What anatomy is superimposed over the junction of the Y on the PA oblique scapular Y projection on a patient with a normal shoulder joint?

Unformatted text preview: Chapter 5 Humerus & Shoulder Girdle Pages 173 – 205 Anatomy Review Humerus Anatomy: Humerus Long bone in the upper arm Head articulates with scapula, specifically the glenoid fossa, to form shoulder joint Distal end forms part of elbow joint Distal anatomy Medial epicondyle Lateral epicondyle Trochlea Capitulum Coronoid fossa Olecranon fossa (posterior) Proximal anatomy Head Neck Surgical neck (common FX location) Greater tubercle Lesser tubercle FX @ Surgical Neck (fracture) AP Lateral AP Ext. ORIF Open Reduction Internal Fixation AP Int. Room, Patient, & Equipment Considerations Humerus Room & Patient Preparation Room: Clean Room Gather supplies Prep equipment Pillow (for supine images) Patient: Remove artifacts from anatomy of interest Examples: clothing and/or bra (waist up) Secure all patient possessions in designated manner and location 6 Patient Instructions Explain and demonstrate positions Respirations suspended on expiration Transthoracic lateral projection may use breathing technique (normal steady breathing) Low mA with long exposure time Console will be set in the mA/time mode (not mAs mode) General Patient Position Ambulatory patients Exam may be completed using either wall bucky or table bucky Nonambulatory patients Most often, exam is completed using the table bucky IR, Collimated Field Size & Markers Collimated field size – 2 inches distal to the elbow joint and superior to the shoulder, and 1 inch on the sides Correct marker is required on all images Marker should not be in area of interest Place maker close to skin line and collimate to the marker – close collimation Marker placed on the lateral side of the patient Radiation Protection For our purposes, we shield EVERY PATIENT Other radiation protection measures Close collimation Optimum technique Full lead apron preferred ½ apron used Radiographic Procedures Humerus Essential Projections: Humerus AP Lateral Transthoracic lateral – RADR 2401 Note: Humerus is usually imaged using the Bucky, if possible. AP Humerus Part position CR Place top border of IR approximately 1½ inches (3.8 cm) above humeral head Slightly abduct humerus from body and supinate hand Coronal plane passing through humeral epicondyles should be placed parallel to IR plane Elbow and should be in the same plane Perpendicular to midportion of humerus and centered to IR Collimation angled to match the long axis of the part AP Humerus Projection Include both shoulder and elbow joints CR to midhumerus 14 Evaluation Criteria Entire humerus demonstrated Greater tubercle in profile Medial and lateral epicondyles in profile Exposure factors 15 Lateral Humerus Part position Place top border of IR approximately 1½ inches (3.8 cm) above humeral head Internally rotate humerus, flex elbow 90 degrees if possible, and rest back of hand on hip Coronal plane passing through epicondyles should be perpendicular to plane of IR Elbow and shoulder must be in the same plane CR Perpendicular to midportion of humerus and centered to IR Collimation angled to match the long axis of the part Lateromedial and Mediolateral Humerus Projections Epicondyles perpendicular to IR CR to midhumerus 17 Lateral Humerus Recumbent Rotational Lateral Epicondyles perpendicular to IR 18 Evaluation Criteria Entire humerus demonstrated Lesser tubercle in profile Epicondyles superimposed Exposure factors 19 Trauma Humerus Transthoracic Lateral Humerus Part position Patient may be erect or supine based on patient comfort Place top border of IR approximately 1½ inches (3.8 cm) above humeral head Place patient in a lateral position, side of interest closest to the IR Affected humerus is in a neutral position • ASSESS your patient. DO NOT move the patient’s humerus if severe TRAUMA is obvious • FX or dislocation Raise opposite arm above patient’s head, elevate shoulder as much as possible to prevent superimposition of affected shoulder. Transthoracic Lateral Humerus CR For lateral recumbent position: perpendicular to midportion of humerus, directed through the thorax and centered to IR For recumbent (supine) position: horizontal beam and perpendicular to midportion directed through the thorax and centered to IR – X-table (TRAUMA) Collimated field Include as much of proximal humerus as possible to below the elbow joint Horizontal Beam Transthoracic Lateral Humerus (Trauma) Demonstrates entire humerus without rotation Unaffected limb raised over head CR to mid aspect to involved humerus 23 Horizontal