IVUS-血管内超声基础和临床.ppt

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VH,IVUS 培训,Rotating Element,Drive Shaft,Multi-element Array,There are two types of imaging systems: Mechanical (rotating transducer) and Electronic Array,IVUS 培训,High frequency sound waves echo off vessel walls and are sent back to system,System electronics process the signal,IVUS 培训,A,L,A = Axial Resolution L= Lateral Resolution,IVUS 培训,Low dynamic range,High dynamic range,IVUS 培训,Intimal disease (plaque) is dense and will appear white Media 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),IVUS 培训,IVUS 培训,Calcium,Bright 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 oscillation of ultrasound between transducer and calcium causing repeating arcs,IVUS 培训,Calcium is quantified by measuring the “arc” it encompasses Calcium is classified by its location within the plaque Superficial calcium is closer to the lumen than to the adventitia Deep calcium is closer to the adventitia than to the lumen,IVUS 培训,Fibrotic Plaque,As bright or brighter than the adventitia (hyperechoic) Majority of atherosclerotic lesions are fibrotic Very dense, fibrous plaques may cause so much acoustic shadowing that they could be misclassified as calcified,IVUS 培训,Soft Plaque,Not as bright as the adventitia (hypoechoic) “Soft” refers to the low echogenicity, generally due to high lipid content in a mostly cellular lesion. Reduced echodensity may also be due to: necrotic zone within plaque intramural hemorrhage thrombus,IVUS 培训,Vulnerable Plaque,Fibrous Cap,Lipid Core,IVUS 培训,Mixed Plaque,IVUS 培训,0,1,4mm,Example of Thrombus,IVUS 培训,Examples of Thrombus,IVUS 培训,Basic Measurements (I),External elastic membrane (EEM) cross sectional area (CSA) = total arterial CSA = media area tracing the boundary between the dark media and the bright adventitia (i.e., the apparent outer edge of the media stripe) Lumen CSA Max and min lumen diameters Stent CSA Max and min stent diameters Plaque+media (P+M) CSA = EEM - Lumen CSA in non-stented lesions = EEM - stent CSA in stented lesions Intimal hyperplasia CSA = Stent - Lumen CSA,IVUS 培训,Basic Measurements (II),Eccentricity = maximum/minimum P+M thickness Plaque Burden (=cross-sectional narrowing or %plaque area) = P+M/EEM CSA Remodeling Index = Lesion/Reference EEM CSA Area Stenosis = (Reference - Lesion)/Reference Lumen CSA Arc of calcium Lesion lengths measured using motorized transducer pullback, ideally at 0.5 mm/sec,IVUS 培训,Non-stented artery,IVUS 培训,Stented Artery,IVUS 培训,Proximal Reference,Lesion Site,Distal Reference,EEM,Lumen,P+M,Max P+M Thickness,Min P+M Thickness,Ca+,IVUS 培训,Proximal Reference,Lesion Site,Distal Reference,EEM CSA = 20.4 Lumen CSA = 9.7 Max lumen diam = 3.7 MLD = 3.1 P+M CSA = 10.7 Eccentricity = 1.0/0.3 Plaque burden = 0.52 Arc of Ca = 60,EEM CSA = 21.6 Lumen CSA = 4.5 Max lumen diam = 32.8 MLD = 2.3 P+M CSA = 17.1 Eccentricity = 3.0/0.1 Plaque burden = 0.79,EEM CSA = 13.3 Lumen CSA = 8.9 Max lumen diam = 3.6 MLD = 3.0 P+M CSA = 4.4 Eccentricity = 0.6/0.2 Plaque burden = 0.33,Average Reference EEM CSA = 16.9 Remodeling Index = 1.3 Average Reference Lumen CSA = 9.3 Area Stenosis = 52%,IVUS 培训,In-Stent Restenosis,In-stent intimal hyperplasia (IH) often appears with a very low echogenicity Could be less echogenic than the blood speckle Appropriate system settings are critical to visualize 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VH,IVUS 培训,Limitations of Coronary