musculoskeletal imaging Flashcards
1
Q
osteoblasts
A
cells that build bone tissue
2
Q
osteoclasts
A
cells that break down bone tissue
3
Q
osteocytes
A
the cells that maintain bone tissue by controlling mineral and calcium homeostasis
4
Q
compact bone
A
hard, smooth outer cortical layer protects the tissue within
5
Q
spongy or cancellous bone
A
porous, honeycombed material inside the medullary cavity of most bones
provides strength yet is lightweight
6
Q
otic capsule
A
aka. osseous labyrinth
dense bone of the petrous temporal bone that surrounds the membranous labyrinth of the inner ear
contains the most dense compact bone tissue in the human body
7
Q
bone matrix
A
non-living extracellular matrix
8
Q
bone matrix is made up of
A
- water
- hydroxyapetite
- collagen fibres
- other minerals, such as calcium carbonate
9
Q
what gives bone matrix hardness
A
hydroxyapetite
10
Q
what gives bone matrix flexibility
A
collagen fibres
11
Q
bone marrow is
A
haemotopoeitic organ
produces blood cells
12
Q
types of cells produced by bone marrow
A
- erythrocytes
- leucocytes (WBC)
- thrombocytes - platelets
13
Q
structure of long bones
A
- articular cartilage
- proximal epiphysis
- metaphysis
- diaphysis
- metaphysis
- distal epiphysis
- articular cartilage
14
Q
4 different types of bones
A
- long bone - long, thin eg. arm and leg bones
- short bone - squat, cubed eg. wrist and ankle bones
- flat bone - flattened, borad surface eg. scapula, ribes, sternum
- irregular bone - does not conform to one of these types eg. vertebrea
15
Q
nutrient canal of a long bone
A
nutrient foramen
nutrient canal
contains the nutrient arteries and veins
16
Q
nutrient canals are found in
A
- diaphysis of long bones
- mandible
- dental alveoli
17
Q
periosteum
A
a dense membrane that covers the outer surface of all bones , except the articular surfaces of long bones
18
Q
endosteum
A
lines the inner surface of the bony wall and covers the bone marrow cavity
19
Q
exception to periosteum and endosteum
A
- double layered structure of dura mater
20
Q
how many bones in the human body
A
206
213 if you view the sacrum as one or 5 bones
21
Q
bones in the skull
A
22 bones total
8 cranial bones
15 facial skeleton bones
22
Q
vertebral column bone
A
33 total (26 in adults) 7 cervical 12 thoracic 5 lumbar 5 sacral (fused in adults) 4 coccygeal (fused in adults)
23
Q
thoracic vertebrae bones
A
2 x 12 ribes
3 bones in ther sternum (manubrium, body, xiphoid)
24
Q
features of the skull - caudal side
A
25
sinuses
26
curve of cervical spine
lordotic
27
curve of thoracic spine
hyphotic
28
curve of lumbar spine
lordotic
29
curve of sacral and coccygeal spine
kyphotic
30
pectoral girdle bones
```
2 bones (clavicle and scapula)
3 joints (sternoclavicular, acromioclavicular, and glenohumoural)
```
31
the upper extremity bones
1 bone of the arm - humerous
| 2 bones of the forerm - ulna and radius
32
hand bones
27 bones total
8 carpal bones
5 metacarpal bones
14 phalangeal bones (4x3 fingers, 1x2 pollux)
33
pelvic girdle bones
os coxae (3 fused bones; ilium, ischium, and pubis)
34
the lower extremity bones
thigh bones - 2- femur, patella
| lower leg bones - 2 - tibia, fibula
35
bones of the feet
```
2 x 26 total
7 tarsal bones
- calcaneus and talus
- 5 midfoot tarsals
5 metatarsal bones
14 phalangeal bones (4x3 toes, 1x2 hallux)
```
36
fibrous joint
adjacent bones are united by fibrous connective tissue, e.g. sutures in the skull
a syndesmosis is a fibrous joint in which the adjacent bones are linked by a strong membrane or ligaments e.g. distal tibiofibular syndesmosis
37
syndesmosis
a fibrous joint in which the adjacent bones are linked by a strong membrane or ligaments e.g. distal tibiofibular syndesmosis
38
cartilaginous joint
bones are joined by a hyaline hyaline cartilage (synchrondosis) or fibrocartilage (symphysis)
39
symphysis
symphysis pubis, intervertebral discs, sacrococcygeal symphysis
40
synchrondrosis
epiphyseal plate of growing long bones, spheno-occipital, ischiopubic, manubriosternal synchondrosis
41
synovial joint
the articulating surfaces of the bones are not directly connected, but instead come into contact with each other within a joint cavity that is filled with a lubricating fluid
42
general structure of a synovial joint
43
uni-axial joints
