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Upper Extremity Imaging By Prof. J. Stelmark. Exposure Factors The principal exposure factors for radiography of the upper limbs are as follows: 1. Lower.

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Presentation on theme: "Upper Extremity Imaging By Prof. J. Stelmark. Exposure Factors The principal exposure factors for radiography of the upper limbs are as follows: 1. Lower."— Presentation transcript:

1 Upper Extremity Imaging By Prof. J. Stelmark

2 Exposure Factors The principal exposure factors for radiography of the upper limbs are as follows: 1. Lower to medium kV (50 to 70) 2. Short exposure time 3. Small focal spot 4. Adequate mAs for sufficient density

3 1. Phalanges (fingers and thumb)14 2. Metacarpals (palm)5 3. Carpals (wrist)8 TOTAL27 HAND AND WRIST

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5 A.First carpometacarpal joint of right hand B.First metacarpal of right hand C.First metacarpophalangeal joint of right hand D.Proximal phalanx of first digit (or thumb) of right hand E.Interphalangeal joint of first digit (or thumb) of right hand F.Distal phalanx of first digit (or thumb) of right hand G.Second metacarpophalangeal joint of right hand H.Proximal phalanx of second digit of right hand I.Proximal interphalangeal joint of second digit of right hand J.Middle phalanx of second digit of right hand K.Distal interphalangeal joint of second digit of right hand L.Distal phalanx of second digit of right hand M.Middle phalanx of fourth digit of right hand N.Distal interphalangeal joint of fifth digit of right hand O.Proximal phalanx of third digit of right hand P.Fifth metacarpophalangeal joint of right hand Q.Fourth metacarpal of right hand R.Fifth carpometacarpal joint of right hand

6 WRIST The wrist has eight carpal bones, which are fitted closely together and arranged in two horizontal rows. The carpals are classified as short bones and are composed largely of cancellous tissue with an outer layer of compact bony tissue. The proximal row of carpals, which is nearest the forearm, contains the scaphoid, lunate, triquetrum, and pisiform. The distal row includes the trapezium, trapezoid, capitate, and hamate.

7 Carpals (Wrist) The third group of bones of the hand and wrist are the carpals, the bones of the wrist Right carpals (dorsal or posterior view)

8 Right carpals (palmar or anterior view)

9 A.Scaphoid B.Lunate C.Triquetrum D.Pisiform E.Trapezium F.Trapezoid G.Capitate H.Hamate h.Hamulus (hamular process of hamate) PA wrist

10 WRIST JOINT MOVEMENT TERMINOLOGY Certain terminology involving movements of the wrist joint may be confusing but must be understood by technologists because special projections of the wrist are described by these movements. The ulnar deviation movement of the wrist “opens up” and best demonstrates the carpals on the opposite side (the radial or lateral side) of the wrist, namely, the scaphoid, trapezium, and trapezoid. Because the scaphoid is the most frequently fractured carpal bone, this ulnar deviation projection is commonly known as a special scaphoid projection. Radial deviation: A less frequent PA wrist projection involves the radial deviation movement that opens and best demonstrates the carpals on the opposite, or ulnar side, of the wrist, namely, the hamate, pisiform, triquetrum, and lunate.

11 PA, OBL, and LAT PROJECTION: FINGERS Pathology Demonstrated Fractures and/or dislocations of the distal, middle, and proximal phalanges; distal metacarpal; and associated joints are demonstrated. Some pathologic processes, such as osteoporosis and osteoarthritis, also may be demonstrated.

