ZENI-Dx Imaging Revisited in the Context of Diff Dx Flashcards
Radiology Value for PTs
4:
- Screening for patho + dx standpoint
- Info for Eval+Treat
- Improved pt confidence in YOU!
- Essential for autonomous practice
Some common studies (imaging)
- Radiographs→ X-rays
- Contrast-Enhanced Radiographs
- Computed Tomography (CT)
- Nuclear Imaging
- Magnetic Resonance Imaging (MRI)
- Ultrasonography
RadioLUCENT means getting ______
DARKER
RadioOPAQUE means getting_________
LIGHTER
RadioLUCENT means DECd ______
Radiographic density
RadioOPAQUE means INCd _________
Radiographic density
For Radiographs….
DARK (radiolucent, DEC radiographic density) images→ LiGHT (radioopaque, INC radiographic density) images
- AIR→ darkest
- Metal→ lightest
NOTE: Air (darkest)→ Metal (lightest)= INC’ing obj radiodensity
NOTE: Metal (lightest)→ Air (darkest)= DEC’ing obj radiodensity
W/ radiographs……..
Need _________ one image
MORE THAN ONE! Multiple views
Routine Exam Scenarios
What are the outcomes after using imagining to inform your dx?
- Positive for suspected dx
- Negative for suspected dx
- Negative for dx, but diff prob ID’d
- Inconclusive→ further imaging reqd
- When?→ not giving you answers you need or no does not match sx’s
- Next?→ MRI, CT, etc..
Case Ex.→ Post-FOOSH
Pt fell and had shoulder injury. X-ray taken.
Name everything you see/what is it?
*Bone tumor
- Bulge @ tumor site
- Growth plate not fully closed→ child patient
Image Ex.
- Trauma, young
What do you notice?
Bone spur @ calcaneus
What do you notice? Which is abnormal? Why?
Left looks good
Right bad→ Decd joint space
How does imaging inform the use of partial over TKA?
- No global OA, Iso’d to single compartment, no huge bone spurs, sclerosis (thickening), abnorm alignment
- *Buys this pt time to get back to rec, vocational activities before s/he progresses to ultimately needing TKA (often ultimate outcome)
What do you see?
L. clavicular fx
Why might this repair cause probs for patient?
- Screws/plates→ VERY superf→ pain, visible
- Concerns w/ brachial plexus probs if residual abnorm in shape of bone
- Imaging used to sx decision making→ realignment necessary? How approximated are edge of bones in fx?
US utility in fx→ Only in ________ cases
SUPERFICIAL
US utility in Fx- only in superficial cases
- Clavicle is so superficial, US imging can be helpful in ID’ing fx’s
- Clear breach of clavicular cortex near is medial end+ associated adjacent soft tissue edema
Knee Skyline View
Takeaways?
Bone spurs→ abnormal “load”
In response to this new “load”: MORE bone→ bone spurs→ MORE bone (cortical thickening)
Post-op TKA w/ Lateral Knee Pain
Notice L. patella and spacing with the prosthesis
What do you see here ?
Loss of disc space
Sclerotic PLL → + excessive bone formation
The Scotty Dog
What makes the neck of the dog?→ Pars Interarticularis
Dog with a collar?→ Stress fx
Dog w/ a broken neck?→ Spondylolysis, *also look for displacement of the vertebra (possible SC/Cauda equina impingement)
What do you see?
R. femoral head AVN → flat (collapsing) R. femoral head
Whats this?
B/L THA
Whats this?
B/L THA
L. side→ HO (calcification)- had to use much larger prosthetic piece deeper into femur
What do you see?
Ask!!!!
X-Ray Viewing
Pros vs. Cons
-
PROS:
- INexpensive
- Relatively available
- Fair→Good Sn in detecting Fx
-
CONS:
- Radiation
- Missed patho*
- Dependent on skill lvl to get proper study
Non-Ionizing→Ionizing (Bad radiation)
see pics
Medical Procedure Doses: Radiation
HIGHEST→
LOWEST→
HIGHEST→ Nuclear Medicine
LOWEST→ X-rays
Other form of X-Ray Imagining
Contrast X-ray Studies
Other form of X-ray Imagining:
Contrast X-ray Studies
What is it + Types
Injection of radio-opaque liquid INTO area of interest
- Arthrogram→ Joint
- Myelogram→ Spinal Column
- Angio/Arteriogram→ Artery/Vessel
Like an X-ray, BUT 100’s of X-rays all around body
Computed Tomography (CT scan)
CT of Lungs Ex.
