3-D TTE. Additionally, 3-D TTE supplemented the diagnostic information to that available from 2-D TTE on atrial and ventricular septal defects. Although primum atrial septal defects were depicted by 2-D and 3-D TTE in all 15 patients, the description of defect size was more precise by the 3-D TTE (80% vs. 100%, respectively). The presence of secundum atrial septal defect was correctly diagnosed by both TTE techniques in 10 of 15 patients. Disagreement regarding the size of the defect was present only in 2 of 10 patients by 2-D TTE. In another 2 patients, 3-D TTE described multiple defect fenestrations that were missed by 2-D TTE. Thus, the agreement score was 73% for 2-D and 100% for 3-D echo. The agreement for the presence and sizing of ventricular septal defects was 67% for 2-D and 93% for 3-D echo. We conclude that 3-D TTE provided accurate anatomic reconstructions of the common atrioventricular junction and that the use of dynamic 3-D TTE enhanced the anatomic diagnostic capability of standard 2-D TTE. Medica, Inc.

Echocardiographic characterization of cardiomyopathy in Friedreich's ataxia with tissue Doppler echocardiographically derived myocardial velocity gradients.

BACKGROUND: Conventional and tissue Doppler echocardiographically derived myocardial velocity gradients (MVGs) were used to characterize the myocardium in patients with Friedreich's ataxia (FRDA), and the relationship between MVGs and the mutation in the FRDA gene, a GAA triplet repeat expansion, was investigated. METHODS AND RESULTS: We studied 29 patients with FRDA (10 men, mean age 31+/-9 years) who were homozygous for the GAA expansion in the FRDA gene and were without cardiac symptoms. A comparison was made with a group of 30 age-matched control subjects. In patients with FRDA, interventricular septal thickness (1.17+/-0.26 versus 0.85+/-0.13 cm, P:<0.005), posterior left ventricular wall thickness (1.00+/-0.24 versus 0.88+/-0.15 cm, P:<0.01), and left atrial diameter (3.3+/-0.5 versus 2.9+/-0.3 cm, P:=0.01) were increased compared with control subjects. MVGs were reduced in FRDA during systole (3.1+/-1.2 versus 4.5+/-0.5 s(-1), P:<0.0001) and in early diastole (4.9+/-2.7 versus 8.8+/-1.8 s(-1), P:<0.0001) but increased in late diastole (2.0+/-1. 3 versus 1.1+/-0.9 s(-1), P:<0.01). The strongest relationship was seen between age-corrected early diastolic MVGs and the GAA expansion in the smaller allele of the FRDA gene (r=-0.68, P:<0. 0001). CONCLUSIONS: MVGs offer a means of further characterizing the myocardial abnormalities in patients with FRDA. Early diastolic MVGs appear to relate most closely to the genetic abnormality and the consequential reduction in frataxin protein.

Differentiation between restrictive cardiomyopathy and constrictive pericarditis by early diastolic doppler myocardial velocity gradient at the posterior wall.

BACKGROUND: The differential diagnosis between restrictive cardiomyopathy (RCM) and constrictive pericarditis (CP) is challenging and, despite combined information from different diagnostic tests, surgical exploration is often necessary. METHODS AND RESULTS: A group of 55 subjects (mean age, 63+/-11 years; 36 men and 19 women) were enrolled in the study; 15 had RCM, 10 had CP, and 30 were age-matched, normal controls. The diagnosis of RCM was supported by a biopsy; in the CP group, the diagnosis was confirmed either surgically or at autopsy. All patients underwent a transthoracic echocardiogram that included the assessment of Doppler myocardial velocity gradient (MVG), as measured from the left ventricular posterior wall during the predetermined phases of the cardiac cycle. MVG was lower (P<0.01) in RCM patients compared with both CP patients and normal controls during ventricular ejection (2. 8+/-1.2 versus 4.4+/-1.0 and 4.7+/-0.8 s(-1), respectively) and rapid ventricular filling (1.9+/-0.8 versus 8.7+/-1.7 and 3.7+/-1.4 s(-1), respectively). Additionally, during isovolumic relaxation, MVG was positive in RCM patients and negative in both CP patients and normal controls (0.7+/-0.4 versus -1.0+/-0.6 and -0.4+/-0.3 s(-1), respectively; P<0.01). During atrial contraction, MVG was similarly low (P<0.01) in both RCM and CP patients compared with normal controls (1.6+/-1.7 and 1.7+/-1.8 versus 3.8+/-0.9 s(-1), respectively). CONCLUSIONS: Doppler myocardial imaging-derived MVG, as measured from the left ventricular posterior wall in early diastole during both isovolumic relaxation and rapid ventricular filling, allows for the discrimination of RCM from CP.

