Final Quiz Flashcards
(28 cards)
What are the indications for CT with myelography?
Thecal sac, nerve root (if MRI is not available) MRI is better
What are the indications for MRI with gadolinium?
Postoperative fibrosis (since scars will have increase in vascularization), recurrent HNP.
What are the indications for radionuclide studies?
To identify metabolic activity benign vs. aggressive, acute vs chronic mets and infections.
What is the best test for herniated nucleus pulposus?
MRI
What is the best test for spondylolisthesis?
Plain film
What are SPECT bone scan used for?
Exact location of a lesion
When would you use ultrasound to image the spine?
Only with neonates
Why would you take a CT or an MRI of the brain?
CT-SAH, acute subdural. MRI-MS, recent infarct, tumors, a VM’s, cerebral aneurysms.
Why would you take a CT or an MRI of the chest?
CT: CXR abnormalities, CA, fibrosis, PE
MRI: problem solving after CT
Why would you take a CT or an MRI of the abdomen?
CT: liver diseases/tumor, lymphoma, pancreatic CA, real colic
MRI: problem solving after CT
Why would you take a CT or an MRI of the pelvis?
CT: appendicitis and diverticulitis.
MRI: uterine problem solving after US and prostate cancer staging.
Why would you take a CT or an MRI of the bones?
CT: Fx
MRI: tumors, osteomyelitis, AVN, stress Fx, Marrow changes.
What are the 3 advantages of plain film radiography?
Cost effective, minimal radiation, widely available
CT image is made up of a ___ and each part of this is known as ____.
Matrix, voxel.
What are the contraindications of CT?
Metallic objects nearby can create artifacts. Radiation, clausrophobia and sensitivity to iodine contrast.
Would you use MRI or CT for sinuses?
CT
What has better soft tissue contrast CT or plain film radiography?
CT
What is the cage used to shield extraneous radiofrequencies from MRI machines?
Faraday cage
What will the radiofrequency do for MRI?
Knock the nuclei out of alignment so they can re-align.
What is the spin density?
The number of hydrogen protons in tissues being imaged
How can you tell the difference between T1 and T2 MRI’s?
T1: fat will be white
T2: water will appear bright
Gadolinium is only used with what type of MRI?
T1 images before and after
What are the contraindications for MRI?
During first trimester of pregnancy, over 300lbs, ferromagnetic artifacts, surgical clips, pacemakers, cochlear implants
What are the 3 phases of scintigraphy?
First: flow phase
Second: blood pool
Third: delayed or bone scan phase
