NUCCA X-Ray Analysis

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NUCCA X-Ray Analysis
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Analysis Equipment

• Cephalometer
• Circumscale
• Relatoscope
• Vertex square

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Lateral Film

• PURPOSE
• To obtain the S line of the atlas
• To tell if the atlas has gone inferior or
  superior
• To determine where to take the Nasium

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Lateral Film Analysis

• S Line
• Place a dot where the posterior arch of atlas
  meets the lateral mass
• Place a second dot about 1/3 down along the
  length of the posterior arch of atlas

Note that because of how the Nasium film is
taken, if the S line does not go through the
mastoid markers, you must move the line up/down
in a parallel fashion so that it does. This way
it will be taken at the proper angle.
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S-Line
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Nasium Film

• PURPOSE
• To determine atlas laterality
• To determine upper and lower angle to determine
  the basic type
• To determine APL, A/O, C/A, Ang, At, OD, BC,
  Sp
• To calculate the height vector
• To determine if C2 spinous rotation is present
  (torque)

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Nasium Film

• Atlas Plane Line (APL)
• Place a dot on the lower border of the posterior
  arch where it crosses the lateral masses on each
  side of atlas

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Nasium Film

• Central Skull Line (CSL)
• Mark the squamous suture on each side of the head
• Mark the vertex of the head on each side
• The CSL will only be determine using the area
  between these two points

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Nasium Film

• CSL Continued
• Use the Cephalometer to match like points on
  either side of the head in order to determine the
  center of the skull
• Mark a lower pivot point intersecting the APL
• Mark an upper pivot point at the top of the skull

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Nasium Film

• CSL Continued
• Starting with the lower pivot point, make your
  way up the skull finding like points with the
  cephalometer by keeping the lower pivot point in
  the slot. The line should match up with the two
  pivot points
• Then make your way down with the upper pivot
  point
• Repeat
• If the line shifts, you have the wrong pivot
  points and need to redo
• Once you have the best points, mark the CSL with
  a solid line

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Nasium Film

• Atlas Laterality (At)
• To find laterality measure the side of the acute
  angle between the CSL and APL

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Nasium Film

• Head Tilt
• To find the head tilt, measure the angle between
  the true vertical and the CSL

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Nasium Film

• Condylar Circle
• Mark the outer 1/3 of the surface of the
  occipital condyles
• Using the circumscale, find the best fit circle
  c
• If it comes out to ½, round down

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Nasium Film

• Axial Circle
• Place a dot (A) on the most lateral aspect of the
  superior surface of C2 on each side
• Also place a dot (B) on the medial aspect of the
  superior surface of C2 on each side
• Connect those dots on each side
• From the medial dots, place another dot (C)
  3/32 down perpendicularly from that line
• Use A and C to find the best fit circle for axis
  a
• If it comes out to ½, round up

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Condylar and Axial Circles
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Nasium Film

• Odontoid Center (OD)
• Mark the center of the Odontoid

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Nasium

• C2 Body Center (BC)
• Using the dots on the lateral aspect of the
  superior surface of C2, place the center of a
  protractor on each dot and scribe and arcs above
  and below
• Use a straight edge to connect the two
  intersections
• Draw a small line down the center in the middle
  of the intersections

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Nasium Film

• BC Continued
• Use the relatoscope that corresponds to the
  condylar circle
• Square up atlas so that the horizontal lines of
  the relatoscope are parallel to the APL and the
  lateral masses are boxed in equally
• Determine the degrees (if any) the body center
  line is off from the 0 mark on relatoscope
• If BC is on the same vertical line as the 0 mark
  then BC At

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Nasium Film

• C2 Spinous (SP)
• Mark the inferior bifurcation of C2 spinous
• Use the relatoscope again to compare position of
  C2 spinous to atlas like you did with BC
• The lateral film can help you locate its position
  if its hard to see by comparing where it is on
  the lateral film in relation to the posterior
  arch of atlas

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OD/BC/SP
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Nasium Film

• Fixed Point
• Mark the lateral aspects of the zygapophyseal
  joints of C7
• Determine the midpoint
• Mark a point (D) between BC and SP if not on same
  vertical line
• Connect the midpoint of C7 to D dot

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Nasium Film

• Lower Angle
• Measure the acute angle between the APL and the
  fixed point line

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Nasium Film

• Height Vector Components
• PL
• A/BC
• C/A
• Ang

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Height Vector Calculations

• PL
• Use a true horizontal and move it up/down until
  it matches up where the APL crosses the ramus of
  the jaw on the side opposite of laterality and
  draw a small straight reference line on the side
  of laterality
• Measure how far above or below the APL is
  compared to that true horizontal
• If APL is lower by
• 1/16th ? - ¼
• 2/16th ? - ¾
• 3/16th ? - 1
• If APL is higher by
• 1/16th ? ¼
• 2/16th ? ¾
• 3/16th ? 1

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PL
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Height Vector Calculations

• A/BC
• Compare the amount of atlas laterality due to
  atlas side slip (ss) versus head tilt (ht)
• If ht ss, then A/BC -1/2 ht but only up to
  amount of laterality
• If ht lt ss, then A/BC -1/2 ht
• If ht 0 or if it does not contribute to
  laterality, then A/BC 0
• If BC gt At like in a Type I with a large lower
  angle, then A/BC 1 for the first degree
  extra

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Height Vector Calculations

• C/A
• This is equal to (a-c)/2

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Height Vector Calculations

• Ang
• Take the difference of At lower angle
• For contralateral acute angles
• ¼ for every 1 difference
• For ipsilateral acute angles
• - ¼ for every 1 difference
• If the lower angle is less than or equal to atlas
  laterality, then Ang 0

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Height Vector Calculation Practice

• At R2
• OD R2
• BC R2
• SP R2

3c
4/16th
8a
L6
PL 1 ¼ A/BC 0 C/A 2 ½ Ang
1 _______________ 4 ¾
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Height Vector Calculation Practice

• At R4 (RS)
• OD R4
• BC R1
• SP R4

3c
2/16th
10a
L4
PL ¾ A/BC - 1 ½ C/A 3 ½ Ang
0 _______________ 2 ¾
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Height Vector Calculation Practice

• At R4 (R4)
• OD R4
• BC R0
• SP R4

3c
5 ½a
L0
PL 0 A/BC - 2 C/A 1 ½ Ang
0 _______________ - ½
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Vertex Film

• PURPOSE
• To determine C1 rotation
• To determine anterior/posterior vector

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Vertex Film

• Mark the anterior and posterior aspect of both
  lateral masses
• Mark the center of the transverse foramen and
  draw a line connecting the two points
• Use the vertex square to box in atlas using the
  lateral masses to make sure all those
  points/lines are parallel
• If the line of the transverse foramen isnt
  parallel to the lateral masses, use the lateral
  masses
• Measure the angle between the true vertical line
  and the transverse foramen or lateral mass line
  on the side of laterality
• If the angle is acute anterior rotation
• If the angle is obtuse posterior rotation
• Vector 1 for every 1 anterior or posterior

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Vertex