IVUS基礎(chǔ)—阜外醫(yī)院錢杰.ppt

1、血管內(nèi)超聲基礎(chǔ)和臨床應(yīng)用進(jìn)展 阜外醫(yī)院 錢杰,IVUS 培訓(xùn),IVUS 培訓(xùn),血管內(nèi)超聲基礎(chǔ)和進(jìn)展,一、血管內(nèi)超聲基礎(chǔ) 二、血管內(nèi)超聲和冠脈造影的關(guān)系 三、主要適應(yīng)癥 四、什么是VH,IVUS 培訓(xùn),Rotating Element,Drive Shaft,Multi-element Array,There are two types of imaging systems: Mechanical (rotating transducer) and Electronic Array,IVUS 培訓(xùn),High frequency sound waves echo off vessel walls

2、and are sent back to system,System electronics process the signal,IVUS 培訓(xùn),A,L,A = Axial Resolution L= Lateral Resolution,IVUS 培訓(xùn),Low dynamic range,High dynamic range,IVUS 培訓(xùn),Intimal disease (plaque) is dense and will appear white Media is made of homogeneous smooth muscle cells and does not reflect

3、ultrasound (appears dark) Adventitia has sheets of collagen that reflect a lot of ultrasound (appears white),IVUS 培訓(xùn),IVUS 培訓(xùn),Calcium,Bright echoes (brighter than the adventitia) Obstructs the penetration of ultrasound (acoustic shadowing) only the leading edge is detected and thickness cannot be det

4、ermined. Results in reverberations - the oscillation of ultrasound between transducer and calcium causing repeating arcs,IVUS 培訓(xùn),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

5、adventitia Deep calcium is closer to the adventitia than to the lumen,IVUS 培訓(xùn),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

6、calcified,IVUS 培訓(xùn),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 培訓(xùn),Vulnerable Pla

7、que,Fibrous Cap,Lipid Core,IVUS 培訓(xùn),Mixed Plaque,IVUS 培訓(xùn),0,1,4mm,Example of Thrombus,IVUS 培訓(xùn),Examples of Thrombus,IVUS 培訓(xùn),Basic Measurements (I),External elastic membrane (EEM) cross sectional area (CSA) = total arterial CSA = media area tracing the boundary between the dark media and thebright adven

8、titia (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 培訓(xùn),Basic Measure

9、ments (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 pull

10、back, ideally at 0.5 mm/sec,IVUS 培訓(xùn),Non-stented artery,IVUS 培訓(xùn),Stented Artery,IVUS 培訓(xùn),Proximal Reference,Lesion Site,Distal Reference,EEM,Lumen,P+M,Max P+M Thickness,Min P+M Thickness,Ca+,IVUS 培訓(xùn),Proximal Reference,Lesion Site,Distal Reference,EEM CSA = 20.4 Lumen CSA = 9.7 Max lumen diam = 3.7 MLD

11、= 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

12、 Plaque burden = 0.33,Average Reference EEM CSA = 16.9 Remodeling Index = 1.3 Average Reference Lumen CSA = 9.3 Area Stenosis = 52%,IVUS 培訓(xùn),In-Stent Restenosis,In-stent intimal hyperplasia (IH) often appears with a very low echogenicity Could be less echogenic than the blood speckle Appropriate syst

13、em settings are critical to visualize IH (do not “black out” center),IVUS 培訓(xùn),血管內(nèi)超聲基礎(chǔ)和進(jìn)展,一、血管內(nèi)超聲基礎(chǔ) 二、血管內(nèi)超聲和冠脈造影的關(guān)系 三、主要適應(yīng)癥 四、什么是VH,IVUS 培訓(xùn),Limitations of Coronary Angiography,Focal Disease,50% Lesion,50% Lesion,Diffuse Disease,Angiogram Silhouette,IVUS 培訓(xùn),Angiographically Silent Disease,In 884 native

14、 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 培訓(xùn),Coronary Remodeling Hypothesis,Compenatory ExpansionMaintains Consistant Lumen,ExpansionOvercome: Lumen Narrows,Normal Vessel,Minimal CAD,Mo

15、derate CAD,Severe CAD,IVUS 培訓(xùn),Proximal reference,Lesion,Distal reference,Intermediate,remodeling,Negative,remodeling,Positive,remodeling,Nishioka.JACC 1996; 27:1571-1576,Dicotomous Classification of Remodeling,IVUS 培訓(xùn),A,B,D,E,f,f,C,F,distal,Lumen,e,b,e,b,Lumen,Positive Remodeling,Negative Remodeling

16、,c,c,distal,EEM,EEM,IVUS 培訓(xùn),Limitations of Coronary Angiography,Angiogram Silhouette,Coronary Cross-section,75%,25%,IVUS 培訓(xùn),Irregular Plaque / Irregular Lumen,A,Cross-section,RAO View,LAO View,B,C,IVUS 培訓(xùn),IVUS EEM CSA = 22.7mm2 Lumen CSA = 16.6mm2 Mean lumen diameter = 4.6mm,QCA 9F guiding catheter

17、Reference diameter = 3.12mm,IVUS 培訓(xùn),血管內(nèi)超聲基礎(chǔ)和進(jìn)展,一、血管內(nèi)超聲基礎(chǔ) 二、血管內(nèi)超聲和冠脈造影的關(guān)系 三、主要適應(yīng)癥 四、什么是VH,IVUS 培訓(xùn),IVUS 培訓(xùn),(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

18、 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

19、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 di

20、fference +4 or -4:4 grades of difference,Clinical site vs Quality control,Clinical site vs Study Group,Study Group vs Quality control,IVUS 培訓(xùn),IVUS 培訓(xùn),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

21、,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 cr

22、itical 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

23、abnormal FFR (Jasti et al Circulation 2004;110:2831-6),IVUS 培訓(xùn),IVUS 培訓(xùn),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

24、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

25、 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-