Place the ruler on the midline of the table and tape it there so that it cannot
move. Position the patient over the ruler and in the supine position with the medial
plane centered to the table and the ruler. You will concern yourself with three joints of
the lower extremities and make three exposures on one masked film. With this in mind,
position the level of the hip to the uppermost part of the ruler. True positions of the
lower extremities are essential. Therefore, if there is any rotation of a part, true
measurement will not be possible. Both extremities are x-rayed for comparison. The
first exposure is made of both hips and is properly collimated to a 14 by 5-inch field.
This will include both hips on the upper part of the film. After the first exposure, without
moving patient or ruler, center the central ray to a point midway to the apex of the
patella. Center the middle portion of the film to that point and make the second
exposure. Center the third exposure to a point midway between the malleoli of the
ankles with the bottom portion of the cassette centered to that point. This will give you a
radiograph of hips, knees, and ankles, along with the ruler, on the same film. The exact
length of the bone can then be determined by measuring from joint to joint.
If the spine is viewed from the posterior or anterior perspective, the vertebral
column is usually nearly straight with little lateral curvature. Occasionally, a slight lateral
curvature occurs in the upper thoracic region of a healthy adult. This curvature is
usually associated with the dominant extremity; this curvature may be convex to the
right in a right-handed person and convex to the left in a left-handed person. An
abnormal or exaggerated lateral curvature is called scoliosis (sko"le-o `sis). This is a
more serious type of problem that occurs when a pronounced S-shaped lateral
curvature exists. This may cause severe deformity of the entire thorax. The effect of
scoliosis is more obvious if it occurs in the lower vertebral column where it may create a
tilting of the pelvis with a resulting effect on the lower limbs, thus creating a limp or
uneven walk. Although many individuals normally have some slight lateral curvature of
the thoracic spine, an abnormal or exaggerated lateral curvature of the spine is
scoliosis. Scoliosis is most common in children 10 to 14; it is more common in girls. It
may require wearing a back brace for a period of time until the condition of vertebral
a. Radiographic Examination.
(1) Radiographs are made as requested by the patient's physician. The
routine radiographs are PA or AP (posterior-anterior or anterior-posterior) projections
and the lateral position. The patient may be positioned either erect or recumbent. The
weight must be evenly distributed on both feet if the patient is erect.
(a) Structures shown: The lumbar and thoracic vertebrae, as well as
the approximately 2 inches (5cm) of the iliac crests.