Imaging Quiz 3 Practice Flashcards

Comprehensive practice flashcards for Imaging Quiz 3, covering C-spine, shoulder, elbow, and hand/wrist imaging based on high-yield lecture notes.

According to the Canadian C-Spine Rule (CCR), what age is considered a high-risk factor requiring imaging?

Age $\ge 65$

What are the three high-risk factors identified in the Canadian C-Spine Rule?

Age $\ge 65$, Dangerous mechanism, and Extremity paresthesia

Name the four low-risk factors in the CCR that allow for Range of Motion (ROM) assessment.

Simple rear-end MVC, Able to sit/ambulatory, Delayed onset neck pain, and No midline C-spine tenderness

What is the specific ROM assessment required to clear a patient under the CCR?

The patient must actively rotate the neck $45^{\circ}$ bilaterally

What is the sensitivity of the Canadian C-Spine Rule for detecting fractures?

$$99.4\%$$

How many criteria must be present to clear a patient using the NEXUS Low Risk Rule?

All $5$ criteria

What are the 5 criteria of the NEXUS Low Risk Rule?

1. No posterior midline C-spine tenderness, 2. No focal neurologic deficit, 3. Normal alertness, 4. No intoxication, 5. No distracting painful injury

What is the primary screening modality for suspected C-spine injury according to ACR 2009?

CT

Compare the sensitivity of radiography versus CT for C-spine fractures.

CT is much more sensitive than radiography$

Which two junctions of the spine are most commonly missed on C-spine radiographs?

Craniovertebral ($C1-C2$) and Cervicothoracic ($C7-T1$) junctions

What percentage of odontoid fractures occur at $C2$?

Hal

Which type of odontoid fracture is most common, and what is its percentage of occurrence?

Type II, accounting for $81\%$

What is the typical mechanism for odontoid fractures in young individuals?

High-impact trauma or MVAs

What is the typical mechanism for odontoid fractures in older adults ($>75$)?

Falls from standing or seated height

What is the anatomical description of a Type II odontoid fracture?

Horizontal fractures across the odontoid

What is the primary risk factor for odontoid fractures in patients over $60$ years of age?

Osteoporosis

What is the 1-year mortality rate for odontoid fractures in the general population versus those over $80$ years old?

General: $\sim 30\%$, Over $80$: $59\%$

Which imaging modality is best for bony elements like the odontoid?

CT

Which imaging modality is best for assessing neural tissues in the cervical spine?

MRI

How common is Atlanto-Axial Subluxation (AAS) in patients with Rheumatoid Arthritis?

$33-50\%$ (often asymptomatic)

What is the normal Anterior Atlanto-Dens Interval (AADI) in adults?

$$<3\,mm$$

An AADI greater than how many millimeters suggests transverse ligament compromise?

$$>3\,mm$$

What are two risk factors for AAS in patients with RA?

Long-standing RA ($>10$ years) and erosive disease

How does neck retraction affect AAS?

It produces similar AAS as flexion

Why should isometric extension be avoided in suspected AAS?

It causes the Atlanto-Dens (AAD) to increase

How does isometric flexion affect the AAD interval?

It causes the AAD to decrease

What is the preferred imaging for chronic neck pain when assessing for instability?

Radiography

What is the average age of onset for Cervical Spondylotic Myelopathy (CSM)?

$$\sim 64$$

Which spinal level is most common for CSM?

$$C5-C6$$

What two health conditions are associated with CSM?

Smoking and diabetes

List three early symptoms of CSM.

UE sensory changes, loss of hand fine motor function, and gait disturbance

What are the 5 findings in the screening cluster for CSM?

1. Gait deviation, 2. Hoffmann's reflex, 3. Inverted supinator sign, 4. Babinski/up-going plantar response, 5. Age $>45$

What is the sensitivity and specificity of Hoffmann's reflex for myelopathy?

Sensitivity: $44\%$, Specificity: $75\%$

What is the specificity of the Trömer Sign?

$$95\%$$

Which myelopathic sign has a specificity of $100\%$?

Finger Escape

When does the clinical significance of Hoffmann's reflex increase?

When it is unilateral or asymmetrical

What are the Likelihood Ratios (LR) for Hoffmann's reflex?

$+LR = 2.6$, $-LR = 0.51$

In which population is Posterior Longitudinal Ligament Ossification (OPLL) more prevalent?

Asian populations

When does OPLL usually become symptomatic?

In the 5th to 6th decades

What is the most common clinical presentation of OPLL?

Cervical myelopathy

Which imaging modality is best for visualizing ossification in OPLL?

CT

What are the four questions in the DOWN Questionnaire for myelopathy screening?

1. Dropping things? 2. Off-balance? 3. Weakness in arms/hands? 4. Numbness/tingling in arms/hands?

What cervical spine condition occurs in $10-30\%$ of individuals with Down Syndrome?

A-A (Atlanto-Axial) instability

What percentage of individuals with Down Syndrome have Os odontoideum?

$$6\%$$

Which condition places a patient at high risk for fractures from simple falls?

Ankylosing Spondylitis

What is the diagnostic contribution of shoulder radiography in the absence of trauma?

$$15-24\%$$

In the absence of shoulder trauma, how often does radiography change management?

<2\%

Compare the sensitivity and specificity of Non-contrast MRI for Rotator Cuff tears.

Sensitivity: $94\%$, Specificity: $93\%$

Compare the sensitivity and specificity of Ultrasound (US) for Rotator Cuff tears.

