Practicum Flashcards
1
Q
PA Projection of Finger
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Patient positioned at end of table with elbow flexed 90
- Fingers separated
- CR at PIP Joint
- Collimate 1in. at the top and distal MCPs
2
Q
PA Oblique Projection of finger, lateral rotation
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Patient positioned at end of table with elbow flexed 90
- Fingers separated, 45* oblique
- CR at PIP Joint
- Collimate 1in. at the top and distal MCPs
- Lateral rotation is recommended for digits 3rd-5th
3
Q
PA Oblique Projection of finger, medial rotation (recommended for 2nd digit)
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Patient positioned at end of table with elbow flexed 90
- Fingers separated, 45* oblique
- CR at PIP Joint
- Collimate 1in. at the top and distal MCPs
- No superimposition of adjacent fingers. IP and MCPJ spaces should be open indicating phalanges are parallel to IR
4
Q
Lateromedial Projection of Finger (3rd-5th digits)
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Patient positioned at end of table with elbow flexed 90
- CR at PIP Joint. Distal MCP & joints should be visible.
- Use radiolucent device to help position/extend finger
- Finger in true lateral position indicated by concave appearance of ant surface of the shaft of phalanges
5
Q
Mediolateral Projection of Finger (2nd digit)
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Patient positioned at end of table with elbow flexed 90
- CR at PIP Joint. Distal MCP & joints should be visible.
- Use radiolucent device to help position/extend finger
- Finger in true lateral position indicated by concave appearance of ant surface of the shaft of phalanges
6
Q
AP Projection Thumb(PA if Unable to Position)
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Patient facing the table, arms extended in front with hand rotated internally to supinate thumb for AP projection
- CR at 1st MCP joint
- Collimation must include entire MC and trapezium
- Anatomy demonstrated: prox. and distal phalanges, 1st MC, trapezium and joints. No rotation shown by equal concavity on both sides of the phalanges & equal amounts of soft tissue. IPJ appears open indicating thumb was fully extended.
7
Q
PA Oblique Thumb (Medial Rotation)
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Seat pt at end of table w/ hand resting on IR
- CR enters at 1st MCP joint. Collimation all 4 sides including all of 1st MCP and trapezium
- Anatomy demonstrated: distal and prox. phalanges, 1st MC, trapezium, associated joints visualized in 45 oblique. IP and MCP joint should appear open if the phalanges are parallel to the IR.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
8
Q
Lateral Position of Thumb
A
- IR 8x10 portrait, 40 SID, 60 kVp
- Seat pt at end of table, elbow flexed 90* w/ hand resting on IR, palm down. Hand pronated, thumb abducted, fingers and hand slightly arched, rotate hand slightly medially until thumb is in true lateral position
- CR enters at 1st MCP joint.
- Demonstrates prox and distal phalanges, 1st mc, trapezium (superimposed) joints in lateral position
Long axis of thumb should be aligned with side border of IR. Thumb in true lateral position evidenced by concave-shape of phalanges and MC anteriorly. IP and MCPJ should appear open if phalanges are parallel to IR and CR - Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
9
Q
PA Projection- Hand
A
- IR 10x12 portrait, 40 SID, kVp range 60
- Patient seated at end of table with hand and forearm extended. Digits slightly separated.
- CR enters at 3rd MCP joint
- Anatomy demonstrated: PA projection of entire hand & wrist, and 1” of distal forearm, PA hand demonstrates oblique view of thumb. Position on image: No rotation demonstrated by symmetric appearance of both sides or concavities of shafts of phalanges and MC 2-5. No ST overlap. MCP and IP joints open.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
10
Q
PA Oblique Projection of Hand
*if metacarpals only are of interest, thumb and fingertips can be touching IR (which will close IP joint spaces)
A
- IR 10x12 portrait, 40 SID, kVp range 60
- Patient seated at end of table with hand and forearm extended. Fingers separated, rotate entire hand and wrist laterally 45 degrees.