Mean myocardial velocity mapping in quantifying regional myocardial contractile reserve in patients with impaired left ventricular systolic function: Doppler myocardial imaging study.

The aim of this study was to use Doppler myocardial imaging-derived mean myocardial velocity (MMV) at baseline and during low-dose dobutamine stress echocardiography (DSE) to quantify regional contractile reserve of the left ventricle (LV). Sixteen patients (mean age 59 +/- 7 years) with coronary artery disease and regional left ventricular wall motion abnormalities were studied. During each increment of Dobutamine infusion, 6 2-dimensional transthoracic apical images were acquired in standard gray-scale and Doppler myocardial imaging modes at 30 degrees steps over 180 degrees. For the analysis, the LV was divided into 18 segments. For each segment, both wall motion score and MMV obtained in systole and both early and late diastole were measured at baseline and at each stage of DSE. In viable segments by wall motion score, MMV increased during DSE in systole and in early and late diastole. In contrast, in nonviable segments, MMV did not change during DSE. Mean myocardial velocity mapping is a promising new approach to quantify regional myocardial contractile reserve of the LV.

The effect of long-term training on age-related left ventricular changes by Doppler myocardial velocity gradient.

Myocardial velocity gradient (MVG) derived from Doppler myocardial imaging and standard echocardiographic parameters were used to investigate whether age-related left ventricular (LV) functional and/or structural changes are different in long-term training athletes than in those leading a sedentary life style. Eighty-nine athletes (64 men, mean age 38 years, range 18 to 64) and 105 age-matched sedentary normal subjects were enrolled into the study. The MVG was analyzed in all patients throughout the cardiac cycle, and peak values were measured in systole and in diastole during both rapid ventricular filling and atrial contraction. No differences were found in LV systolic and late diastolic function between athletes and sedentary normal subjects. However, athletes had higher peak E waves in early diastole (73 +/- 10 cm/s vs 68 +/- 10 cm/s, p <0.001) and rapid ventricular filling MVG (10.2 +/- 1.5 s(-1) vs 7.2 +/- 2.8 s(-1), p <0.001) than sedentary normal subjects, suggesting a better early relaxation pattern. From LV diastolic indexes, the rapid ventricular filling MVG age-related decrease was less pronounced in athletes than in sedentary normal subjects (r = -0.39 vs r = -0.91; p <0.01). All other diastolic variables, including transmitral Doppler inflow, had a similar degree of age-related changes in both study groups. Thus, athletes, compared with those leading a sedentary lifestyle, have higher early diastolic performance, which is less affected by the physiologic aging process. It would appear that MVG derived from Doppler myocardial imaging may play an important role in the assessment of LV functional and/or structural changes.

Three-dimensional echocardiographic evaluation of left ventricular volume: comparison of Doppler myocardial imaging and standard gray-scale imaging with cineventriculography--an in vitro and in vivo study.

