Cardiac MRI: accuracy of simultaneous measurement of left and right ventricular parameters using three different sequences

BACKGROUND AND AIM: We evaluated a value of Qp/Qs (left-to-right shunt measurement) using volumetric cardiac magnetic resonance (CMR) cardiac output (CO) measurements. We defined intraobserver, interobserver variability and reproducibility of left and right ventricular parameters by CMR. Furthermore, we studied whether shortened acquisition time has an effect on the accuracy of left and right ventricular parameters both in healthy volunteers and in patients with cardiovascular disease. METHODS: Sixteen subjects were enrolled in this study. Group A (n = 8, five males) consisted of healthy volunteers with a mean age of 25.9 years (range 24-30). Group B (n = 8, four males) was heterogenic consisting of patients with left ventricular (LV) hypertrophy, hypertension or coronary artery disease with their mean age of 56.3 years (range 38-70). RESULTS: The measured Qp/Qs as calculated from the right and LV CO was 0.87 +/- 0.13. Overall variability [as presented with the lowest coefficient of variation (CV)%- the highest CV % of intraobserver, interobserver variability or reproducibility] of LV parameters were for ejection fraction (EF) 1.5-2.8%, stroke volume (SV) 1.3-3.2%, CO 1.4-3.2%, end-diastolic volume 0.5-3.0%, end-systolic volume 1.8-6.2% and LV mass 1.1-2.6%. Corresponding values for right ventricular parameters were for EF 1.1-4.2%, SV 1.9-8.2%, CO 1.9-7.6%, end-diastolic volume 2.1-7.6%, end-systolic volume 2.8-10.2% and right ventricle mass 2.9-8.3%. There was no statistically significant difference between the results of different sequences. CONCLUSIONS: The CMR allows accurate Qp/Qs observation but the absolute value is at slightly different level compared with reference methods. Both left and right ventricular parameters are highly reproducible and even small clinically relevant changes can be measured with CMR. The shortened acquisition does not affect significantly to the accuracy of CMR-derived parameters.     

Repeatability of echocardiographic measurements in the human fetus.

OBJECTIVES: To determine the repeatability of cross-sectional, M-mode and Doppler echocardiographic measurements in the human fetus. METHODS: This was a prospective echocardiographic study of 10 normal fetuses, involving measurement of 32 different echocardiographic variables in each. The intra- and interobserver error of measurements were quantified. The median (range) gestational age was 23 (17-34) weeks. RESULTS: Cross-sectional echocardiography: for left ventricular end-diastolic volume the intraobserver coefficient of variation was 13% and the interobserver limits of agreement were a ratio of 0.46-2.19. For left ventricular ejection fraction the repeatability was +/- 8.8% and the interobserver limits of agreement were +/- 20%. M-mode echocardiography: the coefficient of variation for left ventricular end-diastolic dimension was 10%, and the interobserver limits of agreement were a ratio of 0.74-1.70. The intraobserver repeatability of left ventricular fractional shortening was +/- 8.8%, and interobserver limits of agreement +/-15%. Limits of agreement for M-mode-derived left ventricular end-diastolic volume were wide, intraobserver coefficient of variation 32% and interobserver limits were a ratio of 0.44-4.36. Doppler echocardiography: the intra- and interobserver errors were high for Doppler variables such as acceleration time, acceleration slope, stroke volume, cardiac output and vessel dimension. There was less error associated with measurements such as maximum Doppler velocity, velocity time integral, ejection time and heart rate. CONCLUSIONS: The repeatability of most echocardiographic measurements in the fetus is poor. This applies particularly to volumetric data such as ventricular volumes and volume flow estimations. Interobserver errors are consistently higher than intraobserver errors, confirming that when sequential measurements are clinically important, the same observer should be used.     

Validity and reproducibility of echocardiographic measurement of left ventricular ejection fraction by acoustic quantification with tissue harmonic imaging technique.