synovial joint allowing motion around a single axis
| pivot (C1/2 articulation, radius/ulna rotation) or hinge (elbow)
44
bi-axial joints
condyloid (radiocarpal and metacarpophalangeal joint)
| saddle (thumb joint)
45
tri-axial joints
ball and socket (hip and shoulder)
| plane (intervertebral disc)
46
pivot joint
allows rotation around a single axis
C1/2 articulation
radius/ulna rotation
47
hinge joint
```
allows flexion and extension
elbow (between humerous and ulna)
interphalangeal joints of the hand and foot
knee joint
ankle joint
```
48
condyloid joint
a condyle is a round, elliptical or ovoid prominence at the end of a bone that serves as an articular surface which is received into an elliptical cavity
49
condylar articulations are found
```
knee (medial and lateral condyles of the femur and tibia)
elbow joint (humerous condyle)
temporomandibular joints (mandibular condyles)
atlanto-occipital joint (occipital condyles)
```
50
saddle joint
a type of synovial joint in which the opposing surfaces are reciprocally concave and convex
offers a wide range of motion, though axial rotation is not possible
51
examples of saddle joints
carpometacarpal joint of the thumb
sternoclavicular joint of the thorax
incudomallear joint of the middle ear (anvil-hammer)
calcaneocuboid joint of the heel
52
tri-axial plane joint
the intervertebral disc
| a cartilagenous joint that unites the bodies of two adjacent vertebrae
53
3 types of muscle tissue
skeletal
smooth
cardiac
54
skeletal muscle
voluntary and striated
| muscle that attach to bones and control conscious movement
55
smooth muscle
involuntary and nn-striated
| in the hollow organs of the body, such as the GI tract and in the walls of the blood vessel
56
cardiac muscle
involuntary and striated
| only found in the heart
57
nuclea medicine
functional imagin technique
a radionuclide is labelled to a molecule, which is responsible for its biodistribution (radiopharmacuticals)
often referred to as tracers as the molecule itself is administered in subtherapeutics quantities, and has no direct biological effect
it is instead used to study or visualise a physiological process
58
radiopharmacuticals are administeress
usually IV
| may be inhaled, ingested or injected into specific sites
59
gamma rayss
ionizing electromagnetic radiation that originates in an unstable nucleus
gamma rays are photons of energy originating in a nucleus
x rays are photons of energy originating outside of the nucleus
gamma rays have a wide range of energy
the energy for each radioisotope is discrete and defined by the decay scheme
60
iodine 123
gamma emitter - 13 hour half life, used for imaging
61
iodine 125
gamma emitter
| 60 day half life, not used for imaging as half life is too long
62
iodine 131
gamma and beta emitter
used for imaging and therapy
8 day half life
63
radiation protection
the patient is the radiation source - they become radioactive
physical properties of the nucleotide - how radioactive it is
time/distance - radiation exposure is inversely proportional to the square of the distance
shielding - gamma rays shielded by lead, beta particles are shielded by perspex
biological factors - excretion (urine, saliva)
63
radiation protection
the patient is the radiation source - they become radioactive
physical properties of the nucleotide - how radioactive it is
time/distance - radiation exposure is inversely proportional to the square of the distance
shielding - gamma rays shielded by lead, beta particles are shielded by perspex
biological factors - excretion (urine, saliva)
64
2 types of gamma cameras
dynamic imaging
| static imaging
65
dynamic imaging
short acquisition times per frame, allow a cine view of activity over time. this is performed after injection, and reflects blood flow and changing biodistribution
66
static imaging
acquired at a single timepoint when biodistribution is usually stable
67
2 types of static imaging
planar imaging - 2D imaging - the patient is moved through the camera detectors
SPECT - (single photon computerised tomography): 3D imaging. the detectors rotate around the patient to create a 3D image
68
timing of imaging
nuclear medicine images the biodistribution of a radiopharmaceutical in a patient
- immediately following administration (eg. bone scan - blood flow)
