Medical Imaging Flashcards
(53 cards)
Which Imaging techniques do not use radiation?
Magnetic Resonance and Ultrasound
How do plain films work?
X ray tubes shoot high energy electrons at target. Electrons go around Tungsten atom and lose energy. Occurs by Bremmstrahlung and K shell knockout. This changes the energy of atom leading to radiation and x ray formation
Live images being obtained while a procedure is performed. Uses fluorescent plate, image intensifier, and TV camera…
Fluoroscopy
High frequency sound ways that reflect to make image in real time..
Ultrasound
Demonstrate speed and direction of flow in a vessel…
Doppler image
Small X ray sensors that take multiple pictures and computers compile many images…
Cat Scan
4 advantages of CT
Covers all anatomic areas, no oral/IV, quick, and can detect different densities
4 Disadvantages of CT
Ionizing radiation, cost, lack of availability, hampered by metal
What do you use CT/MR for?
asymmetry, masses, midline shift, or fluid collection
Would you use CT or MR for calcium or acute bleeds?
CT
Would you use CT or MR for subacute or chronic bleeds or spinal compressions?
MR
How does MR work?
Uses magnetic field and radiofrequency to obtain image. The magnetic field causes protons in body to line up and the high frequency shifts them from being straight. An antenna measures the resonance
What are differences between T1 vs T2 weighted MRI?
Water is white (bright) on T2 and Dark on T1. Bone is dark on T2 and bright on T1. Repetition time Short TR/TE is for T1, and long TR/TE is for T2
When do you use T1 vs. T2?
T1 for air, bone, blood, tissue. T2 is for fat, hemorrhage
When to NOT use MR?
aneurysm clips, pacemakers, artificial valves, exposure to metal
Cervical image on T1
Bone is bright
Cervical image on T2
Bone is dark
Interventional Radiology purposes
angiography visualization, biopsy, stents
complications: hemorrhage, embolus, infection
How does Interventional Radiology work?
dye is administered via catheter, x ray images can show things like stenosis, abnormal vessels, or tumors
When a small amount radioactive isotope is given via IV. These isotopes bind to certain molecules and allow images to be obtained
Nuclear Medicine
When regions take up a lot of isotope?
acute fractures, metastatic disease, growth plates. Use for infections looking at liver/thyroid
Describe the normal radiologic anatomy of the boney spine and the spinal cord as it appears on CT, MRI and x-ray and when to use
Xray is first line, then CT is good for trauma/fracture and myelograms, and MRI is most effective for marrow, discs, and ligaments
structures that surround cord as well as have facet joints for flexibility
posterior arch
Posterior arch includes what structures?
2 pedicles (connect body to lamina), 2 lamina (spinal canal attachment to ligament flava), 7 processes in lumbar (2 transverse, 1 spinous, 4 articular)