The tissue harmonic imaging technique can enhance detection of the cardiac endocardial border. When combined with an acoustic quantification (AQ) method, an improvement of accuracy and reproducibility of real-time measurement of left ventricular (LV) function might be expected. However, few data exist regarding the measurement of LV function by AQ with the harmonic imaging technique. Therefore, we evaluated the validity and reproducibility of AQ measurement of LV ejection fraction with or without harmonic imaging technique. A total of 50 patients (mean age 58 +/- 10 years) who underwent left ventriculography were included in our study. The LV end-diastolic and end-systolic volumes by ventriculography were 131 +/- 52 mL and 72 +/- 43 mL, respectively, and were underestimated by both conventional (70 +/- 32 mL and 36 +/- 25 mL) and harmonic (67 +/- 30 mL and 34 +/- 22 mL) AQ obtained in the apical 4-chamber view. The calculated ejection fraction by ventriculography was 0.49 +/- 0. 11 and correlated with that by conventional AQ (0.51 +/- 0.11; y = 0. 72x + 0.152; r = 0.73). This was a marked improvement when compared with the ejection fraction by harmonic AQ (0.50 +/- 0.11; y = 0.89x + 0.065; r = 0.91). Interestingly, interobserver and intraobserver variabilities of conventional AQ, which were 15.6% and 8.6%, respectively, were much improved by harmonic AQ (8.9% and 4.5%, respectively). These results indicate the feasibility of real-time measurement of LV ejection fraction by harmonic imaging, although absolute LV volume can be underestimated even by this technique.     

Reproducibility of three-dimensional ultrasound endometrial volume measurements in patients with postmenopausal bleeding.

OBJECTIVE: To evaluate the reproducibility of transvaginal three-dimensional (3D) endometrial volume measurement in patients with postmenopausal bleeding and to compare the reproducibility of this technique to that of two-dimensional (2D) endometrial thickness measurement. METHODS: In a prospective, blinded study, transvaginal ultrasound examinations were performed in 51 consecutive patients with postmenopausal bleeding. Three-dimensional volume and 2D thickness measurements were made and intraobserver and interobserver reproducibility of each technique were assessed. RESULTS: The intraobserver correlation of 3D endometrial volume measurement of the first observer was 0.97 and that of the second observer was 0.99. Thus, mean intraobserver correlation was 0.98. The mean interobserver correlation was 0.95 (0.95 vs. 0.96). There was no significant difference in reproducibility at different volume cut-offs. The mean intra- and interobserver correlation of endometrium volume measurements for five patients with endometrial carcinoma did not differ significantly from that for patients without carcinoma (0.98, 0.98 vs. 0.98, 0.95). The intraobserver correlation of 2D endometrial thickness measurements from the first observer was 0.71 and that from second observer 0.87. Thus, mean intraobserver correlation of the endometrial thickness measurements was 0.79. The mean interobserver correlation was 0.76 (0.84 vs. 0.70). CONCLUSIONS: Endometrial volume and thickness measurements by 3D and 2D ultrasound, respectively, show good reproducibility but the reproducibility of 3D ultrasound is better.     

Contrast agent increases Doppler velocities and improves reproducibility of aortic valve area measurements in patients with aortic stenosis.

Observer variability may limit assessment of aortic stenosis by Doppler echocardiography. This study aimed to assess whether echocardiographic contrast agent improves reproducibility of aortic valve area (AVA) measurements for patients with aortic stenosis. In all, 20 patients with aortic stenosis (67 +/- 10 years old) underwent noncontrast and contrast Doppler echocardiography on 2 occasions, 3 weeks apart. Intraobserver and interobserver coefficients of reproducibility were 0.36 and 0.20 cm for left ventricular outflow tract (LVOT) diameter, and 0.38 and 0.24 cm(2) for AVA, respectively. Although intraobserver reproducibility was unaffected, contrast improved interobserver reproducibility for LVOT diameter (mean of differences -0.02 +/- 0.07 cm vs 0.01 +/- 0.10 cm, P <.05) and AVA (mean of differences 0.02 +/- 0.10 cm(2) vs 0.07 +/- 0.12 cm(2), P <.05). Prevalve and postvalve velocities were increased with contrast compared with noncontrast imaging (prevalve, 1.07 +/- 0.20 vs 0.94 +/- 0.19 m/s, P <.01; postvalve, 3.76 +/- 0.87 vs 3.47 +/- 0.78 m/s, P <.01). We conclude that contrast significantly increases Doppler velocities and produces modest improvements in reproducibility of LVOT diameter and AVA. We suggest that, when assessing patients with aortic stenosis, contrast agents should be considered in patients who are difficult to image with poor baseline LVOT images or Doppler studies, or where there is poor interobserver reproducibility.     