BACKGROUND: Standard gray-scale imaging (GSI), three-dimensional (3D) echocardiography has been shown to be superior to two-dimensional echocardiography in measuring left ventricular volume. However, the often relatively poor quality of transthoracic gray-scale data can limit the potential application of this technique. Doppler myocardial imaging (DMI) is a new ultrasound technique that potentially offers higher-quality 3D images with a transthoracic approach than the 3D GSI technique. This study was designed to compare the accuracy of standard GSI and DMI 3D left ventricular volume measurements in vitro and in vivo. METHODS AND RESULTS: In vitro, the minimum and maximum volume of the contracting single-chamber, tissue-mimicking phantom was calculated by using both techniques. In vivo, GSI and DMI 3D left ventricular volume measurements were performed in 16 patients. End-diastolic and end-systolic left ventricular volumes were computed for both techniques and compared with those calculated by cineventriculography. In vitro, both methods tended to underestimate the true phantom volume, but the systematic error was smaller for DMI than for GSI (-1.2% +/- 1.5% vs. -4.3% +/- 3%; p < 0.01) and was more constant in the case of DMI over the range of different sizes of true volume. In vivo, for GSI the end-diastolic volume mean difference was -12.6 ml and the limits of agreement were +/-18 ml, and for DMI the corresponding values were -4.2 and +/- 10.6 ml, respectively. The difference for end-systole was -6.5 +/- 10.6 ml and -1.5 +/- 10 ml for GSI and DMI, respectively. The magnitude of the difference in volume measurement between 3D echocardiography and cineventriculography was significantly smaller when using the Doppler technique. CONCLUSIONS: The results of this in vitro and in vivo study indicate that DMI is superior to GSI as a transthoracic acquisition technique for 3 D volume computation.

Diagnostic value of transesophageal echocardiography in the assessment of congenitally corrected transposition of the great arteries in adult patients.

This study was designed to evaluate the relative diagnostic values of transthoracic (TTE) and transesophageal (TEE) echocardiography in the assessment of congenitally corrected transposition of the great arteries in adult patients. Twelve patients (mean age 29 years, range 21 to 39 years) with congenitally corrected transposition of the great arteries underwent both TTE and TEE examinations to assess this complex cardiac lesion. Of the 12 patients evaluated, situs solitus and inversus were present in 8 and in 4 patients, respectively. TTE correctly identified atrial situs in only 10 patients, whereas TEE, directly evaluating the morphologic features of either appendage, correctly determined situs in every patient. In all 11 patients with intact inlet ventricular septum, the spatial relationship between the septal leaflets of atrioventricular valves was correctly evaluated by both techniques. However, the chordal attachments of both valves were clearly elucidated by TEE in all patients, whereas TTE could obtain images of these in only three patients. TTE was able to evaluate the discordant connection between the right ventricle and the anterior vessel (aorta) in 10 patients, whereas the connection between the left ventricle and the posterior vessel was clearly shown only in 7 patients. Transesophageal longitudinal planes better elucidated these two discordances in all patients irrespective of the position of the heart in the chest and atrial situs. Four patients had an associated ventricular septal defect (inlet defect in one, perimembranous in two, and muscular in one); the inlet defect was unrestrictive and could be easily detected by either imaging technique, whereas the membranous was detected by TTE and by the horizontal transesophageal planes; the muscular defect was recognized only by TTE. Three patients had an associated pulmonary stenosis; Doppler transthoracic echocardiography showed a left outflow peak gradient of 100 mm Hg in two patients and of 80 mm Hg in one but failed to adequately assess the morphologic features of the stenosis, whose features were clearly visualized by transesophageal longitudinal planes in all patients. In conclusion, in our experience TEE is superior to transthoracic imaging in studying congenitally corrected transposition of the great arteries in adult patients; the horizontal plane is best suited to the evaluation of atrial situs and the atrioventricular junction, whereas the longitudinal plane is most valuable in the study of the morphologic features of the ventriculoarterial connections. These findings should be equally applicable to multiplane transesophageal studies.

Assessment of atrial septal defect morphology by transthoracic three dimensional echocardiography using standard grey scale and Doppler myocardial imaging techniques: comparison with magnetic resonance imaging and intraoperative findings.

