1. CONTRAST ECHOCARDIOGRAPHY Detection of Thrombus
Division of Cardiology
Department of Internal Medicine
Tae Kyung Yu

2. I. Detection of Thrombus
Be aware of normal structure or non-pathologic conditions

3. Benign conditions misinterpreted as pathologiesRA
Chiari network
Eustachian valve
Crista terminalis
Catheter/Pacemaker leads
Lipomatous hypertrophy of IAS
Pectinate muscle LA
Suture line of cardiac transplant
Calcified mitral annulus
Coronary sinus
Transverse sinus RV
Moderator band
Muscle bundles
Trabeculations LV
False chordae
Papillary muscles
LV trabeculation

4. I. Detection of Thrombus
Consider the clinical settings for correct diagnosis
Stasis of blood flow
MS, A.fib, severe LV dysfunction, LV aneurysm
Thrombus like lesions without stasis of blood flow
Thrombus less likely

5. I. Detection of Thrombus
Typically amormphous, echogenic structure
Variable shape
adherent to the endocardium
Multiple , mobile and protrude into the cavity
Generally involve the apex of the LV
Presence of akinesia or dyskinesia

6. I. Detection of Thrombus
Can be easily missed in routine echocardiography, if not suspected
TTE Sensitivity 75~95%
Always consider contrast echocardiography if not good apical visualization
Sometimes even MRI or CT can miss apical thrombus, if not suspect

8. II. Contrast Echocardiography
Microbubbles
Agitated saline or contrast agent
Gas-filled microbubbles
Harmonic imaging
Nonlinear oscillation
Intermittent imaging
Real-time myocardial perfusion imaging
Microbubble에 높은 압력의 초음파를 투사하면 nonlinear oscillation하면서 주사된 것과 같은 주파수 이외에 기존의 주파수의 배수가 되는 harmonics를 발생하고 초음파에서 선택적으로 harmonics의 주파수에 해당하는 신호을 받아드린 것이 harmonic imaging
또한 더윽 증가된 세기의 초음파가 투사되면 microbubble은 파괴되고 내부의 gas가 노출되어 더 높은 harmonics를 만드므로 기포를 파괴시키는 것이 microbubble의 신호를 영상화하는데 가장 효과적인 방법으로 한 개의 pulse에 의해 미세비포가 파괴된 후 혈액의 관류에 따라 다시 미세기포가 조직내에 나타날때까지 일정 시간 기다렸다 투사하는 internittent imaging을 써야한다.
최근에는 continuous imaging으로 조영증가를 관찰하기위해 microbubble를 파괴시키지않는 비교적 작은 세기의 초음파로도 영상을 얻을 수 있는 새로운 기술이 발달되어 심근 조영과 함께 심근의 운동까지 동시에 관찰하는 real-time myocardial perfusion imaging이 이용되고 있다.

9. Clinical Applications
A. Identify intracardiac and intrapulmonary shunts
B. Augment doppler velocity signals
C. Enhance the endocardial border
D. Assess myocardial perfusion
3 Cardiac cavity 조영/ 1 심근 조영(most recently)
팔 -> SVC -> RA -> RV -> pul A 폐순환은 통과를 못함

10. A. Evaluation of Shunts Intracardiac and intrapulmonary shunts
Agitated saline
TEE of the right-left arterial shunt for patent foramen ovale (PFO) before (A) and after (B, C,) administration of contrast (Echovist) in patient Nº 35 of this series

11. B. Augmentation of the doppler velocity signal
Right heart chambers by agitated saline
TR velocity for estimation of the RVSP
Left heart chambers by gas-filled microbubbles
폐모세혈관을 통과할 정도로 크기가 작고 혈액내에서 오래 존재할 수 있도록 용해가 어려운 gas를 shell 내부에 넣은 gas-filled microbubbles

12. C. Enhancement of the Definition of the Endocardial Border
Gas-filled microbubbles
evaluation of the ventricular walls is difficult because the patient's body habitus degraded the scan quality. (b) Following injection of a contrast agent, the left ventricular cavity becomes echogenic ("opacified") and this facilitates delineation of the endocardial border (arrowheads) so that the ejection fraction can be assessed.

13. D. Myocardial Perfusion Imaging
Destruction and replenishment of microbubbles in real time
no or decreased perfusion of myocardium
-> not replenishment
-> dark perfusion defect
Visual assessment of myocardial contractility
Combined with pharmacologic stress test
(dobutamine or vasodilators)

14. Destruction replenishment imaging with real time
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demonstrating absent perfusion to the anterior myocardial wall.

15. 4CV at rest (left) and post stress (right)
4CV at rest (left) and post stress (right). Note there is no obvious difference in the shape of the cavity on the grey scale images. Importantly, the LVO images demonstrate a clear change in shape with the basal and mid lateral segments lagging, suggestive of LCx stenosis. In addition, the mid lateral segment has a perfusion defect which was not present at rest. Subtotal occlusion of the LCx was demonstrated at angiography.