Rapid full volume data acquisition by real-time 3-dimensional echocardiography for assessment of left ventricular indexes in children: a validation study compared with magnetic resonance imaging.

OBJECTIVE: We sought to assess the feasibility, accuracy, and reproducibility of a rapid full volume acquisition strategy using real-time (RT) 3-dimensional (3D) echocardiography (3DE) for measurement of left ventricular (LV) volumes, mass, stroke volume (SV), and ejection fraction (EF) in children. METHODS: A total of 19 healthy children (mean 10.6 +/- 2.8 years, 11 male and 9 female) were prospectively enrolled in this study. RT 3DE was performed using an ultrasound system to acquire full volume 3D dataset from the apical window with electrocardiographic triggering in 8 s/dataset. The images were processed offline using software. The LV endocardial and epicardial borders were traced manually to derive LV end-systolic volume, end-diastolic volume, mass, SV, and EF. Magnetic resonance imaging (MRI) studies were performed on a 1.5-T scanner using a breath hold 2-dimensional cine-FIESTA (fast imaging employing steady-state acquisition) sequence. RESULTS: All RT 3DE and MRI data were acquired successfully for analysis. Measurements of LV end-systolic volume, end-diastolic volume, mass, SV, and EF by RT 3DE correlated well by Pearson regression ( r = 0.86-0.97, P < .001) and agreed well by Bland-Altman analysis with MRI. The interobserver and intraobserver variability of RT 3DE measurements were less than 5%. CONCLUSIONS: This prospective study demonstrated that RT 3DE measurements of LV end-systolic volume, end-diastolic volume, mass, SV, and EF in children using rapid full volume acquisition strategy are feasible, accurate, and reproducible and are comparable with MRI measurements.     

Appropriate 3-Dimensional Echocardiography Data Acquisition Interval for Left Ventricular Volume Quantification: Implications for Clinical Application

Volume-rendered 3-dimensional echocardiography (3DE) acquired with small imaging intervals has been validated for accurate left ventricular (LV) volume measurement. However, its clinical application is often impeded by the lengthy acquisition time. The aim of this study was to examine the accuracy of LV volume measurement from 3DE data acquired at different intervals. METHODS: Transthoracic 3DE LV data sets were acquired at intervals of 2 degrees, 6 degrees, 9 degrees, 12 degrees, 15 degrees, 18 degrees, and 20 degrees in 10 human subjects with various cardiac shapes and function. The LV end-diastolic volume and end-systolic volume were measured from each 3DE data set with the "summation of disks" method. Interobserver and intraobserver variability were also examined. Measurements obtained from data acquired at 2 degrees intervals were used as references for comparison. RESULTS: From 10 subjects a total of 70 3DE data sets were obtained. Data acquisition time decreased from 189 +/- 143 seconds at intervals of 2 degrees to 19 +/- 6 minutes at 20 degrees. No statistically significant difference was found among the measurements derived from data obtained at various intervals. Excellent agreement was obtained between interobserver and intraobserver measurements. CONCLUSION: Data acquired at 12 degrees and 15 degrees intervals remained accurate for LV volume measurement and saved over 80% of time in comparison with data acquired at 2 degrees intervals. A further increase in imaging intervals tended to underestimate LV volumes without significant acceleration of the procedure.     

Intraobserver and interobserver variability of ovarian volume, gray-scale and color flow indices obtained using transvaginal three-dimensional power Doppler ultrasonography.

