Intravascular Imaging Flashcards
Intravascular visualization of the stent determines a successful and complete implantation with the absence of?
dissections, thrombus, and strut malposition
- What is the primary purpose of intravascular imaging during stent implantation?
A) To assess blood pressure changes
B) To determine the presence of thrombus, dissections, or strut malposition
C) To visualize the patient’s heart valves
D) To measure cardiac output
B) To determine the presence of thrombus, dissections, or strut malposition
Which of the following imaging modalities uses ultrasound for intravascular visualization?
A) Optical Coherence Tomography (OCT)
B) Magnetic Resonance Imaging (MRI)
C) Intravascular Ultrasound (IVUS)
D) Computed Tomography Angiography (CTA)
C) Intravascular Ultrasound (IVUS)
Optical Coherence Tomography (OCT) differs from IVUS because it utilizes:
A) X-rays
B) Sound waves
C) Laser light
D) Magnetic fields
C) Laser light
A successful stent implantation should show the absence of which of the following?
A) Strut malposition
B) Dissections
C) Thrombus
D) All of the above
D) All of the above
Why is intravascular imaging critical in assessing the stenosis?
A) It determines the anatomic substrate and vascular composition
B) It measures only the diameter of the vessel
C) It identifies blood flow velocity
D) It replaces the need for angiography
A) It determines the anatomic substrate and vascular composition
What is one of the main advantages of IVUS over OCT?
A) Higher axial resolution
B) Deeper penetration into soft tissue
C) Requires blood clearance for imaging
D) Uses near-infrared light
B) Deeper penetration into soft tissue
What is the axial resolution range of high-frequency IVUS (50–60 MHz)?
A) 38–46 μm
B) 20–40 μm
C) 15–20 μm
D) 1–5 μm
B) 20–40 μm
Why does OCT require blood clearance during imaging?
A) Blood absorbs near-infrared light, reducing image clarity
B) Blood increases image contrast
C) Blood increases penetration depth
D) Blood enhances lipidic plaque detection
A) Blood absorbs near-infrared light, reducing image clarity
Which imaging modality provides information about lipidic plaque and cap thickness?
A) IVUS (40–45 MHz)
B) IVUS (50–60 MHz)
C) OCT
D) None of the above
C) OCT
In terms of cross-sectional calcium evaluation, IVUS can determine:
A) Only the angle of calcium
B) The thickness and angle of calcium
C) The total calcium burden
D) The depth of calcium penetration
A) Only the angle of calcium
- What is the typical penetration depth of OCT in soft tissue?
A) >5 mm
B) 3–8 mm
C) 1–2 mm
D) 0.1–0.5 mm
C) 1–2 mm
What are the two types of IVUS systems?
A) Rotational and Optical
B) Rotational and Solid-State
C) Solid-State and MRI-based
D) Optical and Magnetic
B) Rotational and Solid-State
How does the rotational IVUS system generate images?
A) By electronically activating multiple transducers
B) By rotating an internal imaging core via a flexible drive shaft
C) By using magnetic resonance pulses
D) By capturing images with near-infrared light
B) By rotating an internal imaging core via a flexible drive shaft
What is the rotation rate of the mechanical IVUS system?
A) 1200 rpm
B) 1800 rpm
C) 2400 rpm
D) 3000 rpm
B) 1800 rpm
How many ultrasound transducers are arranged circumferentially in a solid-state IVUS catheter?
A) 32
B) 48
C) 64
D) 128
C) 64
What is the current resolution range of IVUS?
A) 50–100 microns
B) 100–150 microns
C) 150–200 microns
D) 200–300 microns
B) 100–150 microns
What is the typical size range of IVUS catheters?
A) 2.0F to 3.0F
B) 3.2F to 3.5F
C) 4.0F to 5.0F
D) 5.5F to 6.0F
B) 3.2F to 3.5F
What size guide catheter is required for an IVUS catheter?
A) 5F
B) 6F
C) 7F
D) 8F
B) 6F
- What medication is administered before IVUS/OCT catheter insertion to prevent vasospasm?
A) Aspirin
B) Heparin and IC nitroglycerin
C) Clopidogrel
D) Atropine
B) Heparin and IC nitroglycerin
What is the purpose of performing an accurate pullback run during IVUS/OCT imaging?
A) To increase blood flow
B) To determine lesion length and volumetric analyses
C) To reduce catheter friction
D) To enhance guidewire stability
B) To determine lesion length and volumetric analyses
Why is an initial saline or contrast flush required for IVUS and OCT catheters?