- CR enters at 3rd MCP joint
- Oblique projection of hand and wrist and 1” of distal forearm
- Long axis of hand and wrist should be aligned with IR 45* oblique evidenced by mid-shaft of MCP should not overlap. Some overlap of distal heads of MCP 3-5, no overlap of 1st & 2nd MC heads (excessive overlap of MC indicated over rotation), (too much separation indicated under-rotation). MCP and IP joints are open w/o foreshortening of mid-phalanges or distal phalanges, indicating digits are parallel to IR
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
11
Q
“Fan” Lateral of Hand(Lateromedial Projection)
A
- IR 10x12 portrait, 40 SID, kVp range 60
- Patient seated at end of table with hand and forearm extended. Rotate hand and wrist into lateral position with thumb side up, spread fingers and thumb into fan position. Ensure all digits are separated and parallel to IR.
- CR enters at 2nd MCP joint. Collimate to all 4 sides of hand and wrist
- Anatomy demonstrated: Entire hand, wrist, and about 1inch of distal forearm visible.
- Position on image, long axis of hand and wrist should be aligned with long axis of IR. Fingers should appear equally separated with phalanges in lateral position, joint spaces open. Thumb is slightly oblique and free of superimposition. Hand and wrist in true lateral position- distal radius and ulna are superimposed. MCPs superimposed
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
12
Q
PA Projection- Wrist
A
- IR 8x10 portrait, 40 SID, kVp range 60
- Patient seated with arm 90*. Hand pronated with arch of hand ( slightly tuck fingers under) helps open up carpals and decreased OID.
- CR enters at mid-carpal area. Proper collimation:
distal radius and ulna, carpals and proximal half of metacarpals. - No excessive flexion of digits to overlap and obscure the metacarpals. No rotation in carpals, metacarpals, radius and ulna separated (possible minimal overlap of distal radio-ulnar joint) Open radio-ulnar joints.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
13
Q
PA Oblique Projection- Wrist (Lateral Rotation)
A
- IR 8x10 portrait, 40 SID, kVp range 60
- Pt seated end of table, forearm and hand extended, shoulder, elbow, wrist on same plane. From pronation, rotate hand and wrist 45* laterally.
- CR perpendicular enter at mid-carpal area. Collimate to mid-carpal field
- Demonstrates: distal radius and ulna, carpals and mid-metacarpal area. Trapezium & scaphoid well visualized long axis of hand through distal forearm aligned with IR.
- True 45* oblique evidenced by ulnar head partially superimposed by distal radius, proximal 3rd-5th MCP bases mostly superimposed
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
14
Q
Lateral Projection- Wrist (Lateromedial)
A
- IR 8x10 portrait, 40 SID, kVp range 60
- Pt seated end of table with arm flexed 90* and wrist resting on table, medial (ulnar side) touching IR, thumb up. Shoulder, elbow, wrist on same plane. Adjust to true lateral position with fingers extended, move thumb slightly anterior
- CR perpendicular entering mid-carpal area. Collimation: 4 sides, including distal radius, ulna, and MCP area.
- Area aligned with long axis of IR (portrait)
True lateral evidenced by, ulnar head should be superimposed over distal radius, prox 2nd-5th MC superimposed and aligned. - Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
15
Q
PA Scaphoid Projection-Wrist(Modified Stecher Method)
*Hand elevated with ulnar deviation. If the IR cannot be elevated 20 degrees, the CR can be directed 20 degrees toward the elbow.
A
- IR 8x10 portrait, 40 SID, kVp range 60
- Pt seated end of table with hand and forearm extended. Shoulder, elbow, wrist on same plane. Place hand and wrist palm side down on IR with hand elevated 20 degrees on sponge. Ensure wrist is in contact with IR. Ulnar deviate unless contraindicated.
- CR perpendicular directed to scaphoid (anatomical snuff box) (3/4” medial and distal to radial styloid).
