Comprehensive Radiographic Pathology- Ch. 2 - Specialized Imaging Techniques KEY TERMS Questions with Correct Answers

Anechoic - ANSWERSecho-free annihilation - ANSWERSInteraction produces two high-energy photons (gamma rays) in opposite directions (separated by 180 degrees) Collimator - ANSWERScontaining multiple parallel channels to allow the rays to pass computed tomography (CT) - ANSWERSProduces cross-sectional tomographic images by first scanning a slice of tissue from multiple angles with a narrow X-ray beam. CT number - ANSWERSattenuation of a specific tissue relative to that of water diffusion imaging - ANSWERSrelies on the movement of molecules and random thermal motion Fat suppression - ANSWERSrequires "saturation or full magnetization" on the T1 sequence to ensure a large contrast difference between fat and water Functional MRI (fMRI) - ANSWERSAllows The localization of specific regions of the brain that correspond to various functions gamma camera - ANSWERSa sodium iodide crystal detects the ionizing radiation emitted from the patient helical - ANSWERSspiral continuous motion Hyperechoic - ANSWERSa term used to make comparisons of echo intensities between adjacent structures Hypoechoic - ANSWERSLow-level echoes within a structure Imagining features - ANSWERSWhen radiologists interpret images using common terminology ("imaging features") - location - size - density - structure - shape - demarcation - structure changes and involvement - perfusion - degree of vascularity, cystic/solid - integration - space occupying