MEDRADSC 3C03 Lecture Notes - Lecture 3: Defoamer, Microbubbles, Simethicone

• School: McMaster University
• Department: Medical Radiation Sciences
• Course: MEDRADSC 3C03
• Professor: Meaghan Jefferson

Document Summary

Aim: adequately opacify the vessel but allow a level of grey-scale that allows branches/filling defects to be seen through the contrast - requires correct volume of cm; increase visibility. Regions of low subject contrast similar shades of gray (ie in the abdomen) To achieve optimal opacification, bolus & timing of contrast is critical. Ultrasound tissue and blood reflectivity how do sound waves get reflected off structures once they interact with them . Cm affects how sound wave interacts with the tissue. Mri tissue relation time cm affects how each photon processes or relaxes (has to do with how mri acquires signal) Positive contrast agents: liquids containing iodine or gadolinium that have a greater attenuation than the patient"s soft tissue. Negative contrast agents: has a lower attenuation that the patient"s tissues; co2 is the only available option. Used bc of its high z# - allows for better contrast & other structures/tissues in the body ie) omnipaque: non-iodinated (+) contrast agent.