경동맥 초음파의 기술적인 문제

[byungin]

Section thickness artifact. or  mirror image artifact ?

    610727- 11-07-01

670501/ 12.2.25

Section thickness artifacts.
http://www.google.co.kr/url?sa=t&rct=j&q=mirror%20artifact%20in%20carotid%20ultrasound&source=web&cd=1&ved=0CC8QFjAA&url=http%3A%2F%2Fwww.neurosonology.or.kr%2Ffunc%2Fdownload.php%3Fpath%3DL2hvbWUvdmlydHVhbC9uZXVyb3Nvbm9sb2d5L2h0ZG9jcy91cGxvYWQvam91cm5hbC8yMDA5MDEwMDEucGRm%26filename%3DMjAwOTAxMDAxLnBkZg%3D%3D&ei=5dJqT8KlFqjkmAXNw7maBg&usg=AFQjCNF8l_Gfzpgk29vJx-cZVoCYwdy1Zg&cad=rjt

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굴곡이 심한 ICA 의 속도 측정을 하였습니다.

첫 번째에는 혈류방향과 동일한 입사각으로,  두 번째에는 혈류방향과 각도를 60도 정도의 입사각으로 측정하였습니다.

어떤 방법이 좋습니까?

Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness > 1.5 mm as measured from the media-adventitia interface to the intima-lumen interface.

The common vascular process consisted of an extended, diffusely distributed, heterogeneous echogenic mass with irregular surfaces distributed in the distal common carotid, proximal internal carotid, and the carotid bifurcation, including the carotid bulb

http://stroke.ahajournals.org/content/22/8/989.full.pdf+html

carotid plaque morphology

Carotid Plaque Echolucency Increases the Risk of Stroke in Carotid Stenting  http://circ.ahajournals.org/content/110/6/756.short

Type 1 plaques were uniformly echolucent, type 2 predominantly echolucent, type 3 predominantly echogenic, type 4 uniformly echogenic and type 5 consisted of plaques that could not be classified owing to heavy calcification and acoustic shadows
http://onlinelibrary.wiley.com/doi/10.1002/bjs.1800801016/abstract

The common vascular process consisted of an extended, diffusely distributed, heterogeneous echogenic mass with rregular surfaces distributed in the distal common carotid, proximal internal carotid, and the carotid bifurcation, including the carotid bulb (Figure LA).
As for atherosclerotic plaques in general, we did not observe regression of large calcified plaques. Rather, regression correlated with the initial observation of exclusively nonencroaching soft plaques in our patients.
http://stroke.ahajournals.org/content/22/8/989.full.pdf+html

A number of investigators have observed that the majority of patients with highly stenotic, atherosclerotic carotid plaques remain asymptomatic. For example, in the Asymptomatic Carotid Atherosclerosis Study (ACAS), unoperated patients with a greater than 60% diameter reducing carotid artery stenosis had only an 11.0% risk for ipsilateral hemispheric stroke at 5 years and a 19.2% 5-year risk for ipsilateral transient ischemic attack or stroke. http://stroke.ahajournals.org/content/28/1/95.short
Avril et al8 classified carotid plaques as "hard" (predominantly composed of collagen or calcium) or "soft" (containing atheromatous debris or intraplaque hemorrhage). Soft plaques were significantly more common in symptomatic carotid lesions. http://stroke.ahajournals.org/content/28/1/95.short

There was no difference between plaques removed from asymptomatic and symptomatic patients with regard to the presence and volume of fibrous intimal tissue, intraplaque hemorrhage, the lipid core, the necrotic core, or calcification.
http://stroke.ahajournals.org/content/28/1/95.short

Plaque constituents were defined as follows: (1) fibrous intimal tissue: plaque regions rich in collagen bundles (Fig 1a); (2) intraplaque hemorrhage: regions of fibrin deposits and lysed red blood cells with some surrounding inflammatory cell infiltrate (Fig 1b). These areas are in contradistinction to hemorrhage caused by operative manipulation, in which intact red blood cells without surrounding tissue reaction are seen; (3) lipid core: distinct regions containing diffusely distributed clefts from which cholesterol crystals have been extracted (Fig 1c); (4) necrotic core: discrete regions with loosely aggregated necrotic debris, no viable cells, and without admixed collagen (Fig 1d); and (5) calcification: aggregates of prominent calcification, usually of either necrotic cellular debris or collagenous stroma, but devoid of cells (Fig 1e). http://stroke.ahajournals.org/content/28/1/95.short

Characterizing the nature of the fibrous cap that overlies the lipid-rich plaque core may be more productive. For example, a thinned fibrous cap may be more prone to plaque rupture. Defining the surface morphology of the lesion may also be important. In a review of patients enrolled in the North American Carotid Endarterectomy Trial, Eliasziw et al24 found a higher risk for subsequent stroke if angiographic evidence of a plaque ulcer was demonstrated. In unoperated patients with a nonulcerated 85% carotid stenosis, the risk for ipsilateral stroke at 24 months was 21.3% compared with 43.9% in patients with an ulcerated 85% stenosis. In patients with a 95% carotid stenosis, the 2-year risk for ipsilateral stroke was 21.3% in patients without evidence of ulcer and 73.2% in patients with ulcerated lesions.
http://stroke.ahajournals.org/content/28/1/95.full

질문: 아래의 wall thickening 은 plaque 라고 표현하는지?

답변: Prof 손: 지난번 CCA에 diffuse plaque에 관해서 언급을 하자면....

책 (Cerebrovascular Ultrasound in stroke prevention and treatment 2nd, pp95)을 보니 이런 내용이 적혀 있네요.

Clearly , homogeneous plaques are most likely to be purely cellular in nature with little evidence of becoming complex (when calcification, significant cholesterol deposition or hemorrhage appear). Homogeneous plaques are commonly associated with intimal hyperplasia.

Carotid plaque area: a tool for targeting and eval‎uating vascular preventive therapy.

Spence JD, Eliasziw M, DiCicco M, Hackam DG, Galil R, Lohmann T.

Stroke. 2002 Dec;33(12):2916-22.

http://stroke.ahajournals.org/content/33/12/2916.short

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indication of TCD
Sickle Cell diseas : Effective, Class 1: MCA의 PV>200cm/s 이면 Hb 저하 위험수위이므로 수혈
Ischemic CVA: Established, Class II
  Proximal intracranial arterial stenosis, Collaterals, Microembolization

SAH:  Established, Class II
Migraine: Doubtfull, Class II
http://www.ispub.com/journal/the-internet-journal-of-emergency-and-intensive-care-medicine/volume-4-number-1/transcranial-doppler-an-overview-of-its-clinical-applications-1.html