Upper Extremity Image Analysis- Ch 4

joint spaces are parallel to the IR and perpendicular to the CR
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joint spaces are parallel to the IR and perpendicular to the CR
Proper finger positioning and CR alignment allows what for the joint spaces?
causes foreshortening of phalanges and superimposition of the joint spaces
What does flexion of the phalanges cause?
do an AP projection instead of a PA; supinate hand, elevate metacarpals until the phalanx of interest is parallel with the IR, and the joint space of interest is perpendicular to the IR
if a patient cannot fully extend fingers, what should be done to demonstrate open IP and MP joint spaces?
1. the thumb is demonstrated at a 45 degree angle
2. the 3rd MTP joint is at the center of the exposure field
3. No tissue overlap
4. the phalanges, metacarpals, carpals, and 1" of the distal radius and ulna are included in the collimated field
5. The IP, MCP, and CM joint spaces are open
5 criteria for a PA hand:
1. the 2nd-5th metacarpal midshafts demonstrate more midshaft concavity and twice as much soft tissue width on the side of the finger that the anterior surface is rotated toward
2. the 1st and 2nd metacarpal heads are not superimposed, the 3rd-5th metacarpal heads are slightly superimposed and a slight space is present between the 4th and 5th metacarpal midshafts
3. there is no tissue overlap from adjacent digits
4. the IP and MP joints are demonstrated as open spaces, and the phalanges are not foreshortened; the thumb position may vary from a lateral to an oblique position
5. the 3rd MTP joint is in the center of the exposure field
6. the phalanges, metacarpals, carpals, and 1" of the distal radius and ulna are included within the collimated field
6 criteria for a PA oblique hand:
1. 2nd-5th digits are separated, demonstrating little superimposition of the proximal bony or soft tissue structures
2. the thumb is demonstrated without superimposition of the other digits and is in a PA to slight oblique position
3. IP joint spaces are open
4. the 2nd-5th metacarpals are superimposed
5. the IP joints are open, and the phalanges are not foreshortened
6. the MP joints are at the center of the exposure field
7. the phalanges, metacarpals, carpals, and 1" of the distal radius and ulna are included in the collimated field
Lateral hand criteria:
1. the radial and ulnar styloid processes are at the extreme lateral and medial edges
2. the radioulnar articulation is open, and superimposition of the metacarpal bases is limited
3. the anterior and posterior articulating margins of the radius are almost superimposed (within 0.25")
4. the 2nd-5th metacarpal joint spaces are open; the scaphoid is only slightly foreshortened, and the lunate is trapezoidal
5. the long axis of the 3rd metacarpal and the mid-forearm are aligned with the long axis of the collimated field; the scaphoid and half of the lunate are positioned distal to the radius
6. the carpal bones are at the center of the exposure field
7. the carpal bones, 1/4 of the distal ulna and radius, and half of the proximal metacarpals are included within the collimated field
PA wrist criteria:
it is a soft tissue structure that should be visible on all PA wrist projections
what is the scaphoid fat stripe?
convex
what shape is the scaphoid fat strip
lateral to the scaphoid in an uninjured wrist
where is the scaphoid fat strip located
a change in convexity of the stripewhat is indicative of a joint effusion, radial-side fracture of the scaphoid, radial styloid process, or proximal first metacarpal fracture?external and internal hand and wrist rotationwhat causes the radial styloid process to rotate out of profile1. ulnar styloid is in profile 2. the trapezoid and trapezium are demonstrated without superimposition 3. the long axis of the 3rd metacarpal and mid-forearm are aligned 4. posterior radial margin superimposes no more than 1/4 of the lunate 5. the 4th and 5th metacarpal midshafts demonstrate a small separation 6. carpal bones, 1/4 of the distal and ulna, and half of the proximal metacarpals are demonstratedCriteria for a PA oblique wrist:1. ulnar styloid is in profile 2. distal radius and ulna are superimposed 3. anterior aspects of the distal scaphoid and pisiform are aligned 4. trapezium is demonstrated without superimposition of the 1st metacarpalCriteria for lateral wrist positioning:like the scaphoid fat stripe, it is seen on accurate wrist positioning; the pronator fat stripe is seen on the correctly positioned lateral wristwhat is the pronator fat stripe?parallel to the anterior surface of the distal radiuswhere is the pronator fat stripe locatedbowing or obliteration of the stripewhat indicates