Ultrasound is a non-imaging modality that uses sound waves to generate images of internal body structures.

The photoelectric effect is the dominant interaction mechanism for X-rays with energies below 100 keV.

Ultraviolet light is a non-ionizing radiation with a wavelength shorter than visible light but longer than X-rays.

The gray (Gy) is the SI unit of absorbed dose, which is defined as the amount of energy deposited per unit mass of material.

Hyperthermia is a treatment modality that uses heat to kill cancer cells, while the other options are types of radiation therapy.

MRI utilizes the phenomenon of nuclear magnetic resonance to generate images of internal body structures.

Air is not typically used as a contrast agent in medical imaging, while the other options are commonly used.

CT utilizes the differential absorption of X-rays by different tissues to generate images of internal body structures.

Photomultipliers are not typically used as radiation detectors in medical imaging, while the other options are commonly used.

PET utilizes the detection of gamma rays emitted from positron annihilation to generate images of metabolic activity in the body.

Neurophysiology is not typically considered a subfield of medical biophysics, while the other options are commonly studied areas.

Radiation therapy primarily kills cancer cells by damaging their DNA, leading to cell death or impaired cell division.

Drug discovery is not typically considered an application of medical biophysics, while the other options are commonly encountered.

Ultrasound utilizes the reflection of ultrasound waves from different tissues to generate images of internal body structures.

Bioengineers are not typically considered medical biophysics professionals, while the other options are commonly associated with this field.