Radiology - Dykstra Flashcards
(29 cards)
imaging modalities for imaging of the upper extremity
radiographs ultrasound CT MRI arthrography nuclear medicine
radiographic density and clinical implication of air
black
- is it in normal or abnormal location
radiographic density and clinical implication of fat and water
fat (dark gray)/ water (light gray)
blood pus appear as water densitieis
both outline margins of organs
evaluate for additional non organ densitiies
radiographic density and clinical implication of bone
WHITE
evalue on every radiograph, CT, MRI
look for mineralized densities including stones
radiographic density and clinical implication of metal
BRIGHT WHITE
- foreign bodies, surgical clips
initial exam of chain in patients with history of
trauma
pain-acute or chronic
evaluating for radiopaque foreign body
RADIOGRAPH
which two hand boens should be in perfect alignment
capitate should be directly on top of lunate!!
this imaging is accessible, technologist dependent and uses no radiation
ULTRASOUND
evaluation of rotator cuff and long head biceps tendons joint fluid radiolucent foreign bodies-ie wood palpable abnormalities vascular structures
use ultrasound!!
US can also be used to
guide injections for MR or CT arthrograms or to administer steroids
accessible and fast axial acquisition reconstruction osseous detail radiation
computer tomography!!
CT densities are measured in?
hounsefield units
density of water air soft tissues compact bone
water - 0
air -1000
soft tissues -100 to +100 with fat below 0
compact bone +3095
CT window level
hounsfield unit set to middle gray
CT window width
range of gray scale
numbers below width - black
numbers above - white
wide CT window width used for
bones
narrow CT window width used for
soft tissue
indications for use of CT
complex fractures visualized with XR needing more detail prior to surgery
abnormal XR with questionable fracture
normal XR with suspected fracture
evaluating soft tissues (including rotator cuff tendons) in patients with MRI contraindications
slightly less accessible slower to perform all planes soft tissue contract high resolution no radiation
MRI
indications for MRI of upper extremity
suspected soft tissue abnormality: muscular, ligamentous, tendinous e.g. rotator cuff tear, biceps tendon tear
- suspected fracture with normal radiographs
- peripheral neuropathy
real time imagine
less accessible
radiation
can be used for arthrography procedures or in fracture fixation
fluoroscopy
indications for upepr extremity arthrography
suspected labral pathology
suspected rotator cuff patohlogy with normal or indeterminate MR without intra articular contrast
less accessible
radiation
radiopharmaceutical used to evaluate physiologic uptake/ activity
poor anatomic detail
nuclear medicine
used more for bone scan if metastasis suspected in patient
nuclear medicine
