Neural tube/musculoskeletal with pathology registry review Flashcards
Neural tube defects
Neural tube fails to close or form properly
Risk factors for NTD
Maternal diabetes, valproic acid (seizure meds), folate deficiency
Folic acid
Supplement taken to reduce risk of anencephaly and spina bifida
Marker for open defects
Elevated AFP
Acrania
Absence of cranial vault above the orbits. Can be with or without brain. “Without cranium”
*elevated AFP
Anencephaly
No cerebral hemispheres, frog like bulging eyes
Exencephaly
Normal amount of brain tissue/no skull. Will appear as misshapen head with no hyperechoic bone surrounding head.
Spina bifida
Neural tube fails to close and there is a gap between the vertebrae/splaying of the vertebral laminae.
*aka spinal dysraphism/meningocele/myelomeningocele
Spina bifida occulta
CLOSED
Covered by skin and no herniation of spinal cord outside of body, defect in vertebrae only
*normal AFP
Postnatal signs for spina bifida occulta
Sacral dimple, lipoma, excessive hair
Spina bifida aperta
OPEN
-Most common form of spina bifida
-Not covered by skin and result in herniation of spinal contents (cystica)
*ELEVATED AFP, strongly associated with Arnold-Chiari II malformation
Meningoceles
Contain meninges only
*cystic appearance
Myelomeningocele
Contains meninges and nerve roots, more complex in appearance. Most commonly in lumbosacral area
*MOST common
Arnold-Chiari II malformation
-Presence of open spina bifida
-Meningocele or myelomeningocele pulls down on spinal contents causing cranial malformations
-Lemon shaped head
-Banana cerebellum
-Obliterated cisterna magna
Cephalocele/Encephalocele
-Herniation of intracranial contents through opening in skull
-Most common in occipital location
-Associated with Meckel-Gruber (occipital cephalocele and PKD)
*ABNORMAL AFP
Iniencephaly
Hyperextension of neck. Closed NTD
“star gazer”
*Possible normal AFP
Ocular diameter
Lateral to medial edge of orbit
*Axial plane
Interocular
Between the 2 eyes. Medial (inner) sides of both
Binocular
Lateral edged of both orbits, both eyes
Anopthalmia
No orbits
*associated with T13
Cyclopia
One fused eye
*associated with T13
Hypertelorism
Closely spaced eyes (decreased interocular)
*associated T13
Hypertelorism
Far apart (increased interocular) anterior cephalocele
Micropthalmia
Small orbits (decreased ocular)
Proboscis
False nose/projection replacing or above nose
*often seen with eye abnormalities
Cleft lip and palate
Abnormal/incomplete closure of lip and/or palate
-Can be unilateral, bilateral, midline or eccentric
-May be isolated or associated with holoprosencephaly and T13(midline), and amniotic band syndrome (asymmetrical)
-Evaluated in coronal view of lips, nose, chin
Nuchal thickening
> or equal to 6mm measurement of nuchal fold between 18-23 weeks
*trisomy 21
Flattened or absent nasal bone
May be normal in some individuals based on ethnicity
-ML sagittal view
*“soft marker” for trisomy 21
Macroglossia
Large tongue/protuberance of tongue
-ML sagittal view tongue sticking out
*associated with T21
*if isolated, associated with Beckwith-Wiedemann syndrome
Micrognathia
Small mandible and recessed chin
-ML sagittal view
*associated with T18
Cystic hygroma
Abnormal accumulation of lymphatic fluid under the skin. Most common within neck but may be in axilla
-Often leads to hydrops
*turners syndrome
Hydrops fetalis
A condition in which large amounts of fluid build up in a baby’s tissues and organs, causing extensive swelling (edema).