12 Central ray: CR ⊥, centered to PIP joint SID: 100–110 cm (40–44″) Position Patient seated at end of table, elbow flexed 90° (lead shield over lap) Pronate hand, separate fingers Center and align long axis of affected finger(s) to portion of IR being exposed

13 Position Patient seated, hand on table, elbow flexed 90° (lead shield over lap) Align fingers to long axis of portion of IR being exposed Rotate hand 45°, resting against 45° angle support block Separate fingers; ensure that affected finger(s) is (are) parallel to IR

14 Position Patient seated, hand on table (lead shield over lap) Hand in lateral position, thumb side up for 3rd–5th digits, thumb side down for 2nd digit Align finger to long axis of portion of IR being exposed

15 Central ray: CR ⊥, centered to lst MP joint

16 Position Patient seated, hand on table, elbow flexed Align thumb to long axis of portion of IR being exposed With hand pronated, abduct thumb slightly. This position tends to naturally rotate thumb into 45° oblique.

17 Position Patient seated, hand on table, elbow Align thumb to long axis of portion of IR being exposed With hand pronated and slightly arched, rotate hand medially until thumb is in true lateral position

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19 Position Patient seated, hand on table, elbow flexed Align long axis of hand and wrist parallel to edge of IR Hand fully pronated, digits slightly separated Central ray: CR ⊥, centered to 3rd MCP joint

20 Rotate entire hand and wrist laterally 45°, support with wedge or step block. Align hand and wrist to IR. Ensure that all digits are slightly separated and parallel to IR

21 for possible foreign body and metacarpal injury

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23 Position Patient seated, arm on table Align hand and wrist parallel to edge of IR Lower shoulder, rest arm on table to ensure no rotation of wrist Hand pronated, fingers flexed, and hand arched slightly to place wrist in direct contact with surface of IR Central ray: CR ⊥, centered to midcarpals

24 Rotate hand and wrist into 45° oblique position Flex fingers to support hand in this position, or use 45° support block

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27 A.Scaphoid B.Lunate C.Triquetrum D.Pisiform E.Trapezium F.Trapezoid G.Capitate H.Hamate h.Hamulus (hamular process of hamate) Ulnar deviation

28 Scaphoid views: CR angle with ulnar deviation Warning: If patient has possible wrist trauma, do not attempt this position before routine wrist series has been completed and evaluated to rule out possible fracture of distal forearm and/or wrist. Pathology Demonstrated Fractures of the scaphoid are demonstrated. Non-displaced fractures may require additional projections or a CT scan of the wrist.

29 Mechanics of scaphoid fracture: The scaphoid is the most commonly fractured carpal bone. One reason for this is its location among the other carpal bones. Two rows of carpal bones exist, a distal row and a proximal row, with joint spaces between them that allow the wrist to flex. The long scaphoid bone, however, is aligned partially with both of these rows with no joint space. When an individual falls on an outstretched hand the wrist is hyperextended, causing the proximal and distal carpal rows to flex at the joints, and a great deal of stress is placed on the narrow waist of the scaphoid. This stress may result in a fracture.

30 Technical Factors IR size—18 × 24 cm (8 × 10 inches) Division in half, crosswise Detail screen, tabletop Digital IR—use lead masking 60 ± 6 kV range

31 Shielding Place lead shield over patient's lap to shield gonads. Patient Position Seat patient at end of table, with wrist and hand on cassette, palm down, and shoulder, elbow, and wrist on same horizontal plane.

32 Part Position Position wrist as for a PA projection—palm down and hand and wrist aligned with center of long axis of portion of IR being exposed, with scaphoid centered to CR. Without moving forearm, gently evert hand (move toward ulnar side) as far as patient can tolerate without lifting or rotating distal forearm

33 Angle CR 10°to 15°proximally, along long axis of forearm and toward elbow. (CR angle should be perpendicular to long axis of scaphoid.)

34 To demonstrate the scaphoid without foreshortening, position the patient's wrist in maximum ulnar deviation; then direct a 15-degree proximal (toward the elbow) central ray angulation to the long axis of the scaphoid.

35 Center CR to scaphoid. (Locate scaphoid at a point 2 cm [¾ inch] distal and medial to radial styloid process.) Minimum SID is 40 inches (100 cm).

36 Collimation Collimate on four sides to carpal region Exposure Criteria: Optimal density and contrast with no motion visualize the scaphoid borders and clear, sharp bony trabecular markings.