OBJECTIVE: To determine whether transthoracic three dimensional echocardiography is an accurate non-invasive technique for defining the morphology of atrial septal defects (ASD). METHODS: In 34 patients with secundum ASD, mean (SD) age 20 (17) years (14 male, 20 female), the measurements obtained from three dimensional echocardiography were compared to those obtained from magnetic resonance imaging (MRI) or surgery. Three dimensional images were constructed to simulate the ASD view as seen by a surgeon. Measured variables were: maximum and minimum vertical and horizontal ASD dimension, and distances to inferior and superior vena cava, coronary sinus, and tricuspid valve. In each patient two ultrasound techniques were used to acquire three dimensional data: standard grey scale imaging (GSI) and Doppler myocardial imaging (DMI). RESULTS: Good correlation was found in maximum ASD dimension (both horizontal and vertical) between three dimensional echocardiography and both MRI (GSI r = 0.96, SEE = 0.05 cm; DMI r = 0.97, SEE = 0.04 cm) and surgery (GSI r = 0.92, SEE = 0.06 cm; DMI r = 0.95, SEE = 0.06 cm). The systematic error was similar for both three dimensional techniques when compared to both MRI (GSI = 0.40 cm (27%); DMI = 0.38 cm (25%)) and surgery (GSI = 0.50 cm (29%); DMI = 0.37 cm (22%)). A significant difference was found in both horizontal and vertical ASD dimension changes during the cardiac cycle. This change was inversely correlated with age. These findings were consistent for both DMI and GSI technique. In children (age < or = 17 years), the feasibility of detecting structures and undertaking measurements was similar for both echo techniques. However, in adult ASD patients (age > or = 18 years) this feasibility was higher for DMI than for GSI. CONCLUSIONS: Transthoracic three dimensional imaging using both GSI and DMI accurately displayed the varying morphology, dimensions, and spatial relations of ASD. However, DMI was a more effective technique than GSI in describing ASD morphology in adults.

Differences in myocardial velocity gradient measured throughout the cardiac cycle in patients with hypertrophic cardiomyopathy, athletes and patients with left ventricular hypertrophy due to hypertension.

OBJECTIVES: We sought to compare the myocardial velocity gradient (MVG) measured across the left ventricular (LV) posterior wall during the cardiac cycle between patients with hypertrophic cardiomyopathy (HCM), athletes and patients with LV hypertrophy due to systemic hypertension and to determine whether it might be used to discriminate these groups. BACKGROUND: The MVG is a new ultrasound variable, based on the color Doppler technique, that quantifies the spatial distribution of transmyocardial velocities. METHODS: A cohort of 158 subjects was subdivided by age into two groups: Group I (mean [+/-SD] 30 +/- 7 years) and Group II (58 +/- 8 years). Within each group there were three categories of subjects: Group Ia consisted of patients with HCM (n = 25), Group Ib consisted of athletes (n = 21), and Group Ic consisted of normal subjects; Group IIa consisted of patients with HCM (n = 19), Group IIb consisted of hypertensive patients (n = 27), and Group IIc consisted of normal subjects (n = 33). RESULTS: The MVG (mean [+/-SD] s-1) measured in systole was lower (p < 0.01) in patients with HCM (Group Ia 3.2 +/- 1.1; Group IIa 2.9 +/- 1.2) compared with athletes (Group Ib 4.6 +/- 1.1), hypertensive patients (Group IIb 4.2 +/- 1.8) and normal subjects (Group Ic 4.4 +/- 0.8; Group IIc 4.8 +/- 0.8). In early diastole, the MVG was lower (p < 0.05) in patients with HCM (Group Ia 3.7 +/- 1.5; Group IIa 2.6 +/- 0.9) than in athletes (Group Ib 9.9 +/- 1.9) and normal subjects (Group Ic 9.2 +/- 2.0; Group IIc 3.6 +/- 1.5), but not hypertensive patients (Group IIb 3.3 +/- 1.3). In late diastole, the MVG in patients with HCM (Group Ia 1.3 +/- 0.8; Group IIa 1.4 +/- 0.8) was lower (p < 0.01) than that in hypertensive patients (Group IIb 4.3 +/- 1.7) and normal subjects (Group IIc 3.8 +/- 0.9). An MVG < or = 7 s-1, as a single diagnostic approach, differentiated accurately (0.96 positive and 0.94 negative predictive value) between patients with HCM and athletes when the measurements were taken during early diastole. CONCLUSIONS: In both age groups, the MVG was lower in both systole and diastole in patients with HCM than in athletes, hypertensive patients or normal subjects. The MVG measured in early diastole in a group of subjects 18 to 45 years old would appear to be an accurate variable used to discriminate between HCM and hypertrophy in athletes.

