Pre-Reading Flashcards
(75 cards)
1
Q
What colour does air appear on an Xray?
A
Black
2
Q
What colour does fat appear on an Xray?
A
Black
3
Q
What colour does water appear on an Xray?
A
Grey
4
Q
What colour does bone appear on an Xray?
A
White (varying shades) radio opaque
5
Q
What colour does metal appear on an Xray?
A
Stark white
6
Q
What is the acceptable exposure of radiation per annum?
A
Australia the average background radiation dose is approximately 1.5 mSv per year 1500 microsieverts (μSv) = 1.5 millisievert (mSv)
7
Q
Order of least to most radiation:
Leg or foot , Mammography, Dental, Barium meal, Chest, Skull, Intestine
A
Dental 5-10 μSv Chest 20 μSv Leg or foot 20 μSv Skull 70 μSv Mammography 400 μSv Barium meal 2500 μSv Intestine 3000 μSv
8
Q
What is the average annual radiation dose (minus medical procedures)?
A
The average annual radiation dose per person per year is approximately 1500 μSv plus any exposure from medical procedures.
9
Q
What is contrast media used for?
A
To focus in on organs, or to examine the blood vessels that make up the circulatory system
10
Q
What is a fluroscopy?
A
In fluoroscopy, the X-rays pass through the body onto a fluorescent screen, creating a moving X-ray image. Doctors may use fluoroscopy to trace the passage of contrast media through the body. Doctors can also record the moving X-ray images on film or video.
11
Q
What views are included in a ‘davies series’ X-ray?
A
- AP open mouth to see C1 and C2
- AP lower cervical
- L lateral
- R and L oblique
- L Flex/Ext
12
Q
If the view is AP which side of the body will show up best?
A
The part of the body closest to the cassette will be seen best so in the case of an AP the spine is best visualized whereas in the case of a PA the chest and lung fields would be better seen.
13
Q
How much bone loss is required before it can be seen on X-ray?
A
40-70%
14
Q
What are the two types of windows for a CT?
A
Bone and Soft Tissue window
15
Q
What contrast studies can be done for a CT?
A
intravenous, intra-arterial, intrathecal, intradiscal and GI
16
Q
What is a SCOUT image?
A
The scout image is like a road map that tells you by number, which slice is which.
Your scout image will generally precede the series of slices it correlates too.
17
Q
What are the common types of Cat Scans?
A
Soft tissue, bone window and MIPS (Maximum Intensity Projection)
18
Q
What can a soft tissue cat scan detect?
A
Usually for viewing Herniation, soft tissue masses, haematoma
19
Q
What can a bone window cat scan detect?
A
Articular sites, Bone Degeneration, trauma, bone congenital abnormalities (ie spina bifida)
20
Q
What can a MIPS cat scan detect?
A
Slices similar to soft tissue window though
Show great vessels. Trauma indicated.
21
Q
Limitations and contraindications for CT scan?
A
- Radiation dose high.
- Contrast media may be contraindicated (iodine).
- Image artefacts may result from metallic objects in area of interest.
- Claustrophobia
22
Q
Physics and principles of MRI
What is the Resonance factor (RF)?
A
(RF) is the energy required to shift nuclei from parallel to antiparallel state. (in or out of magneticfield)
23
Q
What is the difference between a T1 and T2 in regards to Time to Echo (TE) and Time to Repetition (TR)
A
T1 short time to echo (TE) and short time to repetition (TR). Fat density brightest
T2: longer TE and TR. Water density brightest.
24
Q
How much bone loss can an MRI detect?
A
Can pick up osteopoenic bone or bone demineralisation from 1-5%.
25
Limitations and contraindications for MRI
- Very large patients don’t fit Claustrophobia and long immobility
- Ferromagnetic objects in patients body are contraindication; pacemaker, cochlear implant, heart bivalves, aneurysm clips, intraoccular fragments, metal shards or shrapnel, tattooed eyeliner, body piercing, metal objects.
- Not in pregnancy unless mothers life at risk (Risks unknown)
- More expensive than CT (approx.. $250 per region).
- Machine strength variation.
- Over used, Expectation, high interpretation error
26
What does the 'all' encompass?
- Ensure all your films asked for are there
- Patients identifying details are present (e.g. The X-rays are of the patient you requested, or if no age determining age bracket)
- All Bones are present which should normally be present
27
What does the 'A' in All ABCS encompass?
Alignment
of bones with one another in relation to articulation with other bones
(lines of alignment)
28
What does the 'B' in All ABCS encompass?
Bone Quality
- Trabecular patterns
- Density of bones (e.g. high density = whiter film as opposed to low density films)
- Medullary cavities
- Cortical continuity, thickness and integrity
- Periosteal involvement
29
What does the 'C' in All ABCS encompass?
Cartilage
| Note joint space and symmetry
30
What does the 'S' in All ABCS encompass?
Soft Tissues
| Note any increase in density (for example due to soft tissue injury) or absence or presence of
31
What are the 6 stages of bone development?
