Imaging: XR, MRI, CT, etc.. Flashcards
B-I-L
Border, Interface, Line
Use when looking at tissue densities
B-I-L
Wider differences in density lead to…
Sharp Borders!
B-I-L
Similar densities lead to….
Fuzzier Borders
Planes of Imaging
Know these to communicate with your colleagues!
Imaging Technique:
Film in relationship to your patient
Closer to the film: Sharper, Less Magnification
Further from Film = Less Sharp, Greater Magnification
AP View/PA View
AP View = Heart is magnified (b/c the heart is an anterior structure)
PA View = More accurately assess Heart Size; higher quality
Know which view you are looking at!!
Know what view you are looking at!
Is it:
- PA?
- AP?
- Lateral?
- Oblique?
- axial?
- 30° cephalad angulated…?
Know the Patient’s History
This will provide information on what views to order/should you order Additional Views?
Side note: Always let x-ray tech know if an image is bad/needs a change
Sunrise View of the Knee
Aquired if patient can tolerate knee flexion
A.K.A Skyline view
Waters’ View
(Occipitomental view)
Gets a good like at the Sinuses.
Also diagnostic of an orbital blowout (‘teardrop sign’.)
Good technique is crucial!
Shape distortion can occur from unequal magnification!
Develop a Logical Approach!
- Know image type
- Know view/side
- Understand limits
- Confirm name, DOB, side of body
- Review hx & past films
More on Logical Approaches…
- Determine/Describe abnormal images
- Consider all Differential Diagnoses
- Don’t jump to conclusions
- Consider differntial possibilities… Remeber the man who had the seed growing in his lung, yikes!
X-Ray Types
- Plain X-Ray
- Mammogram
- DEXA
- Fluoroscopy
DEXA SCAN
- Low dose x-ray scan
- X-ray energy absorbed by bone mineral
- Measured & mineral content is calculated
-
Used for Osteoporosis/Osteopenia
- Looks at Bone Density - lower dose
- NOT a Bone Scan
- Generates a T-Score
- Looks at Bone Density - lower dose
Mammograms
- Detects Breast Cancer
- Radiographic exam w/ PE
- False positives in younger patients b/c Denser Tissue
- Lots of radiation exposure
- Digital imaging is so clear vs. film!
Fluoroscopy
- Continuous beam of x-ray through patient
- Real-time visualization
- Moving structures!
- Contrast studies, guided procedures
- Used for:
- Swallow studies
- Heart angiograms
- Minimally invasive back procedures
- etc…
CAT SCAN
Don’t say that in the field!
Meow!
Metal in a CT Scan
Metal is okay to go in a CT Scan, but can cause an Artifact!
CT with Contrast
- Used to highlight differently/see layers
- Liquid substance taken PO or IV
- Helps tissue/organ be seen in detail
- Be careful of:
- Obstructions!
- Perforations!
CT, Reformatted
3-D Reconstruction
- CT taken in various planes
- Reformatted in 3-D
- Can be Rotated!
Nice Job!! Take a Deep Breath….
We’re better off than some People…
CT Scan
- Focused radiographic info for ONE slice of the patient
- Range of densities
- Know the different densities of various tissues & organs
- Studies of chest or abdomen can happen w/in 10-90 seconds! Wow.
- Protocols for specific body regions/clinical conditions
**Patient’s Left is on the Viewer’s Right
***View looking from Feet up
Magnetic Resonance Imaging (MRI)
- Powerful magnets; H+ atoms
- Sit Incredibly Still!!
- TAKE A GOOD HISTORY BEFORE AN MRI
- Do not want metal artifacts/ferromagnetic implants in MRI
- Pacemaker - NO!
- Bullets - NO!
- Surgery w/metal implant- NO!
- Do not want metal artifacts/ferromagnetic implants in MRI
- MRIs cost $$money$$
MRI
- No Ionzing Radiation
- Produces images in numerous planes
- Great differentiation of soft tissue structures
MRI
- High signal strength = white items
- Low = dark items
- Compact bone & moving blood = black
- T1 weighted images
- Fat appears bright
- T2 weighted images
- Liquids, tumors, inflammatory masses bright
MRI - Application of use
Multiple Sclerosis - MRIs taken often to see how lesions are changing in the brain
MRI Imaging with Angiography!
“MRA”
- MRA - used for vessels
- Helps ID Abnormalities & Dx Atherosclerotic Disease
- Use Gadolinium for contrast material
Contrast MRA
- Used in:
- Cancer
- specifically w/ metatases concerns
- Lesion types
- Breaches of Blood-Brain Barrier
- MS - demylination plaques
- Cancer
Ultrasound
- Image of a slide of body
- High frequency sound waves
- Beam reflects against density of material
- Can view images in Real-time!
- Air & bone cannot be adequately visualized
- No radiation!
Ultrasound:
Echogenic/Hyperechoic
& Echolucent/Hypoechoic
- Echogenic/Hyperechoic: Solid organs w/ acoustic interfaces; reflect sound
- Echolucent/Hypoechoic: Fluid-filled organs/structures lacking reflectors
Ultrasound
- Images aren’t super sharp/clear
- No radiation
- Portable, less expensive
- Multi-planar views
- Can record in Real-time!
- Good operator = Good quality!
Radioisotope (Nuclear) Scanning
- Inject radioactive isotope
- Visualize tissue, organs
- Can use for bone
- Involves a chemical substance that is normally involved in organ’s metabolism
- Iodine - Thyroid scans
- Albumin - Pulmonary studies
- Blood - myocardial studies
- Glucose - PET Scans
- Short half-lives -
- Remain only for imaging
A Tagging System…
Radioisotope (Nuclear) Scanning
- 2-Part Study:
- Get IV injection & Wait after injection
- Let Patient know
- Get IV injection & Wait after injection
- Will also take a picture after isotope is no longer emitting in body
- for a compare/contrast
Angiograms
Imaging of Arteries or Veins
Different Types: Conventional, MRA, CTA, DSA
- Digital - like conventional, but saved digitally… whoaaa. Also, substracts “noise”
- MRA - MR images made into 3D vascular images; safer for patients in renal failure
Hope you’re having fun!!
SOME MSK PEARLS!!!
- Fat Pad Sign
- “Sail Sign”
- By the radial head
- =’s Radial head fracture!
- By the radial head
- “Sail Sign”
Salter Harris Classification!
Straight Above beLow Through CRushed!
- I. Straight = compression
- II. Above the growth plate
- III. Below the growth plate
- IV. Through distal & proximal
- V. Crushed - growth plate collapsed
Ex: Slipped Capital Femoral Epiphysis (SCFE) = Type I Salter-Harris Fracture
Growth Plates
a.k.a Epiphyseal Plates
- Growth plate = Epiphyseal plate
- Growing tissue near both ends of long bones in children/adolescents
- Determines:
- Length & Shape of mature bone
- Weakest area of the growing skeleton
Fracture Types
Crescent Sign is indicative of…
Avascular Necrosis
- At Femoral Head
- Lack of circulation destroys bone
- Cresent Sign = bone already destroyed
- Pain in AVN may radiate to groin (even the knee)
Compression Fracture of Thoracic Vertebrae
- Caused by excessive force on vertebral body
- Forward & downward pressure on spine
- Bone collapses & anterior portion forms a wedge shape
- Can be extremely painful & cause numbing!!
Stenosis of the Carotid Artery - MRA
X-Ray - Right Lower Lung Pneumonia
Hand X-Ray w/ labeling (For reference)
Foot X-Ray with labels (for reference)
X-Ray with Left Hip Osteoarthritis
Good Luck Studying!!!
