Myocardial Perfusion Imaging With Contrast Ultrasound
Thomas R. Porter, MD*,
Feng Xie, MD
University of Nebraska Medical Center, Omaha, Nebraska
View larger version (25K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1 An Example of the Excellent Background Subtraction
The images are achieved with low–mechanical index pulse sequence schemes designed to assess myocardial perfusion. In this apical 4-chamber view, note that there are virtually no signals from the myocardium before contrast administration (A), but excellent left ventricular cavity opacification (B) and eventual myocardial contrast (C) after venous infusion of ultrasound contrast. The attenuation in the basal segments is most likely due to a high initial concentration of microbubbles in the left ventricular cavity.
|
|
View larger version (63K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2 An Example of Normal Myocardial Replenishment (Apical 3-Chamber)
With real-time perfusion image, the myocardial replenishment is after a high–mechanical index (MI) impulse. Note under resting conditions (A) that normal replenishment occurs within 4 s of the high MI impulse, whereas during stress (vasodilator, dobutamine, exercise), replenishment normally occurs within 2 s (B).
|
|
View larger version (37K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3 An Example of a Subendocardial Perfusion Defect
The defect is evident in the anteroseptal and apical segments of the left ventricle during the replenishment phase of contrast after a high–mechanical index impulse during adenosine stress imaging. Note that because the defect was confined to the subendocardium (black arrows), there was no evident defect noted on the lower-resolution radionuclide single-photon emission computed tomography (SPECT) image despite the presence of significant coronary artery disease at angiography (Angio) (red arrows). Reprinted, with permission, from Xie et al. (33).
|
|
View larger version (47K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4 Proposed Protocols for Dipyridamole or Adenosine Stress Infusions
The images shown are not intended for analysis of perfusion, but to serve as reminders when to examine myocardial contrast echocardiography.
|
|
View larger version (68K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5 An Example of a Subendocardial Wall-Thickening Abnormality
The abnormality is delineated by real-time perfusion imaging during the replenishment phase of contrast (During MCR) after the high–mechanical index (MI) impulse. If only transmural wall thickening were examined in this patient (Pre-MCR after High MI Impulse images), the wall thickening would have appeared normal. Reprinted, with permission, from Xie et al. (55). MCR = myocardial contrast replenishment.
|
|
View larger version (45K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6 An Example of an Inferior Wall Perfusion Defect
The defect was confined to the subendocardium after treadmill exercise stress, where a subendocardial wall-thickening abnormality was also observed (blue arrows). Note also the end-systolic shape change that accompanies the perfusion defect. The open arrows indicate an area of rib shadowing that prevented delineation of perfusion in the basal to mid-anterior segments. A foreshortened apical 2-chamber view can be used to delineate perfusion in these segments.
|
|
View larger version (57K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7 Proposed Protocols for Dobutamine or Treadmill/Bicycle Exercise Stress
The images shown are not intended for analysis of perfusion, but to serve as reminders when to examine myocardial contrast echocardiography (MCE).
|
|
View larger version (64K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8 An Example of a Patient With Left Bundle Branch Block
An example of a patient with left bundle branch block who exhibited normal perfusion with myocardial contrast echocardiography but abnormal perfusion in the septum during radionuclide single-photon emission computed tomography despite no significant coronary artery disease. See text for details. Reprinted, with permission, from Hayat et al. (34).
|
|
|
