Elbow - Radiographic Procedures I
What is patient position for acute flexion elbow projection?
at end of table, with acutely flexed arm resting on IR
Why is elbow flexed only 80 degrees for Coyle method: coronoid process?
because anything greater than 80 degrees may obscure coronoid process
Where is CR for radial head lateral elbow projection?
center CR to radial head region, 2 to 3 cm (1 in) distal to lateral epicondyle
How is part positioned on IR for radial head lateral elbow projection?
center radial head area to center of IR distal humerus and proximal forearm square with borders of IR
What does medial/internal oblique elbow projection best demonstrate?
coronoid process in profile
What does medial (internal) rotation elbow projection best visualize?
coronoid process of ulna and trochlea in profile
In a flexed elbow, the coronoid fossa receives the _______________ and the radial fossa receives the _______________.
coronoid process, radial head
How is correct positioning demonstrated in lateral (external) rotation elbow projection? (2)
correct 45 degree lateral oblique should visualize radial head, neck and tuberosity, free of superimposition by ulna lateral epicondyle and capitulum should appear elongated and in profile
What does lateral elbow projection best demonstrate?
fat pads
What are evaluation criteria for Coyle method projection: radial head? (3)
joint space between radial head and capitulum should be open and clear radial head, neck and tuberosity should be in profile and free of superimposition except for small part of coronoid process distal humerus and epicondyles appear distorted because of 45 degree angle
What is position of epicondyles for AP and lateral elbow projections?
AP elbow: epicondyles parallel to cassette lateral elbow: epicondyles perpendicular to cassette
What projections are done for elbow trauma?
AP with forearm parallel to IR AP with humerus parallel to IR lateral
What is the relationship of the radius and ulna in AP, AP medial rotation and lateral elbow projections?
AP: proximal radius slightly superimposed by ulna AP medial rotation: radius and ulna completely superimposed lateral: radius and ulna separated
A lateral elbow radiograph demonstrates about half of the radial head superimposed by the coronoid process of the ulna. Which error occurred?
no error occurred
How do you ensure there is no rotation in AP elbow (can't fully extend) projection?
no rotation evidenced by appearance of epicondyles in profile and radial head and neck separated or slightly superimposed by ulna on forearm parallel projection
What two structures primarily form the hinge-like structure and movement of the elbow joint?
trochlea and olecranon process
How many projections are required for acute flexion elbow projection?
two - one with CR perpendicular to humerus and one with CR angles so that it is perpendicular to forearm
What does lateral/external oblique elbow projection best demonstrate?
unobstructed view of radial head, neck and tuberosity
Why is the Coyle method used?
when a patient cannot fully extend elbow for medial or lateral oblique elbow projections
What are the clinical indications of AP elbow projection? (2)
fractures and dislocations of elbow pathologic processes, such as osteomyelitis and arthritis
What are the clinical indications for lateral elbow projection? (3)
fractures and dislocations of elbow pathologic processes, such as osteomyelitis and arthritis elevated or displaced fat pads of the elbow joint may be visualized
What should be done if patient can't extend elbow for elbow trauma projections?
if elbow is flexed near 90 degrees, take the two AP trauma elbow projections, but angle the CR 10 to 15 degrees if elbow is flexed more than 90 degrees, use the Jones method (acute flexion projection)
What should be done for heavy muscular forearms for lateral elbow projection? Why?
place support under hand and wrist to elevate hand and distal forearm so that forearm is parallel to IR
What is part position for AP elbow projection? (3)
1. no rotation evidenced by appearance of bilateral epicondyles in profile and radial head, neck and tubercles separated or slightly superimposed by ulna 2. olecranon process should be seated in olecranon fossa 3. elbow joint space appears open
What are the routine elbow projections?
AP lateral/external oblique medial/internal oblique lateral
What is another name for trauma axial lateral elbow projections?
Coyle method
A patient enters ER with an elbow injury. The partial flexion AP & lateral positions reveal a possible fracture of the coronoid process. The patient's elbow is partially flexed, he refuses to extend it further. What projection will confirm the diagnosis?
Coyle method with 80 degree flexion, CR angled 45 degree distally.