a subtle radial fracture1. the radial styloid is demonstrated in profile laterally 2. superimposition of the MC bases and of the radius and ulna is minimal 3. radius and ulna run parallel 4. the ulnar styloid is projected distally to the midline of the ulnar head 5. approximately 0.25" of the radial head should be superimposed over the ulna 6. the olecranon process is situated in the fossaAP forearm criteria:if the radial head demonstrates more or less than 0.25" of superimposition over the ulna of the elbowHow to tell if an AP forearm is rotated?if more than 0.25" of the radial head is superimposed over the ulnaHow to tell if an AP forearm is internally rotated?if less than 0.25" of the radial head is superimposed over the ulnahow to tell if an AP forearm is externally rotated1. midpoint of forearm is at the center of the collimated field 2. the wrist, elbow joints, and soft tissue are visible *3. the anterior aspect of the scaphoid and pisiform are aligned, and the distal scaphoid is demonstrated slightly distal to the pisiform 4. the distal radius and ulna are superimposed 5. the ulnar styloid process is demonstrated in profile posteriorly 6. the elbow is flexed 90 degrees 7. the elbow joint space is open. and the radial head is superimposed over the coronoid processlateral forearm criteria:1. the medial and lateral humeral epicondyles are demonstrated in profile 2. the radial head is superimposed over the lateral aspect of the proximal ulna by 0.25" 3. the radial tuberosity is in profile medially 4. the radius and ulna are parallel 5. the elbow joint is open, the radial head articulating surface is not demonstrated, and the olecranon process is situated within the fossa 6. the elbow joint is at the center of the collimated field 7. 1/4 of the proximal forearm and distal humerus is demonstratedAP elbow criteria:if more or less than 0.25" of the radial head is superimposed over the ulnaHow to tell if an AP elbow is rotated?if more than 0.25" of the radial head is superimposed over the ulnaHow to tell if an AP elbow is internally rotated?if less than 0.25" of the radial head is superimposed over the ulnaHow to tell if an AP elbow is externally rotated?1. the distal surfaces of the capitulum and medial trochlea are aligned 2. anterior surfaces of the radial and the coronoid process are aligned 3. elbow joint is open 4. anterior surface of the capitulum and medial trochlea are near aligned 5. proximal surfaces of the radial head and the coronoid process are alignedlateral elbow criteria:it is immediately anterior to the distal humerus ; formed by the superimposed coronoid process and radial padswhere should the anterior fat pad of the elbow on a lateral projection be seen?change in shape or placementwhat is indicative of joint effusion or elbow injury?radial tuberosity location; it should not be seen on a lateral elbowwhat is a good indicator of lateral elbow rotation?the radial tuberosity is on top (or pointing medially)how to tell if a lateral elbow is internally rotatedthe radial tuberosity is on bottom (or pointed laterally)how to tell if a lateral elbow is externally rotated1. the medial and lateral humeral epicondyles are demonstrated in profile 2. the radial head and tuberosity are superimposed over the lateral aspect of the proximal ulna by about 0.25" 3. the greater tubercle is demonstrated in profile laterally 4. humeral head is demonstrated in profile medially 5. the vertical cortical margin of the lesser tubercle is visible about halfway between the greater tubercle and humeral headAP humerus criteria:under the anode under the cathodewhen taking images of a humerus, where should the thinner part of the arm be in relation to the cathode/anode due to the anode heel effect? where should the thicker part of the arm be?1. humeral epicondyles seen in profile 2. greater tuberosity seen in profile2 ways to determine if an AP humerus is rotated?if more than 0.25" of the radial head and tuberosity are superimposed over the ulnahow to tell is an AP humerus is internally rotatedif less than 0.25" of the radial head and tuberosity are superimposed over the ulnahow to tell if an AP humerus is externally rotated?1. lesser tubercle is seen in profile medially 2. the humeral head and the greater tubercle are superimposed 3. the humeral midpoint is in the center of the exposure field 4. the anterior surfaces of the capitulum and medial trochlea are aligned 5. the shoulder and elbow joints and the lateral humerus soft tissue are includedlateral humerus criteria:1. transthoracic lateral with a breathing technique to blur out vascular markings 2. scapular Y projectionwhat are two alternate positions to be performed if there is a suspected humeral fracture?