1) Hyaline Cartilage Model
2) Calcification of the cartilage
3) Primary ossification centre forms leading to medullary cavity development
4) Secondary ossification centre is established
5) Formation of compact bone
6) Formation of mature bone
32
What happens in the first stage of bone development?
* Chondroblasts form a hyaline cartilage model of the future bone
* Perichondrium is formed over the bone except where it will articulate
33
What happens in the second stage of bone development?
- Blood vessels supply the perichondrium
- Osteoblasts produce a woven bone collar surrounded by periosteum
- Chondrocytes start to hypertrophy in the diaphysis
- The matrix between them is
mineralized with calcium carbonate forming calcified cartilage
- Chondrocytes trapped in their calcified tombs die leaving lacunae with thin calcified matrix walls
34
What happens in the third stage of bone development?
* Blood vessels invade lacunae in the calcified cartilage
* Osteoclasts and osteoblasts travel into the calcified cartilage via the connective tissue of blood vessels
* Osteoblasts then produce bone trabeculae in diaphysis forming cancellous bone
* This part of the future bone is called the primary ossification centre
* Medullary cavity forms when osteoclasts remove bone from the diaphysis
35
What happens in the fourth stage of bone development?
Secondary ossification centres are established in the epiphysis of long bones.
• These appear late in foetal development and a baby is considered to be full term if a secondary ossification centre has appeared at either the head of femur, head of tibia, of head of humerus. The last to appear is the medial epiphysis of the clavicle which does not develop until 18 or 20 years
• No medullary cavity occurs in a secondary ossification centre
36
What happens in the fifth stage of bone development?
•Cartilage is increasingly replaced by bone leaving only the epiphyseal
growth plate which remains until the bone growth is complete.
•Articular cartilage remains throughout development and in adulthood
on all articular surfaces
37
What happens in the sixth stage of bone development?
Compact bone and cancelous bone are completely developed and the epiphyseal growth plate has fused at completion of the bone growth, leaving just the epiphyseal line
• The only cartilage remaining is on the articular surfaces
• All of the perichondrium is now periosteum
38
What are the X-Ray skull series views?
○ AP (or Townes 1⁄2 AP)
○ Axial
○ Lateral
39
What are the X-Ray facial series views?
○ Water’s (occipital-mental) - Head slightly angled upwards PA view
○ Occipital-frontal
○ Lateral
○ Caldwell - Head slightly angled downwards PA view
○ PA sinus - (I think is just a Water's or Caldwell)
40
What are the X-Ray Cx spine views?
```
○ APOM
○ AP Lower Cervical
○ Lateral
○ Right and Left Oblique Posterior
○ Flexion and extension lateral (along with all other films)
```
41
What are the lines of alignment of the Cx spine?
```
▪ ALL (Anterior Longitudinal Line)
▪ PLL (Georges line – posterior longitudinal ligament)
▪ Spino-Laminar line
▪ Spinal Canal Width: <12mm stenosis
▪ Cervical Angle: 35-45 degrees normal
▪ Physiological Line of Stress (Ruth Jackson) Should pass through C4/5 IVD, higher = more extension, lower= more flexion
▪ Vertical Line of Stress (COG)
▪ Atlanto-dental interspace (ADI)
▪ Retro-pharyngeal Line
▪ Retro-Tracheal Line
```
42
What are the lines of alignment of the Tx spine?
```
AP
▪ Side bending (scoliosis)
▪ Rotation pedicular method or SP
▪ Interpedicular distance
▪ Tracheal bifurcation
LATERAL
▪ ALL, PLL, SLL (Georges Line)
▪ Angle of the Thoracic Kyphosis
```
43
What are the four basic parameter investigated in scoliosis?
1) Curvature
2) Rotation
3) Flexibility
4) Skeletal maturation
44
What are the two most common measures of alignment for scoliosis?
Cobb-Lippmann and Risser-Ferguson systems
45
What are the lines of alignment of the Lx spine?
* Georges Line (ALL, PLL, SLL)
* Lumbar Curve Angle (method 1/2)
* Fergusons Line (lumbar gravitational Line)
* Meyerding and Ulman's (for spondy)
* Scoli: Cobb and Risser Method
* Rotation
* Interpedicular distance (should not be bellow 20mm)
46
What are the two most common measures of Lx Spondylolithesis?
Meyerding and Ulman's
47
How much space should be between the atlantodental space?
1-3mm in adults
| 1-5mm in children
48
What can alterations to the trachea be due to?
- Infection
- Tumours
- Mechanical influences
49
What level does the adult trachea bifurcate?
T6 (T4/5 in children and T3 in newborn)
50
What is a variant?
An abnormality in normal ossification
51
What are the common Xray views of the hip/pelvis?
AP widely collimated
Spot AP Hip
Frogleg
Lateral (uncommon due to superimposition)
52
What age do the three ossification centres of the hip develop?
