OK, maybe not the hardest test EVER, but pretty hard anyway. It was one of the most difficult tests so far in my radiography program. It was in Radiographic Techniques, and although I think I did pretty well, I left the classroom brain-fried.
It was one of those tests with questions like:
"If you increase focal spot size how does it affect image detail?", "If kVP is increased by 15% what will happen to image density?", "When you increase OID what happens to radiographic contrast?" "If the patient is larger than average how will the increase in patient thickness affect image density and detail?" yada, yada, yada, blah, blah, blah, etc., etc., etc.......
A lot of if-then statements.........YUCK!! There seem to be endless variables you can change when making an image of a patient, and we have to know what will happen to the image if one or more of those variables are changed. It's a lot to keep straight in your head without having any experience in making x-ray images to use as a reference.
Our instructors said it will come together during clinicals (we shall see!), but for now we essentially had to memorize a + and - chart which tells us how one variable is affected if another variable is increased or decreased. For example, if you increase the mAs (which stands for milliamperes per second) you are basically increasing the amount of radiation leaving the x-ray tube. This increase in radiation means that more radiation will penetrate the patient and pass through to the other side, which in turn exposes more of the x-ray film making it appear more dark or have a higher visual density (degree of blackness).
Here's the chart, in case you're curious.
Fun stuff, huh!?