General Structure Analysis Normals Flashcards
sella turcica A-P range
5-16mm
sella turcica A-P avg
11 mm
sella turcica S-I range
4-12mm
sella turcica S-I avg
8 mm
sella turcica indicates
enlargement/ space occupying lesion of the pituitary
ADI normal adult range
1-3 mm
ADI normal child range
3-5 mm
ADI measurement indicates
instability between atlas and axis b/c instability of transverse lig
cause of enlarged ADI children
infection
cause of enlarged ADI adults
RA
where is George’s line drawn
along posterior aspect of vert bodies to observe the cervical curve
where is the posterior cervical line drawn
on the most convex portion of the spinolaminar junction lines
what is happening when you measure the sagittal dimensions of the spinal canal
what does it indicate
measure between george’s line and the posterior cervical line
space occupying lesion
cervical levels of retropharyngeal interspace
C1-C3
cervical levels of retrolaryngeal interspace
C4-C5
cervical levels of retrotracheal interspace
C6-7
measurements of retropharyngeal interspace
not > 7mm
measurements of retrotracheal interspace
not > 22mm
how is the basilar angle drawn
from frontal/nasal junction to center of sella turcica
from sella to anterior aspect of foramen magnum
normal range for basilar angle
123-152 degrees
> 152 indicates what for basilar angle
platybasia
how is Mcgregor’s line drawn
draw from superior/posterior aspect of hard palate to inferior most aspect of the occiput. measure of dens above the line
normals of McGregor’s line males
not > 8 mm if it is = platybasia
normals of McGregor’s line females
not > 10mm if it is = platybasia
how is chamberlains line drawn
from posterior aspect of the hard palate
to post aspect of foramen mag
measure amt DENS over the line
normal for Chamberlain’s
not >3 mm anything greater is platybasia
Macrae’s line drawn
ant aspect of foramen mag to post aspect foramen mag
perpendicular line from dens to the line drawn
normal for Mac rae
occipital bone should extend below the line if not= platybasia.
apex of DENS ant 1/4 of foramen mag if not = fracture dens
cobb/lipman normals 0-20 degrees
observe for progess
cobb/lipman normals 20-40
bracing
cobb/lipman normals >40
sx
Cervical Lordosis normal
35-45 avg=40
thoracic kyphosis
angles vary by age
angles increase with age
angles increase more rapidly in females
lumbar lordosis
50-60 degrees avg=55
sacral inclination is drawn
line tangent to post aspect of S1
line parallel to side of film at sup/post aspect of SI
mesasure angle
sacral inclination normals
30-72 degrees avg=46
lumbosacral angle is drawn
parallel line to sup vert endplate S1
parallel line to top of the film to ant sup aspect SI
normal for lumbosacral angle
26-57 degrees avg=41
lumbosacral disc angle normals
10-15
15 facet impaction
Ullmann’s line drawn
parallel to sup vert endplate S1
perpendicular to 1st line at ant aspect of S1
check to see if lumbar crossed the line
ullmann’s line normal
if crosses= spondylolisthesis
Meyerding grading 1-4
spondylolisthesis
Meyerding grading >4
spondyloptosis
Meyerding grading L5 behind last line
retrolisthesis
fergusons weight is drawn
X across vert body of L3
parallel to the side of the film at midpt of X
fergusons weight normal
line should cross the ant 1/3 of sacral base
tear drop distance
6-11 mm avg=9
Hip joint width normal
sup and axial should be about 4mm or equal to ea other
medial= teardrop should be double
shentons line
smooth arc
femoral angle noraml
120-130
coxa vara
coxa valga
> 130 degrees
iliofemoral line
bilateral sym
skinners line
fovea cap should be above or level with line
kleins line
bi lat sym