Angiography,Focal Disease,50% Lesion,50% Lesion,Diffuse Disease,Angiogram Silhouette,IVUS 培训,Angiographically Silent Disease,In 884 native coronary arteries, the plaque burden in the angiographically “normal” reference segment was 5113%,Mintz GS, et al. J Am Coll Cardiol 1995;25:1479-1485,IVUS 培训,Coronary Remodeling Hypothesis,Compenatory Expansion Maintains Consistant Lumen,Expansion Overcome: Lumen Narrows,Normal Vessel,Minimal CAD,Moderate CAD,Severe CAD,IVUS 培训,Proximal reference,Lesion,Distal reference,Intermediate,remodeling,Negative,remodeling,Positive,remodeling,Nishioka. JACC 1996; 27:1571-1576,Dicotomous Classification of Remodeling,IVUS 培训,A,B,D,E,f,f,C,F,distal,Lumen,e,b,e,b,Lumen,Positive Remodeling,Negative Remodeling,c,c,distal,EEM,EEM,IVUS 培训,Limitations of Coronary Angiography,Angiogram Silhouette,Coronary Cross-section,75%,25%,IVUS 培训,Irregular Plaque / Irregular Lumen,A,Cross-section,RAO View,LAO View,B,C,IVUS 培训,IVUS EEM CSA = 22.7mm2 Lumen CSA = 16.6mm2 Mean lumen diameter = 4.6mm,QCA 9F guiding catheter Reference diameter = 3.12mm,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VH,IVUS 培训,IVUS 培训,(Fisher et al. CCD 1982;8:565-575),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 reading,Of all the coronary segments, the LM is the one with the greatest inter-observer variability Poor interobserver agreement in the angiographic assessment of LMCA stenosis in the CASS study - I,Poor 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 severity,1: 0-24% DS 2: 25-49% DS 3: 50-74% DS 4: 75-89% DS 5: 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 difference,Clinical site vs Quality control,Clinical site vs Study Group,Study Group vs Quality control,IVUS 培训,IVUS 培训,Reference,Lesion,10 mm,Lumen CSA = 18.3mm2 Lumen diameter = 5.0mm,Lumen CSA = 3.6mm2 Lumen diameter = 1.3mm,Lumen CSA = 11.9mm2 Lumen diameter = 3.5mm,Patient with normal ostial LMCA who previously underwent CABG for presumed LMCA disease,Patient with severe, but unrecognized, distal LMCA stenosis who was referred for PTCA of LAD,Suggested IVUS Criteria for a Significant LMCA Stenosis,Most IVUS LMCA studies show either insignificant disease or critical disease, only a minority require careful quantification Lumen CSA 6.0mm2 or MLD 3.0mm are suggested criteria for a significant LMCA stenosis The sum of the lumen areas of the two daughter vessels (LAD and LCX, each of which should be 4.0mm2) = 150% of the parent (LM) These correlated with an abnormal FFR (Jasti et al Circulation 2004;110:2831-6),IVUS 培训,IVUS 培训,Unusual Lesions: IVUS Classification of Angiographic Aneurysms,Of 77 angiographic aneurysms 21 (27%) true aneurysm 3 (4%) pseudoaneurysm 12 (16%) complex plaques or unhealed dissections 41 (53%) normal segment adjacent to one or more stenoses,(Maehara et al. Am J Cardiol 2001;88:365-70),Normal Segment with Adjacent Stenoses,True Aneurysm,Pseudoaneurysm,Ruptured Plaque,Proximal,Distal,Lesion,Max LD = 3.5 mm,Max LD = 3.3 mm,Stent sizing using IVUS,Reference segment disease provides a cushion for oversizing,The high predictive value (90%) for the minimum stent CSA in Cypher stents suggests that most causes of Cypher stent failure will be “mechanical”,Predictors of angiographic restenosis in 550 pts with 670 native artery lesions treated with Cypher stents,Angiographic restenosis (%),Angiographic restenosis (%),IVUS MSA (mm2),IVUS total stent length (mm),(Hong et al. unpublished),Comparison of IVUS-