Imaging in Radiation Therapy PP-In class Flashcards
How does MRI produce images of the body?
MRI uses a strong magnetic field and radio frequency (RF) pulses to produce images by mapping hydrogen distribution in the body. A computer controls the timing of RF pulses and gradient coils and reconstructs the image.
Why is MRI ideal for diagnosing brain tumors?
MRI can differentiate between tumors and surrounding edema, especially with the use of gadolinium-based contrast agents, which highlight tumor vasculature.
Can radiation therapists legally administer intravenous contrast?
Yes, if we are trained to do so, but CSN wont train us and most centers in Vegas wont require us to do so.
However, we may have to inject contrast in rectums, vaginas, penises…
What principle does medical ultrasound use to generate images?
Medical ultrasound uses the SONAR principle, where a short pulse is directed, and the echo time delay is used to calculate tissue depth.
How is the Doppler effect used in medical ultrasound?
It measures the movement of blood and tissue by detecting changes in frequency when sound waves reflect from a moving structure.
Why is ultrasound not suitable for imaging the lungs or gastrointestinal tract?
AIR
Ultrasound cannot effectively image air-filled spaces, making it unsuitable for lungs and the gastrointestinal tract.
What motivates the continual improvement of mammography techniques?
The high incidence of breast cancer drives ongoing advancements in mammography to improve early detection and treatment success rates.
What are the ACS mammography screening recommendations for women aged 45-54?
Women aged 45-54 should get mammograms every year.
What are the advantages of compressing the breast during mammography?
Compression spreads tissue for better imaging, reduces motion blur, minimizes scatter radiation, and ensures uniform tissue exposure, resulting in improved image quality and reduced patient dose.
What is fluoroscopy?
Fluoroscopy provides real-time imaging of internal structures, showing motion, unlike static X-rays.
Explanation: This technique is useful for procedures that require observation of internal movements, such as guiding catheters or checking organ functions.
What is a major concern for patients and professionals during fluoroscopy?
Exposure to radiation is a key concern, requiring proper safety measures such as wearing radiation badges.
she mentioned one in particular in class…
Why is it more difficult to image the breast in younger women?
Younger women have denser breast tissue, which is harder to image due to the higher amount of glandular tissue compared to fat.
Explanation: Dense tissue can obscure small abnormalities, making it harder to detect cancers without specialized imaging techniques.
Why is gadolinium-based contrast used in MRI?
Gadolinium highlights areas with increased vasculature, making tumors easier to identify.
Why is ultrasound used to differentiate between solid tumors and fluid-filled cysts?
Ultrasound can identify abnormal structures by differentiating between solid masses and cysts, which appear differently on ultrasound.
Explanation: Solid tumors have different acoustic properties compared to cysts, making ultrasound useful for breast, prostate, and ovarian imaging.
Why do technologists use gel during an ultrasound procedure?
Ultrasound gel helps transmit sound waves by eliminating air between the transducer and the skin.