Soft tissue + Bony anatomy
see pics
3D Reconstruction CT Scan
Radial Head Fx
see pics
CT Scans
PROS vs. CONS
-
PROS:
- Soft tissue + Tumors
-
3D reconstruction*
- visualization of subtle & complex fxs
- Bone Mineral Density (BMD) test
- DEXA→ MUCH LESS radiation
-
CONS:
- Avg volume effect
- discerning subtle diff’s in small tissue volumes
- tumors of similar tissue density NOT visualized
- Artifacts
- patient mvmt, metal implants
- Radiation exposure
- Avg volume effect
Nuclear Imagining aka
Bone Scan (Scintigraphy)
Nuclear Imagining:
Bone Scan (Scintigraphy)
- Injection of polyphosphate and radioactive isotope (tracer) binds to hydroxyapatite found in metabolically active bone.
- Pinpoints molecular activity w/in body
- Pot. to ID disease in earliest stages
- Before things “look” bad (think MRI or Xray), there may be underlying changes in physiology
- Detecting bone tumors and metastasis
- Early detection of Stress Fx’s
Three-phase Bone Scan measure __________, NOT ___________
Measure physiology, NOT anatomy
Three Phase Bone Scan
3 phases?
A) Perfusion phase
B) Blood pool phase
C) Delayed pool***
Three-Phase Bone Scan
All 3 phases
- A) Perfusion phase
- occurs in seconds
- can look @ blood flow
- B) Blood Pool phase
- occurs 5-30mins
- where does blood end up in soft tissue
- aka soft-tissue phase
- C) Delayed Pool
- looks @ metabolic activity of bone
- AKA bone phase or sequestration phase (looks @ bony uptake)
- Cx, Stress fx
Three-Phase Bone Scan
A) Perfusion Phase
- A) Perfusion phase
- occurs in seconds
- can look @ blood flow
Three-Phase Bone Scan
B) Blood Pool Phase
- B) Blood Pool phase
- occurs 5-30mins
- where does blood end up in soft tissue
- aka soft-tissue phase
Three-Phase Bone Scan
C) Delayed Pool
- C) Delayed Pool
- looks @ metabolic activity of bone
- AKA bone phase or sequestration phase (looks @ bony uptake)
Bone Scans
PROS vs. CONS
-
PROS:
- Image based on physiology
- provides info not obtained from anatomical studies
-
Detects:
- Stress fx’s, Metastatic bone CA, Bone dis’s and infx’s
- Image based on physiology
-
CONS:
- Lacks specificity for diff dx
-
NOT an end study→ req’s correlation
- Not the end of the diff dx pathway!
-
Exposure to radiation
- actually emitting radiation until it is discharged from body
This is the Evolution of Bone Scans
(Like how CT is evolution of X-ray….this is evolution of Bone Scans)
Single-Photon Emission Computed Tomography (SPECT)
Incs _Sensitivity_ and _Specificity_ compared to Bone scan
See Case Description
See Imaging
*B. CT on top, SPECT bottom
SPECT for MSK Conditions (PARS Dysf.)
Bone Scan on LEFT
SPECT on RIGHT
*NOTE: INCd ability to ID lesion w/ SPECT
see pics
Scintigraphic findings in a patient w/ R. L5 pars stress fx on SPECT (A)
NOT see on planar bone scintigraphy (B)
see pics
SPECT Summary
Key Takeaways
4:
- Important Advance in the field of Nuclear Medicine
- ID’s areas of high bone metabolism (turn over)
- Can be coupled with CT and MRI*
- *SAME limitations as bone scans!
- # Radiation
SPECT Summary
Advancement in field of Nuclear Medicine
- INCd sensitivity/specificity of ID’ing lesions
- Can locate even very small abnorms*
SPECT Summary
ID’s areas of high bone metabolism (Turn-over)
- Occurs in areas where bone is over-loaded→ Stress fx’s, stress conditions
- Also occurs in areas of tumors where there is a high rate of bone metabolism
SPECT CAN (note “Can be”) BE coupled w/____ and _____
CT and MRI
Positron Emission Tomography (PET)
Measures what?
Measures Photon Emission from tracers
- Flourine-18 linked to glucose== MOST COMMON tracer*** (good for soft tissue*)
- Dramatically expands physiology studies to soft tissue (think about SPECT, but NOW we can look @ metabolic issues in soft tissues, NOT JUST BONE*)
PET is also OFTEN (note “often coupled w/”) coupled w/ _____ and _____
CT and MRI
PET Scan
Complex and Costly to perform
SHORT half-life of the tracer
PET Scan MOST OFTEN used to what?
ID and Stage Cx
- Can localize lesion
- Can help w/ Sx planning***
PET Scan
Combining PET scan w/ MRI or CT scan can help make images easier to interpret.
