Advanced Skeletal Flashcards
Inferosuperior Tangential Wrist: Clinical Indications
abnormal calcifications and bony changes in the carpal sulcus that may impinge on the median nerve; carpal tunnel syndrome. Possible fractures of the hamulus process, pisiform and trapezium
Inferosuperior tangential wrist: Technical factors
SID: 40inches
IR: 8X10; non grid
Exposure factors: 60kV and 4-5mAs
Inferosuperior tangential wrist: positioning and central ray
Position: patient seated at the end of the table. Hand aligned with the long axis of IR. Hyperextend hand (dorsiflex wrist) so that the metacarpals are perpendicular (90 degrees) to the IR without lifting the forearm or wrist. Internally rotate (radially) the hand 10 degrees.
CR: angled 25-30 degrees to the long axis of the hand. Directed 1 inch distal to the base of the third metacarpal (center of hand).
Inferosuperior tangential wrist: evaluation criteria
Anatomy:
- the carpals are demonstrated in a tunnel-like, arched arrangement.
Position:
- the pisiform and the hamulus 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 the aspect of the trapezium that articulates with the first metacarpal
- CR and center of collimation to the midpoint of the carpal canal
Exposure:
- optimal density (brightness) and contrast as indicated by visualization of soft tissues and possible calcifications in carpal canal regian and outlines of the superimposed carpals are visable without overexposure of the carpals in profile.
- no motion as indicated by trabecular markings appearing sharp and clear
inferosuperior tangential wrist: adaption
If the patient is unable to dorsiflex wrist to place metacarpals perpendicular (90 degrees to the IR.
- align CR parallel to the long axis of the patient’s palm
- increase the angle 15 degrees from there
Clinical indication: Carpal Tunnel Syndrome
Symptoms -Numbness in 2 or more fingers -Pain that can extend to the elbow -Tingling or burning -Unable to tell the difference between hot and cold -Difficulty gripping small objects Treatment -Medication and or bracing -Ergonomics - surgery
Acute flexion elbow: clinical indications
Fractures and moderate dislocations of the elbow in acute flexion when the elbow cannot be extended to any degree
Acute flexion elbow: technical factors
SID:
40inches
IR:
10X12; landscape (2 exposures) ; nongrid
Exposure factors:
kV: 60 for distal humerus, 65 for proximal forearm
4-6mAs
Acute flexion elbow: positioning and Central ray
positioning
- patient seated with acutely flexed eblow resting on IR and the patients fingertips resting on their shoulder. Align and center humerus to the long axis of the IR. Center the elbow joint region. palpate humeral epicondyles and ensure they are parallel to the IR (no rotation).
Central Ray
- distal humerus: perpendicular to IR and humerus, directed midway between the epicondyles
-proximal forearm: perpendicular to the forearm (angle as needed). directed 2 inches proximal (superior) to the olecranon process
Acute flexion elbow: evaluation criteria
four sided collimation borders should be visable with CR and center of collimation field between epicondyles
Distal humerus
- forearm and humerus directly sumerimposed
- medial and lateral epicondyles and parts of trochlea, capitulum and olecrannon process are seen in profile
- optimal exposure should visualize distal humerus and olecrannon process through superimposed structures
- soft tissue detail is not readily visable
Proximal forearm
- proximal ulna and radius, including radial head and neck should be viable through the superimposed distal humerus
- optimal exposure visualizes outlines of proximal ulna and radisu superimposed over humerus
- soft tissue detail not readily availble
Acute flexion study MUST include both projections unless otherwise specified
Oblique elbow: Clinical Indications
- Fractures and dislocations of the elbow,
primarily the radial head and neck
-Certain pathologic processes, such as
osteomyelitis and arthritis
-Lateral (External Rotation) Oblique Best
visualizes radial head and neck of the radius and capitulum of humerus
-Medial (Internal Rotation) Oblique Best
visualizes coronoid process of ulna and
trochlea in profile
Oblque elbow: technical factors
SID:
40inches
IR:
10X12in ; landscape (two exposures) ; nongrid
Exposure factors
60 kV
3.2-5 mAs
Internal Oblique elbow: position and central ray
Patient seated with arm fully extended with elbow and shoulder on the same horizontal plane
Align arm and forearm with long axis of IR
Medial (internal) rotation
- pronate hand
- rotate arm until distal humerus and elbow are rotated 45 degrees. the interepicondylar line is approximately 45 degrees to the IR (this should be achieved by simply pronating the hand)
CR
perpendicular to IR directed 3/4th of an inch distal to interepicondylar line
External Oblique elbow: positioning and CR
Patient seated with arm fully extended with elbow and shoulder on the same horizontal plane
Align arm and forearm with long axis of IR
Lateral (external rotation
- supinate hand and roate entire arm laterally so that the distal humerus and the anterior surface of the elbow joint are approximately 45 degrees to the IR (this can be achieved by leaning laterally so that the patient shoulder is is resting on the table)
Central ray (both medial and lateral obliques)
- perpendicular to IR
- directed approximately 2cm distal to the midpoint between the humeral epicondyles
Medial Oblique elbows: Evaluation Criteria
Anatomy
-Oblique view of distal humerus
and proximal radius and ulna is visible.