- Ilium ~ 2 months fetal life
- Ischium 3 months
- Pubis at 4 months
53
What age does the growth plates of the hip conjoin?
- Ischial and pubic rami 7 years
| - The 'Y' shaped cartilaginous physis of the three bones after puberty (15yr)
54
What age do the three ossification centres of the femur develop?
1: Centre of the head 1 yr
2: Greater trochanter 3 yrs
3: Lesser trochanter 12 yrs
55
Where abouts are the hip joint width (Teardrop) distances?
- Superior Joint Space: The space from the most superior aspect of articular surface of femur and adjacent acetabular cortex.
- Axial Joint Space: Space btw the femoral head and acetabulum immediately lateral to acetabular notch.
- Medial Space (also Teardrop distance): Space between the most medial surface of femoral head and opposing acetabular surface.
56
What are the normal measurements of the hip distances?
Superior: 3-6 (4mm)
Axial: 3-7 (4mm)
Medial: 6-11 (8mm)
57
Name five alignments of the hip joint
* Hip joint width (Tear drop distance)
* Acetabular depth
* Symphysis pubis width
* Shenton’s line
* Ilio-femoral line
* Skinners line
* Femoral angle
* Acetabular angle
* Kohlers Line (protrusio acetabuli) • Klein’s line (child SFCE)
58
What is the significance of the medial teardrop distance?
if exceeds 11mm or > 2mm discrepancy from side to side then hip disease is most likely present. (even 1mm difference can indicate disease). Early sign in Perthes, inflammatory conditions, septic arthritis.
59
How is acetabular depth measured?
A line drawn from the superior margin of the pubis at the symphysis joint to upper outer
acetabular margin. The greatest distance from this line to the acetabular floor is measured.
60
How is the femoral angle measured?
Angle formed by the axis of the neck and the
| long axis of the shaft of femur.
61
What is the normal range of degrees in the femoral angle?
Normal Measurement: 120-130 degree's
| Significance: < 120 Coxa Vara, > 130 Coxa Valga)
62
How is the ilio-femoral line measured?
A line along lateral margins of the ilium should continue as an unbroken curve along the superior margins of the femoral neck.
63
How is Shenton's line measured?
Curvilinear line traced along under-surface of femoral neck and continued across the joint to the inferior margin of the superior pubic ramus.
64
What do interruptions to Shenton's line and the olio-femoral line suggest?
nterrupted or discontinuous line is useful in detecting hip dislocations/dysplasia , fem neck #, SFCE.
65
How is Skinner's line measured?
Line drawn through and parallel to axis of femoral shaft. 2nd line at right angle to the shaft line is constructed tangential to the tip of the greater trochanter.
66
What are you trying to detect using skinners line?
Normal: Relationships to the fovea is assessed and fovea should lie above or at the level of the level of the trochanteric line.
Significance:Conditions causing Coxa Vara #
67
How is Kelin's line measured and what is it assessing?
Measured: Line drawn tangential to the superior margins of the femoral neck. Bilateral examinations should be made.
Normal Measurement: If there is a failure of the femoral head to cut the line drawn, then SFCE suspected.
68
What are the normal X Ray views of the knee?
```
AP
Lateral
Intercondylar
Skyline
Medial oblique
```
69
What are the ossification times of the femur?
1: Centre for the shaft 8th week intra-uterine life
2: Centre of the head 1 year
3: Greater trochanter 3 years, Lesser trochanter 12 years
4: All fuse with the shaft at about 18 years of
5: Centre of the lower end appears at the end of the 9th month (the
time of birth) and unites with the shaft at about 20 yrs.
70
What are the ossification times of the patella?
Centre appears at 3 years and ossification is complete soon after puberty
71
What are the ossification times of the tibia?
Primary centre of the shaft 8 weeks intra-uterine life.
Upper epiphysis: immediately after birth and joins with the shaft at about 20 years Secondary centre for the tuberosity: about puberty
Distal epiphysis: 2 yr. joins the shaft at about 18 yrs
72
What are the ossification times of the fibula?
appears at 8 weeks fetal life
| Proximal end 4th yr. fuses with the shaft at about 20 years Distal end 2nd yr. and fuses with the shaft at about 18 yrs.
73
What are the axial relationships F, T, FC, TP, FA and TA in the xray of the knee?
F: Femoral Shaft Line- Line mid-axis femoral shaft.
T: Tibial Shaft line- Line mid-axis tibial shaft.
FC: Femoral Condyle Line- Line tangential to articular surfaces of condyles.
TP: Tibial Plateau Line- Line through medial and lateral tibial plateau margins.
FA: Femoral Angle- Angle between femoral shaft and femoral condyle lines.
TA: Tibial Angle (TA)- Angle between tibial shaft and tibial plateau lines.
74
What is the Q angle of men:women?
QA Men 14 degrees women 17 degrees
| Significance: Altered in a variety of biomechanical issues and pathologies.
75
What are you assessing in the Lateral Patella X Ray?
Patella Alta: High riding patella
| Patella Baja: Low riding pat