LEFT→ CT
CENTER→ PET
RIGHT→ PET-CT
*Bright spot in the chest==> Lung Cx
Ex. PET vs. MRI vs. PET/MRI
Diagnostic Ultrasound
Common use….BABIES! `
Dx Ultrasound Ex.
Supraspinatus
see pics
Dx Ultrasound
What is it?
Using sound waves to recreate a 2D image of tissue under the probe
GREAT for: superf tears, suprasp, Achilles
Dx US
MSK Imaging vs. Doppler US
-
MSK:
- Tendon tears/recovery, MM tears, Calcific tendinosis, masses or fluid collections, Joint or bursal effusions
-
Doppler US:
- Measures velocity of blood flow→ Suspected DVTs***
*See pic for Calcific tendinitis example
Dx US
Achilles Tendon Rupture
Left→ Normal
Right→ Rupture+hemorrhage
KEEP LOOKING UNTIL YOU “GET IT” YOU GOT THIS!
YOUTUBE HOW TO READ/INTERPRET!!!!
MRI aka
Magnetic Resonance Imagining
Measures energy of Hydrogen atoms
MRI
MRI
FACTS
- Measures spatial distribution of protons from hydrogen atoms in the body when excited by radio freq waves in a magnetic field
- Signal emitted→ Nuclear Magnetic Resonance (NMR)
- Radiowaves “tuned” to change NMR in order to visualize diff types of tissues
MRI is GREAT FOR:
SOFT TISSUE!
AND… NO Ionizing radiation!!!!
T1 MRI vs. T2 MRI
Key diffs to help remember
- T1→ FAT really bright
- T2→ WATER really bright
Measures energy from structures such as FAT
T1 MRI
Measures energy late in decay of transverse relaxation and selectively images structures that do not readily give up energy→ such as WATER
T2 MRI
T1 MRI:
- Measures energy from structures such as FAT→ gives up energy rapidly→ EARLY in process of remagnetization
- Provides images of good ANATOMIC detail→ displays tissues in fairly balanced manner
T2 MRI
- Measures energy LATE in decay of transv. relaxation and selectively images structures that DO NOT readily give up energy→ WATER
- *Particulalry valuable in detecting INFLAMMATION!! → BC fluid is brighter
T1 Image components broken down
ex. ankle/foot
Fat→ HIGH signal (Bright)
Cartilage→ LOW signal
Cortical Bone→ LOW signal
Fluid→ LOW signal
T2 Image components broken down
ex. ankle/foot
Fat→ LOW signal
Cartilage→ LOW signal
Cortical bone→ LOW signal
Fluid→ HIGH signal (Bright)
MOST COMMON contrast used in MRI imaging
Gadolinium (Gad for short)
- Shorten the relaxation time of most tissues
- INCs intensity of T1
Gad (contrast) inc’s intensity in ____ image
T1
MRIs and Contrast
Gadolinium most common*
- Usually IV
- Adverse rxns possible
- Nephrogenic systemic fibrosis in pts w/ renal failure or kidney disease
Contrast is MORE COMMONLY USED in…….
NON-MSK applications
Magnetic Resonance Arteriogram (MRA)
Uses and Ex.
- Aneurysm, Aortic stenosis, Aortic dissection (or bleed), Stroke site, Coronary blockage, Vessel stenosis (Renal artery stenosis, Peripheral vessel stenosis of arms/legs)*
MRA Ex’s
see pics
ID this condition
**Vesicular based Thoracic Outlet Syndrome (TOS)
*Note: blockage of vessel in L. image
fMRI most commonly used in…
Brain tissue
fMRI
Facts
- Common use→ brain tissue
- Measures→ change in blood oxygenation and blood flow
- Uses BOLD contrast
- DeO2’d Hb= magnetic
- O2’d Hb= resistant to magnet
- Looks @ HOW tissue using O2
- shows areas actively using O2 more/less vs others
- ACTIVE areas of brain/SC create INC in blood flow
Chronic Back Pain and active brain regions
During spontaneous LBP, pts had INCd activity in brain regions assocd w/ suffering/sense of self.
This was different when SAME pts (+controls) experienced thermal types of pain
Moral of story: move towards emotional, behavioral tx’s for LBP
see pics!!!
MRI
PROS vs. CONS
-
PROS:
- NON-ionizing radiation
- Ideal for soft tissue
- Great resolutions w/ higher lvl magnets
-
CONS:
- Noise
- Claustrophobia
- Contraindications (ex. metal implants, joint replacements)
Acute Trauma MSK “Rules”
ADD EACH AS A SLIDE WHEN YOU START STUDYING!!!!
- Ottawa Ankle and Foot Rules
- Ottawa Knee Rules
- Pittsburgh Decision Rules
- Cervical Spine:
- NEXUS Low Risk
- Canadian C-Spine (pictured below)
