bone path midterm Flashcards
What is the most widely used skeletal imaging method used?
Plain film radiography.
How much bone loss must be present to be seen on an X-ray or on an MRI? How large must lesion be?
X-ray- 30-50%. MRI- 1%. X-ray- at leaste 1-5 cm.
What will be darker fat or water?
Fat.
What is radiopaque and radiolucent?
Radiopaque- white. Radiolucent- dark.
Name the 3 rules of I don?t know just name the 3 rules?
- Anomalies occur more commonly in transitional areas. 2. Anomalies may be isolated but are frequently associated with other skeletal/spinal anomalies. 3. Anomalies may have an increased frequency of organ/soft tissue anomalies.
How can you tell if occipitalization has taken place?
use lateral view and check for space between posterior arch of C1-occiput.
What things are seen with occipitalization?
up to 70% of the time C1-C2 will be unstable and there can be basilar impression.
Name 4 occipital vertebrae and what views they can be seen on?
- Third condyle- lateral film. 2. Epitransverse process. 3. Paracondylar process. 4. Paramastoid process. 2-4 seen on APOM.
What is a third condyle?
An anterior midline bony process located between the 2 occipital condyles and continuous with the anterior foramen magnum extends a variable distance caudally. Occasionally forms an articulation with the apex of the dens or anterior arch.
What are paracondylar, paramastoid and epitransverse processes?
variations of congenital bone bars that extend between the occiput and transverse processes of the atlas. They may be unilateral or bilateral.
What is a paramastoid process?
Bony protuberance from jugular process of occiput and projects inferiorly toward the atlas TP.
What is the paracondylar process?
arises slightly more medial and anterior in the paracondylar area of the occiput and projects inferiorly.
What is the epitransverse process?
Attached to atlas TP and directed superiorly toward the adjacent occiput.
What is Basilar impression/invagination?
Dens encrochment into foramen.
What are the 2 types of Basilar impression/invagination?
primary- congenital- occipitalization, C1 posterior arch agenesis, SBO.. Secondary- bone softening diseases like pagets, osteomalacia, fibrous dysplasia.
What is arnold-chiari 1 malformation?
Downward displacement and elongation of the brainstem and cerebellar tonsils.
What are the symptoms of Arnold-chiari malformation?
variable with headaches, neck pains, and other more serious stuff.
Arnold-chiari malformation is associated with what?
Skeletal anomalies, occipitalization, basilar impression, wrong way scoliosis, blocked cervical vertebrae, cervical ribs.
What other findings are commonly seen with arnold-chiari malformation?
Syringomyleia (syrinx), hydrocephalus.
What is a normal variant of arnold-chiari malformation?
less than 3 mm downward displacement.
Name 5 things to do when evaluating a flim?
- Identify the study. 2. Identify info markers. 3. Note collimation, sheilding, and artifacts. 4. Note techniqual quality. 5. Search pattern like ABC’S.
What are the categories of lesions?
CATBITES= Congenital/dysplasia, Arthritis, Trauma, Blood/vasculature, Infection/inflammatory, Tumor/tumor like, Endocrine/metabolic, Soft tissue.
How can you tell C7 apart from T1?
C7- TP’s point out laterally. T1- TP’s point up.
What causes Pars defects?
Repetitive trauma causing fractures and they were not healed up usually happens in youth.
With plain film it is absolutly necessary to have how many views?
Atleaste 2 and they should be perpendicular to eachother.
Tomo means what?
A cutting.
What are the advantages to Tomography?
Evaluate complex structures like the skull and spine and complex deformities can be readily analyzed.
What are the disadvantages of tomography?
Increased radiation.
What is xeroradiography used for?
detecting foreign bodies in soft tissues like mammography.
What is platybasia?
Flat skull base.
What causes platybasia?
Congenital sphenoid and/or occipital maldevelopment.
Basilar impression can be complicated by what?
Sudden hearing loss, pyramidal signs, posterior column signs and wasting of the upper limbs.
What is spina bifida occulta AKA SBO?
failure of fusion of the 2 posterior arch ossification centers producing a midline default.
What is the clinical significance of SBO?
Y and R say none, but others say it can have a increased incidence of posterior disc herniation and associated isthmic sponlylisthesis.
How is a C1 anterior arch agenesis seen?
Absence of a D shaped anterior arch on lateral cervical film.
Name 2 bone destroying diseases?
tumor and infection.
What causes agenesis of posterior arch of C1?
lack of cartilage template or a cartilage template that did not ossify. May be partial or complete.
What is usually seen with agenesis of posterior arch of C1?
Hypertrophy of anterior arch and megaspinous of C2.
Can a missing posterior arch of C1 be due to a tumor?
Not usually since there is a lack of blood supply to C1 since there is no body.
What is a posterior ponticle?
Partial or complete ossification of the oblique portion of the atlanto-occipital membrane.
Where is the atlanto-occipital membrane located at?
It bridges the posterior lateral mass and the posterior arch and forms the peripheral border of the arcuate foramen.
What travels through the arcuate foramen?
Vertebral artery and veins, first cervical nerve and perivascular sympathetics.
Will a posterior ponticle be uni or bi lateral?
Most common unilateral.
What radiographic feature is seen in Down’s syndrome?
20% are born without a transverse ligament and this leads to axial instability. This will be seen as increased ADI on flexion and lateral view.
What is ossiculum terminale and it is aka?
non-fusion of secondary growht center of the dens and it is aka persistens of Bergmann.
What is the clinical significance of ossiculum terminale aka persistens of Bergmann?
No clinical significance.
What is Os odontoideum?
2 halves of the odontoid unite and do not fuse to C2 body.
What causes Os odontoideum?
Probably due to old fracture with nonunion.
Will Os odontoideum be stable and why or why not?
Not stable the transverse ligament if intact, but dens is not attached to C2 body.
When can os odontoideum be diagnosed?
Not until after age 5 unless hypermobility of dens is demonstrated.
What is hypoplastic/agenetic odontoid?
The odontoid halves do not develop fully or at all.
What is the cause of hypoplastic/ agenetic odontoid?
Hypoplastic- partial formation of dens. Agnetic- complete agenesis of dens and is very rare.
What films should be ordered and why when a hypoplastic/ agenetic odontoid is seen?
Flexion/ extension to see if it is stable.
What might need to be done to a patient with hypoplastic/ agenetic odontoid?
Possible surgery.