A) To lubricate the catheter for smoother insertion
B) To clear the plastic sheath of microbubbles and reduce image artifacts
C) To enhance blood contrast for better visualization
D) To prevent clot formation on the catheter tip
B) To clear the plastic sheath of microbubbles and reduce image artifacts
What artifact is caused by uneven drag on the IVUS catheter driveshaft in tortuous vessels?
A) Ring-down artifact
B) Nonuniform rotational distortion (NURD)
C) Blooming artifact
D) Acoustic shadowing
B) Nonuniform rotational distortion (NURD)
What is the main characteristic of the ring-down artifact seen in solid-state IVUS systems?
A) Smearing of one side of the image
B) White circles surrounding the ultrasound catheter
C) Loss of blood flow signal
D) Blurring of vessel walls
B) White circles surrounding the ultrasound catheter
How can the ring-down artifact in solid-state IVUS systems be minimized?
A) Increasing the guidewire stiffness
B) Adjusting settings on newer solid-state systems
C) Using a larger guide catheter
D) Performing rapid saline flushes during imaging
B) Adjusting settings on newer solid-state systems
How is the IVUS/OCT catheter advanced to the region of interest?
A) Free-floating in the bloodstream
B) Over the guidewire
C) Directly through the lesion without a guidewire
D) Through a separate dedicated lumen
B) Over the guidewire
What is the main advantage of using an automated pullback device for OCT?
A) It reduces contrast usage
B) It provides a more standardized and accurate pullback for analysis
C) It eliminates the need for a guidewire
D) It prevents catheter-induced vasospasm
B) It provides a more standardized and accurate pullback for analysis
What is the primary reason for using contrast instead of saline in OCT imaging?
A) To improve catheter lubrication
B) To clear blood from the field of view for better image clarity
C) To enhance the guidewire’s visibility
D) To prevent clot formation
B) To clear blood from the field of view for better image clarity
What type of vessel anatomy is most likely to cause nonuniform rotational distortion (NURD) in mechanical IVUS?
A) Straight, large-diameter arteries
B) Tortuous or highly curved vessels
C) Calcified vessels only
D) Small-diameter vessels with minimal disease
B) Tortuous or highly curved vessels
What is the function of the plastic sheath in a mechanical IVUS catheter?
A) To protect the rotating imaging core and prevent image artifacts
B) To reduce the size of the catheter for easier insertion
C) To act as a contrast reservoir for OCT imaging
D) To enhance axial resolution
A) To protect the rotating imaging core and prevent image artifacts
Why is it important to have specialized support staff for IVUS/OCT imaging?
A) To reduce the cost of the procedure
B) To ensure proper equipment operation and image interpretation
C) To eliminate the need for an imaging console
D) To perform angiographic procedures instead of the physician
B) To ensure proper equipment operation and image interpretation
What is one advantage of using an automated pullback device for IVUS/OCT?
A) It prevents excessive contrast use
B) It standardizes the procedure and improves image quality
C) It eliminates the need for physician supervision
D) It allows imaging at any vessel angle
B) It standardizes the procedure and improves image quality
How do modern IVUS/OCT systems differ from older “stand-alone” units?
A) They require manual image capture
B) They integrate fully into the angiographic imaging system
C) They require separate consoles for image viewing
D) They cannot transfer images to an archival network
B) They integrate fully into the angiographic imaging system
What is the main purpose of a separate image review station?
A) To allow independent image review without interrupting the IVUS/OCT machine
B) To increase the speed of imaging during procedures
C) To store catheters and guidewires
D) To perform real-time imaging adjustments
A) To allow independent image review without interrupting the IVUS/OCT machine
How does direct transfer of DICOM images to an archival network improve workflow?
A) It reduces radiation exposure
B) It allows image review at multiple stations
C) It eliminates the need for IVUS/OCT imaging
D) It speeds up catheter placement
B) It allows image review at multiple stations
What is a key requirement for optimal use of IVUS/OCT in a catheterization lab?
A) Using only manual pullback for imaging
B) Having specialized support staff trained in equipment operation
C) Keeping IVUS/OCT as a stand-alone system
D) Limiting image review to the primary operator only
B) Having specialized support staff trained in equipment operation
What is one benefit of integrating IVUS/OCT into the angiographic imaging system?
A) It eliminates the need for catheterization
B) It removes the requirement for heparin administration
C) It avoids the need for separate consoles and improves workflow efficiency
D) It prevents the need for guidewire use
C) It avoids the need for separate consoles and improves workflow efficiency
Why is maintaining IVUS/OCT-related records, such as videotapes and CD-ROMs, important?
