Chapter 21: Coronary Intravascular Imaging
The echogenicity and texture of different tissue components may exhibit comparable acoustic properties. Which of the following items may not appear as an echolucent intraluminal image?
B. Coronary calcification
C. Atheroma with a high lipid content
The answer is B. (Hurst’s The Heart, 14th Edition, Chap. 21) The similar appearance of different materials represents an inherent limitation of all gray-scale IVUS systems. An echolucent intraluminal image, for instance, may represent thrombus, atheroma with a high lipid content, retained contrast, or an air bubble. Calcified structures are, conversely, very echobright.
Most mechanical limitations of IVUS imaging are specific to the construct of each system. Which of the following parameters is a common cause of nonuniform rotation distortion (NURD) artifacts?
B. Small guide lumen size
C. Slack in the catheter shaft
D. Tightened hemostatic valve
The answer is E. (Hurst’s The Heart, 14th Edition, Chap. 21) Common causes of NURD are tortuosity; severely stenotic segments; small guide lumen size; and guide catheters with sharp secondary curves, slack in the catheter shaft, or tightened hemostatic valve.
Studies comparing optical coherence tomography (OCT) with IVUS suggest that time domain (TD)-OCT is safe and can be performed with success rates at least comparable to those of IVUS. Which of the following adverse effects are not empirically associated with the OCT procedure?
C. ST-T changes on electrocardiography (ECG)
D. Decompensated heart failure
The answer is D. (Hurst’s The Heart, 14th Edition, Chap. 21) The most frequent complication with TD-OCT using the occlusive OCT technique is transient chest discomfort, bradycardia or tachycardia, and ST-T changes on ECG, all of which tend to resolve immediately after the procedure.1 Similar transient events were also seen during IVUS imaging procedures. Decompensated heart failure is not a reported complication of the OCT procedure.
Some image artifacts are common to both OCT and IVUS. Which of the following artifacts is specific to the new generation of Fourier-domain ...