37 PA SCAPHOID—HAND ELEVATED AND ULNAR DEVIATION: WRIST Modified Stecher Method Warning: If patient has possible wrist trauma, do not attempt this position before routine wrist series has been completed and evaluated to rule out possible fracture of distal forearm and/or wrist.

38 PA wrist for scaphoid: Hand elevated 20° Ulnar deviation if possible No CR angle

39 Severe pain: Hand elevated 20° No ulnar deviation No CR angle

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41 Shielding Place lead shield over lap to shield gonads. Patient Position Seat patient at end of table, with elbow flexed and resting on table, wrist and hand on cassette, and palm down, with shoulder, elbow, and wrist on same horizontal plane. Part Position Place hand and wrist palm down on cassette with hand elevated on 20°angle sponge. Ensure that wrist is in direct contact with cassette. Gently evert or turn hand outward (toward ulnar side) unless contraindicated because of severe injury

42 Central Ray Center CR perpendicular to IR and directed to scaphoid. (Locate scaphoid at a point 2 cm [¾ inch] distal and medial to radial styloid process.) Minimum SID of 40 inches (100 cm)

43 Hand elevated, ulnar deviation, and no CR angle. Hand elevated, no ulnar deviation or CR angle.

44 PA wrist—radial deviation Pathology Demonstrated Fractures of the carpal bones on the ulnar side of the wrist, especially the lunate, triquetrum, pisiform, and hamate, are demonstrated Technical Factors IR size—18 × 24 cm (8 × 10 inches) Division in half, crosswise Detail screen, tabletop Digital IR—use lead masking 60 ± 6 kV range

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46 Shielding Place lead shield over patient's lap to shield gonads. Patient Position Seat patient at end of table, with elbow flexed at 90° and resting on table, wrist and hand on cassette, and palm down, with shoulder, elbow, and wrist on same horizontal plane. Part Position Position wrist as for a PA projection—palm down with wrist and hand aligned with center of long axis of portion of IR being exposed. Without moving forearm, gently invert the hand (move medially toward thumb side) as far as patient can tolerate without lifting or rotating distal forearm.

47 Central Ray CR perpendicular to IR, directed to midcarpal area Minimum SID of 40 inches (100 cm) Collimation Collimate on four sides to carpal region

48 Structures Shown: The distal radius and ulna, the carpals, and the proximal metacarpals are visible. The carpals are visible, with adjacent interspaces more open on the medial (ulnar) side of the wrist. Position: The long axis of the forearm is aligned with the side border of the IR Extreme radial deviation is evidenced by the angle of the long axis of the metacarpals to that of the radius and ulna and the space between the triquetrum/pisiform and the styloid process of the ulna. No rotation of the wrist is evidenced by the appearance of the distal radius and ulna.

49 Collimation and CR: Collimation should be visible on four sides to the area of the affected wrist. CR and center of the collimation field should be to the midcarpal area. Exposure Criteria: Optimal density and contrast with no motion visualize the carpal borders and clear, sharp bony trabecular markings.

50 CARPAL CANAL (TUNNEL)—TANGENTIAL, INFEROSUPERIOR PROJECTION: WRIST Gaynor-Hart Method Pathology Demonstrated This projection is performed most commonly to rule out abnormal calcification and bony changes in the carpal sulcus that may impinge on the median nerve, as with carpal tunnel syndrome. It also visualizes fractures of the hamulus process of the hamate, pisiform, and trapezium.

51 CARPAL SULCUS The anterior or palmar surface of the wrist is concave from side to side and forms the carpal sulcus. The flexor retinaculum, a strong fibrous band, attaches medially to the pisiform and hook of hamate and laterally to the tubercles of the scaphoid and trapezium. The carpal tunnel is the passageway created between the carpal sulcus and flexor retinaculum. The median nerve and the flexor tendons pass through the carpal canal. Carpal tunnel syndrome results from compression of the median nerve inside the carpal tunnel.