A) For future reference, documentation, and quality control
B) To reduce the cost of imaging procedures
C) To increase the speed of IVUS pullback
D) To comply with radiation safety guidelines
A) For future reference, documentation, and quality control
What problem does an automated pullback device help prevent?
A) Excessive blood flow interference
B) Too rapid scanning, which may affect image quality
C) Increased need for contrast use
D) Loss of guidewire position
B) Too rapid scanning, which may affect image quality
What is the primary purpose of a DICOM image-archival network in IVUS/OCT imaging?
A) To improve contrast resolution
B) To enable image storage and access from multiple review stations
C) To replace angiography as the primary imaging modality
D) To enhance catheter maneuverability
B) To enable image storage and access from multiple review stations
What causes the black circular ring in the center of an IVUS image?
A) Blood flow artifacts
B) Dead zone and ringdown artifact of the imaging catheter
C) Calcification in the vessel wall
D) High-density plaque
B) Dead zone and ringdown artifact of the imaging catheter
What is the echolucent area between the catheter and the vessel wall called?
A) Media
B) Lumen
C) Adventitia
D) Intima
B) Lumen
In normal arteries, why is the intima often not visible on IVUS?
A) It is too thin to be reliably seen
B) It is obscured by the catheter artifact
C) It blends with the adventitia
D) It is always echogenic and appears bright
A) It is too thin to be reliably seen
What does a thick echogenic layer surrounding the lumen indicate in a diseased artery?
A) Normal vessel wall
B) Atheromatous intima
C) Blood turbulence
D) Ringdown artifact
B) Atheromatous intima
What is the echolucent layer in the middle of the vessel wall composed of?
A) Calcium deposits
B) Smooth muscle cells and elastin fibers
C) Dense collagen fibers
D) Lipid-rich necrotic core
B) Smooth muscle cells and elastin fibers
What structure may appear as an echodense layer at the media-adventitia interface?
A) Internal elastic lamina
B) External elastic lamina
C) Lumen
D) Dead zone
B) External elastic lamina
What is the outermost echogenic layer seen on IVUS?
A) Media
B) Lumen
C) Adventitia
D) Internal elastic lamina
C) Adventitia
What feature contributes to the increased echodensity of the adventitia?
A) High elastin and collagen content
B) High lipid content
C) Blood-filled microvessels
D) Necrotic core deposits
A) High elastin and collagen content
What type of echoes are considered abnormal in IVUS imaging?
A) Echoes less intense than the adventitia
B) Echoes equal in intensity to the media
C) Echoes more intense than the adventitia
D) All echoes within the lumen
C) Echoes more intense than the adventitia
What adjacent structures can sometimes be seen near the adventitia in IVUS imaging?
A) Veins and pericardium
B) Nerve fibers and capillaries
C) Endothelium and myocardium
D) Aortic valves and pulmonary artery
A) Veins and pericardium
What is one advantage of IVUS over angiography?
A) IVUS is less invasive
B) IVUS provides more precise measurements of lumen size and wall thickness
C) IVUS is cheaper than angiography
D) IVUS does not require a catheter
B) IVUS provides more precise measurements of lumen size and wall thickness
Why might the intima appear thicker in IVUS imaging than in histologic measurements?
A) Due to image compression artifacts
B) Because the catheter distorts the vessel shape
C) Due to a “trailing-edge” effect causing intimal image blooming
D) Because IVUS cannot differentiate between layers
C) Due to a “trailing-edge” effect causing intimal image blooming
What is routinely measured in IVUS imaging?
A) Blood flow velocity
B) Oxygen saturation in the vessel
C) Lumen and vessel diameters
D) Red blood cell count
C) Lumen and vessel diameters
How is percentage plaque area (plaque burden) calculated?
A) (Lumen area ÷ total vessel area) × 100
B) (Total vessel area - lumen area) ÷ total vessel area × 100
C) (Plaque thickness ÷ lumen diameter) × 100
D) (Lumen diameter ÷ reference segment diameter) × 100
B) (Total vessel area - lumen area) ÷ total vessel area × 100
What category of plaque distribution is defined by a maximum plaque thickness of greater than 1.7 times the minimum plaque thickness?
A) Concentric plaque
B) Moderately eccentric plaque
C) Severely eccentric plaque
D) Diffuse plaque
C) Severely eccentric plaque
Which measurement method in IVUS is most closely correlated with histologic dimensions?
A) Lumen area determination
B) Media thickness measurements
C) Adventitia thickness measurements
D) Total vessel area measurement
A) Lumen area determination
How is total vessel area defined in IVUS?
