Intravascular Ultrasonography Procedures Periprocedural Care

Updated: Aug 07, 2023
  • Author: Kartika Shetty, MD, FACP; Chief Editor: Karlheinz Peter, MD, PhD  more...
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Periprocedural Care


A catheter consists of a miniaturized transducer and a console that reconstructs the image. High ultrasound frequencies, typically centered at 20 to 50 MHz, are used, providing excellent resolution.

Monorail rapid exchange intracoronary ultrasound catheters have an outer diameter ranging between 2.6 and 3.5 Fr (0.87-1.17 mm diameter) and can be advanced through a 6-Fr guide catheter.

Two different types of transducers are available for IVUS: the mechanically rotating transducer, and the electronically switched multielement array system.

A single rotating transducer is driven by a flexible drive cable at 1,800 rpm (30 revolutions per second) to sweep a beam almost perpendicular to the catheter. At approximately 1-degree increments, the transducer sends and receives ultrasound signals. Flushing with saline is required to provide a fluid pathway for the ultrasound beam because even small air bubbles can degrade image quality. In most mechanical systems, the transducer spins within a protective sheath while the imaging transducer is moved proximally and distally. This facilitates smooth and uniform mechanical pullback.

Electronic systems use an annular array of small crystals rather than a single rotating transducer. The transducers are activated sequentially to generate the image. The coordinated beam generated by groups of elements is known as a synthetic aperture array. Currently available electronic systems provide simultaneous colorization of blood flow.

The imaging console includes components and software necessary to convert the ultrasonography signal to a graphic image on the monitor. Three display modes are currently available:

  1. Cross-sectional tomographic views are single-cut cross-sectional images that are limited by spatial orientation and cannot provide information regarding length and distribution of plaque.
  2. In longitudinal imaging (L mode), computerized image reconstruction techniques present a series of evenly spaced ultrasound images along a single-cut plane to approximate the longitudinal appearance of the artery. Motorized transducer pullback and digital storage of cross-sectional images are necessary for L mode. [31]  
  3. Three-dimensional (3D) reconstructions of data are also available. [32]

Regarding patient preparation, local anesthesia and minimal general sedation are used, and the patient should lie supine on the angiography table.