Evaluation of a new ultrasound contrast agent (AI-700) using two-dimensional and three-dimensional imaging during acute ischemia.
BACKGROUND
A new intravenous contrast agent, AI-700, was evaluated to determine whether a bolus injection could be used to detect myocardial perfusion abnormalities during acute ischemia by using 2-dimensional (2D) and 3-dimensional (3D) myocardial contrast echocardiography.


METHODS
2D MCE was performed in 14 closed-chest dogs during coronary occlusion by using both continuous and triggered gray scale harmonic imaging and triggered power Doppler imaging. 3D MCE (open-chest) and nuclear perfusion imaging were performed in 10 of the 14 dogs. Postmortem triphenyl tetrazolium chloride (TTC) staining was performed to verify infarction.


RESULTS
Thirteen of the 14 dogs had infarct by TTC; all 10 that had nuclear imaging showed a perfusion defect. Of the 13 dogs that had infarction, perfusion defects were detected in all (13 of 13) by gray scale harmonic imaging (sensitivity = 100%), and in 11 of 13 by power Doppler imaging (sensitivity = 85%). All 10 dogs that had nuclear imaging showed perfusion defects by gray scale harmonic imaging (sensitivity = 100%) and 8 of 10 by power Doppler imaging (sensitivity = 80%). The perfusion defect size, derived from 3D imaging (25% +/- 12%) correlated well with that from nuclear imaging (24% +/- 12%) (y = 0.9x + 3.8, r = 0.96, mean difference = 1.3% +/- 2.6%). The perfusion defect mass by 3D (22 +/- 14 g) also correlated well with the infarct mass by TTC staining (24 +/- 16 g) (y = 0.8x + 2.9, r = 0.89, P <.001, mean difference = -2.8 +/- 7.6 g).


CONCLUSIONS
After a single bolus of AI-700, both 2D and 3D MCE could accurately detect perfusion defects representing the area at risk of infarction during acute ischemia compared with nuclear imaging and predicted the size of infarction as verified by TTC staining.
Yao
Jiefen
J
Cardiovascular Imaging and Hemodynamic Laboratory Division of Cardiology, Department of Medicine, New England Medical Center, Tufts University School of Medicine, Boston, USA.
Takeuchi
Masaaki
M
Teupe
Claudius
C
Sheahan
Malachi
M
Connolly
Raymond
R
Walovitch
Richard C
RC
Fetterman
Robert C
RC
Church
Charles C
CC
Udelson
James E
JE
Pandian
Natesa G
NG
D000818:Animals; D003287:Contrast Media; D004195:Disease Models, Animal; D004285:Dogs; D019560:Echocardiography, Three-Dimensional; D005466:Fluorocarbons; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D019344:Lactic Acid; D008863:Microspheres; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi
D003287:Contrast Media; D005466:Fluorocarbons; D011108:Polymers; D019275:Radiopharmaceuticals; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017256:Technetium Tc 99m Sestamibi