OBJECTIVE: To assess intraobserver and interobserver variability in ovarian volume and gray-scale and color flow index measurements using transvaginal, three-dimensional, power Doppler ultrasonography. METHODS: Eleven women (22 ovaries) were examined on day 8 of controlled ovarian hyperstimulation therapy, which was part of their in vitro fertilization treatment protocol. The patients were examined twice by the first observer and once by the second observer. The acquired volume datasets were analyzed using the VOCAL imaging program, enabling the assessment of ovarian volume, vascularization index (VI), flow index (FI), vascularization flow index (VFI) and mean grayness (MG). For these parameters the intraclass (intra-CC) and interclass (inter-CC) correlation coefficients, within-observer and between-observers repeatability coefficient (r) and limits of agreement were calculated. RESULTS: Both intraobserver and interobserver repeatability of ovarian volume measurements were considered very good with an intra-CC value of 1.00 and inter-CC value of 0.99, respectively. Also VI, FI, VFI and MG measurements were repeatable by a single observer, the intra-CC ranging from 0.82 to 0.91. The interobserver reproducibility was also good for VI, VFI and MG measurements (inter-CC values 0.73, 0.70 and 0.81, respectively), but for FI measurements the reproducibility was poor (inter-CC = 0.29, r = 7.87). CONCLUSIONS: In general, the intraobserver reproducibility was better than interobserver reproducibility for all parameters. The volume assessments were reproducible both by one observer and by two separate observers. The intraobserver and interobserver variabilities were acceptable for VI, VFI and MG, whereas for FI the interobserver reproducibility was poor. Our results suggest that measurement of gray-scale and color Doppler flow indices is reproducible thus allowing them to be used in clinical practice and research.     

Operator induced variability in left ventricular measurements with cardiovascular magnetic resonance is improved after training.

BACKGROUND: Accurate and reproducible measurement of left ventricular (LV) mass and function is a significant strength of Cardiovascular Magnetic Resonance (CMR). Reproducibility and accuracy of these measurements is usually reported between experienced operators. However, an increasing number of inexperienced operators are now training in CMR and are involved in post-processing analysis. The aim of the study was to assess the interobserver variability of the manual planimetry of LV contours amongst two experienced and six inexperienced operators before and after a two months training period. METHODS: Ten healthy normal volunteers (5 men, mean age 34+/-14 years) comprised the study population. LV volumes, mass, and ejection fraction were manually evaluated using Argus software (Siemens Medical Solutions, Erlangen, Germany) for each subject, once by the two experienced and twice by the six inexperienced operators. The mean values of experienced operators were considered the reference values. The agreement between operators was evaluated by means of Bland-Altman analysis. Training involved standardized data acquisition, simulated off-line analysis and mentoring. RESULTS: The trainee operators demonstrated improvement in the measurement of all the parameters compared to the experienced operators. The mean ejection fraction variability improved from 7.2% before training to 3.7% after training (p=0.03). The parameter in which the trainees showed the least improvement was LV mass (from 7.7% to 6.7% after training). The basal slice selection and contour definition were the main sources of errors. CONCLUSIONS: An intensive two month training period significantly improved the accuracy of LV functional measurements. Adequate training of new CMR operators is of paramount importance in our aim to maintain the accuracy and high reproducibility of CMR in LV function analysis.     

A validation study on the intraobserver and interobserver reproducibility of renal artery duplex ultrasound.

Aim of the present study was to evaluate intraobserver and interobserver reproducibility of direct renal artery Doppler velocimetry. Healthy volunteers were evaluated by one examiner on three separate occasions and by three different examiners in a single day. Peak systolic velocities of the aorta (PSV.Ao) and proximal renal arteries (PSV.RA) were taken at an optimal angle below 60 degrees. The renal-to-aortic ratio (RAR) was calculated dividing PSV.RA by PSV.Ao. Mean values +/- 2 SD were 85 +/- 34 (49-150) cm/s for the PSV.RA, 38 +/- 20 (0-60 degrees) for the Doppler angle of insonation, 102 +/- 37 (63-153) cm/s for the PSV.Ao, and 0.85 +/- 0.41 (0.49-1.58) for the RAR. Correlation coefficients and coefficient of variation were 0.64-0.82/7.8%-10.1% (PSV.RA), 0.75-0.82/9.9%-13.8% (RAR) for intraobserver evaluations; and 0.79-0.80/7.7%-12.5% (PSV-RA), 0.65-0.78/9.5%-12.3% (RAR) for interobserver evaluations. Reliable results of direct renal artery Doppler velocimetry confirm clinical applicability and suitability for repeated measurements after catheter-based interventions or surveillance of low-grade stenoses.     

