Imaging the Shoulder

In an US image of the soft tissue of the shoulder what structures appear anechoic, hypoechoic and hyperechoic?

*the descriptive terms are based in "echogenicity", or the way the ultrasound wave is reflected back to the transducer. 1. Hyperechoic - more echogenic (brighter) than normal (Hyperechoic masses are not as dense as hypoechoic ones are. They may contain air, fat, or fluid) 2. Hypoechoic - less echogenic (darker) than normal (Solid masses of dense tissue are hypoechoic) 3. Anechoic - The term is usually used in medicine when discussing images of body parts that appear black on ultrasound scans, meaning that they do not produce echoes (like the urinary bladder).

A trauma series of a radiograph includes an AP in neutral rotation; What are the other two special projections and what are they specialized for?

1. AP axillary radiograph = demonstrates the exact relationship of the humeral head to the glenoid fossa 2. AP scapular Y radiograph = demonstrates a lateral view of the humeral head & scapula without having to move the arm from a neutral position. *these are both used to rule out fractures or dislocations

What are the two basic pulse sequences for MRI of the shoulder and what do these sequences highlight?

1. Anatomy defining sequences: T1 weighted, gradient echo (GRE), and photon density (PD) 2. Fluid-sensitive sequences: inversion recovery, T2 weighted fat saturation. Also these sequences are variations in methods to reduce the bright signal from fat which can hinder a diagnosis

What are the three imaging planes for both the CT and MRI of the shoulder?

1. axial = visualization in cross section and from superior to inferior 2. oblique sagittal = from lateral to medial 3. oblique coronal = from front to back

shoulder radiograph example

A = acromion B = distal end of the clavicle C = superior border of the scapula D = coracoid process E = body of scapula F = inferior angle of the scapula G = humeral head H = shaft of the humerus

What do the ABCDs stand for when evaluating an MRI of the shoulder?

A = alignment B = Bone signal (marrow edema, stress fractures, osteochondral injuries, define radiographically ambiguous fractures) C = Cartilage D = eDema S = Soft & synovial tissues

What do the ABCs stand for when evaluating a CT of the shoulder?

A = alignment B = bone density C = cartilage spaces S = soft tissue

What's the goal of a radiograph for the shoulder?

A radiographic examination of the shoulder complex is to identify or exclude anatomic abnormalities or disease processes.

Which of the following is NOT one of the key observations of the shoulder in an Oblique Coronal MRI protocol? A. Cross-section of the rotator cuff B. Longitudinal view of the supraspinatus and infraspinatus C. Subacromial space D. Superior and Inferior portions of the labrum

A. Cross-section of the rotator cuff

The routine radiographic evaluation of the scapula includes which two projections?

AP & lateral views of the scapula: ~ checks for fractures on the scapular body that are readily visible

The "B" in the search pattern for a CT stands for: A. Boney anatomy B. Bone density C. Bone fragments D. Bone cortex

B. Bone density

Which of the following is NOT a indication for an MRI? A. Rotator cuff pathology B. Comminuted fracture of the humeral head C. Osteochondral and articular cartilage abnormalities D. Neoplasms and infections of the bone , joint or soft tissue

B. Comminuted fracture of the humeral head

The major advantage of the AP-Internal rotation view as compare to the other is: A. The greater tuberosity is now seen in profile B. The lesser tuberosity is now seen in profile. C. Visualization of the glenohumeral joint space without superimposition D. The vertebral and axillary borders of the scapula are not superimposed.

B. The lesser tuberosity is now seen in profile.

An advantage of the Oblique Sagittal view of the shoulder by CT includes all of the following EXCEPT: A. AC joint B. Subacromial space C. Greater tuberosity of the humerus D. Shape and slope of the acromion

C. Greater tuberosity of the humerus

When using ultrasound to evaluate the shoulder complex the transducer is moved in all but one of these directions to capture both transverse and longitudinal views of tissue structure, which one is incorrect? A. Anteriorly B. Laterally C. Medially D. Posteriorly

C. Medially

Which grade of AC joint sprain is it when the space between the acromion and clavicle is 1-1.5 cm and the coracoid and clavicle is 25-50% increased from 1-1.3 am. A. Normal AC joint B. Mild-Grade I C. Moderate-Grade II D. Severe-Grade III

C. Moderate-Grade II

Which of the following processes are NOT cartilaginous at birth? A. Acromion B. Coracoid process C. Inferior angle of the scapula D. Body of the scapula

D. Body of the scapula

The Field of View of a CT scan of the shoulder: A. Extends from the acromion to the surgical neck of the humerus and from from the axillary border of the scapula to the deltoid. B. Extends from the proximal humeral head to the shaft of the humerus and the acromion to the ribs C. Extends from the AC joint to the proximal humeral diaphysis and from the ribs to the deltoid attachment D. Extends from the AC joint to the proximal humeral diaphysis and from the axillary border of the scapula to the deltoid.

D. Extends from the AC joint to the proximal humeral diaphysis and from the axillary border of the scapula to the deltoid.

