Nonmechanical pathology Flashcards
if infection is suspected, what should you look for in radiological images of soft tissue?
soft tissue swelling, ulcers, subcutaneous air, skin thickening, cellulitis abscesses, fluid
if bone infection is suspected, what do you look for in images?
periosteal reaction, destruction
septic arthritis
infection involving a joint
bone infection
osteomyelitis
first line test for infection? 2nd line test (more sensitive)?
First line: X-ray (often negative); Second line; MRI or nuclear medicine bone scan
when looking for infection on MRI, what should you look for?
abnormal fluid collections and marrow edema
imaging signs of OA/DJD/Secondary arthritis
- loss of articular cartilage
- joint space narrowing
- osteophyte formation
- sclerosis
- subchondral cysts
most common jts for DJD/OA?
WB jts-hips, knees
Hands
Jts less frequently affected by DJD?
shoulder
RA: about
chronic autoimmune inflammatory disease; immune complex disease; characterized by joint swelling, joint pain and destruction; synovial inflammation
How is RA best diagnosed?
Classification criteria for RA; American College of Rheumatology (2010)
Categories of classification for RA
Joint involvement (# of jts involved, large vs. small jts); serology; acute phase reactants; duration of sx
Radiographic findings-RA
bilateral, proximal process; soft tissue swelling, osteoporosis, joint space narrowing, marginal erosions (away from WB portion of jt)
do you need an XR or MRI to diagnose RA?
NO: use classification scale; imaging shows response to tx, severity of jt damage
about gout
Gout caused by hyperuricemia resulting in deposition of monosodium urate crystals
Types: primary (inborn error of metabolism); secondary (disorders affecting urate metabolism-alcoholism); acute (mimics septic arthritis-jt swelling and pain); chronic (tophi erode bone)
Common sites: 1st MTP 90%; metatarsal, olecranon bursitis
Radiographic features of gout
Tophi: eccentric soft tissue swelling, usually not calcified; erosions with overhanging edges: reactive bone around a tophus, occur far from joint; joint space PRESERVED b/c deposition in articular cartilage is focal; narrowing only occurs late in the process
Bisphosphonate-related atypical femoral fx: etiology
bisphosphonate: osteoporosis medication; reduces bone resorption resulting in increased bone mineral density; but also suppresses normal bone turnover resulting from normal activity; atypical fracture risk increased
types of atypical fx related to bisphosphonate: radiologic signs
focal lateral cortical thickening: stress or fatigue fx involving cortex of bone
transverse fx
medial femoral spike: sharp medial cortical projection, typically arising from distal femoral segment
lack of comminution
