Measurement of Ventricular Torsion by Two-Dimensional Ultrasound Speckle Tracking Imaging
Yuichi Notomi, MD*,
Peter Lysyansky, PhD ,
Randolph M. Setser, DSc ,
Takahiro Shiota, MD, FACC*,
Zoran B. Popovi , MD*,
Maureen G. Martin-Miklovic,
Joan A. Weaver, RT*,
Stephanie J. Oryszak*,
Neil L. Greenberg, PhD, FACC*,
Richard D. White, MD*, and
James D. Thomas, MD, FACC*,*
* Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, Cleveland, Ohio
Department of Radiology, The Cleveland Clinic Foundation, Cleveland, Ohio
GE Ultrasound Israel Ltd, Tirat Hacarmel, Israel
View larger version (89K):
[in a new window]
|
Figure 1 Left ventricular rotation (LVrot) at apical and basal levels during systole by "overlaid" speckle tracking images. End-systolic speckle tracking imaging acquisitions are overlaid on the end-diastolic image with corresponding local trajectories (tail and head of arrows indicate the location of end-diastole and end-systole). The LVrot was estimated from all of these regional angle displacements. Normally, at apical level, the left ventricle rotates counterclockwise as viewed from apex, whereas the base rotates clockwise, as in this representative case. This gradient of LVrot between the two levels creates a "wringing" motion of the left ventricle. Videos of speckle tracking imaging in apical and basal short-axis views are available at www.onlinejacc.org.
|
|
View larger version (81K):
[in a new window]
|
Figure 2 Speckle tracking of successive two-dimensional images obtained from a speckle tracking imaging movie at the apical level during systole in a representative patient. Shown is every sixth frame from successive apical short-axis images, from end-diastole (ED) (onset of QRS of the electrocardiogram) to end-systole (ES), as displayed on the workstation. The small red dots depict the endocardial (Endo) and epicardial (Epi) borders, with the midmyocardium shown more boldly, defining the region of interest. The colored points track individual locations throughout the cardiac cycle. The left ventricular (LV) centroid is shown as a small red cross in the LV cavity and is determined from the midmyocardial line in each frame. The blue crossed lines indicate the averaged LV rotation calculated from the angle displacement of all of mid-myocardial dots.
|
|
View larger version (110K):
[in a new window]
|
Figure 3 (A) Quantification of local angle displacement of the specific region. A representative apical rotation is shown. Regional angle displacement ( ) was defined by position of a specific tissue element at two different time points and center of the gravity determined by the midmyocardial points. (B) and (C) Profile curve of left ventricular rotation and rotational velocity in a cardiac cycle displayed on the workstation. Left ventricular rotation was calculated from the average of regional points in the midmyocardium (B). Left ventricular rotational velocity was estimated by time-derivation of the left ventricular rotation profile (C). See Figure 2 legend for definitions of ED, ES, red cross, and blue lines.
|
|
View larger version (29K):
[in a new window]
|
Figure 4 Left ventricular (LV) torsion and torsional profile curve by tagged magnetic resonance (MRI), Doppler tissue imaging (DTI), and speckle tracking imaging (STI) in a representative patient. Arrows indicate peak LV torsion and peak LV systolic and untwisting velocity.
|
|
View larger version (42K):
[in a new window]
|
Figure 5 Correlation and agreement plots of torsion and torsional velocity between imaging modalities. The correlation using all the time points was analyzed by repeated-measures regression model, whereas the peak values (filled symbols) were analyzed by simple linear regression. DTI = Doppler tissue imaging; LV = left ventricular, MRI = magnetic resonance imaging; STI = speckle tracking imaging.
|
|
|
