USAHS Neuro Test 1 Unit 3 Questions With Correct Answers

What are the 3 most common imaging modalities? - Answer CT, MRI, and neruoangiography. Most CT and MRI are? - Answer 2D slices What are the 3 imaging planes? - Answer Horizontal (axial), coronal, Sagittal MRI scans are? - Answer True horizontal slices What was CT scan developed from? - Answer Conventional Xray What does CT measure? - Answer Density of tissues What are the differences b/w CT and conventional Xray? - Answer - Slices are obtained simultaneously - Multiple xray beams pass through pt from different angles. - Densities are displayed as cross section image of head. How does bone/dense structures show up on conventional X-rays? - Answer White = hyper dense How does air/less dense structures show up on conventional X-rays? - Answer Black = hypodense How does immediate dense structures show up on conventional X-rays? - Answer Gray = isodense (CSF) Density is expressed in what? - Answer Hounsfield Units HU = 0? - Answer Water HU = -1000? - Answer Air An acute abnormal finding with a CT would be? - Answer Hyperdense b/c of blood coagulation. An acute abnormal finding one week post with a CT would be? - Answer Isodense An acute abnormal finding 2-3 weeks post with a CT would be? - Answer Hypodense Epidural hematoma - Answer B/w dura mater and skull (lens/football shape) Acute Subdural Hematoma - Answer B/w dura mater and arachnoid/pia mater (crescent) Chronic subdural hematoma - Answer Dark subarachnoid hemorrhage - Answer Acute hemorrhages show up as _______ on the CT? - Answer Hyperdense (white) Chronic hemorrhages show up as __________ on the CT? - Answer Hypodense (Dark) Contusion CT - Answer Acute cerebral infarction cannot be seen on CT within? - Answer First 6-12 hrs Neoplasms may appear as? - Answer Hypodense, hyperdense, or isodense depending on type and stage. Intravenous contrast dye cna help image? - Answer Neoplasm disorders What is mass effect? - Answer Anything that distorts brain's usual anatomy by displacement. (Edema, neoplasms, hemorrhages) Mass effect can cause? - Answer Compression of ventricular space, effacement of sulk Why is intravenous contrast used to show neoplasms and brain abscess? - Answer It contains iodine which is denser and appears white in the CT. What structures take the IV contrast? - Answer Arteries, venous sinus, chroid plexus, dura What is myleography? - Answer CT scan combined with contrast How are iodinated dye injected? - Answer Into the CSF though a lumbar puncture. Iodinated bye in a myelography enhances? - Answer Visualization of nerve roots and