The routine radiographic evaluation of the acromioclavicular joint includes which two projections?

an upright AP view WB & NWB bilaterally: ~ the weights are to test the integrity of the AC joint

The routine radiographic evaluation of the shoulder includes which two projections?

anteroposterior view for ER:term-14 ~ good for spotting calcium deposits in tendons, muscles, or bursas ~ greater tuberosity is shown best ~ arm is in true anatomical position anteroposterior view for IR: ~ arm is IR ~ lesser tuberosity is shown best ~ used to screen for avulsions or bony destruction *AP axillary view: ~ helps determine the relationship of GH dislocations ~ can spot coracoid process fractures, indicative of other traumas

What advanced imaging modalities are used for soft tissue injuries or subacute and acute shoulder pain if radiographs are normal?

diagnostic ultrasound

The basic CT exam of the shoulder extends from where to where (Superior-Inferior) and from where to where (Medial-Lateral)?

extends from the top of the AC joint to the proximal humeral diaphysis, and from the scapular body out to the deltoid muscle

A disadvantage of the Scapular Lateral view is the body of the scapula is superimposed with the shaft of the humerus (T/F)

false

The difference between the search pattern for a CT and MRI when considering the letter "C" is that in an MRI it stands for cartilage space not the cartilage itself (T/F)

false

The disadvantage of the scapular Y lateral view is the patient has to be able to move there arm away from the body (T/F)

false

The two basic projections for a routine evaluation of the shoulder includes an AP-External Rotation and an Scapular Y view (T/F)

false

When evaluating via US the biceps tendon the tendon is hypoechoic (T/F)

false

Advantage of the Oblique Sagittal protocol is to see the rotator cuff in cross-section (T/F)

true

MRI of the Shoulder Complex involves two sequence at least including an anatomical and fluid sensitive sequence (T/F)

true

The advantage of the AP Scapular view is that all three borders and angles are visible (T/F)

true

The four centers of ossification for the proximal humerus include the shaft, the head, the greater and less tuberosities (T/F)

true

The goal of a radiograph is to identify or exclude abnormal anatomy or disease processes (T/F)

true

The main reason to order a CT of the Shoulder is for severe trauma where there are alignment issues or displaced fractures (T/F)

true

The paired sequence for an axial protocol of the shoulder includes a Proton Density (anatomy) and T2 with fat saturation (T/F)

true

The reason for doing a CT of the shoulder is that you suspect or have structural or spatial information about the bones or joint articulations of the shoulder complex (T/F)

true

The two sequences in US evaluation of the shoulder is long axis and short axis (T/F)

true

Using a Axial CT scan cut you can see a Hill-Sachs lesion which occurs with chronic dislocation and is a defect on the posterolateral humeral head (T/F)

true

CT exam of the shoulder: axial view

~ GH articulation ~ articular cartilage integrity at the humeral head ~ bony irregularities or bone reabsorption (from absence of pull from the supraspinatus) at the greater tuberosity ~ Bankart Lesion (fracture @ glenoid rim) ~ Hill Sachs (compression defect at the posterolateral humeral head)

CT exam of the shoulder: oblique sagittal view

~ assesses AC joint for degradation, spurs, hypertrophy ~ assesses sub acromial space for space for soft tissue structures ~ assesses inferior cortex & shape & slope of acromion

CT exam of the shoulder: oblique coronal view

~ assesses superior & inferior portions of the labrum Checks the following structures: ~ GH surfaces ~ glenoid rim ~ greater tuberosity ~ sub acromial space ~ configuration of acromion

What are the normal joint separation for the AC joint and the Coracoclavicular space, and what are those readings for the grades of AC joint separations?

~ grade 1 (AC ligament only) ~ grade 2 (AC torn 1-1.5 cm, and CC is sprained 25-50%) ~ grade 3 (AC torn > 1.5 cm, and CC is torn > 50%)

MRI of the Shoulder- Oblique Coronal

Ø Longitudinally the supraspinatus and infraspinatus muscle and tendon Ø Acromioclavicular joint Ø Acromion Ø Subacromial/ Subdeltoid bursa Ø Labrum (superior/ inferior portions) ØGH joint

Indications for a CT scan is needed for the shoulder

Ø Severe trauma ØAlignment and displacement of fracture fragments ØLoose bodies in the GH joint ØEvaluation of the labrum or rotator cuff tears and other conditions evaluated by MRI if MRI is unavailable or contraindicated

MRI of the Shoulder- Oblique Sagittal

ØIn cross-section: supraspinatus, infraspinatus, teres minor, and subscapularis Ø Rotator interval Ø Acromion and AC joint Ø Coracoacromial ligament Ø Coracoacromial arch Ø GH ligaments Ø Bone marrow

MRI of the Shoulder- Axial

ØLong head of the biceps in the bicipital groove in cross-section Ø Subscapularis muscle and tendon, longitudinally Ø Labrum, anterior and posterior portions Ø Capsule and GH ligaments Ø GH joint

Indications that an MRI is needed for the shoulder

ØRotator cuff pathology ØLong head of the biceps tendon pathology ØGlenoid labrum pathology ØSoft tissue or osseous coracoacromial arch impingement syndromes ØOsteochondral and articular cartilage abnormalities ØLoose bodies, chondral, osteochondral, or osseous lesions ØMarrow abnormalities: contusions, osteonecrosis, stress fractures ØNeoplasms or infections of bone, joint or soft tissue

Indications that a radiograph is needed for the shoulder

ØTrauma ØPhysical abuse ØOsseous changes secondary to metabolic, or systemic diseases or nutritional deficiencies ØNeoplasms ØInfections Ø Primary bone pathology ØJoint pathology ØPre and Post-operative and follow-up studies ØCongenital syndromes ØDevelopmental disorders ØVascular lesions ØSoft tissue (foreign body) ØPain ØCorrelation with other imaging studies