Imaging Notes Year 3 - finished Flashcards
What is McGregors Line (Basal Line)?
Measured: Line drawn from posterosuperior margin of hard palate to most inferior surface of occipital bone. The superior, (apical), aspect of the dens should not exceed 8mm above this line (10mm female)
Significance: Indicates basilar impression, Atlas occipitalisation, Bone softening conditions (OM, Pagets, fibrous dysplasia) RA
What are the Cervical views?
- AP open mouth
- AP Lower Cervical
- Lateral
- Right and Left Posterior Oblique
- Davis Series = Flexion and extension lateral (along with all other films)
What are the cervical lines of alignment in a lateral Cx view? What is the significance of interruptions/discrepancies in these lines?
▪ ALL, PLL, SLL ▪ Cervical canal width ▪ Georges Line (PLL) ▪ Angle of the Cervical Spine ▪ Ruth Jackson physiological Line ▪ Vertical line of stress (cervical body gravity Line) ▪ ADI ▪ Retropharyngeal and retro tracheal spaces
SIGNIFICANCE: Traces curvature of lordosis Spondylolisthesis Interruptions indicative of osteophytes Fractures/dislocations
What does the space between the PLL and the SLL indicate? What is the clinical significance?
Distance between PLL and SLL is spinal canal space <12mm = stenosis
What does the cervical measure, what are the measured landmarks and what is normal?
Measures the angle of lordosis in the cervical spine.
Measured: Midpoints of anterior and posterior tubercles of the atlas and a line through inferior endplate of C7. Perpendiculars are constructed if required.
Angle: 35-45 degrees normal lordosis
What does the Physiological Line of Stress (Ruth Jackson) measure?
How is it measured and what is normal?
What does an abnormal measurement signify?
Measures the line of gravity through the Cx spine
MEASURED BY: 2 lines and where they intersect:
1 - Along the posterior aspect of the dens
2 - Along the posterior aspect of C7
NORMAL:
Neutral: Should pass through C4/5 IVD
Flexion: Should Pass through C5/6
Extension: Should Pass through C4/5 posterior
SIGNIFICANCE:
Biomechanical compensation
What does the Atlanto-dental interspace (ADI) measure?
How is it measured and what is normal?
What does an abnormal measurement indicate?
The space between the front of the dens and the back of the C1 arch anteriorly.
MEASURED BY: Anterior aspect of dens and posterior aspect of anterior tubercle.
NORMAL:
1-3mm adults
1-5mm children
INDICATIONS: PARRS, Down Syndrome
List all of the lines of alignment in the Cervical Spine (6)
- Georges (PLL, ALL and SLL) for all of spine
- Physiological line of stress (Ruth Jackson)
- Angle of Cx. Spine
- Cervical body gravity line
- ADI
- Retropharyngeal and Retro tracheal space
List the lines of alignment in the Thoracic Spine (4)
- Thoracic curve angle
- Pedicular method of rotation
- Tracheal bifurcation level in pediatric to geriatric
- Scoliosis
What are the views of thoracic spinal imaging?
AP
Lateral
Specific rib views
What are the lines of alignment of a lateral of the thoracic spine?
▪ ALL, PLL, SLL
▪ Angle of the Thoracic Kyphosis
▪ Tracheal bifurcation
When look at the alignment of the Tx spine in an AP, the interpedicular distance should not be less than what?
14mm
Describe the 2 measuring systems for quantifying scoliosis deviation
Cobb Lippman Method:
- A line is drawn along superior border of cephalad (top) vertebrae.
- A line is drawn along inferior of caudad (bottom) vertebrae.
If endplates not visible then bottoms and tops of pedicles used.
Perpendicular lines are then drawn from each horizontal line, and the angle of their intersection measured.
Seven groups: 1: 0-20 degrees, 2: 21-30 degrees,3: 31-50 degrees,4: 51-75 degrees,5: 76- 100 degrees, 6: 101-125 degrees ,7: 126 and above,
Cobb method gives larger measurements then Risser technique by average of 25% or about 10 degrees.
Risser-Ferguson Method:
- The centres of the end (top and bottom) and apical vertebral bodies are identified. These points are then connected and the angle of intersection measured.
What can alter the tracheal bifurcation level?
Where is the tracheal bifurcation level at the ages:
1 - newborn?
2 - 10 yrs old?
3 - adult?
Infections
Tumours
Mechanical Influences
Newborn - T3
10 years old: T5
Adult: T6
What are the views in a lumbo-sacral series?
AP (tilt 15 degree SIJ)
Lateral
Oblique R & L
L5/S1 spot (AP and Lat)
What are all of the lines of alignment in the lumbar spine?
- George’s line (ALL,PLL,SLL)
- Ferguson’s line
- Lumbosacral disc angle
- McNab’s line
- Lumbar curve angle
- Ulman’s line
- Myerdings classification
- Sacral base angle
- Pedicle Rotation, Interpedicular distance
What is Meyerding classification used for? How is it measured?
Classifying spondylolisthesis.
Sacral base is divided into 4 equal parts. The relative slip of the vertebrae above is classified.
What is Ulman’s line? How is it measured?
Helps identify a spondylolisthesis.
Line extended upwards at a 90 degree angle to the superior surface of the sacral base at its anterior margin and it should clear the anterior inferior margin of the L5 body.
When look at the alignment of the Lx spine in an AP, the interpedicular distance should not be less than what?
20mm
What are the views of a pelvic and hip series?
AP widely collimated
Spot AP Hip
Frogleg
Lateral (uncommon due to superimposition)
What are the ages of ossification of the pelvis?
Three centres of ossification
1: Ilium ~ = 2 months fetal life
2: Ischium = 3 months
3: Pubis = 4 months
4: Ischial and pubic rami = 7 years
5: The ‘Y’ shaped cartilaginous physis of the three bones after puberty = 15yr