A patient enters the ER with a possible dislocation of the elbow. The patient has the elbow flexed more than 90 degrees. Which one of the following routines should be performed to confirm the diagnosis?
Jones method and limited lateral projection
What changes the position of the posterior fat pad?
a change in the joint incorrect flexion (>90 degrees) of elbow
How is part positioned on IR for acute flexion elbow projection?
align and center humerus to long axis of IR, with forearm acutely flexed and fingertips resting on shoulder adjust IR to center of elbow joint region palpate humeral epicondyles and ensure that they are equal distances from cassette for no rotation
How is part positioned on IR for medial (internal) rotation elbow projection?
align arm and forearm with long axis of IR center elbow joint to CR and IR pronate hand and rotate arm as needed until distal humerus and anterior surface of elbow joint are rotated 45 degrees
What is part position for lateral (external) rotation elbow projection?
align arm and forearm with long axis of IR center elbow joint to CR and IR supinate hand and rotate entire arm laterally so that distal humerus and anterior surface of elbow joint are 45 degrees to IR
What are the fat pads shown in lateral elbow radiograph?
anterior, posterior and supinator
What structures are significant in the evaluation of a true lateral position of the elbow?
capitulum and superimposed epicondyles
What does the 90 degree flexion of elbow joint in lateral elbow projection help to diagnose?
certain important joint pathologic processes, e.g. possible visualization of posterior fat pad
How is correct positioning demonstrated in medial (internal) rotation elbow projection? (4)
correct 45 degree medial oblique should visualize coronoid process of the ulna in profile radial head and neck should be superimposed and centered over proximal ulna medial epicondyle and trochlea should appear elongated and in partial profile olecranon process should appear seated in olecranon fossa and trochlear notch partially open and visualized with arm fully extended
What is anatomy demonstrated for AP elbow projection?
distal humerus elbow joint space proximal radius and ulna
Where is CR for acute flexion elbow projection? (2)
distal humerus - CR perpendicular to IR and humerus, directed to a point midway between epicondyles proximal forearm - CR perpendicular to forearm (angle CR as needed), directed to a point approximately 2 in (5 cm) proximal or superior to olecranon process
What is anatomy demonstrated in AP elbow (can't fully extend) projection? (hint: depends on which projection)
distal humerus on humerus parallel projection proximal radius and ulna on forearm parallel projection structures in elbow joint region can be partially obscured
What are evaluation criteria for Coyle method projection: coronoid process? (5)
distal/anterior portion of coronoid appears elongated but in profile joint space between coronoid process and trochlea should be open and clear radial head and neck should be superimposed by ulna optimal exposure factors should visualize clearly the coronoid process in profile bony margins of superimposed radial head and neck should be visualized faintly through proximal ulna
What is part position for Coyle method projection: coronoid process? Where is CR?
elbow flexed 80 degrees from extended position, hand pronated CR angled 45 degree from shoulder, into midelbow joint
How is part positioned on IR for Coyle method projection: radial head? Where is CR?
elbow flexed 90 degrees if possible, hand pronated CR directed at 45 degree angle toward shoulder, centered to radial head
How is correct positioning demonstrated in lateral elbow projection? (5)
elbow joint flexed 90 degrees one half of radial head superimposed by coronoid process olecranon process visualized in profile true lateral demonstrated by three concentric arcs of the trochlear sulcus, double ridges of the capitulum and trochlea and the trochlear notch of the ulna superimposition of the humeral epicondyles
What are evaluation criteria for radial head lateral elbow projection?
elbow should be flexed 90 degrees in true lateral epicondyles should be superimposed radial neck and head should be partially superimposed by ulna but completely visualized in profile radial tuberosity should be visualized in various positions and degrees (1. - slightly anterior, 2. - superimposed over radial shaft, 3. - slightly posterior, 4. - seen posteriorly, adjacent to ulna)
How does anterior fat pad appear when there has been trauma or infection?
elevated
A radiograph of an AP projection of the elbow reveals that there is complete separation of the radius and ulna. What positioning error has been committed?
excessive lateral rotation
A radiograph of an AP oblique elbow with medial rotation reveals that the radial head is superimposed over part of the coronoid process. What positioning error has been committed?