52 Part Position Align hand and wrist with long axis of portion of IR being exposed. Ask patient to hyperextend wrist (dorsiflex) as far as possible by grasping the fingers with other hand and gently but firmly hyperextending the wrist until the long axis of the metacarpals and the fingers are as near vertical (90° to forearm) as possible (without lifting the wrist and forearm from the cassette). Rotate entire hand and wrist about 10°internally (toward radial side) to prevent superimposition of pisiform and hamate.

53 Central Ray Angle CR 25°to 30°to the long axis of the hand. (The total CR angle in relationship to the IR must be increased if patient cannot hyperextend wrist as far as indicated.) Direct CR to a point 2 to 3 cm (1 inch) distal to the base of third metacarpal (center of palm of hand). Minimum SID is 40 inches (100 cm).

54 Structures Shown: The carpals are demonstrated in a tunnel-like, arched arrangement. Position: The pisiform and the hamulus process should be separated and visible in profile without superimposition. The rounded palmar aspects of the capitate and the scaphoid should be visualized in profile, as well as that aspect of the trapezium that articulates with the first metacarpal. Collimation and CR: Collimation should be visible on four sides to area of affected wrist. CR and center of collimation field should be to midpoint of the carpal canal. Exposure Criteria: Optimal density and contrast should visualize soft tissues and possible calcifications in carpal canal region, and outlines of superimposed carpals should be visible without overexposure of these carpals in profile. Trabecular markings and bony margins should appear clear and sharp, indicating no motion.

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56 Position Patient seated at end of table with arm extended and hand supinated (shield across lap) Ensure that both wrist and elbow joints are included (use as large an IR as required to include both wrist and elbow joints) Have patient lean laterally as needed for a true AP of forearm Central ray: CR ⊥, centered to midpoint of forearm SID: 100–110 cm (40–44″)

57 Position Patient seated at end of table Elbow should be flexed 90° Hand and wrist must be in a true lateral position (distal radius and ulna should be directly superimposed) Ensure that both wrist and elbow joints are included unless contraindicated

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60 A.Medial epicondyle B.Trochlea (medial aspect) C.Coronoid tubercle D.Radial head E.Capitulum F.Lateral epicondyle G.Superimposed epicondyles of humerus H.Olecranon process

61 I.Trochlear sulcus J.Trochlear notch K.Double outer ridges of capitulum and trochlea (capitulum being the smaller of the two areas and trochlea the larger) L.Coronoid process of ulna M.Radial head N.Radial neck

62 AP PROJECTION: ELBOW (When Elbow Cannot Be Fully Extended) Pathology Demonstrated Fractures and/or dislocations of the elbow and pathologic processes, such as osteomyelitis and arthritis, are demonstrated Technical Factors IR size—24 × 30 cm (10 × 12 inches) Detail screen, tabletop, division in half, crosswise Digital IR—use lead masking 64 ± 6 kV range; exposure increased 4 to 6 kV because of increased part thickness caused by partial flexion

63 Patient Position Seat patient at end of table, with elbow partially flexed. Part Position Obtain two AP projections—one with forearm parallel to IR and one with humerus parallel to IR. Place support under wrist and forearm for projection with humerus parallel to IR, if needed, to prevent motion. Central Ray CR perpendicular to IR, directed to mid elbow joint, which is approximately 2 cm (¾ inch) distal to midpoint of a line between epicondyles Minimum SID of 40 inches (100 cm)

64 AP elbow (partially flexed); forearm parallel to IR.

65 AP elbow (partially flexed); humerus parallel to IR

66 Position Elbow extended and hand supinated (shield across lap) Lean laterally as needed for true AP (palpate epicondyles)

67 Internal (medial) oblique (45°). Elbow extended, hand pronated Palpate epicondyles to check for 45° internal rotation

68 External (lateral) oblique (40°–45°)

69 Position Elbow flexed 90°, shoulder dropped as needed to rest forearm and humerus on table and IR (shield across lap) Center elbow to center of IR or to portion of IR being exposed, with forearm aligned parallel to edge of cassette Place hand and wrist in a true lateral position

70 Structures Shown: Distal humerus is best visualized on “humerus parallel” projection, and proximal radius and ulna on “forearm parallel” projection. Note: Structures in elbow joint region are partially obscured and slightly distorted, depending on the amount of elbow flexion possible. Position: Long axis of arm should be aligned with side border of IR. No rotation is evidenced by the following: Epicondyles seen in profile; radial head and neck separated or only slightly superimposed over ulna on forearm parallel projection. Collimation and CR: Collimation should be visible on four sides to area of affected elbow. CR and center of the collimation field should be to the mid elbow joint.