Ovarian volume measurements in mice with high-resolution ultrasonography.

OBJECTIVE: The aim of our study was to evaluate the intraobserver and interobserver variability of ovarian volume measurements in mice with high-resolution 2-dimensional ultrasonography (2DUS) and 3-dimensional ultrasonography (3DUS). METHODS: Ovaries of 10 nude mice were visualized with a small-animal ultrasound scanner and a 40-MHz probe. For each ovary, volume was measured 3 times by 2 independent readers using both 2DUS and 3DUS methods. The 2DUS method used a biplane ellipsoid model. The 3DUS method estimated the volume by integrating 10 to 12 parallel image planes of the ovary after semiautomated outlining of the boundaries. For each type of measurement, intraobserver and interobserver standard error of measurement (SEM) values and minimal detectable volume changes were calculated by analysis of variance. RESULTS: Two-dimensional ultrasonography showed much poorer reproducibility, with higher absolute intraobserver and interobserver SEM values (0.50 and 0.61 mm3, respectively) than 3DUS (0.20 and 0.35 mm3; P < .01). Relative intraobserver and interobserver SEM values were also much higher for 2DUS (12.20% and 14.88%) than for 3DUS (5.12% and 8.97%; P < .01). The minimal volume changes that could be detected with a 95% confidence level in successive measurements by the same (or different) observers were 33.90% (41.22%) for 2DUS and 14.10% (24.87%) for 3DUS. CONCLUSIONS: High-resolution 3DUS can provide a reliable tool for noninvasive, longitudinal ovarian volume measurements in mice.     

Index of myocardial performance is afterload dependent in the normal and abnormal left ventricle.

BACKGROUND: The index of myocardial performance (IMP) has been used as a prognostic systolic-diastolic index for patients with dilated cardiomyopathy and postmyocardial infarction. To date, systematic evaluation of afterload alteration (arterial pressure) on IMP has not been performed with normal or reduced left ventricular (LV) function. METHODS: We studied 15 mongrel dogs at baseline, after the induction of acute ischemic LV dysfunction, and with chronic LV dysfunction. Each dog was atrially paced, and the arterial pressure was reduced with nitroprusside (NTP) (>10 mm Hg) and increased with methoxamine (Methox) (>30 mm Hg) in random order. Hemodynamics and transmitral and transaortic pulsed Doppler were obtained. RESULTS: With normal LV function, there were no changes in IMP with NTP. Methox reduced IMP (0.51 +/- 0.12-0.45 +/- 0.12, P < .05) as a result of a shortened isovolumic contraction time (ICT). With acute LV dysfunction, IMP declined with NTP (0.74 +/- 0.19-0.65 +/- 0.17, P < .01) because of a shortened ICT and isovolumic relaxation time. Methox prolonged IMP (0.73 +/- 0.16-0.83 +/- 0.21, P < .05). With chronic LV dysfunction, NTP resulted in a reduced IMP (0.75 +/- 0.27-0.57 +/- 0.27, P < .01) as a result of a reduced ICT and isovolumic relaxation time and a prolonged LV ejection time associated with an increased LV ejection fraction. Methox increased IMP (0.72 +/- 0.26-1.31 +/- 0.43, P < .001) because of an increased ICT and isovolumic relaxation time and a reduced LV ejection time associated with a reduced LV ejection fraction. Forward stepwise regression indicated that both LV systolic pressure ( P = .0006) and LV ejection fraction ( P = .0222) were independent predictors of IMP. CONCLUSION: IMP is afterload dependent in the normal LV. IMP is afterload dependent with acute and chronic LV dysfunction by influencing the isovolumic indices and LV ejection time in opposite directions. Further systematic evaluation of IMP is needed if this index is to be useful as a prognostic indicator.     

