what position shoulder is used to isolate the greater tubercle of the humerus in profile laterally
ap external rotation
what position of shoulder would you use to view the lesser tubercle in profile more medially
ap internal rotation
when do we perform the neutral rotation of the scapula
when the patient is in pain and cannot move it at all
what are the exposure factors
70-80 kvp use a grid depending on size of patient
high mA short exposure time
small FSS
center cell AEC
40-44in SID
what joint calls for a 72 inch SID
AC joint or acromioclavicular joint
List all positioning requirements for ap shoulder external rotation
10x12 crosswise or lengthwise
erect or supine
abduct arm slightly; then externally rotate the arm until epicondyles of distal humerus are parallel to IR
Hold respiration
CR perpendicular to the IR centered 1 inch inferior to the coracoid process (above armpit midway)(3/4 inch inferior to the lateral portion of the clavicle)
where is the lesser tubercle on an ap external rotation
superimposed by the humeral head so will not be seen best
List all positioning requirements for ap shoulder internal rotation
10x12 crosswise or lengthwise
erect or supine
abduct arm slightly; then internally rotate the arm until epicondyles of distal humerus are perpendicular to IR
Hold respiration
CR 1in inferior to the coracoid process (above armpit midway)(abt 3/4 inch inferior to the lateral portion of the clavicle
where is the lesser tubercle on an ap internal rotation radiograph
where is the greater tubercle
medial aspect of the humerus it puts lesser tubercle into profile
superimposed over the humeral head
what is the position of the arm in an inferosuperior axial projection
externally rotated
what is the position factors in an inferosuperior axial projection
shoulder raised 2 inches from table top
rotate head toward opposite side place vertical IR on the table as close to neck as possible
abduct the arm 90 degrees and arm externally rotated (palm up)
why is the exaggerated rotation of the arm done for an inferiorosuperior axial projection
what is this reason
hill sachs defect
it is a compression fracture of the articular surface of the humeral head
what are other reasons we would use the inferosuperior axial projection
osteoperosis osteoarthritis and fractions and dislocations of the proximal humerus
what is the best position to view the glenoid cavity in perfect profile
posterior oblique position (grashey method)
how do we position for the grashey method
where is the CR
erect or supine
rotate body 35-45 degrees toward affected side
CR perpendicular to the IR centered to the scapulohumeral joint which is 2 inferior and medial to the superolateral border of the shoulder
suspend respiration
what are the routine trauma positions if the patient cannot move
AP neutral
transthoracic lateral -lawrence method
scapular y lateral (patients arm over the stomach
what structures are best shown when doing the FISK method
what position of the body is this method best done
anterior margin of the humeral head and intertubercular groove and other pathologies
supine
what is the positioning for the tangential projection -fisk method
best supine
set up like an inferosuperior but do no abduct the arm
CR is 10-15 degrees posterior from horizontal directed to intertubercular groove
where is the CR when doing an ap projection neutral rotation position and position
what is the breathing instructions
leave patients arm "as is" erect or supine
perpendicular to IR centered to
midscapulohumeral joint (3/4 inch and slightly lateral to the coracoid process)
suspend respiration
why do we do a transthoracic lateral projection (lawrence method)
if patient cannot get into position so this position is used to see certain structures through the ribs that are on the shoulder
Demonstrates fractures and dislocations of the proximal humerus
list the positioning factors for a transthoracic lateral projection
where is the CR
what is the breathing technique
erect or supine
place patient in a lateral position with a side of interest against IR
leave affected arm in a neutral position and aks patient to drop shoulder as much as possible
raise opposite arm and place hand over head
surgical neck of the affected side
shallow breaths like panting and (long exposure tech factors)
what do we do to prevent superimposition of the shoulder if the patient is unable to drop the shoulders and raised the unaffected arm in a transthoracic lateral projection
angle the tube 10+15 degrees cephalad
why do we perform a scapular y and transthoracic positioning (reason pathologically)
demonstrates fractures and dislocations of proximal humerus and scapula
how do we perform a scapular y
where is the CR
10x12 crosswise or lengthwise
erect or recumbent
rotate the patient into a 45 to 60 degree oblique
palpate scap borders to determine correct rotation for a true lateral
CR perpendicular to the IR centered to midscapulohumeral joint