The New Development of Diagnostic Ultrasound in Cardiovasology
This article briefly reviews the new development of diagnostic ultrasound in cardioradology. These new developments include intravascular ultrasound imaging,stress eehoeardiography,contrast e- choeardiography,three-dimensional echoeardiography,transesophagedal echocardiography and new tech- niques such as DTI,and CK. IVUS:The small ultrasound imaging catheter possesses high frequency ultrasound 20～30MHz.The catheter-ultrasound system can provide circumferetial 2D imaging of the coronary arteries.IVUS provides the images of atherosolerosis plaque,which will define the definite thickness,size,position and morpholo- gy of the plaque,measure the lumen and are in vascular IVUS also used in conjunction with eatheferbased interventional therapy(balloon angioplasty,atherectomy and metallic stent). MCE:Contrast echocardiography provides an efficient and reliable method for combining tomic and physi- ologic information.The contrast agents include four types: 1.Sonicated contrast agent albumin 2.Galactose-stabilized microbubbles 3.Fluorocarbon chemicals: a.dodecafluoropentane such as the commercial prepared agent Echoger,QW 3600,QW 563A b.PESUA(perfluoropopane exposed sonicated dextrose ablumin) c.Sulphur Hexafluoride,BRI d.perflouropropane-filled albumin,FS069 4.Lipid-based contrast agent,MRXll5,a lipid-coated porfluoropropane contrast agent. One of the most useful clinical applications of contrast has been the assessment of"area at risk"during coronary occlusion,and also the assessment of infarct size,the collateral blood flow,and the coronary blood flow reserve (CFR),used to detect the hibernating myocordium,stunning myocardiun and myocar- dial viability. Stress echo:Bicycle exercise stress testing and dobutamin pharmacologic stress echo are the two most used agents for stress echo.Stress echo can be used in the detection of coronary artery disease and myocar- dial infarct.An exciting area in the field of stress echo is the assessment of myocardial viability,stunning myocardium,hibernating myoxardium,and the predicted outcome in patients with myocardial infarct. Three-dimensional echocardiography:3D echocardiography provides an accurate,non-invasive assessment of rentricular systolic functions,such as ventricular volume,ejection fraction,and cardioal output.3D may be used in the diagnosis of valve disease,cardiomyopathy,congenital heart disease and coronary artery disease. Transesophageal echocardiography(TEE):The multi-plane transducer is the new generation of TEE,u- tilizing a single array that can be rotated 180 degrees,thus produing a continual multi-plane views.Opti- mal imaging of left and atrial appendages,IAS,AO,RVOT,PV(value),pulmonary rein,coronary artery and prosthetic value. DTI(Doppler tissue imaging)and CK(color kinesis):New techniques used for the ventricular wall mo- tion analysis.