Validation of diameter measurements by ultrasound: intraobserver and interobserver variations assessed in vitro and in fetal sheep.

OBJECTIVES: Blood flow evaluation in the fetus is hampered by inaccuracy in the measurement of vessel diameter. The impact of biological variation on reproducibility studies is unknown. The present study evaluated diameter measurements carried out with modern ultrasound equipment by assessing inter- and intraobserver variations. DESIGN: Repeated measurements analyzed by a general factorial model of analysis of variance. METHODS: Three observers measured repeatedly (six or more times for each tube and session) silicone tube implants (0.6, 2.2 and 6 mm), applying ultrasound imaging in eight fetal sheep, and the same silicone tubes in vitro. Analysis of variance was carried out on 199 observations made in vitro and 537 in vivo. RESULTS: The upper 95% confidence limit for the intra- and interobserver variations was higher for measurements made in vivo than in vitro. It was highest for the largest diameter and varied between 0.10 and 0.38 mm. When the diameter was determined as an average of repeated measurements, the error was reduced: six measurements in vivo had upper 95% confidence limits for intraobserver variation of 0.04 and 0.09 mm for diameters of 0.6 and 6 mm, respectively. CONCLUSIONS: The results show that ultrasound diameter measurements have a high reproducibility even for vessels of small dimensions when repeated measurements are taken with high-frequency ultrasound under favorable conditions. The low variation described in the present investigation of silicone tubes, compared to previous studies, suggests that diameter changes of living vessels represent a separate source of measurement variation.     

Quantification of left ventricular volumes and ejection fraction using freehand transthoracic three-dimensional echocardiography: comparison with magnetic resonance imaging.

OBJECTIVES: Our aim was to validate 3-dimensional echocardiography (3DE) for assessment of left ventricular (LV) end-diastolic volume, end-systolic volume (ESV), stroke volume, and ejection fraction (EF) using the freehand-acquisition method. Furthermore, LV volumes by breath hold-versus free breathing-3DE acquisition were assessed and compared with magnetic resonance imaging (MRI). METHODS: From the apical position, a fan-like 3DE image was acquired during free breathing and another, thereafter, during breath hold. In 27 patients, 28 breath hold- and 24 free breathing-3DE images were acquired. A total of 17 patients underwent both MRI and 3DE. MRI contours were traced along the outer endocardial contour, including trabeculae, and along the inner endocardial contour, excluding trabeculae, from the LV volume. RESULTS: All 28 (100%) breath hold- and 86% of free breathing-3DE acquisitions could be analyzed. Intraobserver variation (percentual bias +/- 2 SD) of end-diastolic volume, ESV, stroke volume, and EF for breath-hold 3DE was, respectively, 0.3 +/- 10.2%, 0.3 +/- 14.6%, 0.1 +/- 18.4%, and -0.1 +/- 5.8%. For free-breathing 3DE, findings were similar. A significantly better interobserver variability, however, was observed for breath-hold 3DE for ESV and EF. Comparison of breath-hold 3DE with MRI inner contour showed for end-diastolic volume, ESV, stroke volume, and EF, a percentual bias (+/- 2 SD) of, respectively, -13.5 +/- 26.9%, -17.7 +/- 47.8%, -10.6 +/- 43.6%, and -1.8 +/- 11.6%. Compared with the MRI outer contour, a significantly greater difference was observed, except for EF. CONCLUSIONS: 3DE using the freehand method is fast and highly reproducible for (serial) LV volume and EF measurement, and, hence, ideally suited for clinical decision making and trials. Breath-hold 3DE is superior to free-breathing 3DE regarding image quality and reproducibility. Compared with MRI, 3DE underestimates LV volumes, but not EF, which is mainly explained by differences in endocardial contour tracing by MRI (outer contour) and 3DE (inner contour) of the trabecularized endocardium. Underestimation is reduced when breath-hold 3DE is compared with inner contour analysis of the MRI dataset.     

Reproducibility of pulsed wave tissue Doppler echocardiography.

