Page 207 - A Practical Guide to Equine Radiography

188 A PRACTICAL GUIDE TO EQUINE RADIOGRAPHY

Right 20º ventral-left dorsal oblique Note: this is the opposite way in the neck
VetBooks.ir (R20V-LDO) and left 20º ventral-right due to the different orientation of the artic-

ular process joints.
dorsal oblique (L20V-RDO)
(Figs 16.38–16.41) 5. Focus–film distance: 120 cm. If a grid is
1. Stand the horse square with all limbs used, adjust the focus–film distance to the
equally weight-bearing with the neck in distance specified for the grid.
neutral position and the head resting on a 6. Angle the X-ray beam 20 degrees upwards
head stand. Avoid any rotation or tilting of from the horizontal, perpendicular to the
the trunk. long axis of the thoracolumbar spine.
2. Place the plate on the dorsolateral side of 7. Centre the X-ray beam approximately
the trunk in landscape orientation on the 20–25 cm ventral to the dorsal outline of
contralateral side of the joint of interest. the back using these markers as a reference:
3. Indicate right/left (plate’s side) with a marker.
4. Position the X-ray machine on the ventro- − Mid thoracic articular process joints:
lateral aspect of the trunk on the side of the between first and second marker
joint of interest. Usually one would acquire − Caudal thoracic articular process joints:
radiographs from both sides. between second and third marker.

− R20V-LDO: outlines the right-sided artic- 8. Align the field of view with the long axis
ular process joints. of the thoracolumbar spine and collimate
− L20V-RDO: outlines the left-sided articu- around the area of interest.
lar process joints. 9. Exposure guide: 100 kVp, 40 mAs.

A B

Figure 16.38 Diagram (A) and positioning (B) to obtain an L20V-RDO view of the caudal thoracic spine that
outlines the left-sided articular process joints.

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