Exam #4: MSK, Neonatal (head, hip, and spine)

What does SAX stand for?

Short axis

What does LAX stand for?

Long axis

What is anisotropy?

Change in properties of a structure when measured/evaluated in different directions

What is the largest organ in the human body?

Skin

What is the functional layer of the skin?

Dermis

What is a tendon?

An extension of muscle

Tendons attach… to…

Bone to muscle

Tendons facilitate… and…

1. Flexion

2. Tension

What are bursa?

Closed connective and synovial sacs that contain a small amount of fluid

Where are bursa located?

At high-potential friction points where tendons or muscles slip through joints

What do bursa produce? Why?

Viscous fluid that facilitates gliding of MSK structures

How do bursa appear on an US image?

1. Small, hypoechoic, flat, fluid-filled, sac

2. Hyperechoic

   1. Wall

   2. Peribursal fat

What nickname describes the appearance of nerves in the short axis?

Honeycomb

What nickname describes the appearance of nerves in the long axis?

Railroad track (fascicular)

Ligaments attach… to…

Bone to bone

Ligaments facilitate… and…

1. Stability

2. Strength

Cartilage is known as a…

Shock absorber

How many types of muscle are there? What are they?

1. Three Types

   1. Smooth muscle

   2. Cardiac muscle

   3. Skeletal muscle

Muscles facilitate… and…

1. Contraction

2. Extension

Endomysium, perimysium, and epimysium are continuous with fibrous structures that connect… to…

Muscle to bone

What is compartment syndrome?

When edema (swelling) of muscle and tissue causes a compression of blood vessels and nerves that eventually deprives all blood flow in that compartment

What is rhabdomyolysis?

1. A muscular disorder that results from

   1. Drug or alcohol abuse

   2. Infection

   3. Crush injuries

   4. Collagen disease

   5. Extensive exercise

What is bursitis?

Inflammation of bursa

What are the most common locations for bursitis?

1. Shoulder

2. Knee

3. Elbow

4. Hip

What is a schwannoma?

Benign tumor involving myelin sheath of nerves

What nerve do schwannomas frequently affect? What is this nerve responsible for?

1. Eighth cranial nerve (acoustic nerve)

2. Sensations of

   1. Hearing

   2. Balance

What is synarthrosis?

When a joint is fixed (immoveable)

Which joints are classified as synarthrosis?

Fibrous joints

What is amphiarthrosis?

When a joint is slightly moveable

Which joints are classified as amphiarthrosis?

Cartilaginous joints

What is diarthrosis?

When a joint is freely moveable

Which joints are classified as diarthrosis?

Synovial joints

The supraspinatus shares an insertion point with the… at the…

1. Infraspinatus

2. Humerus

Which nerves are evaluated with rotator cuff imaging?

1. Subscapularis

   1. Subscapular nerve (both)

   2. C5

   3. C6

   4. C7

2. Supraspinatus

   1. Suprascapular nerve

   2. C4

   3. C5

   4. C6

What is the geyser sign?

Common finding with a supraspinatus tendon tear

What is the criteria for a major rotator cuff injury?

1. Focal nonvisualization of cuff

2. Localized absence or focal nonvisualization

3. Discontinuity

4. Focal abnormal echogenicity

What is the criteria for a minor rotator cuff injury?

1. Subdeltoid bursal effusion (most reliable 2nd finding)

2. Concave subdeltoid bursal contour

3. Humeral head evaluation

4. Joint effusion

What does common flexor osteotendinopathy (golfer elbow) affect?

Superficial flexor tendons

What does common extensor tendinopathy (tennis elbow) affect?

Superficial extensor tendons combined with vascular insult

Which nerve is struck if someone complains about their “funny bone”?

Ulnar nerve

Which nerve is compressed in someone with carpal tunnel?

Median nerve

Which bone is considered the largest sesamoid bone in the body?

Patella

What is the primary support structure of the medial knee?

Medial collateral ligament (MCL)

What is the most frequently injured joint of the body?

Ankle

What is the most often injured area of the ankle? What is this caused by?

Lateral ankle due to inversion foot injuries

What is the medial ankle acronym? What does it stand for?

1. “Tom, Dick, and a very nervous Harry”

   1. Tom = Posterior Tibialis Tendon (PTT)

   2. Dick = Flexor Digitorum Longus (FDL)

   3. Nervous = Tibial artery, paired with veins and nerves

   4. Harry = Flexor Hallucis Longus (FHL)

What is a retinaculum?

A band of thickened deep fascia around tendons that holds them in place

Complete tendon interruption on an US can be described as what?

Full-thickness tear 

What window is commonly used to scan neonatal head?

Anterior fontanelle

When does the anterior fontanelle close?

1. Closure begins around 9 months of age

2. Closure finished by 15 months of age

What is another name for the mastoid fontanelle?

Posterolateral fontanelle

Where is the largest part of the choroid plexus located?

Lateral ventricle

What is leukomalacia?

CNS dysfunction due to hypoxic-ischemic insult, infection, or embolism sustained during perinatal period that causes softening of white matter

What is an intracranial hemorrhage (ICH)?

Brain bleed associated with gestation of less than 34 weeks and/or birth weight less than 1500 g

What population is ICH most common in? Why?

Premature infants due to low birth weight and underdeveloped blood vessels

Are males or females more likely to develop ICH?

Males (2:1)

What is the most common type of bleeding among
premature infants?

Germinal Matrix Hemorrhage

What is a “Grade 0” germinal matrix hemorrhage characterized as?

Baseline normal scan

A baby presents with no symptoms. The ultrasound shows normal findings and no evidence of hemorrhage. What condition does it have?

