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
What condition is detected by McGregor’s line?
Basilar impression
What are the general symptoms of cord problems (example = basilar impression)?
Myelopathic
What are the 4 most common disorders that can cause basilar invagination?
1 Paget’s (Beethoven)
2 osteomalacia
3 fibrous dysplasia
4 rheumatoid arthritis
What are the four areas used to determine vertebra alignment?
1 anterior body
2 posterior body
3 spinolaminar line
4 tips of spinous (hardest to do)
What are the possible causes of antero- or retrolisthesis?
1 fracture 2 dislocation 3 ligamentous laxity 4 DJD 5 anatomic/physiologic
Is DJD of the facet joints most likely to result in anterior or posterior vertebral body displacement?
Posterior
What is another term for anterolisthesis?
Spondylolisthesis
What is the space called between the posterior surface of the anterior tubercle and the anterior surface of the odontoid?
Atlantodental interval (ADI)
What structure maintains the ADI?
Transverse atlantal ligament
What are the normal ADI measurements for both adults and children?
Adults = less than 3mm Children = less than 5mm
What is the most common cause of a weak ADI?
Rheumatoid arthritis
What are the possible causes for a weak ADI?
1 trauma 2 inflammation 3 arthropathies 4 Down syndrome 5 upper cervical abnormalities
What are the top three most common cases for a weak ADI?
1 RA
2 upper cervical abnormalities
3 Down syndrome
If an increased ADI is seen on a lateral cervical X-ray, what other views should then be taken?
Flexion/extension
What is significant about a large ADI in the realm of chiropractic?
Contraindication to adjust atlas (requires neurologic referral)
Is a large or small ADI a more clinically significant finding?
Large
What is the atlantoaxial “overhand” sign?
Lateral margin of the lateral masses of atlas extend more lateral bilaterally than the superior articular processes of the axis
What does lateral displacement of the lateral margin of the lateral masses of atlas over the superior articular processes of the axis indicate?
Fracture of atlas
Mild atlantoaxial “overhang” is a normal variant among wha population?
Children (seen in a 1 year old, for example)
What type of fracture results in the atlantoaxial “overhang” sign?
Burst fracture of atlas (injured transverse atlantal ligament)
What are the degree measurements that indicate hypo- or hyperlordosis of the cervical spine?
Hypolordosis = less than 35 degrees Hyperlordosis = greater than 45 degrees
Where is the line drawn and what is measured for the cervical lordosis depth method?
Line from tip of odontoid to posterior surface of C7; measure the depth at C4
What is the average range seen with the cervical lordosis depth method?
8-12mm
Where are the two lines drawn to establish the Harrison posterior tangent method for cervical lordosis?
Along posterior body of C2 and another along the posterior body of C7
What is the average value of the cervical curvature from C2-C7 via the Harrison posterior tangent method for evaluating cervical lordosis?
34 degrees (SD = 9)
Which angles are assessed for the Harrison posterior tangent method for cervical lordosis?
Superior and inferior angles
Where are the lines drawn for Ruth Jackson stress lines?
Along posterior aspects of C2 and C7 bodies
Where should the Ruth Jackson stress lines intersect on flexion? Extension?
Flexion = C5/C6 disc or facets Extension = C4/C5 or facets
What does it mean when the cervical gravitational line does not touch the anterior body of C7?
Anterior weight placement
Where is the cervical gravitational line drawn?
From the middle of the odontoid tip to the anterior superior aspect of C7 (perpendicular to bottom of film)
Where is George’s line drawn?
Along posterior aspect of all vertebral bodies
Where are the lines drawn to measure the width of the sagittal canal?
Anterior line = posterior vertebral body
Posterior line = spinolaminar line
What is the normal range for a sagittal canal measurement?
12-16mm
At what sagittal canal measurement can stenosis be determined?
Less than 12mm
What kinds of conditions can cause a sagittal canal measurement to be less than 12mm?
1 disc facet degeneration
2 disc herniation
3 congenital
At what segmental level is the cord the largest?
C5/C6
What things could cause an enlarged retropharyngeal or retrotracheal space?
1 edema
2 hemorrhage
3 pus
4 tumor
The retropharyngeal space is measured in front of which vertebral level?
C2
The retrotracheal space is measured in front of which vertebral level?
C6
What should be the normal measurements for the retropharyngeal and retrotracheal spaces?
Retropharyngeal = less than 7mm Retrotracheal = less than 22mm
Where are the lines drawn to measure thoracic spine kyphosis?
Along superior endplate of T1 and inferior endplate of T12 (then lines perpendicular to them to form angle)
What is the average angle of thoracic spine kyphosis?
30 degrees
What is the upper limit of normal of thoracic spine kyphosis for both genders?
