Scanner Type, Types of transducer elements, Specialized Ultrasound Transducers and Systems

2. By
Hafsa Talat

3.  Scanner Type
 Types of transducer elements
 Specialized Ultrasound Transducers and Systems

4.  Linear Array. A transducer with
many small electronically
coordinated elements oriented side
by side, producing a rectangular
image. Useful in small parts,
intraoperative, and vascular imaging.
The long bar shape interferes with
imaging between the ribs, making
abdominal imaging di cult.

5.  Sector Scanner.
Transducer with a small head that produces a
wedge-shaped image. May be a mechanical or
phased array

6.  Vector Array. Small footprint transducer
that utilizes the entire transducer ace to form
the image. Produces a trapezoid image with a
larger field fo view than the traditional sector

8. 1. Mechanical transducers
 The transducer crystal is physically moved to
provide steering or the beam. Although
mechanical steering is less commonly used in
modem equipment than phased-array
transducers, mechanical transducers are o
ten used in volume transducers or 3D or 4D
applications.
Types of transducer elements

9.  The drive motor and transducer array are
housed in the transducer case. The motor
drives the transducer array back and forth to
generate an image. Volume transducers are
available in curved array, linear array, and
sector formats

10. 3. Electronically steered systems
 In this type of transducer, multiple
piezoelectric elements are used. A separate
electrical signal is provided or each element.
Steering and focusing occur by sequentially
exciting individual elements across the ace o
the transducer. Focusing is controlled
electronically by the operator through
placement o the focal zone or focus caret.
The images are displayed in a sector, vector,
linear, or curved linear format.

11.  The phased array consists of multiple
transducer elements mounted compactly in a
line. All elements are pulsed as a group with
small time delays to provide beam steering
and focusing. The resulting image is in a
sector or vector format and is particularly
useful in cardiac and intercostal imaging.

14.  Special transducers have been produced to
help view specific areas:
 1. Small parts (7.5- to 15-MHz) transducer
 2. Rectal transducers in longitudinal (linear)
and transverse (radial) configurations
(biplane)
 3. Biopsy transducer
 4. Doppler probes

16.  Endocavity Ultrasound Systems
The transducer array, which can be a linear,
curved, or phased array (or mechanical sector)
scanner, is placed at the end of the transducer
shaft. This transducer shaft is inserted into the
rectum or vagina to produce high-resolution
images of the male or female pelvic organs.

17. Transesophageal Transducers
 A transesophageal transducer may be
introduced into the esophagus to visualize
the heart. This transducer provides a higher
resolution image than does transthoracic
echocardiography. Modern transesophageal
transducers may be offered for 2D or 3D
imaging. Smaller pediatric transducers are
also available.

19. Smaller transducers at the ends of catheters can
be introduced into vessels, the biliary duct, or
the ureter (transluminal transducers). These
transducers allow close visualization o the
anatomy that is being examined. These
transducers are not commonly used and may be
found more frequently in research applications.

20.  Intra cardiac catheters have been
developed more recently. A small catheter
(10F or 8F), which may be introduced into the
right heart ,provides very high-resolution
imaging and may be used or interventional
and electrophysiology applications.

22.  Sanders RC, Winter TC, editors. Clinical
sonography: a practical guide. Lippincott Williams
& Wilkins; 2007.