Doppler myocardial imaging vs. B-mode grey-scale imaging: a comparative in vitro and in vivo study into their relative efficacy in endocardial boundary detection.

Doppler myocardial imaging (DMI) is a new ultrasound imaging modality in which colour Doppler algorithms are adapted to visualise the myocardium. It allows measurement of regional intramyocardial velocities and quantification of intramural left ventricular function. However promising the technique is, to date the accuracy of endocardial boundary detection by DMI has not been validated. As Doppler velocity estimation is based on measurement of phase shift rather than signal strength, the technique is relatively independent of chest wall attenuation. In the current study, a series of in vitro and in vivo studies was performed to compare standard B-mode grey-scale imaging (GSI) and DMI techniques in endocardial boundary detection. In vitro, the minimum and maximum volumes of a single-chamber tissue-mimicking phantom were calculated using both imaging techniques. In vivo, left ventricular end-diastolic (ED) volume and end-systolic (ES) volume indices were measured from GSI and DMI images in a group of 40 volunteers. All images were obtained in the freeze-frame mode with the Doppler display turned on and off so that simultaneous DMI and GSI information was obtained. In vitro, the limits of agreement between the minimum volume of the phantom and the minimum volume measured by GSI and DMI was 4% and 3%, respectively. For maximum volumes, limits of agreement were 3% for GSI and 2% for DMI. In vivo, the limits of agreement between the two imaging techniques in volume measurements were 6 mL (9%) for ED and 4 mL (11%) for ES. The comparison of the endocardial boundary detection by GSI vs. DMI showed DMI to be significantly superior: ED (72 +/- 16% vs. 85 +/- 8%, respectively; p < 0.05) and ES (71 +/- 13% vs. 88 +/- 7%, respectively; p < 0.05). The results of the study show that: (1) in vitro, based on two-dimensional algorithms, DMI provides as accurate volume measurements as GSI; and (2) in vivo, there is a very good agreement of left ventricular volume measurements between GSI and DMI. However, the endocardial boundary is more reliably displayed and visually easier to detect using DMI than GSI.

Doppler myocardial imaging: a new method of data acquisition for three-dimensional echocardiography.

The precise morphologic characteristics of any intracardiac tumor have important implications regarding surgical planning and operative repair. Three-dimensional echocardiography has proved to be a valuable clinical technique in this field. Current methods of three-dimensional reconstruction of two-dimensional images are based on the standard gray-scale imaging technique. However, precordial gray-scale data-set information is frequently of suboptimal quality because of data degradation caused by ultrasound attenuation by chest wall structures. This has limited the use of the transthoracic three-dimensional technique to "echogenic" patients. Doppler myocardial imaging (DMI), a new ultrasound technique based on the Doppler principle, is influenced less by chest wall attenuation and in addition offers a better boundary detection algorithm for the cardiac structures. To determine if there may be a potential benefit of DMI to acquire data for three-dimensional reconstruction, a 33-year-old woman with a large intracardiac mass was studied. In this case three-dimensional gray-scale and DMI data sets were compared and contrasted with pathologic information. DMI allowed both the qualification of mass volume and the correct definition of the morphology of the mass. It was also possible to identify the precise site of attachment of the mass to the mitral valve leaflets. The information thus obtained was correlated with both operative and pathologic findings.

