IVUS 血管内超声基础和临床课件

1、血管内超声基础和临床应用进展IVUS 培训 IVUS 培训 血管内超声基础和进展一、血管内超声基础二、血管内超声和冠脉造影的关系三、主要适应症四、什么是VHIVUS 培训 Rotating ElementDrive ShaftMulti-element ArrayThe CardiovascularResearch FoundationLenox Hill Heart and VascularInstitute of New YorkThere are two types of imaging systems: Mechanical (rotating transducer) and Elec

2、tronic ArrayIVUS 培训 High frequency sound waves echo off vessel walls and are sent back to systemSystem electronics process the signalThe CardiovascularResearch FoundationLenox Hill Heart and VascularInstitute of New YorkIVUS 培训 Low dynamic rangeHigh dynamic rangeThe CardiovascularResearch Foundation

3、Lenox Hill Heart and VascularInstitute of New YorkIVUS 培训 Intimal disease (plaque) is dense and will appear whiteMedia is made of homogeneous smooth muscle cells and does not reflect ultrasound (appears dark)Adventitia has sheets of collagen that reflect a lot of ultrasound (appears white)The Cardio

4、vascularResearch FoundationLenox Hill Heart and VascularInstitute of New YorkIVUS 培训 CalciumBright echoes (brighter than the adventitia)Obstructs the penetration of ultrasound (acoustic shadowing)only the leading edge is detected and thickness cannot be determined.Results in reverberations - the osc

5、illation of ultrasound between transducer and calcium causing repeating arcsIVUS 培训 80SuperficialDeepDeepCalcium is quantified by measuring the “arc” it encompassesCalcium is classified by its location within the plaqueSuperficial calcium is closer to the lumen than to the adventitiaDeep calcium is

6、closer to the adventitia than to the lumenThe CardiovascularResearch FoundationLenox Hill Heart and VascularInstitute of New YorkIVUS 培训 Fibrotic PlaqueAs bright or brighter than the adventitia (hyperechoic)Majority of atherosclerotic lesions are fibroticVery dense, fibrous plaques may cause so much

7、 acoustic shadowing that they could be misclassified as calcifiedIVUS 培训 Vulnerable PlaqueFibrous CapLipid CoreIVUS 培训 Mixed PlaqueIVUS 培训 Examples of ThrombusIVUS 培训 Basic Measurements (I)External elastic membrane (EEM) cross sectional area (CSA) = total arterial CSA = media areatracing the boundar

8、y between the dark media and thebright adventitia (i.e., the apparent outer edge of the media stripe)Lumen CSAMax and min lumen diametersStent CSA Max and min stent diametersPlaque+media (P+M) CSA = EEM - Lumen CSA in non-stented lesions = EEM - stent CSA in stented lesionsIntimal hyperplasia CSA =

9、Stent - Lumen CSAIVUS 培训 Basic Measurements (II)Eccentricity = maximum/minimum P+M thicknessPlaque Burden (=cross-sectional narrowing or %plaque area) = P+M/EEM CSARemodeling Index = Lesion/Reference EEM CSAArea Stenosis = (Reference - Lesion)/Reference Lumen CSAArc of calciumLesion lengths measured

10、 using motorized transducer pullback, ideally at 0.5 mm/secIVUS 培训 Non-stented arteryEEMGuidewiresIVUS catheterPlaque+mediaLumenIVUS 培训 Stented ArteryEEMLumenStentGuidewireIVUS catheterPlaque+mediaIntimal hyperplasiaIVUS 培训 Proximal ReferenceLesionSiteDistal ReferenceEEMLumenP+MMax P+M ThicknessMin

11、P+M ThicknessCa+The CardiovascularResearch FoundationLenox Hill Heart and VascularInstitute of New YorkIVUS 培训 In-Stent RestenosisIn-stent intimal hyperplasia (IH) often appears with a very low echogenicityCould be less echogenic than the blood speckleAppropriate system settings are critical to visu

12、alize IH (do not “black out” center)IVUS 培训 血管内超声基础和进展一、血管内超声基础二、血管内超声和冠脉造影的关系三、主要适应症四、什么是VHIVUS 培训 Angiographically Silent DiseaseIn 884 native coronary arteries, the plaque burden in the angiographically “normal” reference segment was 5113% Mintz GS, et al. J Am Coll Cardiol 1995;25:1479-1485IVUS

