Measurements in Skeletal Radiology (Quiz 2) Flashcards
What is another name for basilar impression?
basilar invagination
What is basilar impression?
test q
protrusion of odontoid process into foramen magnum
What are the 2 types of basilar impression?
congenital or acquired
What are the 3 congenital causes of basilar impression?
1) occipitilization (lacking space)
2) condylar hypoplasia (underdeveloped condyles)
3) achondroplasia (most common type of dwarfism)
What are the 6 acquired causes of basilar impression?
1) paget’s disease
2) RA
3) osteomalacia
4) rickets
5) fibrous dysplasia
6) upper cervical trauma (MVA, falls, driving accident)
What does PORT+ fd stand for?
bone softening conditions mneumonic
P= paget’s disease
O= osteoporosis and osteomalacia
R= RA
T= trauma
fd= fibrous dysplasia
Black spinal fluid on MRI=
T1 weighted image/ hypointense signal
White spinal fluid on MRI=
T2 weighted image/ hyperintense signal
What are the 4 assessments to check for basilar impression?
1) basilar angle/ Welcker’s basilar angle/ Martin’s basilar angle
2) McGregor’s line
3) Chamberlain’s line
4) Macrae’s line/ Mcrae’s line/ foramen magnum line (FML)
Which line assessments use a lateral skull/lateral cervical view?
1) basilar angle/ Welcker’s basilar angle/ Martin’s basilar angle
2) McGregor’s line
3) Chamberlain’s line
4) Macrae’s line/ Mcrae’s line/ foramen magnum line (FML)
5) method of bull
6) George’s line/ posterior vertebral alignment line/ posterior body line (PBL)
7) Cervical gravity line
8) Cervical lordosis/ angle of the cervical curve/ cervical lordotic angle
9) Eisenstein’s cervical method for sagittal canal measurement
What is the procedure for a basilar angle assessment?
Exam 1 q
-3 points located and joined together by 2 lines
-the points used are the nasion, center of sella turcica, and basion (anterior margin of FM)
What is the normal range for a basilar angle assessment?
Exam 1 q
123-152 degrees
Increased basilar angle is associated with….
platybasia and potential basilar impression
What is the procedure for McGregor’s line assessment?
-line drawn from posterior superior margin of hard palate to most inferior surface of occipital bone
-relationship of odontoid apex to line is assessed
What is the normal measurement for McGregor’s line assessment?
odontoid apex should be above line no more than 8mm in males, 10mm in females
What does it mean if McGregor’s line assessment has an abnormal superior position?
basilar impression
Which line assessment is the most accurate/reproducible measure of basilar impression?
McGregor’s line assessment
What is the procedure for Chamberlain’s line assessment?
Exam 1 q
-line drawn from posterior margin of hard palate to posterior aspect of foramen magnum (opisthion)
-relationship of odontoid apex to this line is assessed
The posterior aspect of FM is called….
opisthion
A line drawn from posterior margin of hard palate to opisthion is called?
Chamberlain’s line
What is the normal measurement for Chamberlain’s line assessment?
tip of odontoid should NOT project above line, it may be up to 3mm above line
What does it mean if Chamberlain’s line is >3 mm above odontoid tip?
possible basilar impression
The anterior aspect of FM is called…
basion
What are the other names for Macrae’s line?
test q
Mcrae’s line or foramen magnum line (FML)