Collimate to 4 sides of carpal region. - Scaphoid shown without foreshortening. Long axis of wrist and forearm aligned with IR. Ulnar deviation demonstrated by little to no superimposition of scaphoid distally. No rotation of wrist shown by radius and ulna and little to no superimposition of distal radio-ulnar joint
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
16
Q
AP Projection- Forearm
A
- IR 14x17 portrait, 40 SID, kVp range 65-75
- Seat patient at end of table with hand and arm fully extended (supinated). Place shoulder, elbow and wrist on same plane. Have patient lean laterally to have arm in true AP, epicondyles should be parallel to IR. Extending the fingers helps keep a true AP distally.
- CR perpendicular to mid forearm
- Anatomy: AP projection of entire radius and ulna is shown with minimum of prox. carpal row and distal humerus. ST shown such as fat pads and stripes of wirst and elbow.
- Position: Long axis of arm aligned with long axis of IR, no rotation demonstrated by humeral epicondyles visualized in profile. Radial head, neck and tuberosity slightly superimposed by ulna. Wrist and elbow joint only partially open due to beam divergence.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
17
Q
Lateral Projection- Forearm (Lateromedial)
A
- IR 14x17 portrait, 40 SID, kVp range 65-75
- Pt at end of table with elbow flexed 90*. Drop shoulder to place on horizontal plane. Rotate hand and wrist to true lateral position, support hand to prevent motion. For muscular forearms, place support under hand and wrist to keep parallel to IR.
- CR perpendicular to IR, directed to mid-forearm. Collimate to both lateral borders of forearm avoiding clipping anatomy at either joint. Include 1- 1.5” distal to wrist and elbow joint.
- Anatomy: Both articulating joints, all of radius and ulna included, ST included.
- Position: no rotation shown by ulna superimposed over radius, humeral epicondyles superimposed. Radial head should superimpose coronoid process. Radial tuberosity demonstrated anteriorly.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
18
Q
AP Projection- Elbow(Fully Extended)
A
- IR 10x12 portrait, 40 SID, 65 kVp
- Pt seated at the end of table elbow fully extended, support under hand if necessary. Extend elbow, supinate hand & align arm/forearm with long axis of IR. Pt leans laterally for true AP. Palpate humeral epicondyles to ensure they are parallel to IR
- CR enters mid-elbow joint
- Anatomy: Distal humerus, elbow joint space & prox. radius & ulna visualized
- Position: Long axis of arm aligned with IR. No rotation evidenced by appearance of bilateral epicondyles seen in profile. Radial head, neck, & tuberosity (tubercle) separated or only slightly superimposed by ulna. Olecranon process in olecranon fossa. Open elbow joint space
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
19
Q
AP Oblique Projection-Elbow(Lateral/External Rotation)
A
- IR 10x12 portrait, 40 SID, 65 kVp
- Seat patient and end of table, arm fully extended, shoulder elbow and wrist on same plane. (have patient lean laterally, point thumb towards table or IR)
- CR perpendicular enters mid-elbow joint. Center elbow to CR & IR
- Anatomy: Oblique projection of distal humerus and prox. radius and ulna. Long axis of arm with IR. Correct 45* lateral oblique should visualize radial head, neck & tuberosity free of superimposition from ulna. Lateral epicondyle and capitulum elongated and in profile.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
20
Q
AP Oblique Projection-Elbow(Medial/Internal Rotation)
A
- IR 10x12 portrait, 40 SID, 65 kVp
- Pt seated at end of table with shoulder, elbow on same horizontal plane. Pronate hand to natural palm down position & rotate arm as needed till distal humerus & ant. surface of elbow are rotated 45 degrees (inter-epicondylar plane 45 from IR)
- CR perpendicular to mid-elbow joint.