13、培训 Coronary Remodeling HypothesisCompenatory ExpansionMaintains Consistant LumenExpansionOvercome: Lumen NarrowsNormal VesselMinimal CADModerate CADSevere CADIVUS 培训 Proximal referenceLesionDistal referenceIntermediateremodelingNegativeremodelingPositiveremodelingNishioka.JACC 1996; 27:1571-1576Dico

14、tomous Classification of RemodelingIVUS 培训 ABDEffCFdistalLumenebebLumenPositive RemodelingNegative RemodelingccdistalEEMEEMIVUS 培训 Limitations of Coronary AngiographyAngiogram SilhouetteCoronary Cross-section75%25%IVUS 培训 Irregular Plaque / Irregular LumenACross-sectionRAO ViewLAO ViewBCIVUS 培训 The

15、CardiovascularResearch FoundationLenox Hill Heart and VascularInstitute of New YorkIVUSEEM CSA = 22.7mm2Lumen CSA = 16.6mm2Mean lumen diameter = 4.6mmQCA9F guiding catheterReference diameter = 3.12mmIVUS 培训 血管内超声基础和进展一、血管内超声基础二、血管内超声和冠脉造影的关系三、主要适应症四、什么是VHIVUS 培训 IVUS 培训 (Fisher et al. CCD 1982;8:565

16、-575)Comparison between percent stenosis assessment from the quality control lab vs the clinical site*area of the square is proportional to the number of cases with the given readingQC labClinical site10001000Of all the coronary segments, the LM is the one with the greatest inter-observer variabilit

17、y Poor interobserver agreement in the angiographic assessment of LMCA stenosis in the CASS study - IPoor interobserver agreement in the angiographic assessment of LMCA stenosis in the CASS study - II(Cameron et al. Circulation 1983;68:484-489)Five grades of LM severity1: 0-24% DS2: 25-49% DS3: 50-74

18、% DS4: 75-89% DS5:90-100%DS# of grades of difference in assessment of LM severity 0:no difference+1 or -1:1 grade difference+2 or -2:2 grades of difference+3 or -3:3 grades of difference+4 or -4:4 grades of differenceClinical site vs Quality controlClinical site vs Study GroupStudy Group vs Quality

19、controlIVUS 培训 IVUS 培训 ReferenceLesion10 mmLumen CSA = 18.3mm2Lumen diameter = 5.0mmLumen CSA = 3.6mm2Lumen diameter = 1.3mmLumen CSA = 11.9mm2Lumen diameter = 3.5mmPatient with normal ostial LMCA who previously underwent CABG for presumed LMCA diseasePatient with severe, but unrecognized, distal LM

20、CA stenosis who was referred for PTCA of LADSuggested IVUS Criteria for a Significant LMCA StenosisMost IVUS LMCA studies show either insignificant disease or critical disease, only a minority require careful quantificationLumen CSA 6.0mm2 or MLD 4.0mm2 (%)Cypher5.0*sensitivityspecificity01020304050

21、607080901003.54.04.55.05.56.07.07.58.08.5F/U MLA 4.0mm2 (%)Bare Metal Stents6.5*Minimum stent area (mm2)Minimum stent area (mm2)(Sonoda et al. J Am Coll Cardiol 2004;43:1959-63)*predictive value=56%*predictive value=90%Predictors of angiographic restenosis in 550 pts with 670 native artery lesions t

22、reated with Cypher stents0204060801000204060801003.54.04.55.05.56.06.57.07.5Angiographic restenosis (%)Angiographic restenosis (%)IVUS MSA (mm2)10152025303540455560657075IVUS total stent length (mm)40mm17.7%8.6%(Hong et al. unpublished)Comparison of IVUS-measured minimum stent diameter (MSD) and minimum stent area (MSA) with the predicted measurements from Cordis (Cypher in yellow, n=133) and BSC (Taxus in red, n=67). DES achieve an average of only 75% of the predicted MSD (66% of MSA)IVUS Measured MSA (mm2)Predicted MSA (mm2)IVUS Measured MSD (mm)Predicted MSD (mm)24%Peri-Stent Haziness