Irene Gold PART 2: Diagnostic Imaging (Purple IG
Book, Blue Section) – Questions With Solutions
What special imaging is this?
• Presents structures in different planes with equal clarity
• Uses contract and is 1-x better than plain film
• Visualizes occult fx, bone fragment location, intra-articular fx, calcified soft
tissue lesions, and Brodie's abscess
• Traumatic lesions, pathology, or anomalies
What special imaging is this?
• Provides optimal visualization of spatial relationships and distinct soft tissue
contrast to view: IVD, spinal cord, meninges, bone, meniscus, ligaments
• Shows soft tissue contrast 100x better than CT
• No radiation dose; gadolinium; utilizes signal intensities; uses surface oils
•Best for multiple sclerosis for plaguing in the brain and spinal cord
• MRI best for all AVN's
• T1 weighted fatty pathologies (ex muscular dystrophy)
• T2 weighted water density
• Whatever is weighted is white; other density will appear gray; cortical bone
is ALWAYS black (signal void) ✔️Ans - MRI
What special imaging is this?
• dual emission Xray Absorptiometry → measures bone densities for
osteoporosis ✔️Ans - DEXA (DXA) Scan
What special imaging is this?
• Uses an injection of radioactive substance (usually Technetium 99)
• Measures the body's "attempt" to lay down new bone
• Hot is positive: All AVN's, Blastic and Lytic Mets, Paget's, Hodgkin's, and
fractures
,• Cold means nothing is occurring. MM. ✔️Ans - Bone Scan (Scintigraphy)
What Line of Mensuration am I?
• Landmarks: A line is drawn from the nasion to the center of the sella turcica
• A line is drawn from the basion (anterior foramen magnum) to the center of
the sella turcica
• Significance: If this angle is >152° it is indicative of platybasia which may be
associated with basilar impression ✔️Ans - Basilar Angle aka Martin's
Basilar Angle
What Line of Mensuration am I?
• Landmarks: Anterior foramen magnum (basion) to the posterior foramen
magnum (opisthion)
• Significance: If the occipital bone is above the line, this indicates basilar
impression ✔️Ans - Macrae's Line
What Line of Mensuration am I?
• Landmarks: C1 anterior tubercle to the odontoid
• Significance: If this space is >3mm in adults or >5mm in children, this
indicates transverse ligament rupture or instability due to trauma, Down's
syndrome, or inflammatory arthritis ✔️Ans - Atlantodental Interspace
What Line of Mensuration am I?
• Landmark's: a line is drawn from the hard palate to the base of the occiput
• Significance: If the odontoid is >8mm above this line in males or >10mm
above this line in females, this indicates basilar impression
• This is the most accurate line to evaluate for basilar impression
• should not exceed this line superiorly more than 8mm in males and 10mm in
females ✔️Ans - McGregor's Line
What Line of Mensuration am I?
• Landmarks: the hard palate to the opisthion (posterior foramen magnum)
• Significance: If the odontoid is >7mm above this line, this indicates basilar
impression ✔️Ans - Chamberlain's Line
Chamberlain's Line ✔️Ans - What Line of Mensuration am I?
,McGregor's Line ✔️Ans - What Line of Mensuration am I?
Basilar Angle aka Martin's Basilar Angle ✔️Ans - What Line of Mensuration
am I?
Macrae's Line ✔️Ans - What Line of Mensuration am I?
Atlantodental Interspace ✔️Ans - What Line of Mensuration am I?
What Line of Mensuration am I?
• Landmarks: Posterior body margins are checked for alignment with what
should be a smooth, continuous line
• Significance: Discontinuous line may indicate A to P vertebral malposition
such as anterolisthesis or retrolisthesis ✔️Ans - George's Line
What Line of Mensuration am I?
• Landmarks: Lines drawn at each spinolaminar junction should form a
smooth arc-like curve
• Significance: Discontinuous line may indicate A to P vertebral malposition
such as anterolisthesis or retrolisthesis ✔️Ans - Posterior Cervical Spine
What Line of Mensuration am I?
• Landmarks: Lines drawn at the posterior bodies of C2 and C7
• Significance: Flexion should intersect at C4/C5; may be altered by muscle
spasm, joint fixation, or disc degeneration ✔️Ans - Stress Lines of the
Cervical Spine
What Line of Mensuration am I?
• Landmarks: Anterior vertebral bodies to posterior margin of air shadow of
the pharynx, larynx, and trachea
• Significance: The following is indicative of a soft tissue mass (tumor,
infection, or hematoma)
- Retropharyngeal (C2-4): >7mm
- Retropharyngeal (C5): >14mm
- Retrotracheal (C6-7): >22mm ✔️Ans - Prevertebral Soft Tissue
What Line of Mensuration am I?
• Landmarks: Locate superior an inferior extremes of scoliosis
, •Draw a parallel line through the superior end plate of extreme superior
vertebra and through inferior end plate of extreme inferior vertebrae.
Interesting perpendicular lines are drawn and the angle is measured
• Significance: Scoliosis evaluation (Preferred method) ✔️Ans - Cobb's
Method of Scoliosis
What Line of Mensuration am I?
•Landmarks: Locate superior and inferior extremes of scoliosis and apical
segment. Diagonal lines are drawn to locate the center of the vertebral bodies.
Two lines are drawn connecting center of apical segment with each end
vertebra and resultant angle measured
Significance: Scoliosis evaluation. Values are 25% below Cobb Method of
evaluation ✔️Ans - Risser-Ferguson Method of Scoliosis Evaluation
What Line of Mensuration am I?
• Landmarks: Tangential line is drawn parallel and through the posterior
margin of S1 and a vertical line is drawn intersecting the sacral line
Significance:
Normal Angle: 30°-72°
Average Angle: 46° ✔️Ans - Sacral Inclination
What Line of Mensuration am I?
• Landmarks: Oblique line drawn through and parallel to the sacral base.
Horizontal line parallel to the bottom edge of the film
•Significance:
Normal Angle: 26°-57°
Average Angle: 41° ✔️Ans - Lumbosacral Angle aka Sacral Base Angle aka
Ferguson's Angle
Cobb's Method of Scoliosis Evaluation ✔️Ans - What Line of Mensuration am
I?
Risser-Ferguson Method of Scoliosis Evaluation ✔️Ans - What Line of
Mensuration am I?
Sacral Inclination ✔️Ans - What Line of Mensuration am I?
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