What is COmputed Tomography? Why is it a useful alternative modality for skull pathology?
Computed Tomography ( CT ) is a proecudre that provides sectional images of the brain and bones of the skull in axial. saiggital, or coronal planes.
Its very useful with head injuries because ti can differentiate between blood clots, white and gray matter, crebrospinal fluid, cerebral edema and neoplasms.
What is Magnetic Resonance Imaging? Why is it a useful alternative modality for skull pathology?
MRI proviedes axial, saggital and coronal planes like CT. But it is more sensitive in detecting differences between normal and abnormal tissues in the brain and associated soft tissues.
Does not requrie radiation or harmful ionizng exposures.
What is ultra sound? Why is it a useful alternative modality for skull pathology?
Ultrasound ( Sonography ) is a procedure that allows for rapid evaluation and screeining of premature infants for intracranial hemmorahge.
Its highly preferreedf because its portable and there is no need for sedation as well as it doesnt have ionizing radiation.
Also good for follow ups of hydrocephalus. You can also evaluate cranial sutures this way.
How is nuclear medicine technology used for the skull? Why is it beneficial?
Nuclear medicien provideds a sensntivive screening procedure ( radionuclide bone scan ) for detection of skeletal metasteses of which the skull is a common site.
Basically, its very useful with people who are at risk of metastses.
Also used for studies of the brain. Patients include peopel who have alzhemiers, seizure diorders and dementia.
Can also help with tumors.
What is a Linear Fracture of a skull?
Linear fractures of a skull may appear as jagged or irregular lucent lines that lie at righjt angles to the axis of the bones.
What is a depressed fracture?
Konwn as the "ping pong" fracture. Its when a fragment of the bone is seperated and depressed into the cranial cavity.
What is a basal skull fracture?
- A basal skull fractureare fractures through the dense inner structures of the temporal bone.
- Very difficult to visualize because of the complexity in anatomy.
If there is bleeding, plain x-rays can reveal air fluid levels in the sphenoid sinus.
What are neoplasms?
New ansd abnormal growths
What are metasteses?
These are prmariy maglinant neoplasms that spread to distant sites via blood and lymphatic system.
What is osteolyitic mean?
Destructive lesions with irregular margins.
What is osteblastic?
proliferative bony lesions of increased density.
What is combination osteolyitic and osteoblastic lesions?
Have amothj eaten apperance of bone because of the mix of destructive and blastic lesions.
What is multiple myeloma?
Consist of one or more bone tumors taht originate in the bone marrow.
What is ptiutary adenomas?
Tumors of the ptiuitary gland that may demonstrate enlargemnet of the sella tucica and erosion of hte dorsum salae.
What is pagets disease?
"Cotton-wool" appearance that begins as a stage of bony destruction followed by bony repair.
Whsat is mastoiditis?
Acute mastoiditis is a bacterial infecito nof the mastoid process thatn can estroy the inner part of the mastoid process.
Mastoid air cells are replafced wtih fluid-filled abscess which can lead to progressive hearing loss.
What is an acoustic neuroma?
Benign tumor of the auditory nerve sheathe.
Origiantsei n the internal auditory canal.
What is cholesteatoma?
Benign cystlike mass or tumor common in the middl eear or mastoid region secondary to trauma to this region.
Destroys bone, which can lead to serious complciations including hearing loss.
What is a polyp?
Growth which arrises fro ma mucuous membrane and projects into a cavity.
May cause chronic sinusitis.
What is Osteroclerosis?
The hereditary disease which involves exvessive spongy bone formation of the middle and inner ear.
How is a trauma lateral skull centered?
- CR is 2 inch superior to EAM
- Cross table.
If you cant do a PA Caldwell, what do you do?
- You do a AP 0 degree and a AP reverse caldwell.
- For the AP 0 Degrees, just enter through the glabella with OML perpendicular to IR.
With the caldwell. Same rule applies with the PA as long as the OML is perpendicular. Enter htrough the nasion with a 15 degree cephalic angle.
For the AP axial skull trauma, how much do you angle?
30 degree caudal.
For a lateral facial bone, where do you center?
Midway between outer canthus and eam.
How do you do an AP reverse waters/
- CR parallel to MML.
- CR entereing acanthion.
For a modified AP waters, hwo do you center?
CR should be parallel to LML and entering through acanthion.