Week 1 - Intro to Radiology

Question 1

What is Computed Tomography and are images generated?

Answer 1

CT - It uses electromagnetic energy (ionizing radiation) to generate a 3D image. A gantry moves around a patient, scanning from many angles. Data can be manipulated so that the physician can view structures in more than one plane - this makes it so that you can focus on one organ or system.

Question 2

What type of energy does Ultrasound use?

Answer 2

Ultrasound is a medical imaging technique that uses high frequency sound waves. (no ionizing radiation, no radiation exposure/cancer risks)

Question 3

What is CT contrast?

Answer 3

Oral contrast is something the patient drinks. This liquid opacifies the bowel in abdominal studies.
IV contrast opacifies vessels and better demonstrates lesions in organs (abdominal). It also allows physician to determine whether a object is a lymph node/lymph or blood vessels

Question 4

What risks are associated with IV contrast?

Answer 4

Allergic reactions (small number severe - hypotension, bronchospasm, and death), Contrast-Induced Nephropathy: this is the 3rd most common cause of hospital acquired acute renal failure, after surgery and hypotension. This causes decline in renal function within 24 hours of contrast administration

Question 5

What do physicians screen before giving IV contrast?

Answer 5

Renal function - contrast is only administered if fxning properly.
Risk factors for IV contrast: preexisting renal function (most imp.), diabetes mellitus, nephrotoxic drugs, and reduced intravascular volume