Page 314 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition
P. 314

Musculoskeletal system: 1.8 Soft-tissue injuries                       289



  VetBooks.ir  1.545                                     1.546





















          Figs. 1.545, 1.546  Podotrochlear bursography in a horse that sustained a puncture wound through the frog.
          After placement of a needle in contact with the proximal part of the fibrocartilage (1.545), 5 ml of iodinated
          contrast medium (iothalamate) are injected into the bursa (1.546). The medium not only fills the bursa (b) but
          also the distal interphalangeal joint (j), indicating a probable fistula between the two cavities. There is leakage
          of contrast medium in the soft tissues palmar to the DDFT (l).

          Fig. 1.547  Electronic array transducers are most   1.547
          commonly used for musculoskeletal applications.
          (a) Linear array tranducer. This is the probe of choice
          for most musculoskeletal applications in horses.
          5–12 MHz probes are probably optimal for most
          applications in equine medicine. (b) Microconvex
          linear array transducer (pediatric abdominal).
          Works at high frequencies (8–15 MHz) or mid-range
          frequencies (5–12 MHz) and gives out a pie-shaped
          image. Allows access to a wide area through a small
          skin interface and over a broad range of angles, as the
          probe may be tilted in relation to the skin. (c) Convex
          linear array transducer. Similar to (b) but with a   a          b              c
          larger radius and usually working at lower frequencies
          (2–6 MHz). Useful to image deeper areas covered by
          large muscle masses (e.g. back or pelvis) or for the
          abdomen.


          of tendons and ligaments. It is also useful to assess   structures or in horses with highly attenuating skin,
          joint soft tissues, bone surfaces and all periarticu-  such as cobs, ponies and draught horses.
          lar structures. High-definition equipment is neces-  The  choice  of  the  optimal  probe  will  therefore
          sary to accurately evaluate structures. Transducers   depend not only on the location, size and depth of
          working at 7.5 MHz or higher are generally adequate   the structures to be assessed but also on the trans-
          and the greater the frequency, the better the spatial   mitting  properties  of the  individual  patient’s  skin
          resolution. Very high frequency beams (14 MHz or   (Fig.  1.547). Linear array transducers (a) tend to
          higher) are rapidly attenuated by superficial tissues   be most practical in the distal limb. Curved array
          and may not provide adequate imaging of deeper   (microconvex or convex) transducers (b, c) will be
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