Differentiate between positive and negative contrast agents.
DefinitionDifferentiation should include how the chemical properties of radiologic contrast agents (positive and negative) are used to enhance images.
- How does density affect radiation visibility and penetration?
- What is the atomic weight of barium? Iodine?
- What anatomical parts are not visible without a contrast agent?
- What is meant by contrast?
- How does air serve as a contrast agent?
- What are the chemical properties of barium?
- What are the chemical properties of iodine?
- When would air be used vs. barium?
Related Standards of Learning
The student will read, interpret, analyze, and evaluate a variety of nonfiction texts.
- Use critical thinking to generate and respond logically to literal, inferential, and evaluative questions about the text(s).
- Identify and synthesize resources to make decisions, complete tasks, and solve specific problems.
- Analyze multiple texts addressing the same topic to determine how authors reach similar or different conclusions.
- Recognize and analyze use of ambiguity, contradiction, paradox, irony, overstatement, and understatement in text.
- Analyze false premises claims, counterclaims, and other evidence in persuasive writing.
The student will investigate and understand that experiments in which variables are measured, analyzed, and evaluated produce observations and verifiable data. Key concepts include
- designated laboratory techniques;
- safe use of chemicals and equipment;
- proper response to emergency situations;
- manipulation of multiple variables, using repeated trials;
- accurate recording, organization, and analysis of data through repeated trials;
- mathematical and procedural error analysis;
- mathematical manipulations including SI units, scientific notation, linear equations, graphing, ratio and proportion, significant digits, and dimensional analysis;
- use of appropriate technology including computers, graphing calculators, and probeware for gathering data, communicating results, and using simulations to model concepts;
- construction and defense of a scientific viewpoint; and
- the use of current applications to reinforce chemistry concepts.