Operator Induced Variability in Cardiovascular MR: Left Ventricular Measurements and Their Reproducibility

106

112

Purpose: To assess normal values for biventricular function, volumes, and mass with current cardiovascular magnetic resonance (CMR) imaging sequences in children. Materials and Methods:Included in the study were 60 healthy children aged 8 -17 years. A short axis set of contiguous slices was acquired with CMR imaging employing steady-state free precession. Biventricular end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and mass were determined. Uni-and multivariate linear regression analyses were performed to study the interrelation of age, gender, and body surface area (BSA) on biventricular volumes and mass. The coefficient of variation was calculated for intra-and interobserver variability.Results: EF did not differ between boys and girls (mean LV-EF 69 Ϯ (SD) 5%, mean RV-EF 65 Ϯ 5%). BSA had good (EDV, mass) and modest (ESV) correlation with biventricular measurements. Gender appeared a significant modifier of these relations, whereas age had no independent contribution. The intra-and interobserver coefficient of variation was in the range 2.1%-13.9% for biventricular EDV, ESV, and mass. Conclusion:This study reveals gender-specific normative data for biventricular function, volumes, and mass in children age 8 -17 years that can be used as reference data in the follow-up of pediatric cardiac patients.

Section: Discussionsupporting

confidence: 85%

Normal biventricular function, volumes, and mass in children aged 8 to 17 years

Robbers‐Visser

Boersma

Helbing

2009

106

112

“…The consistency of manual CMR planning was reported in Ref. 24. According to the same criterion, the intraoperator planning accuracy was 2.67°Ϯ 1.5°.…”

mentioning

confidence: 60%

“…An experienced operator would not have much difficulty in identifying the important anatomical landmarks, such as the apex and atrioventricular ring, and aligning the first and last imaging planes of the SA stack with these landmarks. Additionally, the average angular deviation of the LV axis from the optimal orientation amounts to 2.67°and may be considered negligible (24). However, in automated CMR planning the first and last imaging planes of the SA stack do not always coincide with the apex and mitral valve, and the average angular deviation of the LV axis is considerably larger (7.13°) than that in manual planning (23).…”

Section: Discussionmentioning

confidence: 98%

“…Therefore, our findings confirm the importance of adequate imaging of the most basal slice, and its contribution to the derived volumetric measurements. Including all slices that showed a Ͼ50% circumference of the LV myocardium (23,24,28) turned out to be a practical approach for reducing variability in CMR measurements.…”

Section: Discussionmentioning

confidence: 99%

“…The minimal and maximal angles were approximately equal to the average angular deviation of the LV axis Ϯ the standard deviation (SD) for the automated CMR planning, as reported in Ref. 24. Three types of experiments were performed for each interslice distance.…”

Section: Theoretical Studymentioning

confidence: 99%

See 2 more Smart Citations

Influence of positional and angular variation of automatically planned short‐axis stacks on quantification of left ventricular dimensions and function with cardiovascular magnetic resonance

Danilouchkine

Geest

Westenberg

et al. 2005

Purpose: To theoretically and experimentally investigate the influence of the automated cardiovascular magnetic resonance (CMR) scan planning pitfalls, namely inaccurate positioning and tilting of short-axis (SA) imaging planes, on quantification of the left ventricular (LV) dimensions and function. Materials and Methods:Eleven healthy subjects and eight patients underwent CMR. Manually and automatically planned SA sets were acquired. To obtain the quantitative measurements of LV function, one observer performed image analysis twice. The agreement between planning methods, as well as the decomposition of the total variation into interstudy and intraobserver components was measured. Results:The decomposition of the total variation showed that the interstudy factor accounts for 70 -85% of the total variation, while the rest is due to the intraobserver factor. Moreover, the relative contribution of the interstudy factor remains independent from errors in slice positioning and small angular deviation of SA stacks from the optimal orientation. Good agreement between the theoretical and measured variability factors was observed. Conclusion:Global LV function derived from the automatically planned CMR acquisitions yield accurate quantification of the human cardiovascular system. Inaccurate positioning and tilting of SA images does not affect the quantitative measurements of LV function. The computeraided system for automated CMR has proven clinical applicability.

Quantitative assessment of ventricular function using three‐dimensional SSFP magnetic resonance angiography

Greil

Boettger

Germann

et al. 2007

Purpose: To evaluate three-dimensional (3D), free-breathing, steady-state free precession (SSFP) magnetic resonance angiography (MRA) for volumetric assessment of ventricular function. Materials and Methods:In 18 subjects (mean age ϭ 21.5 years) 3D datasets of the heart and great vessels were acquired using an ECG-triggered, free-breathing SSFP technique with a T2-preparation prepulse. Data were acquired during end-systole (ES) and end-diastole (ED) for assessment of stroke volumes (SVs). Through-plane flow measurements of the great arteries were performed as well as 2D-cine SSFP imaging for comparison. For image analysis of the 3D SSFP datasets a simplex mesh model was used. Papillary muscles were excluded from ventricular volumes using thresholds. Intra-and interobserver variability (Bland-Altman analysis) and correlations (Pearson's coefficient) between volumetric and flow measurements were assessed.Results: ES and ED datasets were acquired successfully in all subjects. The best correlation was observed between flow vs. 3D SSFP SV for the LV (r ϭ 0.85, mean difference ϭ -1.0 mL) and the RV (r ϭ 0.89, mean difference ϭ -2.2 mL) with high intra-(LV: r ϭ 0.93; RV: r ϭ 0.94) and interobserver (LV: r ϭ 0.91; RV: r ϭ 0.93) reproducibility. Conclusion:3D SSFP datasets combined with semiautomatic segmentation algorithms allow highly accurate and reproducible assessment of left (LV) and right ventricular (RV) SVs in free-breathing subjects.