excessive medial rotation
What are evaluation criteria for acute flexion elbow projection: distal humerus?
forearm and humerus should be directly superimposed medial and lateral epicondyles and parts of trochlea, capitulum and olecranon process all should be seen in profile optimal exposure should visualize distal humerus and olecranon process through superimposed structures
How many projections are taken for radial head lateral elbow projection? How are they taken?
four, from maximum of external rotation to maximum internal rotation of hand and wrist demonstrate near complete rotation of radial head clear of coronoid process 1. supinate hand and externally rotate as far as tolerated 2. place hand in true lateral (thumb up) 3. pronate hand 4. internally rotate hand (thumb down) as far as tolerated
What are the clinical indications for medial (internal) rotation elbow projection?
fractures and dislocations of elbow, primarily the coronoid process pathologic processes, such as osteomyelitis and arthritis
What are the clinical indications for lateral (external) rotation elbow projection?
fractures and dislocations of elbow, primarily the radial head and neck pathologic processes, such as osteomyelitis and arthritis
What are the clinical indications for acute flexion elbow projection?
fractures and moderate dislocations of the elbow in acute flexion
What is the supinator fat pad used for diagnosing?
issues with radial head or neck fractures
What is anatomy demonstrated in lateral elbow projection?
lateral projection of distal humerus and proximal forearm, olecranon process, and soft tissues and fat pads of elbow joint
A radiograph of the elbow demonstrates the radius directly superimposed over the ulna and the coronoid process is in profile. Which projection of the elbow has been performed?
medial rotation oblique
What is anatomy demonstrated in lateral (external) rotation elbow projection?
oblique projection of distal humerus and proximal radius and ulna are visible
What is anatomy demonstrated in medial (internal) rotation elbow projection?
oblique projection of distal humerus and proximal radius and ulna are visible
What are the clinical indications for radial head lateral elbow projection?
occult fractures of radial head or neck
How is part positioned on IR for AP elbow (can't fully extend) projection?
one AP projection with forearm parallel to IR one AP projection with humerus parallel to IR
Where should humeral epicondyles be for AP elbow projection?
parallel to the IR
What are the clinical indications for Coyle method projection?
pathologic processes or trauma to area of radial head (part position 1) or the coronoid process of ulna (part position 2)
Where is CR for AP and oblique elbow projections?
perpendicular to IR directed to mid-elbow joint, 2 cm/.75 in distal to midpoint of line between epicondyles
Where is CR for lateral elbow projection?
perpendicular to IR directed to mid-elbow joint, 4 cm/1.5 in medial to posterior surface of olecranon process
What is position of superimposed epicondyles seen in a true lateral elbow image?
proximal to circular appearance of trochlear sulcus
What are evaluation criteria for acute flexion elbow projection: proximal forearm?
proximal ulna and radius, including outline of radial head and neck, should be visible through superimposed distal humerus optimal exposure visualized outlines of proximal ulna and radius superimposed over humerus
What does lateral (external) rotation elbow projection best visualize?
radial head and neck capitulum of humerus
What is patient position for medial (internal) rotation elbow projection?
seat patient at end of table extend arm fully shoulder and elbow on same horizontal plane
What is patient position for lateral (external) rotation elbow projection?
seat patient at end of table extend arm fully shoulder and elbow on same horizontal plane lean laterally if necessary
What is patient position for AP elbow projection?
seat patient at end of table extend elbow fully lean laterally if necessary
What is patient position for radial head lateral elbow projection?
seat patient at end of table with arm flexed 90 degrees and resting on IR humerus, forearm and hand on same horizontal plane
What is patient position for lateral elbow projection?
seat patient at end of table with elbow flexed 90 degrees drop shoulder so that humerus and forearm are on the same horizontal plane rotate hand and wrist into true lateral, thumb side up
What is patient position for Coyle method projection?
seated at end of table for erect position supine on the table for cross-table imaging
What is a good criterion to check for a true lateral elbow?
tree concentric arcs - appear symmetrically aligned 1. trochlear sulcus - smallest 2. double outer ridges of capitulum and trochlea - double-lined 3. trochlear notch
