Roentgenometrics Flashcards
Does distortion/magnification occur when the position is closer or further from the central ray?
Further from
What are the normal (max) dimensions of the sella turcica?
16mm in sagittal plane
12mm in depth
What is the significance of an enlarged sella turcica?
1 empty sella
2 tumor
3 normal
4 aneurysm
An enlarged sella turcica would be seen on which view?
Lateral cervical
What are the symptoms of an enlarged sella turcica?
Headaches, hormonal changes, growth issues, visual issues
What does the sella turcica house?
Pituitary gland
Why are visual disturbances associated with an enlarged sella turcica?
Optic chiasm located directly above
What measurement is used to determine platybasia?
Martin’s basilar angle
What is the range of normalcy of Martin’s basilar angle?
137-152 degrees
What are the anatomical points that make up Martin’s basilar angle?
Nation to center of sella to basion
What is the most common pathological cause of platybasia?
Bone softening diseases (Paget’s, osteomalacia, fibrous dysplasia = top 3)
What condition is seen with a martin’s basilar angle measurement of greater than 152 degrees?
Platybasia
What bones are mal-developed from congenital platybasia?
Sphenoid and/or occipital bones
What is the term for the anterior margin of the foramen magnum and inferior aspect of the clivus?
Basion
Upon what imaging system does cortical bone appear black? White?
Black = MR White = CT and X-ray
What is the term for the posterior margin of the foramen magnum?
Opisthion
Chamberlain’s line extends from which two anatomical points?
Hard palate to opisthion
The odontoid should not extend more than how many millimeters above Chamberlain’s line?
7mm
What condition is detected by Chamberlain’s line?
Basilar impression
Which is a congenital and which is pathological in nature: basilar invagination or basilar impression?
Basilar invagination = congenital
Basilar impression = pathological (bone softening diseases)
What is basilar invagination?
Upward displacement of the vertebral elements into the normal foramen magnum with normal bone
What is basilar impression?
Upward displacement of vertebral elements into the normal foramen magnum due to softening of bones at the base of the skull
McGregor’s line extends from which two anatomical points?
Hard palate to inferior occiput
The odontoid should not extend above McGregor’s line by how many millimeters?
8-10mm in males and females respectively