Four hundred and eighty paired recordings obtained from 16 patients (55 +/- 10 yrs; 10 men, 6 women) were analyzed to determine the reproducibility of both acquiring and measuring myocardial velocities recorded by tissue Doppler echocardiography. To assess intraobserver variability, 1 observer recorded and measured the data twice, from the same patients, and to assess interobserver variability, patients were examined by 2 independent observers. For the left ventricle, intraobserver reproducibility was higher when assessing long-axis velocities (+/- 10% to 16%) than short-axis velocities (+/- 14% to 24%). For the right ventricle, intraobserver reproducibility was high for the tricuspid annulus (+/- 9% to 15%), but unsatisfactory for the right ventricular anterior wall (+/- 21% to 25%). The highest interobserver reproducibilities were obtained for systolic and diastolic velocities of the lateral mitral annulus (+/- 9% to 17%) and systolic velocity of the tricuspid annulus (+/-13%). Interobserver reproducibility of the ratio of early-to-late peak diastolic velocities was very low for all investigated sites (+/- 20% to 52%). With the use of current techniques and software, reproducibility of acquiring and measuring tissue Doppler echocardiography is suboptimal for both systolic and diastolic myocardial velocities.     

Reproducibility of three-dimensional ultrasound diagnosis of congenital uterine anomalies.

OBJECTIVE: To examine the reproducibility of the diagnosis of congenital uterine anomalies and the repeatability of measurements of uterine cavity dimensions using three-dimensional (3D) ultrasound. METHODS: The reproducibility of diagnosis of congenital uterine anomalies was examined by re-slicing stored 3D ultrasound volumes. Each data set was evaluated by two independent observers. Assessment of uterine morphology was performed in a standardized plane, with the interstitial portions of the Fallopian tubes used as reference points. Additionally, in 35 cases of congenital uterine anomalies the width of the uterine cavity (W), fundal distortion (F) and the length of unaffected uterine cavity (C) were measured. Intraobserver and interobserver variabilities were evaluated by each observer performing all three measurements twice. RESULTS: Eighty-three 3D ultrasound volumes were examined. Both operators classified 27 uteri as normal, 33 as arcuate, 19 as subseptate and three as unicornuate. A single case of uterine anomaly was described as arcuate uterus by one operator and subseptate by another (kappa 0.97). The intraobserver variability for each of the three measurements (W, F and C) was satisfactory with limits of agreement ranging from +/-1.43 to +/-2.51 mm. The examination of the interobserver variability showed no significant differences between the two observers (F = 0.484, P > 0.05). CONCLUSION: 3D ultrasound is a reproducible method for the diagnosis of congenital uterine anomalies and for the measurement of uterine cavity dimensions.     

Reproducibility of pulsed Doppler measurements of the maternal renal circulation in normal pregnancies and those with pregnancy-induced hypertension.

OBJECTIVE: To assess the inter- and intraobserver reproducibilities of pulsed Doppler measurements of the maternal renal circulation in normal pregnancies and those affected by pregnancy-induced hypertension. MATERIALS AND METHODS: Color and pulsed Doppler ultrasound was used to measure acceleration time and resistance index in the renal segmental and interlobar arteries. For the investigation of interobserver reproducibility, two sonographers performed measurements blindly in six normal pregnant women and 14 women with pregnancy-induced hypertension between 28 and 36 weeks' gestation. A second group of 10 patients between 30 and 35 weeks' gestation were examined by one sonographer to assess the level of intraobserver reproducibility of measurements. For each patient in this group, the flow waveform was measured three times in succession. Calculations of the intraclass correlation coefficient Ri were used to determine the level of reproducibility. RESULTS: The interobserver Ri and intraobserver Ri for acceleration time in the segmental artery were 0.95 and 0.96 and for the interlobar artery they were 0.97 and 0.98, respectively. For the resistance index, these values were 0.01 and 0.01 in the segmental artery and 0.52 and 0.29 in the interlobar artery. CONCLUSION: Both the inter- and intraobserver reproducibility of acceleration time measurements in the renal segmental and interlobar arteries were clinically acceptable but the equivalent reproducibilities of resistance index measurements were poor.     