- Anatomy: Oblique view of distal humerus & prox. radius and ulna
- Position: Long axis of arm aligned with side border or IR. Correct 45 degree medial oblique should visualize coronoid process of ulna in profile. Radial head and neck should be superimposed & centered over the prox. ulna. Medial epicondyle & trochlea elongated and in partial profile. Olecranon process should appear seated in olecranon fossa and trochlear notch partially open and visualized with arm fully extended.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular marking
21
Q
Latero-medial Projection-Elbow
A
- IR 10x12 portrait, 40 SID, 65 kVp
- Pt seated end of table with elbow flexed 90 degrees shoulder humerus and forearm on same plane. Rotate hand and wrist into true lateral position, thumb side up. Elevate hand/wrist if necessary for large muscled patients
- CR perpendicular to mid-elbow joint, 1 ½” medial to posterior surface of olecranon.
- Anatomy: Lateral projection of distal humerus and prox. forearm, olecranon process, ST and fat pads of the elbow joint are visible.
- Position: About one-half of radial head should be superimposed by coronoid process, and olecranon process should be in profile. True lateral indicated by 3 concentric arcs of trochlear sulcus, double ridges of capitulum and trochlea, and trochlear notch of the ulna. Superimposition of epicondyles.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular markings as well as ST margins of the anterior and posterior fat pads.
22
Q
AP Projection- Humerus
*Do not rotate arm if fracture is suspected
A
- IR 14x17 portrait, 40 SID, 65 kVp
- Extend hand and forearm as much as pt can tolerate. Abduct arm slightly and slightly supinate hand so epicondyles are parallel to IR.
- CR perpendicular at mid-point of humeral shaft. Collimate to area of interest to include elbow and shoulder joints
- Anatomy: entire humerus including shoulder and elbow joints are included.
- Position: True AP demonstrated by prox. humerus, greater tubercle in profile laterally. Humeral head partially seen in profile medially with partial superimposition of the glenoid cavity. Distal humerus will have medial and lateral epicondyles visualized in profile.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular markings at both prox. and distal portions of humerus
23
Q
Lateral Projection of Humerus(Lateromedial Projection)
A
- IR 14x17 portrait, 40 SID, 70-75 kVp
- Position patient with back to IR. Body slightly rotated towards affected side to reduce OID. Internally rotate arm until epicondyles are perpendicular to IR
- CR enters perpendicular to mid-point of humerus. SUSPEND RESPIRATION
- Anatomy: Lateral projection of the entire humerus, including elbow and shoulder joints visible
- Position: True lateral projection demonstrated by; Lesser tubercle in profile medially (partially superimposed by glenoid cavity)
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular markings of entire humerus
24
Q
Lateral Projection of Humerus (Mediolateral Projection)
A
- IR 14x17 portrait, 40 SID, 70-75 kVp
- Place patient erect in PA position (facing IR). Slightly oblique patient 20-30 degrees from PA to prevent OID. Flex elbow 90 degrees. Adjust IR so equidistance from shoulder and elbow joints
- CR enters perpendicular to mid-humerus shaft. Collimate to four sides so all of ST, elbow and shoulder joints are included. SUSPEND RESPIRATION
- Anatomy: Lateral projection of the entire humerus, including elbow and shoulder joints visible
- Position: True lateral projection demonstrated by; Lesser tubercle in profile medially (partially superimposed by glenoid cavity)
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular markings of entire humerus
25
Q
AP Projection- Shoulder (External Rotation)
A
- IR 10x12 landscape, 40 SID, 75-80 kVp
- Pt with back against board, rotate body slightly toward affected side to prevent OID. Position patient to center scapulohumeral joint to center of IR. Slightly abduct arm and externally rotate until epicondyles are parallel to IR.
- CR enters 1” inferior to coracoid process
- Anatomy: AP projection of proximal humerus and lateral 2/3 of clavicle and upper scapula, including relationship of humeral head and glenoid cavity.
- Position: full external rotation is demonstrated by greater tubercle visualized in full profile on lateral aspect of prox. humerus. Lesser tubercle superimposed over humeral head. Collimate to area of interest.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular markings with ST detail visible for possible calcium deposits
26
Q
AP Projection-Shoulder(Internal Rotation)
A
- IR 10x12 landscape, 40 SID, 75-80 kVp
- Position patient to center scapulohumeral joint to center of IR. Abduct extended arm slightly, internally rotate arm so dorsal surface of hand is touching leg and epicondyles are perpendicular to IR.