Females = 56 degrees Males = 66 degrees
Where are the lines drawn to measure lumbar spine lordosis?
Along superior endplate of L1 and base of sacrum (then lines perpendicular to them to form angle)
What is the range of average measurement for lumbar spine lordosis?
50-60 degrees
On what films are thoracic spine kyphosis and lumbar spine lordosis measured?
Lateral thoracic and lateral lumbar
Where is the lumbar gravity line drawn?
Vertically from mid portion L3 body to interact anterior 1/3 of sacrum
What does the lumbar gravity line assess?
Weight bearing direction
What two lines make up the lumbosacral/Ferguson’s angle?
Line 1 = across sacral base
Line 2 = horizontal to ground
What is the range of normalcy for the lumbosacral/Ferguson’s angle?
26-57 degrees
What is the grading system used for spondylolisthesis involving dividing the sacrum into 4 parts?
Meyerding’s method
What measurement is used to assess for spondylolisthesis using one line across the sacral base and another perpendicular to it on the anterior margin of sacrum?
Ulmann’s line
Which is more sensitive to spondy: Ulmann’s or Meyerding’s method?
Meyerding’s
What method is used to assess for scoliosis?
Cobb’s method
Where are the lines drawn for Cobb’s method?
Line 1 = across superior plate of upper most vertebra tipped maximally into curve
Line 2 = across inferior plate of the lower most vertebra tipped maximally into curve
(then perpendiculars drawn to form angle)
What is the specific Cobb’s angle needed for the official diagnosis of scoliosis?
Greater than 10 degrees (zero is normal, less than 10 = a curve)
What is the distance called that is measured of the medial hip joint space?
Tear drop distance
What is the normal range for the tear drop distance?
9-11mm
What could cause an enlarged tear drop distance (greater than 11mm)?
1 trauma
2 infection
3 inflammation (Legg-Calve-Perthes disease or joint disease )
4 aka space occupy lesions
Is the tear drop distance usually increased or decreased in pathologies involving children? Adults?
Children = larger tear drop Adults = smaller tear drop
The distance between two tear drop distances should never be more than how many millimeters?
2
What is the eponym associated with tear drop distance?
Kohler’s tear drop
Kline’s line is used to assess for what condition?
Slipped capital femoral epiphysis (SCFE)
Where is Kline’s line drawn?
Across lateral border of femoral neck
What should Kline’s line intersect?
Outer aspect of femoral head
What is the next procedure needed if suspecting an infection due to an increased tear drop distance?
Aspiration
The “beak sign” upon a pelvic X-ray is suggestive of what condition?
Slipped capital femoral epiphysis (SCFE)
What is the “beak sign” upon a pelvic X-ray?
Sharp point at the margin of the femoral head due to SCFE
If SCFE is seen upon X-ray, what would be the next film to take?
Frog leg
Slipped capital femoral epiphysis is most commonly in which hip?
Left
What is the typical patient profile for slipped capital femoral epiphysis?
Obese boys
What does it mean when Kline’s line does not intersect the outer aspect of the femoral head?
SCFE
Shenton’s line is drawn between what pieces of anatomy?
Medial femoral neck to superior margin of the obturator foramen (arc)
Shenton’s line is abnormal in what conditions?
1 hip dislocation
2 femur fracture
3 SCFE
What conditions can cause acetabular protrusion?
1 arthritic joint disease
2 Paget’s disease
3 bone softening diseases
4 idiopathic
What condition is Kohler’s line assessing for?
Acetabular protrusion
Where is Kohler’s line drawn?
From medial pelvic rim to external margin of obturator foramen
What finding involving Kohler’s line means acetabular protrusion has occurred?
Acetabulum exceeds past Kohler’s line
What is the condition called involving bilateral acetabular protrusion?
Otto’s pelvis
What is the purpose of Boehler’s angle?
Determining calcaneus fracture or dysplasia
How is Boehler’s angle made?
2 lines connecting the 3 highest points of the calcaneus
What is the range of normalcy for Boehler’s angle?
28-40 degrees (average = 30-35 degrees)
What measurement of Boehler’s angle is indicative of a calcaneal fracture or dysplasia?
Less than 28 degrees
The acromiohumeral space is measured between what to structures?
Under surface of acromion and superior surface of humeral head
What is the average measurement for the acromiohumeral space?
10mm
Narrowing of the acromiohumeral space is associated with what condition?
Supraspinatus tendinopathy
What is the normal size of the AC joint space on X-ray?
Less than 5mm
The right and left AC joint spaces should not differ by no more than how many millimeters?
2-3mm
What is the normal coracoclavicular distance?
Less than 11-13mm
The right and left coracoclavicular distances should not differ by no more than how many millimeters?
Less than 5mm