A) The area within the lumen-intima interface
B) The area within the external elastic lamina (EEL) or media-adventitia interface
C) The minimal cross-sectional diameter of the vessel
D) The sum of lumen area and plaque burden
B) The area within the external elastic lamina (EEL) or media-adventitia interface
How is “soft plaque” characterized in IVUS imaging?
A) Bright echoes with acoustic shadowing
B) Thick and dense echoes with homogeneous echo density greater than adventitia
C) Thickened intimal echoes with homogeneous echo density less than adventitia
D) Hyperechogenic structures that shadow underlying ultrasound anatomy
C) Thickened intimal echoes with homogeneous echo density less than adventitia
What is a key distinguishing feature of calcified plaque in IVUS?
A) Homogeneous echo density greater than or equal to adventitia
B) More than 80% of the plaque composed of thickened intimal echoes
C) Acoustic shadowing occupying more than 90% of the vessel wall circumference
D) Concentric thickening with an echolucent zone greater than 500 microns
C) Acoustic shadowing occupying more than 90% of the vessel wall circumference
What is the definition of mixed plaque in IVUS imaging?
A) A mixture of soft and fibrous plaque, each occupying less than 80% of the plaque area
B) Bright echoes with acoustic shadowing covering more than 90% of the vessel wall
C) More than 80% of the plaque composed of dense echoes involving the intimal leading edge
D) Thickened intimal echoes with homogeneous density less than adventitia
A) A mixture of soft and fibrous plaque, each occupying less than 80% of the plaque area
What type of plaque consists of thick and dense echoes with homogeneous density equal to or greater than the adventitia?
A) Soft plaque
B) Fibrous plaque
C) Calcified plaque
D) Mixed plaque
B) Fibrous plaque
Why is detecting calcium in IVUS important for treatment planning?
A) It determines the degree of plaque burden in the vessel
B) It identifies if high-speed rotational atherectomy may be required
C) It helps classify the extent of vessel stenosis
D) It confirms the presence of subintimal thickening
B) It identifies if high-speed rotational atherectomy may be required
How is subintimal thickening defined in IVUS imaging?
A) A concentric prominent leading-edge echo with a widened subintimal echolucent zone >500 microns
B) More than 80% of the plaque area occupied by dense intimal echoes
C) The presence of calcification with more than 90% vessel wall circumference shadowing
D) A mixture of fibrous and soft plaque with each component occupying less than 80%
A) A concentric prominent leading-edge echo with a widened subintimal echolucent zone >500 microns
How is stent edge dissection identified in IVUS or OCT?
A) As a bright echo with acoustic shadowing
B) As a linear structure with or without a free edge
C) As a hyperechogenic structure with clear vessel wall definition
D) As a smooth, homogeneous area without disruption
B) As a linear structure with or without a free edge
What is a characteristic feature of fresh thrombus on IVUS?
A) A highly echogenic structure with strong acoustic shadowing
B) A low to moderately echogenic or granular mass with irregular borders
C) A hypoechoic structure with smooth, well-defined edges
D) A completely anechoic area within the lumen
B) A low to moderately echogenic or granular mass with irregular borders
How can radiographic contrast injection assist in detecting intimal flaps or dissections?
A) By improving the visibility of stent struts
B) By defining the lumen and indicating communication with an echo-free area
C) By reducing background noise in the ultrasound image
D) By eliminating motion artifacts from vessel pulsation
B) By defining the lumen and indicating communication with an echo-free area
What feature differentiates an aneurysm from a side branch in IVUS imaging?
A) Aneurysms appear as expanded, thin-walled structures adjoining the lumen
B) Aneurysms show bright, hyperechoic signals with shadowing
C) Side branches always appear larger than aneurysms
D) Side branches appear as dense, calcified structures
A) Aneurysms appear as expanded, thin-walled structures adjoining the lumen
What IVUS finding is associated with vulnerable plaque?
A) Echolucent zones within the plaque, representing large necrotic lipid pools
B) Thick fibrous caps greater than 100 microns
C) Homogeneous, highly echogenic plaque structures
D) Complete absence of positive remodeling
A) Echolucent zones within the plaque, representing large necrotic lipid pools
Why does IVUS have limitations in detecting vulnerable plaques?
A) It cannot directly visualize thin fibrous caps (<65 microns)
B) It cannot detect lipid content within a plaque
C) It does not provide real-time imaging of plaque rupture
D) It cannot differentiate between soft and calcified plaques
A) It cannot directly visualize thin fibrous caps (<65 microns)
What is the term for vessel enlargement in response to plaque buildup to maintain lumen size?
A) Negative remodeling
B) Positive remodeling
C) Vessel constriction
D) Lumen atrophy
B) Positive remodeling