- CR enters 1” inferior to coracoid process. Collimate to include soft tissue of superior and lateral borders.
- Anatomy: Lateral view of prox. humerus & 2/3 of clavicle, relationship of humeral head in glenoid cavity
- Position: Full internal rotation position demonstrated by lesser tubercle in profile medially. Outline of greater tubercle visualized superimposed by humeral head.
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular markings with ST detail visible for possible calcium deposits
27
Q
AP oblique Projection-Shoulder(Grashey Method)
A
- IR 10x12 landscape, 40 SID, 75-80 kVp Suspend respiration
- Pt erect or supine. Rotate body 35-45 degrees towards the affected side. *usually more rotation for smaller patients. Adjust IR so top of IR is approx 2” above shoulder & 2” from lateral border of humerus. Abduct arm slightly with arm flexed and in neutral position.
- CR perpendicular to IR centered to scapulohumeral joint. SUSPEND RESPIRATION- GRASHEY GASSY
- Anatomy: Glenoid cavity seen in profile without superimposition of humeral head
- Position: Scapulohumeral joint space open, ant and post. rims of glenoid superimposed. Collimate to margins of interest (ST margins)
- Optimal density and contrast, no motion, show ST margins, clear & sharp bony trabecular markings with ST detail of joint space and axilla should be visualized
28
Q
PA Oblique Projection-Shoulder(Scapular Y Lateral)
A
- IR 10x12 portrait, 40 SID, 75-80 kVp
- Pt erect or recumbent, (if recumbent perform AP with affected side rotated away from IR). Rotate pt between 45 & 60 degrees. into an anterior oblique position. Palpate the superior angle of the scapula & AC joint. Rotate the pt until an imaginary line between those 2 points is perpendicular to IR. Center scapulohumeral joint to CR & center of IR.
- CR perpendicular to IR directed to scapulohumeral joint (2” below AC joint). SUSPEND RESPIRATION
- Anatomy: True lateral view of scapula, prox. humerus & scapulohumeral joint.
- Position: Thin body of scapula should be seen on end without rib superimposition. Acromion and coracoid processes should appear as nearly symmetric upper limbs of the Y. Humeral head should appear superimposed over the base of the Y ( if no dislocation).
Collimation to area of interest (all 4 sides) - Optimal density and contrast, no motion, visualize sharp bony borders and the outline of the body of scapula through the proximal humerus.
29
Q
Superoinferior Axial- Shoulder
A
- IR 10x12 portrait, 40 SID Tabletop
- Pt. is seated at end of table. Place IR parallel with the long axis of the arm. Pt. will lean laterally over the IR until shoulder joint is mid IR. Pt will flex arm 90 degrees and place their hand in the prone position. Pt’s head is turned away from the affected shoulder. Shield gonads.
- CR: Angled 5-15 degrees through the shoulder joint toward the elbow.
Note- the angle is greater if the pt. cannot extend laterally over the IR.
Collimation: Adjust to 12” in length and 1” on the sides.
Respiration: Suspend. Inform patient to hold still.
30
Q
AP Projection-AC Joints(Pearson Method)
A
- IR 14x17 bilateral, 10x12 unilateral. 72 SID bilat, can use 40 for unilateral, 70-75 kVp.
- Must mark or annotate with and without weights on image. Use 5-10 lb weights. Do image without weights 1st to evaluate for possible fx. Pt erect standing with back against IR, equal weight on both feet, arms by side, no rotation.
- CR midway between AC joints 1” above jugular notch perpendicular beam. Top of IR should be approx 2” above shoulders. For unilat, CR 1” below affected AC joint. Suspend respiration
- With weights: Keep patient in same position, have patient hold weights without resisting, relaxed shoulders. Give patient weight of unaffected side first.