Position
- Long axis of arm should be aligned with side
border o IR.
-Correct 45° medial oblique should visualize
coronoid process of the ulna in profile.
-Radial head and neck should be superimposed and centered over the 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.
-CR and center
of collimation field should be at mid-elbow joint.
Exposure:
-Optimal density (brightness) and contrast with
no motion should visualize soft tissue detail; bony cortical
margins; and clear, bony trabecular markings
External (lateral) oblique elbow: evaluation criteria
Anatomy
- Oblique projection of distal
humerus and proximal radius and ulna is visible
Position
-Long axis of arm should be aligned with side
border of IR.
- correct 45-degree oblique evident by visualization of radial head, neck and tuberosity, free of superimposition by ulna
-lateral epicondyle and capitulum should appear elongated and in profile
- CR and center of collimation should be to mid-elbow joint
Exposure
- Optimal density (brightness) and contrast with
no motion should visualize soft tissue detail; sharp, bony
cortical margins; and clear, bony trabecular markings
Radial Head lateral (4 views) : Clinical indications
fractures of radial head and neck
Radial Head laterals: technical factors
SID:
40inches
IR:
10X12in ; landscape (all four projections); nongrid
exposure factors:
60kV
3.2-6 mAs
Radial head laterals: position and CR
Center radial head to IR so that humerus and proximal forearm are parallel with IR borders.
4 projections:
-1. supinate hand (palm up) and externally rotate as far as the patient can tolerate
-2. place hand in true lateral position (thumb up)
-3. pronate hand (palm down)
-4. internally rotate hand (thumb down ) as far as patient can tolerate
CR
perpendicular to IR, directed to the radial head (approximately 1 inch distal to lateral epicondyle)
Radial head laterals: evaluation criteria
- Elbow should be flexed 90° in true lateral position, as
evidenced by direct superimposition o epicondyles
-radial head and neck should be partially superimposed by ulna but completely visualized in profile in various projections
-radial tuberosity should be visualized in various positions as follows from external to internal rotation of the hand:
1. slightly anterior
2. superimposed over radial shaft
3. slightly posterior
4. most posterior, seen adjacent to the ulna
Optimal exposure with no motion should clearly
visualize sharp, bony margins and clear trabecular markings of
radial head and neck area
Fat Pad signs
Indication of synovial effusion, bursal hemorrhage or fracture
Elbow
Anterior pad is normally slightly visible in lateral view
Posterior pad is not normally illustrated
With trauma the anterior pad is more rounded and pronounced and the posterior pad is visible
‘Sail’ sign
Other joints: hip, wrist & ankle
Weight-bearing foot: clinical indications
- Demonstrates the position of the bones of the feet under full body weight
- Shows the longitudinal arches
- Joint fusions
- Pathology i.e. arthritis
weight-bearing foot: technical factors
SID:
40in
IR:
10X12 in for unilateral, 14X17 in for bilateral study; landscape; non-grid
Exposure factors:
60kV; 3.2-4mAs