radiographic critique off the shoulder chapter 4

Radiographic Critique off Radiographic Critique off the Shoulderthe Shoulder

Chapter 4Chapter 4

Shoulder APShoulder AP

ContrastContrast Controlled by kVp Controlled by kVp (optimal 70-80)(optimal 70-80) Adequate to demonstrate bony trabecular Adequate to demonstrate bony trabecular

patterns and cortical outlinespatterns and cortical outlines DensityDensity

Overall not too dark or too lightOverall not too dark or too light


Bony trabecular patterns and cortical Bony trabecular patterns and cortical outlines are sharply definedoutlines are sharply defined kVp is correctkVp is correct Respiration and motion are haltedRespiration and motion are halted Using a small focal spotUsing a small focal spot Short OIDShort OID

Shoulder AP with No RotationShoulder AP with No Rotation

The glenoid fossa is visualizedThe glenoid fossa is visualized The superiolateral border of the scapula is The superiolateral border of the scapula is

not over the thoraxnot over the thorax The clavicle is horizontal The clavicle is horizontal The medial end of clavicle articulates with The medial end of clavicle articulates with

the vertebral columnthe vertebral column The glenoid fossa and the medial margin The glenoid fossa and the medial margin

of the humeral head are slightly of the humeral head are slightly superimposedsuperimposed


Detecting RotationDetecting Rotation Away from the affected shoulderAway from the affected shoulder

• Clavicles will superimpose the vertebral bodiesClavicles will superimpose the vertebral bodies• Increased visualization of glenoid fossaIncreased visualization of glenoid fossa

Toward affected shoulderToward affected shoulder• Clavicles will not superimpose the vertebraClavicles will not superimpose the vertebra• Scapula will superimpose the thoraxScapula will superimpose the thorax


Determining rotation from dislocationDetermining rotation from dislocation If all factors remain unrotated with the If all factors remain unrotated with the

exception of the humeral headexception of the humeral head• Posterior dislocationPosterior dislocation

Humeral head is demonstrated beneath the acromion or Humeral head is demonstrated beneath the acromion or spine of the scapulaspine of the scapula

• Anterior dislocationAnterior dislocation Humeral head is demonstrated anteriorly, b beneath the Humeral head is demonstrated anteriorly, b beneath the

coracoidcoracoid


Is shoulder in center of the film?Is shoulder in center of the film? The glenohumeral joint, and coracoid are at The glenohumeral joint, and coracoid are at

the center of the collimated fieldthe center of the collimated field Should also include the lateral 2/3 of the Should also include the lateral 2/3 of the

clavicle, the proximal 1/3 of the humerus and clavicle, the proximal 1/3 of the humerus and the superior scapulathe superior scapula


Determining rotation of the humeral headDetermining rotation of the humeral head Neutral rotationNeutral rotation

• Greater tubercle is partially in profile laterally and Greater tubercle is partially in profile laterally and humeral head is partially profile mediallyhumeral head is partially profile medially

External rotationExternal rotation• Greater tubercle is profile laterally, the humeral Greater tubercle is profile laterally, the humeral

head is in profile mediallyhead is in profile medially Internal rotationInternal rotation

• The lesser tubercle is demonstrated in profile The lesser tubercle is demonstrated in profile medially and the humeral head is superimposed by medially and the humeral head is superimposed by the greater tuberclethe greater tubercle

Shoulder Y viewShoulder Y view

No RotationNo Rotation The medial and lateral borders are The medial and lateral borders are

superimposedsuperimposed The scapular body does not superimpose the The scapular body does not superimpose the

thoracic cavitythoracic cavity The scapular body, acromion, and coracoid The scapular body, acromion, and coracoid

form a Y form a Y


To determine Rotational DirectionTo determine Rotational Direction If the lateral border (thick border) is If the lateral border (thick border) is

demonstrated next to the ribs the patient was demonstrated next to the ribs the patient was rotated too far toward the film (increase rotated too far toward the film (increase obliquity) pg 183obliquity) pg 183

If the vertebral border is demonstrated over If the vertebral border is demonstrated over the thorax then the patient is rotated to far the thorax then the patient is rotated to far away from the film (decrease obliquity) pg 183away from the film (decrease obliquity) pg 183


Detecting shoulder dislocationDetecting shoulder dislocation When the humeral head is not located over When the humeral head is not located over

the glenoid fossathe glenoid fossa• Posterior dislocationPosterior dislocation

The humeral head is located beneath the acromion (pg The humeral head is located beneath the acromion (pg 182) 182)

• Anterior dislocationAnterior dislocation Shoulder head will be beneath the coracoid (pg 184)Shoulder head will be beneath the coracoid (pg 184)


Anatomical parts to be included on filmAnatomical parts to be included on film Midscapular body in the center of the filmMidscapular body in the center of the film Entire scapulaEntire scapula CoracoidCoracoid AcromionAcromion Proximal humerusProximal humerus

Clavicle APClavicle AP

True AP projectionTrue AP projection The medial end of the clavicle lies next to the The medial end of the clavicle lies next to the

lateral edge of the vertebral column, and the lateral edge of the vertebral column, and the thoracic cavity superimposes the vertebral thoracic cavity superimposes the vertebral scapular borderscapular border


Positioning for KyphosisPositioning for Kyphosis Easier to position the patient in the erect Easier to position the patient in the erect

positionposition If erect position is not attainable, place If erect position is not attainable, place

shoulders and thorax in the same planeshoulders and thorax in the same plane


Detecting rotationDetecting rotation Medial end of the clavicle superimposes the Medial end of the clavicle superimposes the

vertebral column the patient is rotated away vertebral column the patient is rotated away from affected sidefrom affected side

Medial end of the clavicle does not Medial end of the clavicle does not superimpose the vertebral column, the patient superimpose the vertebral column, the patient is rotated toward the affected side. (Pg 186 is rotated toward the affected side. (Pg 186 RAD 24)RAD 24)


Anatomy to be included on the filmAnatomy to be included on the film Entire clavicleEntire clavicle Acromion Acromion

Clavicle AP AxialClavicle AP Axial



Detecting RotationDetecting Rotation Determined identical to AP viewDetermined identical to AP view


Central Ray angulationCentral Ray angulation 15 – 30 degrees 15 – 30 degrees

cephalicallycephalically Clavicle should appear Clavicle should appear

slightly superior to the slightly superior to the acromion acromion

The medial end should The medial end should superimpose the 1superimpose the 1stst and and 22ndnd rib rib

Compare RAD 26 and Compare RAD 26 and 27 on page 188 and 27 on page 188 and 189189

Scapula APScapula AP


THE ENDTHE END

radiographic critique off the shoulder chapter 4

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