- Anatomy: Both ac joints, entire clavicles & SC joints (for bilateral)
- Position: Both ac joints in same horizontal plane, no rotation shown by symmetric appearance of SC joints on each side of vertebral column
- Optimal density & contrast of AC joints and ST, sharp appearance of trabeculae to demonstrate no motion. R & L markers
31
Q
AP Projection- Clavicle
A
- IR 10x12 landscape, 40 SID, 70-75 kVp
- Pt erect or recumbent, arms at side, chin raised & looking straight ahead. Posterior shoulder of affected side in contact with IR (or TT). No rotation. Center clavicle to IR & CR. Use jugular notch and AC joint as landmarks.
- CR perpendicular to mid-point of clavicle.
- Anatomy: entire clavicle including AC & SC joints & acromion.
- Position: Clavicle demonstrated without foreshortening. Mid-clavicle is superimposed on the superior scapular angle. Collimation visible.
- Midclavicle, sternal, and acromial extremities demonstrate clear, sharp ST & bony trabecular detail.
32
Q
AP Axial- Clavicle
A
- IR 10x12 landscape, 40 SID, 70-75 kVp
- Pt erect or recumbent, arms at side, chin raised & looking straight ahead. Posterior shoulder of affected side in contact with IR (or TT). No rotation. Center clavicle to IR & CR. Use jugular notch and AC joint as landmarks.
- CR 15-30 degrees cephalic to midpoint of clavicle (thin patients (asthenic). Need more angle for larger (hypersthenic) patients. Suspend respiration on end of inspiration to elevate clavicle
- Anatomy: Entire clavicle including acromion, AC & SC joints.
- Position: Correct angulation of CR projects most of the clavicle above the scapula and 2nd-3rd ribs. Only medial portion is superimposed by 1st & 2nd ribs
- Optimal demonstrates distal clavicle and AC joints w/o excessive density. Bony margins and trabecular markings appear sharp, no motion, medial clavicle and SC joint visualized through thorax.
33
Q
AP Projection- Scapula
A
- IR 10x12 portrait, 40 SID, 75 kVp
- Have patient erect (preferred) or supine. Posterior surface of shoulder in contact with IR without rotation of thorax. Center mid-scapula to CR. IR approx 2” above shoulder and 2” lateral to border of thorax (rib-cage). Abduct patients arm 90 degrees, supinate hand and rest dorsal surface of hand on forehead.
- CR perpendicular to mid scapula 2” inferior to coracoid and 2” medial to lateral border of thorax. Collimate to area of scapula. ORTHOSTATIC BREATHING to blur out ribs.
- Anatomy: Lateral portion of the scapula is free of superimposition. Medial portion of scapula id seen through thoracic structures
- Position: Affected arm abducted 90 degrees with hand supinated evidenced by lateral border free of superimposition.
- Optimal density, contrast, sharp, clear bony trabecular detail with blurring of ribs and lung markings
34
Q
Lateral Position- Scapula
A
- IR 10x12 portrait, 40 SID, 75 kVp
- Pt erect or recumbent facing IR in anterior oblique position. Have patient cross arm across chest and reach hand to unaffected shoulder (body of scapula). For acromion/coracoid have pt drop affected arm, flex elbow & place arm behind lower back with arm partially abducted. Can be neutral position of arm. Palpate superior angle of scapula & AC joint. Rotate patient towards the affected side until the ac/sup angle line is perpendicular to IR. Less rotation required when arm is across chest and hand on opposite shoulder. Align mid-vertebral border of scapula to CR & IR. SUSPEND RESPIRATION.
- CR to medial border of scapula.
- Anatomy and position: Entire scapula should be visualized in a lateral position shown by superimposition of vertebral and lateral borders. Scapula in profile, free of superimposition of ribs. As much as possible of humerus should not superimpose area of interest.
- No motion, sharp bony edges and trabecular detail. Bony borders of acromion and coracoid seen through head of humerus.