- after delay period for steady state (bone scan 2-4hr, gallium citrate 48hrs)
69
administered activity of radiopharamcuetical is determined by
test requirements
| adjusted according to patient weight and/or age
70
ALARA principle
as low as reasonably achievable
71
pregnancy and breast feeding
some tests will be absolutely contraindicated and others can be performed but are modified for pregnancy and breastfeeding
72
impaired renal function
impaired renal function is usually not a contra-indication for nuclear medicine imaging, as the radioisotopes decay with short t1/2
73
drug allergy/ allergic reactions
nuclear medicine radiopharmaceuticals are administered in tracer doses and it is extremely rare to have any side-effects or allergic reaction
74
technetium-99m
the most common nuclear medicine radioisotope for imaging due to ideal imaging properties and flexible radiochemistry
physical half-life - 6 hours
gamma energy 140KeV (ideal photopeak for imaging)
generator eluted (molybdenum 99)
75
mechanism of uptake of Tc99m
- local blood flow (hyperaemia_
- bone repair
binds to hydroxyapatite during active bone formation
uptake reflects osteoblastic activity
76
patient preparation for a bone scan
non requred
77
restrictions for bone scan
no restriction for renal impairment and no interaction with medications
must not be pregnant
breast feeding - radiation excreted in breast milk, delay breastfeeding post scan
keep well hydrated and encourage to drink water on the day of test
78
after injecting radiotracer
1) image immediately for FLOW/BLOODPOOL to assess vascularity - for fracture or infection (performed only if clinically indicated)
2) delayed imaging (at 2-4 hours post injection) to assess for sites of increased osteogenesis/osteoblastic activity
79
radiation dose to pateint
6mSv (normal background radiation in perth is 2mSv per year)
80
indications
whole body or localised imaging can be performed
indications for a bone scan include
- oncology (metastases)
- orthopaedics (fracture, infection, assessment of joint replacements)
- rheumatology (arthritis)
- endocrinology (metabolic bone disease, paget's disease)
81
skeletal metastases
bone scan is commonly used for detection and follow up of skeletal metastatic disease in oncology patients
82
advantages for use of bone scan in skeletal metastases
whole body imaging, easily accessible, inexpensive
| sensitivity 79-86% and specificity 81-88% for detection of skeletal metastases
83
causes of false positives in skeletal metastases
fracture, degenerative change, benign bone lesion
84
commonest sites of bone metastases
```
axial skeleton (spine, pelvis, ribs, skull) and proximal appendicular skeleton (proximal long bones)
low sensitivity for lytic regions
```
85
superscan
widespread skeletall metastases
bone activity much higher than soft tissue or renal activity
activity prominent in axial and proximal appendicular skeleton
86
lytic metastasis
gap in activity on scan
87
bone scan has poor sensitivity in assessment of
myeloma
88
bone scan used for fractures
very sensitive for detecton of fractures
only used for evaluation of fractures which is difficult to assess on X-ray eg.
- stress fractures (sports, repetitive injury)
- osteoporotic fractures - vertebral compression fracture rib fracture, pelvic insufficiency fractures
- undisplaced fractures - neck of femur
89
undisplaced fractures
radiogrraphic features of undisplaced fracture may take days to weeks to evolve, however bone scan changes occur within 1-2 days of injury
90
periostitis
shin splints
usually shows minimal hypereamia on blood pool imaging
delayed imaging shows linear activity in posterior or posteromedial tibia
91
rheumatological bone scan
can be useful in the evaluation of sites of bone pain in pateints with arthritis and rhuematological conditions
- osteoarhtirits
- rheumatoid arhtiritis
- seronegative spondyloarthropathy
bone scan can localise site of pain and direct treatment
92
metabolic bone disease
```
diffuse increased bone activity
loss of soft tissue and renal outline
skull activty, perpheral bone involvement and periarticular activity are common
may be seen incidentally - important to recognise and differentiate from skeletal mets
dfferential disgnosis
- primary hyperparathyroidism
- renal osteodystrophy
- hyperparathyroidsim
```