Sonographic appearance of cystic hygroma
Cystic mass behind neck with midline septation
-Sagittal view: bubble appearance
-Transverse view: cystic with midline septations
Axial skeleton
Cranial and spinal bones
Appendicular skeleton
Bones of the limbs and pelvis
Normal bones sonographic appearance
Hyperechoic with posterior shadowing
Long bone measurements
Sagittal plane with beam close or at perpendicular (90 degrees) to axis. Calipers include entire shaft (diaphysis), no epiphysis should be included in measurement
*femur and humerus (proximal limbs)
Leg imaging and biometry
Normal ankle/foot relationship in sagittal to rule out club foot
-Tibia (closer to skin and more medial in coronal view)
-Fibula
Forearm imaging and biometry
Hands should open and move freely
-Radius (thumbside/shorter)
-Ulna (pinky side/longer/goes to elbow)
VACTERL
V: vertebral defect
A: anorectal atresia
C: cardiac defects
T: tracheoesophageal fistula
E: esophageal atresia
R: renal anomalies
L: limb defects
VACTERL association
At least three defects make up the association. If one is detected CAREFULLY examine for others
Scoliosis
Abnormal curvature laterally or S-shaped spine
Kyphosis
Abnormal posterior curvature
Musculoskeletal curvature
Associated with amniotic band, limb body wall complex and VACTERL
Limb-body wall complex
Fatal condition caused by vascular occlusion, amnion rupture, or embryonic dygenesis. Appears as if front of abdomen is stuck to placental wall due to very short or absent cord
-AKA body stalk anomaly
-ELEVATED AFP
-Body wall defects, limb defects, craniofacial defects, marked scoliosis
Achondroplasia
Without bone/cartilage growth “dwarfism”
Heterozygous achondroplasia
Autosomal dominant
*MOST common NON lethal dysplasia
Homozygous achondroplasia
Autosomal recessive
*FATAL
Achondroplasia findings
Macrocrania, frontal bossing, trident hand, rhizomelia
Frontal bossing
Prominent forehead
Trident hand
Space between 3rd and 4th digits
Rhizomelia
Proximal limbs are much shorter than distal
Achondrogenesis
Rare, LETHAL condition
Absent mineralization/ossification of bones, especially pelvis, spine and cranium
-No shadowing, micromelia, fratures, polyhydramnios
-Without bone/cartilage development/formation
Micromelia
Rare bone dysplasia that causes abnormally short and underdeveloped limbs
Osteogenesis imperfecta
Brittle bone disease, results in multiple fractures in utero and under-ossified bones
-Soft skull=compressible cranium with probe pressure
*Type II FATAL
*Type I, II, IV diagnosed after birth and compatible with life
Thanatophoric dysplasia
Abnormal shaped bone growth. Death secondary to pulmonary hypoplasia
*MOST common LETHAL dysplasia
Thanatophoric dysplasia findings
Cloverleaf skull, bell shaped chest, bowed long bones
Craniosynostosis
Premature fusion of the cranial sutures
*cloverleaf skull
Caudal regression syndrome
Absence of sacrum and coccyx. Defects in lumbar spine and lower limbs.
-AKA sacral agenesis
*strong association with uncontrollable maternal (pre gestational) diabetes/ diabetes mellitus
Sirenomelia
Fusion of lower extremities
-Mermaid syndrome
-May be accompanied by renal agenesis
*FATAL when accompanied by renal agenesis
Sacrococcygeal teratoma
Germ cell tumor seen as complex mass extending posteriorly and inferiorly from distal spine
-More common in females
-Malignant potential
Talipes equinovarus
Medial inversion of foot, bottom of foot and metatarsals appear in the same plane as the tibia and fibula
-AKA clubfoot
*association with T13
Rockerbottom
Rounded bottom of foot, normal foot/ankle angle
*association with T18
Sandal gap
Space between big toe and 2nd digit
Thrombocytopenia absent radius
Absent radius, hypoplastic ulna, missing thumb
-AKA: radial ray defect, TAR syndrome
-dactyly
Digits
Polydactyly
Too many digits
*associated with T13
Clinodactyly
Clenched digits
*associated with T18
Syndactyly
Fused digits
*Associated with triploidy
Clino-
Clenched
Syn-
Fused
Amniotic band syndrome
Sticky bands of amnion result from rupture of the amnion. Fetal parts can be caught and cause amputations and odd facial clefts
-May see damage or may see fetal limbs stuck in membrane
