infant spine Flashcards
sono examination if useful for spint unless sonogrpahy is limited to?
- infants under the age of 6 month (posterior spinous processes are not yet ossified)
- surgical procedures
- known spinal defects where an acoustic window is available
Clinical Indications for spine ultrasound?
- evaluation of spinal dystaphism and any associated mass
- patients with lumbosacral skin anomalies
- spinal tumors, masses, cysts, syrinx
- ## aquired lesions
Evaluation of spinal dysraphism and any associated mass includes? (4)
anomalies associated with incomplete fusion of neural tube
Meningoceles
Myelomeningoceles (MMCs)
Lipomyelomeningoceles
Lipomas
Patients with lumbosacral skin anomalies inclue? (5)
Pigmented spots Hairy nevus Dermal sinuses - a scaly, multi-layered channel of tissue Dimples Hemangiomas.
what is a syrinx?
rare, fluid filled cavity within spinal cord
Acquired lesions include> (3)
cord birth trauma
subarachnoid and epidural hemorrhage
epidural abscess
Intraoperative sonography is helpful in ?
localizing intramedullary lesions, including tumors, cysts, hydrosyrinx, and vascular malformations
Patient position for spine??
- Place the patient in the prone position with a towel or pillow under them
- this will round out the back, creating a slight kyphosis - splaying the spinous processes
- Decubitus positon also used, ‘fetal position’
spinal canal is bordered by?
anteriorly by echogenic vert. bodies with hypoechoic intervert. disks
posteriorly by the hypoechoic spinous processes
the spinal canal is surrounded by?
a thin brightly echogenic layer which represents the arachnoid-dural layer
where is the epidural space?
Just posterior to the arachnoid-dural layer and anterior to the spinous process
CSF surround?
the spinal cord and occupies the subarachnoid space
spinal cord on us?
- Spinal cord is hypoechoic
- defined by two parallel echogenic lines anteriorly and posteriorly with an echogenic central canal
- The cord tapers to the conus medullaris
- At L1 and L2
- Echogenic nerve roots are seen extending distally (arrowheads).
where is the filum terminale?
extends from the conus and floats among the echogenic nerve roots (cauda equina) in the anechoic cerebrospinal fluid
Filum terminale vs. spinal cord?
more echogenic and thicker ≤ 2 mm
Cauda equina roots move freely with?
changes in patient position
Thecal sac contains?
spinal cord cloating in CSF
Spinal Cord – Axial plane?
A slightly more prominent echogenic round filum terminale floats among echogenic nerve roots
Nerve roots can appear as?
small echogenic dots or clump together, sometimes obscuring the filum terminale.
Cord is larger in what region?
cervical
Locating the level of vertebral column allows determination of abnormal position of?
conus medullaris and location of intraspinal abnormalities
the spinal cord should terminate where?
between L1 and L2
An objective method of determining the level of the conus is to count vertebrae ?
up from the sacrum (last echogenic structure in sacrum)
5 Sacral vertebrae to LSJ
5 Lumbar vertebrae to TLJ (T12/L1)
down from the thoracolumbar junction (T12 with rib)
Confirming with x-ray – locate conus with US, mark and take x-ray.
what does ectroderm form?
neural plate
- crease appears on a plate that becomes a groove
Groove deepens and neural folds join to form a?
neural tube
Each end of neural tube has ?
neuropores
neuropores?
They will be closed soon after
If anterior neuropore does not close – anencepahly
If posterior end doesn’t close – spina bifida, pilondial cyst
Ventriculus Terminalis?
- normal varient
0 slight widening of distal central canal - linear and anechoic
ventriculus terminalis
filar cyst?
- normal varient
- Ovoid midline anechoic structure just inferior to the tip of the conus
Spinal Dysraphism?
- congenital anomalie
- An array of spinal abnormalities caused by inadequate or improper fusion of the neural tube (NT) early in fetal life
spinal dysraphism is most commonly located where?
- lower spine
- lumbarsacrum
2 types of spinal dysraphism?
OPEN Spinal Dysraphism (OSD)
CLOSED Spinal Dysraphism (CSD)
OSD (overt SD)?
Neural tissue exposed without skin covering
Myeloceles
Myelomeningoceles
increased AFP in maternal serum & amniotic fluid
CSD (occult SD)?
Skin covered spinal abnormality
Can present as a subcutaneous mass or various cutaneous markers
3 subcutaneous masses?
Lipomyelocele
Lipomyelomeningocele
Myelocystocele
CSD without mass ? (4)
Thethered cord
Spinal lipoma
Diastomyelia
Dorsal dermal sinus
CSD without mass presentation?
present as cutaneous markers (hair tufts, sacral dimples or pits, pigment changes, hemangiomas, skin tags)
Two forms of OSD in which there is a failure of the spinal cord to fold into a NT?