Beam Transthoracic Lateral Humerus (Trauma) Demonstrates entire humerus without rotation Glenohumeral joint visualized through thorax No superimposition of unaffected humrus 24 Lateral Mid and Distal Humerus Trauma Position 25 Evaluation Criteria Mid and distal humerus Distal ⅔ humerus demonstrated 90° perspective from AP projection Epicondyles superimposed Exposure factors 26 Anatomy Review Shoulder Girdle Shoulder Girdle Consists of Articulates with Clavicle Scapula Head of humerus (shoulder joint) Manubrium of sternum (sternoclavicular [SC] joint) Acromioclavicular (AC) joint Functions to connect the upper limb to the trunk of the body Shoulder Articulation of the upper limb with the girdle Humerus is not considered to be part of the shoulder girdle Because the upper portion articulates with the shoulder girdle, proximal humeral anatomy is considered in evaluation of radiographs of the shoulder joint Proximal Humerus 30 Joints of Shoulder Girdle (Synovial, Diarthrodial) Acromioclavicular (AC) Scapulohumeral Sternoclavicular (SC) 31 Room, Patient, & Equipment Considerations Shoulder Clavicle Classified as a long bone Lies just above the first rib Acromial extremity (lateral end) articulates with acromion on scapula (AC joint) Sternal extremity (medial end) articulates with manubrium of sternum (SC joint) Double curve to body Curve more pronounced in males than in females Scapula Classified as a flat bone Forms the posterior portion of the shoulder girdle Triangular in shape Two surfaces Costal (anterior) Dorsal (posterior) Three borders Lateral Medial Superior Three angles Superior Inferior Lateral Anterior Posterior Lateral Aspect of Shoulder Girdle General Procedural Guidelines Shoulder General Procedural Guidelines Patient preparation General patient position 10 x 12 Collimation open to IR size SID Upright or recumbent IR/Collimated field size Remove artifacts 40” ID markers - ALWAYS Radiation protection - ALWAYS Patient Instructions Respirations suspended on expiration Transthoracic lateral projection may use breathing technique (normal steady breathing) Low mA with long exposure time Console will be set in the mA/time mode (not mAs mode) Radiographic Procedures Essential Projections of the Shoulder Essential Projections: Shoulder AP projections External rotation Internal rotation Neutral position Transthoracic lateral (Lawrence method) AP oblique (Grashey method) Inferosuperior axial (Lawrence method) PA oblique (scapular Y) AP Projection in External Rotation Patient position Part position Rotate patient slightly toward affected shoulder in necessary to place shoulder in contact with bucky Place body of scapula parallel with plane of IR Important for patients with extreme kyphosis (humpback curvature of the spine) Center scapulohumeral joint to the IR Abduct arm slightly Rotate arm externally and supinate hand Place humeral epicondyles parallel to IR CR 1 inch distal to coracoid, perpendicular to IR AP Shoulder External Rotation (AP Proximal Humerus) Epicondyles parallel CR 1 inch (2.5 cm) inferior to coracoid process 42 AP Proximal Humerus (External Rotation) Epicondyles parallel to IR Shoulder joint collimation A. Greater tubercle lateral (in profile) B. Lesser tubercle anterior 43 Evaluation Criteria AP Shoulder (External Rotation) Greater tubercle profiled laterally Scapulohumeral joint centered Proximal humerus, upper scapula, and clavicle visualized Optimal exposure factors 44 AP Projection in Internal Rotation Patient position Part position Rotate patient slightly toward affected shoulder Place body of scapula parallel with plane of IR Important for patients with extreme kyphosis (humpback curvature of the spine) Center scapulohumeral joint to the IR Abduct arm slightly Flex elbow slightly Rotate arm internally and rest back of hand on hip Place humeral epicondyles perpendicular to IR CR 1 inch distal to coracoid, perpendicular to IR Internal Rotation (Lateral Proximal Humerus) Epicondyles perpendicular CR 1 inch (2.5 cm) inferior to coracoid process 46 Evaluation Criteria (Internal Rotation) Lesser tubercle profiled medially Scapulohumeral joint centered Proximal humerus, upper scapula, and clavicle visualized Optimal exposure factors 47 AP Projection in Neutral Position For trauma cases If possible, have patient rest the palm of the hand against the thigh Part position Leave arm in neutral position Center scapulohumeral joint to the IR Place patient’s arm “as is” neutral position • epicondyles usually at 45-degree angle to IR CR Perpendicular to IR to midscapulohumeral joint 3/4 inch inferior to coracoid and slightly lateral AP