Download Dx Image Study Guide Test 1

Dx Image Study Guide Test 1
These are the notes I took at the tutor. These are the things she felt were the most
important/most tested. I would still know general stuff about all of the lines/measures he
has on the list. She mentioned if he had it on a quiz, most likely he won’t have it on the
test. She also said don’t worry about all the numbers, only know the ones she mentioned.
(ADI, prevertebral soft tissue, coxa vera/valga…) Take that advice for what it’s worth.
You never know!
Skull: Basilar invagination is when skull sits lower.
Stella Turcica: Pituitary mass causes enlargement.
Basilar Angle: Basilar invagination causes greater angle due to bone softening disease
(Pagets)
McGregors Line: Basilar invagination causes odontiod process to be above line more
than normal. Due to bone softening disease (Pagets, osteomalacia)
Chamberlin’s Line: Same as above
Digastric Line: Same as above
Cervical
Cervical Gravity Line: Drawn from odontioid, should pass through C7 body.
Georges Line: Drawn on posterior aspect of body on lateral cervical. Looks for fracture,
dislocation, anteriolisthesis or retro. Use posterior cervical line instead.
ADI: Odontiod process to anterior tubercle of C1. Know adult is 1mm-3mm, child
1mm-5mm. Increases with downs syndrome or RA.
Sagittal Dimension of Cervical Spine: Space btw spinolaminar junction and posterior
body. Small measurement could mean spinal cord stenosis.
Atlantoaxial Alignment: Looking for C1/C2 overhang. Odontiod fractures or alar
ligament instability when overlap. Children will have bilateral overhang.
Prevertebral Soft Tissue: Space in front of vertebral bodies in C spine. C2 is about 6mm,
C6 is about 22mm. Increase could be due to blood, pus, or cells. (blood-hematoma, pusinfection, cells-cancer)
Thoracic
Riser-Ferguson: Scoliosis evaluation, not preferred method.
Cobbs Angle: Scoliosis evaluation, preferred method.
Thoracic Cage: Posterior sternum to anterior of T8. Decreased measurement is called
straight back syndrome which can cause many health problems, mainly heart.
Thoracic Kyphosis: From endplates of T1 to T12. Kyphosis increases with age and
Scheuermann’s fractures.
Lumbar
Hadley’s S Curve: Done on A-P and oblique xray. If broken could be subluxation,
fracture, or dislocation.
Lumbar Gravity Line: Line from body of L3, should intersect with sacral base.
Meyerding’s Rating System: Used for grading anteriolisthesis, sacrum is divided into
quarters. Preferred method is percentage (more accurate and removes magnification)
Lower Extremity
Kline’s Line: Femoral head should intersect line, if not, slipped capital femoral epiphysis
(SCFE)
Shenton’s Line: Line should be smooth. Usually in children. SCFE, dislocation, or
fracture
Iliofemoral Line: Line should be smooth. SCFE , dislocation, or fracture
Teardrop: More than 1mm difference between the two sides is pathology. Legg-CalvePerthes (LCP), avascular necrosis of femur head.
Hip Joint Space: Measure of space from femur head-acetabulum (superior, axial, and
medial). Do not average. RA will have uniform change in all portions and OA the
superior portion is affected first.
Center Edge Angle: Line from center of femoral head and line to acetabular edge.
Shallow could be acetabular dysplasia or DJD.
Acetabular Angle: Decreases with down’s syndrome. Increases with congenital hip
dislocation.
Acetabular Depth: Decreased could be OA
Kohler’s Line: Protrusio Acetabuli. If acetabulum is medial to line, Pagets disease.
Pre-sacral Space: Blood, pus, cells will increase space.
Femoral Angle: <120 degrees is coxa vera, >130 degrees is coxa valga (coxa mean hip)
Skinner’s Line: Fovea below line could mean fracture.
Heel Pad Measurement: Increase is acromegaly
Boehler’s Angle: Angle <28 degrees is fracture or dislocation of calcaneus. Caused by
trauma (falls, jumping off shit….)
Upper Extremity
Glenohumeral Jt Space: Measures of superior, middle, and inferior space. Average due
to increased joint ROM. Decrease will be some type of arthritis (degenerative, posttrauma). Increase will be acromegaly or posterior dislocation.
Acromiohumeral Jt Space: Decrease is rotator cuff tear or degenerative tendonitis.
Increase is dislocation.
Acromioclavicular Jt Space: Decrease is DJD. Increase is RA, trauma.
General notes she pointed out
Know the + and – of plain film, CT and MRI
Plain film: attenuating, ionizing rad.
CT: attenuating, ionizing rad.
Bone Scan: emission
MRI: emission (H protons)
SPECT: emission
CT is to plain film as SPECT is to bone scan. Meaning: CT’s are slices of plain film,
SPECT are slices of bone scan.
To see bone loss:
Plain film needs 30-50% decrease in bone
Bone scan: 3-5%
MRI/CT: 1-3%
Plain film: best line/pair resolution
CT best with bone
MRI best with soft tissue
Bone scan: osteoblastic activity
Enchondral bone formation: increases length and ends when growth plates close
Intermembranous bone formation: increases width, we have into adulthood.
Know the parts of bone
**Imaging is for DOCUMENTAION not EDUCATION**
**Physical exam ALWAYS before xray (even with trauma….but just looking at patient
can be exam)
You need at least 2 views with xray. Need to be at right angles to each other.
Plain film misses fractures in the C spine often, C2 fracture is the most commonly
missed.
CT:
Bone window you see actual parts of bone (trabecular and cortical) soft tissue window
will see bone as all white.
Cortical bone is ALWAYS white on CT
Helical CT is fast, great bone detail
MRI:
CSF dark on T1
CSF white on T2 (H20)
Cortical bone is ALWAYS black on MRI
Know T1/T2 characteristics of TE and TR
Know 3-4 contraindications of MRI (needs to be non-ferrous metal)
1) pacemaker
2) steel workers
3) ear implants
4) claustrophobia
Know tumor table and terms
**cancer does not cross joint space**
Know the regulators of bone formation (calcium, Vit D, parathyroid, HGH…..)
She gave us a pneumonic to remember cervical obliques: POOP and ASS
Posterior Oblique you are looking at the OPposite IVF and structures
Anterior oblique you are looking at the Same Side IVF and structures
**lumbar obliques are exactly the opposite** Know Scotty dog structures