Limits...
Effect of variable breath-hold positions during cardiac magnetic resonance on measures of left ventricular mechanics

View Article: PubMed Central - HTML

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Measures of left ventricular cardiac mechanics such as strains and torsion are becoming increasingly important for assessing heart function... The effects of different breath-hold positions on measures of cardiac mechanics have not been investigated... A 3T Siemens Tim Trio scanner was equipped with a navigator feedback system to enable subjects to view their diaphragm position in real time during image acquisition... We used this navigator feedback system to acquire a navigator-gated basal, mid-ventricular, and apical slice of two-dimensional cine DENSE at three different breath-hold positions spaced 4 mm apart for a total range of 8 mm... A narrow navigator acceptance window of ± 2 mm was used to properly simulate the different diaphragm positions... Radial strains, circumferential strains, and torsion were calculated for each subject and compared between diaphragm locations using a repeated measures ANOVA with a Huynh Feldt correction... Diaphragm position had a minimal effect on left ventricular radial strain, circumferential strain, and torsion (Figure 1)... The only significant difference between navigator positions was for the mid-ventricular and global peak radial strains (p = 0.01 for both)... Estimated power for detecting a difference was adequate between 70 and 100% suggesting a low probability for Type II errors... Different breath-hold positions simulated with a navigator feedback system had minimal effects on the calculation of peak left ventricular cardiac strains and torsion from two-dimensional DENSE CMR... It will be important to determine whether this result holds true in a future study which includes patients with potentially heterogeneous contraction patterns in the left ventricle.

No MeSH data available.


Related in: MedlinePlus

Average (global) radial and circumferential peak left ventricular strain at the basal, mid-ventricular and apical locations in the heart for 3 different breath-hold positions: baseline, plus 4 mm, and plus 8 mm. Bars indicate the standard deviations. * indicates p < 0.05 when comparing the three breath-hold positions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4043316&req=5

Figure 1: Average (global) radial and circumferential peak left ventricular strain at the basal, mid-ventricular and apical locations in the heart for 3 different breath-hold positions: baseline, plus 4 mm, and plus 8 mm. Bars indicate the standard deviations. * indicates p < 0.05 when comparing the three breath-hold positions.

Mentions: Diaphragm position had a minimal effect on left ventricular radial strain, circumferential strain, and torsion (Figure 1). The only significant difference between navigator positions was for the mid-ventricular and global peak radial strains (p = 0.01 for both). Estimated power for detecting a difference was adequate between 70 and 100% suggesting a low probability for Type II errors.


Effect of variable breath-hold positions during cardiac magnetic resonance on measures of left ventricular mechanics
Average (global) radial and circumferential peak left ventricular strain at the basal, mid-ventricular and apical locations in the heart for 3 different breath-hold positions: baseline, plus 4 mm, and plus 8 mm. Bars indicate the standard deviations. * indicates p < 0.05 when comparing the three breath-hold positions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4043316&req=5

Figure 1: Average (global) radial and circumferential peak left ventricular strain at the basal, mid-ventricular and apical locations in the heart for 3 different breath-hold positions: baseline, plus 4 mm, and plus 8 mm. Bars indicate the standard deviations. * indicates p < 0.05 when comparing the three breath-hold positions.
Mentions: Diaphragm position had a minimal effect on left ventricular radial strain, circumferential strain, and torsion (Figure 1). The only significant difference between navigator positions was for the mid-ventricular and global peak radial strains (p = 0.01 for both). Estimated power for detecting a difference was adequate between 70 and 100% suggesting a low probability for Type II errors.

View Article: PubMed Central - HTML

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Measures of left ventricular cardiac mechanics such as strains and torsion are becoming increasingly important for assessing heart function... The effects of different breath-hold positions on measures of cardiac mechanics have not been investigated... A 3T Siemens Tim Trio scanner was equipped with a navigator feedback system to enable subjects to view their diaphragm position in real time during image acquisition... We used this navigator feedback system to acquire a navigator-gated basal, mid-ventricular, and apical slice of two-dimensional cine DENSE at three different breath-hold positions spaced 4 mm apart for a total range of 8 mm... A narrow navigator acceptance window of ± 2 mm was used to properly simulate the different diaphragm positions... Radial strains, circumferential strains, and torsion were calculated for each subject and compared between diaphragm locations using a repeated measures ANOVA with a Huynh Feldt correction... Diaphragm position had a minimal effect on left ventricular radial strain, circumferential strain, and torsion (Figure 1)... The only significant difference between navigator positions was for the mid-ventricular and global peak radial strains (p = 0.01 for both)... Estimated power for detecting a difference was adequate between 70 and 100% suggesting a low probability for Type II errors... Different breath-hold positions simulated with a navigator feedback system had minimal effects on the calculation of peak left ventricular cardiac strains and torsion from two-dimensional DENSE CMR... It will be important to determine whether this result holds true in a future study which includes patients with potentially heterogeneous contraction patterns in the left ventricle.

No MeSH data available.


Related in: MedlinePlus