Neutral Rotation CR to scapulohumeral joint 49 Evaluation Criteria Greater tubercle superimposed Scapulohumeral joint centered Optimal exposure factors 50 AP Oblique (Grashey Method) Patient position 35 to 45 degrees posterior oblique position Affected shoulder closer to IR More rotation may be necessary if patient is recumbent Rotation should place scapula parallel to IR Head of humerus will be in contact with IR AP Oblique (Grashey Method) Part position Rotate body 35-45 degrees toward affected side Center midscapulohumeral joint to IR Abduct arm slightly with neutral rotation Place palm of hand on abdomen CR Perpendicular to glenoid cavity Enters 2 inches (5 cm) medial and inferior to superolateral border of shoulder Collimation Adjust to 8 x 10 inches (18 x 24 cm) To visualize just the shoulder joint Posterior Oblique: Glenoid Cavity (Grashey Method) 35°-45° oblique CR perpendicular CR 2 inches (5 cm) inferior and medial from superolateral border of humerus 53 Evaluation Criteria: (Posterior Oblique) Glenoid cavity profiled Scapulohumeral joint centered Optimal exposure factors 54 Shoulder Trauma Routine Routine AP–neutral rotation Scapular Y Transthoracic lateral 55 PA Oblique (Scapular Y) So named because when properly positioned, the acromion and coracoid process form a Y shape Position is particularly useful to diagnose shoulder dislocations In the normal shoulder, the humeral head is directly superimposed over the junction of the Y (acromion and coracoid) PA Oblique (Scapular Y) Patient position Upright, 45 to 60 degrees anterior oblique position Affected shoulder closer to IR Part position Arm position in a neutral position Maintain patient comfort Palpate superior angle of scapula and AC joint Rotate patient until an imaginary line between the two points is perpendicular to the IR PA Oblique (Scapular Y) CR Perpendicular to scapulohumeral joint 2 to 2 ½ inches distal to the top of the shoulder Collimation Adjust to 12 inches (30 cm) in length and 1 inch (2.5 cm) from the lateral shadow PA Oblique (Scapular Y) For lateral shoulder and proximal humerus CR to proximal humerus-2 inches (5 cm) below top of shoulder 59 Evaluation Criteria (Scapular Y Lateral) Body of scapula superimposed on end Acromion and coracoid processes in profile Humeral head and glenoid cavity superimposed Optimal exposure factors Dislocated 60 Inferosuperior Axial Projection (Lawrence Method) Patient position Supine Head and shoulder elevated on 3-inch radiolucent support Head turned away from CR Inferosuperior Axial Projection (Lawrence Method) Part position Elevate arm about 2 inches above the table to help place anatomy closer to the center of the IR Abduct arm 90 degrees from body If possible, place arm in external rotation Place IR crosswise on table (in a holder) centered to shoulder joint Collimation Adjust to 12 inches (30 cm) in length and 1 inch (2.5 cm) above the anterior shadow of the shoulder Inferosuperior Axial Projection (Lawrence Method) CR Horizontal Medial angulation of 25 to 30 degrees Centered to axilla and humeral head Enters axilla; passes through AC joint Angle depends on abduction of humerus More abduction = greater angle Inferosuperior Axial (Lawrence Method) CR 25°-30° medial to axilla Arm supinated, abducted 90° (or as near 90° as possible) Special • Inferosuperior axial 64 Evaluation Criteria (Inferosuperior Axial Projection) Lesser tubercle profiled anteriorly Humeral head and glenoid fossa profiled Optimal exposure factors 65 Trauma Shoulder Transthoracic Lateral (Lawrence Method) Note: Projection used for trauma patients who cannot abduct arm Patient position Supine or upright lateral Affected limb closer to IR Unaffected limb elevated over head Transthoracic Lateral (Lawrence Method) Part position Do not move injured limb Ensure elevated shoulder is higher than injured shoulder Center surgical neck of humerus to IR Transthoracic Lateral (Lawrence) CR Perpendicular to surgical neck If shoulders are in same plane, CR angled 10 to 15 degrees cephalad Collimation Adjust to 10 x 12 inches (24 x 30 cm) LW The light field will appear smaller on the skin because of OID. Do not collimate larger than stated size. Transthoracic Lateral Proximal Humerus CR perpendicular to surgical neck Breathing technique Similar positioning to transthoracic humerus but… CHANGE IN CR & IR size 70 Evaluation Criteria Proximal humerus clearly seen Humeral head and glenoid cavity seen Humeral head in neutral rotation Optimal exposure factors 71 Questions? Next Lecture: Chapter 5 clavicle, scapula, & ACJ 72 ...
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