Magnetic resonance spectroscopy (MRS) in the evaluation of pediatric brain tumors, Part II: Clinical analysis.

Over a 1-year period (1994-1995), 75 children with brain neoplasms were evaluated with a new automated magnetic resonance spectroscopy (MRS) software package called Proton Brain Exam/Single-Voxel (PROBE/SV) to determine the efficacy of this modality in children. The children ranged in age from newborn to 17 years and were comprised of 30 girls and 45 boys. The types of brain neoplasms consisted of 45 astrocytomas, 4 medulloblastomas, 2 ependymomas, 3 craniopharyngiomas, 3 germinomas, 1 pineoblastoma, 2 teratomas, 1 choroid plexus papilloma, 4 meningiomas, 2 astroblastomas, 3 rhabdoids, and 5 metastases from primary brain neoplasms. All children underwent magnetic resonance imaging (MRI) at the same setting as the MRS examination. The MRS examination was performed with the stimulated echo acquisition mode (STEAM) pulse sequence in all children, and occasionally the point resolved spectroscopy (PRESS) sequence also was used. Qualitative spectra were obtained in all children, and at times quantification data also were obtained. We found that our spectra over the brain neoplasms were consistent with the MRS findings of brain neoplasms in the literature. There was markedly elevated choline with markedly decreased or absent N-acetylasparate and at times elevated lactate and lipid peaks. In children with meningiomas, there was also an elevated alanine peak. We found MRS to be extremely useful in 1) characterizing a brain mass as a neoplasm, 2) differentiating radiation necrosis and radiation-induced meningiomas from the recurrent primary tumor, 3) following treatment response of the primary neoplasm, 4) differentiating residual or recurrent primary neoplasm from postsurgical changes, and 5) identifying inactive neoplasms or neoplasms in remission.

Regional variations of ultrasonic integrated backscatter in normal and myopathic left ventricles. A new multi-view approach.

The purpose of the present study was to determine whether the cyclic variation of integrated backscatter is measurable and quantifiable in all left ventricular walls and whether the information obtained using both parasternal and apical transducer positions can be used to identify changes in myocardial structure and contractility. The cyclic variation of integrated backscatter was measured from the parasternal long-axis, apical four-chamber and two-chamber views in 26 patients with idiopathic dilated cardiomyopathy (mean age 58 +/- 9 years; ejection fraction 29 +/- 10%) and compared with information obtained from 30 aged-matched healthy volunteers. For each subject, the cyclic variation of integrated backscatter was calculated from 16 predetermined regions-of-interest located within the myocardium of the basal and mid-segments of the left ventricle imaged from the long-axis view and also the basal mid and apical left ventricular segments imaged from the two apical views. The cyclic variation of integrated backscatter was found to be present in 100% of the analysed regions-of-interest in healthy volunteers and in 87.5% of the analysed regions-of-interest in patients with idiopathic dilated cardiomyopathy. The mean value of cyclic variation of integrated backscatter, averaged from all regions-of-interest in the idiopathic dilated cardiomyopathy group, was significantly reduced compared to that in the healthy volunteers group (3.2 +/- 2.5 dB [mean +/- SD] vs 4.8 +/- 2.9 dB, P < 0.0001). Additionally, the healthy volunteers group demonstrated marked regional variability in the magnitude of cyclic variation of integrated backscatter which closely followed the regional changes in the contractile function of the normal heart. These regional differences in the magnitude of the cyclic variation of integrated backscatter were only partially retained in the idiopathic dilated cardiomyopathy group, and suggest that a multi-view approach of the recording of cyclic variation of integrated backscatter can be of value to differentiate normal from myopathic myocardium and to quantify regional differences in myocardial contractile performance throughout the left ventricular walls.