71 Exposure Criteria: Optimal density and contrast with no motion should visualize soft tissue detail and sharp, bony cortical margins and clear, bony trabecular markings. Distal humerus, including epicondyles, should be demonstrated with sufficient density on “humerus parallel” projection. On “forearm parallel” projection, the proximal radius and ulna should be well visualized with density so as to allow visualization of both soft tissue and bony detail.

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73 A.Head of humerus B.Greater tubercle C.Intertubercular groove D.Lesser tubercle E.Anatomic neck F.Surgical neck G.Body

74 Position Erect or supine with humerus aligned to long axis of IR (unless diagonal placement is needed to include both elbow and shoulder joints). Place shield over gonads. Abduct arm slightly, supinate hand for true AP (epicondyles parallel to IR)

75 Position (May Be Taken Erect AP or PA, or Supine) Erect (PA): Elbow flexed 90°, patient rotated 15°–20° from PA or as needed to bring humerus and shoulder in contact with IR holder (epicondyles ⊥ to IR for true lateral) Erect or supine AP: Elbow slightly flexed, arm and wrist rotated for lateral position (palm back), epicondyles ⊥ to IR IR centered to include both elbow and shoulder joints

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77 TRANSTHORACIC LATERAL PROJECTION: HUMERUS (TRAUMA) Pathology Demonstrated Fractures of the diaphysis of the humerus are demonstrated. An AP with neutral rotation is required in addition to the transthoracic lateral projection Technical Factors IR size—35 × 43 cm (14 × 17 inches), lengthwise Moving or stationary grid, vertical, CR to centerline 75 ± 5 kV range Minimum of 2 seconds exposure time with breathing technique (between 2 and 4 seconds is desirable)

78 Fracture of proximal humerus, neutral rotation. This is a required projection for a trauma humerus in addition to a transthoracic lateral projection.

79 Patient Position Perform radiograph with the patient in an erect or supine position. (The erect position, which also may be more comfortable for patient, is preferred.) Place patient in lateral position with side of interest closest to IR. With patient supine, place portable grid lines horizontally and center CR to centerline to prevent grid cutoff

80 Part Position Place affected arm at patient's side in neutral rotation; drop shoulder if possible. Raise opposite arm and place hand over top of head; elevate shoulder as much as possible to prevent superimposition of affected shoulder.. Center mid-diaphysis of affected humerus and center of IR to CR as projected through thorax. Ensure that thorax is in a true lateral position

81 Central Ray CR perpendicular to IR, directed through thorax to mid-diaphysis Minimum SID of 40 inches (100 cm)

82 Radiographic Criteria (Transthoracic Lateral) Structures Shown: Lateral view of the entire humerus and glenohumeral joint should be visualized through the thorax without superimposition of the opposite humerus. Position: The outline of the shaft of the humerus should be clearly visualized anterior to the thoracic vertebrae. The relationship of the humeral head and the glenoid cavity should be demonstrated. Collimation and CR: Collimation should be visible on four sides to area of affected humerus. CR and center of collimation field should be at the mid- diaphysis of the affected humerus. Exposure Criteria: Optimal density and contrast will demonstrate the entire outline of the humerus. Overlying ribs and lung markings should appear blurred because of breathing technique, but bony outlines of the humerus should appear sharp, indicating no motion of the arm during the exposure.

83 (Mid- and Proximal Humerus)

84 (Mid- and Distal Humerus)


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