Humerus Positioning Quiz

LABEL AP/ LATERAL/ TRANSTHORACIC LATERAL (LAWRENCE METHOD)/ SCAPULAR-Y

What is the most comfortable patient position for the humerus typically?

upright

Know the collimated field . What is the upper margin? How far past the upper and lower

1 ½ to 2 inches

AP Projection Anatomic landmarks and relation to IR

Humeral Epicondyles parallel with the IR

Lateral Projection Anatomic landmarks and relation to IR

Humeral epicondyles perpendicular to the IR

Central Ray: AP Projection

Perpendicular to the midportion of the humerus and the center of the IR

Central Ray: Lateral Projection

Perpendicular to the midportion of the humerus and the center of the IR

Tubercle in profile for AP projection

Humeral head and greater tubercle in profile

Tubercle in profile for Lateral projection

Lesser tubercle in profile on medial aspect

Tubercle in profile for Transthoracic Lateral projection

Greater tubercle

What is clearly demonstrated on the lateral projection of the humerus?

The elbow and shoulder joint

What’s the breathing technique for both AP and Lateral?

Suspend respiration (stop the breath)

What position would be used to perform a lateral projection of the distal humerus on a patient who has a suspected fracture?

Lateral recumbent or recumbent

What accompanies the lateral recumbent?

transthoracic (proximal humerus)

Which projection is used when the patient is unable to abduct their injured arm?

Transthoracic (Lawrence method)

Central Ray: Transthoracic

-Perpendicular to the IR, entering the midcoronal plane at the level of the surgical neck
- If the patient cannot elevate the unaffected shoulder, angle the CR 10 to 15 degrees cephalad to obtain a comparable radiograph

If we are trying to blur out lung detail, what kind of technique are we\ going to use?

Decrease the mAs and increase exposure time

if your patient cannot do the breathing technique, you need to know what the breathing technique is for the transthoracic and why?

If the patient can be sufficiently immobilized to prevent voluntary motion, a breathing technique can be used to blur the pulmonary vasculature. In this case, instruct the patient to practice slow, deep breathing. A minimum exposure time of 3 seconds (4 to 5 seconds is desirable) gives excellent results when low milliamperage is used.
- Having the lungs full of air improves contrast and decreases the exposure necessary to penetrate the body

Know where the scapular body should be free of?

ribs and humeral head

Why do we do the scapular y projection?

To see dislocations

What anatomical structure is in lateral profile in the scapular y projection?

The scapula