- myelocele
- myelomeningocele
myelocele?
herniation of the meninges through a defect in the dura matter
myelomeningocele (MMC)?
- More common
herniation also contains neural tissue
Myelocele/MMC presents as?
The skin, paraspinal musculature and bony vertebral arches overlying the defect are splayed lateral to the defect
The spinal cord is tethered at the level of the abnormality
Abnormality is visible and there is a risk of infection – US is usually skipped
MMC is almost always associated with?
chiari 2 malformation
myelocele/MMC sono?
Chiari II (lemon and banana signs prenatally)
Absent spinous processes in the midline
Laminae are everted anteriorly
MMC or myelocele is an anechoic mass that is continuous with the spinal canal through the defect
Spinal cord in low position, may not taper to conus
Mass may contain septa.
CSD - Tethered Cord?
Low-lying cord with a thickened filum terminale
CSD - Tethered Cord almost always associated with?
dysraphic anomalies
CSD - Tethered Cord may present when?
May present later as child grows when the spinal cord is pulled and neurological symptoms occur
- Early detection can reduce nerve damage
clinical presentation- CSD tethered cord?
- Neurological symptoms
Limb, bowel, urinary dysfunction - Skin markers
CSD - Tethered Cord sono?
Spinal cord in low-lying position
- at or below L3
Conus is elongated
- and pulled dorsally
Nerve roots have decreased movement
Abnormally thick terminal filum.
CSD-Diastomyelia?
separation of the spinal cord into 2 hemicords
- the split cord can be separated by a bony or fibrous septum
CSD-Diastomyelia defect most commonly occurs where?
in the thoracolumbar region and is usually associated with a cutaneous marker in the region of the defect
Two hemicords reunite to form?
a single distal cord in the majority of cases
Diastomyelia sono?
- Axial plane used
- Two hemicords
- Sag scan fails to demonstrate two hemicords simultaneously
CSDDorsal Dermal Sinus?
A thin, epithelial lined tract that passes from the skin toward the spinal canal
Focal disruption in the development or fusion of the spinal canal
Mostly in lumbosacral region
CSDDorsal Dermal Sinus clinical presentation?
Deep midline dimples or pits
At risk for meningitis - open tract to the spinal canal
CSDDorsal Dermal Sinus sono?
Midline opening/tract from the skin toward the spinal canal
Echogenic line if narrow
Triple tract if lumen is large
Two parallel lines of echogenicity with a central hypo space
Tethered cord.
CSD: Sacral Dimple/Pilonidal Sinus?
Sacral dimple or pit is the most common reason for an infant to be referred to U/S of the spine
This skin anomaly, which can be a normal variant, is located in the gluteal fold <2.5cm from the anus
Dimple can be blind ended or have a pilonidal sinus/tract extending to the coccyx
CSD: Sacral Dimple/Pilonidal Sinus sono?
Sonographically appear as dimples in the skin that lead to a hyper/hypo tract
The tract may lead to a pilonidal cyst (fluid filled collection)
Should not be confused with a DDS as it has no connection to the normal spine.
Intradural LipomaLipoma of the filum terminale
Not associated with a subcutaneous mass
May or may not be associated with a tethered cord
Intradural Lipoma?
Lies within the spinal cord and is completely confined by the dura
Lipomas of the FT?
presents as a thickened filum >2mm or a small echogenic fatty mass in the FT
Lipomyelocele/LMMC?
Presents with a skin covered back mass typically located in the lumbar region
Midline
Can present as a bony defect and an echogenic fatty mass that distorts and tethers the spinal cord
LMMC has an enlarged subarachnoid space and the fatty mass extends through the posterior bony defect
Lipomyelocele stays within the spinal canal.
CDS: Terminal Myelocystocele?
Skin covered, fluid filled lumbar mass protruding through a dysraphic defect
Communicates with the central canal
The cyst does not communicate with the subarachnoid space
CDS: Terminal Myelocystocele associated with?
Omphalocele
Bladder exstrophy
Imperforate anus
Decreased functions of lower extremity, bowel and bladder.
CDS: Terminal Myelocystocele on sono?
Large skin covered fluid filled mass in the lumbar region
Central canal widens and directly communicated with the mass
Large sac herniates through the dysraphic bony defect
Hydromelia (dilated central canal) may be seen.
MISC Spinal Abnormalities Spinal Cord Injuries?
Trauma from birth - difficult breech delivery
Majority are evaluated by MRI
spinal Cord Injuries sono?
Edematous cord
Hematomyelia
Hemorrhage outside the cord
Extramedullary hematomas can compress and displace the spinal cord
Failed or traumatic lumbar puncture
50% failure
Evaluate for epidural hematoma.