Sensitivity: $92\%$, Specificity: $93\%$

Which modality is superior specifically for partial-thickness rotator cuff tears?

Ultrasound

Which modality is best for assessing capsulolabral lesions in the shoulder?

MR Arthrography

List the 4 predictors for a full-thickness rotator cuff tear.

1. Age $\ge 60$, 2. Painful arc, 3. Positive infraspinatus test, 4. Positive drop arm test

What is the Positive Likelihood Ratio ($+LR$) if all 4 full-thickness tear predictors are present?

$$28.0$$

List the 3 predictors for a partial or full rotator cuff tear.

1. Weakness on external rotation, 2. Age $\ge 65$, 3. Night pain with loss of sleep

What is the $+LR$ if all 3 partial/full tear predictors are present?

$$9.8$$

What is Goutallier Stage 0?

Normal muscle

What defines Goutallier Stage 2?

$<50\%$ fatty muscle atrophy

What defines Goutallier Stage 4?

$>50\%$ fatty muscle atrophy

How soon does fatty infiltration begin after tendon detachment?

By $4$ weeks

In fatty infiltration of the shoulder, what is considered the best outcome post-repair?

No worsening (no improvement occurs)

Fatty infiltration of which muscle indicates a poor prognosis?

Infraspinatus

At what amount of displacement is surgical stabilization needed for a Greater Tuberosity fracture?

$$>5\,mm$$

What is the imaging recommendation for persistent shoulder pain post-trauma with negative radiographs?

MRI

Who is the typical demographic for proximal humerus fractures?

Older women with osteoporosis and falls

What is the sensitivity and specificity of MR Arthrography for capsulolabral lesions?

Sensitivity: $88\%$, Specificity: $93\%$

Which imaging modality is considered the gold standard for bone deficiency (bone loss) in the shoulder?

3D CT

What range of glenoid bone loss is considered critical for stability?

$$15-20\%$$

Define a Hill-Sachs lesion.

Humeral head compressed or abraded against the glenoid fossa, accompanying GH dislocations

Distinguish between a fibrous and bony Bankart lesion regarding imaging choice.

MRI for fibrous Bankart; CT for bony Bankart

Why is non-contrast MRI considered inaccurate for SLAP lesions?

Low sensitivity and high false negatives

What are the two best clinical tests for a suspected SLAP lesion?

Passive Compression and Passive Distraction

What is the sensitivity and specificity of an MR Arthrogram for SLAP lesions?

Sensitivity: $95.6\%$, Specificity: $85.7\%$

How are stress radiographs performed for the Acromioclavicular (AC) joint?

By suspending $10-15\,lbs$ of weight from the patient

What is the normal acromio-clavicular (A-C) interval?

$$1-3\,mm$$

What A-C interval measurement is considered pathologic?

$>6-7\,mm$ or $>2-3\,mm$ compared to the opposite side

What is the normal coracoclavicular interval?

$$11-13\,mm$$

What increase in coracoclavicular interval relative to the opposite side is pathologic?

$$>5\,mm$$

List three MRI findings associated with adhesive capsulitis.

Coracohumeral ligament thickening, axillary recess thickening, and rotator interval fat pad obliteration

Match the acromial morphology types: Type I, II, III, IV.

I: Flat, II: Curved/Concave, III: Hooked, IV: Inferiorly Convex

Which acromial morphology type is associated with increased rotator cuff tears?

Type III (Hooked)

What is the normal acromiohumeral distance?

$$8-12\,mm$$

At what acromiohumeral distance do tendon tears become more prevalent?

$$<8\,mm$$

If the acromiohumeral distance is $<7\,mm$, what percentage of patients have a normal appearing tendon?

$$4.2\%$$

In asymptomatic subjects over age $60$, what are the prevalence rates for full and partial-thickness tears?

Full-thickness: $28\%$, Partial-thickness: $26\%$

At what age do Rotator Cuff abnormalities become nearly universal?

After age $40$

What four active movements can clear the elbow without imaging after trauma?

1. Full extension, 2. Flexion to $90^{\circ}$, 3. Full pronation at $90^{\circ}$, 4. Full supination at $90^{\circ}$

In which population are the elbow trauma clearance rules less accurate?

Pediatric patients

What is the common age group for supracondylar fractures?

Children (age $5-7$) and seniors

Which nerve is commonly injured in supracondylar fractures?

Ulnar nerve

What is the mean age for radial head fractures?

$$43$$

What is the common mechanism for a radial head fracture?

FOOSH (Fall On OutStretched Hand) where the radial head impacts the capitellum

What is the 'Fat Pad Sign' or 'Sail Sign' indicative of?

An intra-articular problem

If a fat pad sign is present but no fracture is visible on radiographs, what is the next step?

Additional imaging is indicated

What two things does Ultrasound look for when screening for elbow fractures?

Overt fracture evidence or intra-articular effusion

When does the medial epicondyle ossification center usually appear and close?

Appears at $\sim 4-6$ years; open until $\sim age\,14-15$

What is the typical age of onset for a medial epicondyle avulsion fracture?

$11-12$ years

Which demographic is most at risk for medial epicondyle avulsion fractures?

Male throwing athletes (especially baseball pitchers)

Medial epicondyle avulsion fractures often present as which Salter-Harris type?

Salter-Harris I

Which imaging modality can reveal medial epicondyle pre-avulsion injury before symptoms appear?

MRI

In which two sports is Osteochondritis Dissecans (OCD) of the capitellum most prevalent?

Baseball (males) and Gymnastics (females)