Intraobserver and interobserver variability of transabdominal Doppler velocimetry measurements of the fetal ductus venosus between 10 and 14 weeks of gestation.

OBJECTIVE: To assess the intraobserver repeatability and interobserver reproducibility of transabdominal Doppler ultrasound measurements of ductus venosus blood flow in fetuses between 10 and 14 weeks of gestation. DESIGN: A prospective study with the following end-points: coefficient of variation, intraclass correlation coefficients within and between observers, repeatability coefficient and Cohen's kappa coefficient. SUBJECTS AND METHODS: Doppler velocimetry indices (maximum peak systolic velocity during ventricular systole, end-diastolic velocity during atrial contraction, peak systolic velocity/end-diastolic velocity ratio and pulsatility index for veins) were successfully measured three times by the same trained observer in 67 fetuses. Of these, in 24 fetuses, the measurements were then repeated by a second trained observer. In addition, both observers classified qualitatively the blood flow as being normal or abnormal with regard to the presence or absence/reversal of flow during atrial contraction. RESULTS: The intraobserver repeatability of the pulsatility index for veins measurements was considered good with a coefficient of variation of 8.9% and an intraclass correlation coefficient value of 0.62. However, inconsistencies occurred in maximum peak systolic velocity, end-diastolic velocity and systolic/diastolic ratio measurements, which had coefficients of variation of 19%, 28.5%, and 25.4%, respectively. The corresponding intraclass correlation coefficient values were 0.70, 0.69 and 0.60. Interobserver reproducibility of these indices was unsatisfactory, the coefficient of variation varying between 11.5% and 47.2% and the intraclass correlation coefficient between 0.18 and 0.44. Agreement between the repeated observations with regard to interpretation of normal or abnormal blood flow varied from moderate (interobserver) to very good (intraobserver). CONCLUSIONS: There was considerable variability in all Doppler indices except for the intraobserver repeatability of the pulsatility index for veins measurement. This makes the implementation of the semiquantitative Doppler indices in a screening setting difficult. On the contrary, qualitative classification of the flow velocity waveforms seemed to be a reproducible method.     

Colour doppler ultrasound of the lumbar arteries: a novel application and reproducibility study in healthy subjects

Lumbar arteries are important because they are the main source of blood supply to the lumbar spine structures. However, these vessels and their flow characteristics have received little attention and their role in conditions such as low back pain remains unclear. The present study 1. describes the application of duplex ultrasonography in the assessment of lumbar artery blood flow and 2. evaluates the interobserver and intraobserver reproducibility of lumbar artery Doppler velocimetry. A total of 13 healthy volunteers were evaluated by two different examiners successively on the same day and measurements repeated by the same examiners 1 week later. Peak systolic velocities of lumbar arteries were recorded at an optimal angle below 60 degrees . Overall mean peak systolic velocity (+/-SD) for lumbar arteries was 0.158 +/- 0.051 m/s, and mean Doppler angle (+/-SD) was 24.6 +/- 14.5 degrees . For interobserver variability, the coefficient of variation was 23.4% and SD of differences 0.037 m/s. Reliable results of lumbar artery Doppler velocimetry demonstrate its applicability in future clinical investigations in patients with low back disorders. (E-mail: ).     

Technique of color Doppler quantification of vascularity in transplanted kidneys

A new technique for the quantification of vascularity based on the analysis of color Doppler images is described. We utilized velocity information obtained directly from cineloops transferred to a computer for off-line analysis. This methodology was used in transplanted kidneys to assess parenchymal vascularity on the basis of percentage color pixel density and mean flow velocity in mid-kidney cross-sectional regions of interest and the distance from the most peripheral color pixels to the capsule of the kidney. Other color Doppler quantitative methods have lacked reproducibility, and therefore before evaluation of the clinical usefulness of this technique, intraobserver reproducibility and interobserver reliability were assessed in 42 patients; no statistically significant variation was demonstrated. In 13 patients with normally functioning transplants, the mean maximum color pixel density was 34.7+/-13.4%, the mean flow velocity was 5.2+/-0.9 cm/second, and the mean distance to the capsule was 3.3+/-1.1 mm.