Intravascular ultrasound (IVUS) uses a catheter-mounted ultrasound transducer to visualize the inside of blood vessels. The transducer emits high-frequency sound waves that bounce off vessel tissues and are converted into images. IVUS provides accurate measurements of vessel size and plaque buildup. It is used pre-and post-intervention to assess plaque and guide procedures like stenting. While it adds little risk, IVUS imaging may be limited in very narrow vessels. The detailed images aid clinical decisions regarding lesion assessment, stent selection and placement, and detection of complications.

1. CHAIRPERSON:DR.SANJAY NEERALAGI
M.D
STUDENT :DR.ANUSHA S J

2.  Intravascular ultrasound (IVUS) is a medical imaging methodology using a
specially designed catheter with a miniaturized ultrasound probe attached to
the distal end of the catheter.
 The proximal end of the catheter is attached to computerized ultrasound
equipment.
 It allows the application of ultrasound technology to see from inside blood
vessels out through the surrounding blood column, visualizing the endothelium
(inner wall) of blood vessels in living individuals.

3. IVUS uses echocardiography : Very high frequency sound waves, called
ultrasound, are emitted by a transducer.
 These ultrasound waves, which are beyond the range of human hearing,
bounce off the various types of tissue structures in the body and the echo of
these waves is then converted into a picture.

4. Physics and equipment
 IVUS systems contain a special transducer mounted catheter and an electronics
console to reconstruct the image. The ultrasound signal is produced in the
transducer by passing an electrical current through the piezoelectric (pressure-
electric) crystalline material (usually ceramic) that expands and contracts when
electrically excited.
 After reflection from tissue, part of the ultrasound energy returns to the
transducer and is converted into the image. High ultrasound frequencies (20–
40 MHz) are employed resulting in an axial resolution in the range of 80–
150 μm and lateral resolution of 200–250 μm.

10. PRE-INTERVENTION
 Accurate quantitation
 Assessment of reference segment disease
Interventional strategy & device selection
In-stent restenosis
Plaque composition
 Length of lesion

11. POST-INTERVENTION
Recognition of an ambiguous appearance
 Optimal balloon angioplasty
 IVUS-guided stenting
 Plaque shifting
 Dissection

12. Arterial wall abnormalities
wall thickness
calcium
dissection
aneurysm assessment
Stent
in-stent re-stenosis
 stent strut apposition

15.  Contraindication for IVUS guidance,
small vessels,
tortuous vessels and
degenerated vein grafts.

17.  A very small skin incision is made at the site. A sheath is first inserted into an artery or vein
(usually in the groin). Using x-ray or ultrasound guidance, the catheter is inserted into the
sheath and gently maneuvered through the vessel to the target location over a very thin, soft
wire.
 Once in place, the transducer on the end of the catheter uses sound waves to produce pictures
of the blood vessels.we can move the catheter to obtain images of the inside of the vessels at
different locations. At the end of the procedure, the catheter will be removed and pressure will
be applied to stop any bleeding. The opening in the skin is then covered with a dressing. No
sutures are needed.

23.  IVUS has many benefits including:
 showing the presence and amount of plaque in arteries measuring the degree to which
the vessel has become narrowed from plaque
 providing information about what the plaque is made of
 detection of restenosis
 more accurate stent placement and
 reduced incidence of stent thrombosis in arteries and veins
 finding stenosis or narrowing which is not well seen with angiography
 finding areas of vein external compression, which may be predisposed to blood clots
 no exposure to ionizing radiation

24. Any procedure that involves placement of a catheter inside a
blood vessel carries certain risks. These risks include
 damage to the blood vessel, bruising or bleeding at the puncture site, and
infection. However precaution is taken to mitigate these risks.
 Other risks may include:
 irregular heart rhythms (arrhythmia)
 a blood clot
 an allergic reaction to the medications used during the procedure
 very rare cases, a heart attack, stroke, or blood clot in the lung
 IVUS itself adds little additional risk to angioplasty and catheter angiography

25.  Because of the catheter's size and stiffness, IVUS sometimes cannot be
navigated through very narrowed or twisted blood vessels.
 The technology sometimes produces image artifacts.
 There is conflicting information regarding the ability of IVUS to characterize
high-risk plaques and thrombus.

28.  How to determine lesion length morphology
 How to identify dissections
 Determining appropriate stent placement
 Determining lesion size
 Understanding the shortfalls of angiography

29. THANK YOU

30.  Coronary intravascular ultrasound: a closer view :BMJ JOURNAL