Grade 0 germinal matrix hemorrhage

What is a “Grade I” germinal matrix hemorrhage characterized as?

1. Grade I: Subependymal hemorrhage (SEH)

   1. Blood confined to germinal matrix

A baby presents with low hematocrit and PO2 levels and a presence of blood in CSF. The ultrasound shows a highly echogenic lesion at the caudothalamic groove, located at the head of the caudate nucleus. It also shows a bulbous focal area of increased echogenicity. What condition does it have?

Grade I: Subependymal hemorrhage (SEH)

What is a “Grade II” germinal matrix hemorrhage characterized as?

1. Grade II: Intraventricular hemorrhage (IVH)

   1. SEH breaks through ependymal lining and into ventricle floor

   2. Bleeding enters ventricular cavity

A baby presents with low hematocrit and PO2 levels and a presence of blood in CSF. The ultrasound shows echogenic blood layered in the dependent portion of the occipital horn. It also shows prominent third and fourth ventricles, but there is no ventricular dilation present. What condition does it have?

Grade II: Intraventricular hemorrhage (IVH)

What is a “Grade III” germinal matrix hemorrhage characterized as?

1. Grade III: Intraventricular hemorrhage (IVH)

   1. Expansion of ventricles by large amounts of blood

   2. Aqueductal obstruction from clot or ventriculitis

A baby presents with slight mental retardation and motor problems. The ultrasound shows echogenic blood layered in the dependent portion of the occipital horn. It also shows prominent third and fourth ventricles and ventricular dilation is present. What condition does it have?

Grade III: Intraventricular hemorrhage (IVH)

What is a “Grade IV” germinal matrix hemorrhage characterized as?

1. Grade IV: Intraparenchymal Hemorrhage (IPH)

   1. Expansion of hemorrhage into brain parenchyma

   2. Results in porencephaly

A baby presents with major handicaps, including motor disabilities and cognitive defects. The ultrasound shows hematoma extension lateral to the edge of the lateral ventricle(s) and into the cerebral hemisphere. What condition does it have?

Grade IV: Intraparenchymal Hemorrhage (IPH)

What are the three segments of the brain?

1. Cerebrum

2. Cerebellum

3. Brainstem

What is hydrocephalus?

A progressive increase in volume (dilatation) of ventricles secondary to a relative obstruction of CSF under pressure

What is the most common neonatal congenital infection?

Cytomegalovirus (CMV)

What is the second most common infection in the world?

Toxoplasmosis

What is a complete agenesis of the corpus callosum?

Vascular lesion or inflammation of commissural
formation before 12 weeks

What is a partial agenesis of the corpus callosum?

Destruction of previously well-formed corpus callosum after 12 weeks

What is the “sunburst sign”?

Radial arrangement of cerebral sulci and gyri consistent with agenesis of corpus callosum

The Classic Dandy-Walker Malformation is typically seen with…

Hydrocephalus

The Dandy-Walker Variant is typically seen with…

NO hydrocephaly

What is the most common intracranial vascular anomaly presenting in the neonatal period?

Vein of Galen Malformation

What acronym is used to describe antenatally acquired infections? What does it stand for?

1. TORCH

   1. Toxoplasmosis

   2. Other (syphilis, hepatitis)

   3. Rubella

   4. Cytomegalovirus (CMV)

   5. Herpes simplex virus

A baby presents with symptoms consistent with the TORCH entities. The ultrasound shows microcephaly with calcifications. What condition does it have?

Rubella

What is the major source of transmission of herpes?

Through mother’s infected cervix or lower genital tract at time of delivery

What are the two most common methods of evaluating DDH?

1. Clinical Assessment

2. Sonography

What are the risk factors for DDH?

1. High birth weight/large for GA

2. Abnormal physical exam

3. Living in cultures that swaddle infants in extension and hip adduction

4. First pregnancy/firstborn

5. Oligohydramnios in utero

6. Female

7. Breech birth

8. Positive family history

What is the mean femoral head coverage for females? Males?

1. Females = 54%

2. Males = 56%

Hip instability will present with femoral head coverage of approximately…

36-37%

What angle measurement for the hip is classified as normal?

Alpha angle > 60 degrees

What angle measurement is classified as a dislocated hip?

Alpha angle < 43 degrees

What is hip effusion?

Swelling of hip joint caused by presence of increased synovial fluid surrounding the joint

Transient synovitis is…

Not an emergency

Septic Arthritis is a…

Medical emergency

When does the femoral head begin to ossify? How?

From center outward at 2-8 months of age

What are the scanning planes used to evaluate the femoral head?

1. Coronal neutral

2. Coronal flexion

3. Transverse flexion

Which scanning plane will show a ‘U’ when evaluating a normal femoral head?

Transverse flexion

What are the lumbosacral anomalies that are an indication for neonatal US?

1. Skin anomalies

   1. Pigmented spots

   2. Hairy patch

   3. Hemangiomas

   4. Dermal sinuses

   5. Dimples

What is the optimal range for a neonatal spine exam? What is the max?

1. Optimal = 3-4 months of age

2. Max = 6 months of age

What transducer will be used for a neonatal spine exam?

1. High frequency = 8-15 MHz

2. Transducer

   1. Linear

   2. Sector

When may a sector transducer be used to evaluate the neonatal spine?

When scanning older infants where acoustic window is small

When may a curvilinear transducer be used to evaluate the neonatal spine?

Optimize identification of craniocervical junction

How does the spinal canal appear on an ultrasound?

Anechoic due to CSF

Where should a normal spinal cord terminate?

Between L1 and L2

Where does the conus medullaris taper in someone with a tethered cord?

At or below L3