Chapter 2 Lab Flashcards
Even a slight amount of rotation on a PA chest projection results in distortion of
the size and shape of the heart shadow because the heart is located anteriorly in the thorax.
For a PA chest position, To prevent rotation, ensure that the patient is
standing evenly on both feet with both shoulders rolled forward and downward. Also, check the posterior aspect of the shoulders and the lower posterior rib cage and pelvis to ensure no rotation.
What could make it more difficult to prevent rotation for PA chest
Scoliosis and excessive kyphosis
Rotation on PA chest radiographs can be determined by examination of both
sternal ends of the clavicles for a symmetric appearance in relationship to the spine. On a true PA chest without rotation, both the right and the left sternal ends of the clavicles are the same distance from the center line of the spine.
The direction of rotation for a PA cheat can be determined by
noting which sternal end of the clavicle is closest to the spine. For example, in Fig. 2.36, the left side of the thorax is rotated toward the IR (right side moved away from IR), which creates a slight left anterior oblique (LAO) that decreases the distance of the left clavicle from the spine.
What do you do to ensures that the chin and neck are not superimposing the uppermost lung regions, the apices of the lung, for a PA chest
Sufficient extension of the patient’s neck
What position lessens the effect of breast shadows over the lower lung fields for PA chest
lift them up and outward and then to remove her hands as she leans against the chest board (IR) to keep them in this position.
A _ lateral more accurately demonstrates the heart region (without as much magnification) because the heart is location
Left
How to check against rotation for a true lateral chest
confirm that the posterior surfaces of the shoulder and the pelvis are directly superimposed and perpendicular to the IR.
With a true lateral chest the side farthest away from the IR are
magnified slightly and projected slightly posterior compared with the side closest to the IR on a true lateral chest;
For a true lateral chest, separation of posterior ribs resulting from divergence of the x-ray beam at the commonly used 72-inch (180-cm) SID should be
only ¼ to ½ inch (about 1 cm).
a lateral chest with excessive rotation, is indicated by the amount of separation of
the right and left posterior ribs and separation of the two costophrenic angles.
The direction of rotation on a lateral chest is identifying by the
left hemidiaphragm by the gastric air bubble in the stomach or the inferior border of the heart shadow, both of which are associated with the left hemidiaphragm.
The direction of rotation on a lateral chest is identifying by the
left hemidiaphragm by the gastric air bubble in the stomach or the inferior border of the heart shadow, both of which are associated with the left hemidiaphragm.
With a lateral chest the midsagittal plane must be _ to the IR.
parallel
Should there be a tilt when taking a lateral chest?
No tilt. If the patient’s shoulders are placed firmly against the chest board (IR) on a lateral chest, the lower lateral thorax or hips or both may be 1 or 2 inches (2.5 to 5 cm) away.
For a lateral chest, do patients have to raise their arms?
Yes, to Ensure the patient raises both arms sufficiently high to prevent superimposition on the upper chest field.
The vertebra prominens corresponds to the level of _ and the uppermost margin of the apex of the lungs.
T1
This landmark, which can be palpated at the base of the neck, is the preferred landmark for locating the CR on a PA chest
C7
What method can you use to find the landmark that centers up with the CR on a PA chest
hand spread method
For most patients, this CR level for PA chests is near the level of the _, which corresponds to the level of T7
inferior angle of the scapula
The easily palpated _ is the recommended landmark for location of the CR for AP chest radiographs.
jugular notch
level of T7 on an average adult is _ below the jugular notch.
3 to 4 inches (8 to 10 cm)
is recommended that for most AP chest radiographs, the 14 x 17-inch (35 × 43-cm) IR should be placed
landscape
A reliable method for upper and lower chest collimation is to adjust the upper border of the illuminated light field to the
vertebra prominens,
4 Guidelines listed should be followed when chest images are acquired through the use of digital imaging technology.
Collimate
Accurate centering
Exposure factors
Postprocessing evaluation of exposure indicator
What do we close collimate
close collimation is critical for patient dese reduction and improved image quality. Close collimation also allows the computer to provide accurate information regarding the exposure indicator.
