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Digital Imaging and Radiology

Digital Imaging and Radiology . Traditional x-rays. Use electromagnetic waves to make pictures. New imaging techniques use computers to generate pictures of internal body organs. Computers can make pictures using mathematical information. Newer Technologies.

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Digital Imaging and Radiology

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  1. Digital Imaging and Radiology

  2. Traditional x-rays • Use electromagnetic waves to make pictures

  3. New imaging techniques use computers to generate pictures of internal body organs

  4. Computers can make pictures using mathematical information

  5. Newer Technologies • Computerized tomography is a diagnostic procedure that uses special x-ray equipment to obtain cross sectional pictures of the body. • The CT computer displays these pictures as detailed images of organs, bones, and other tissues. • In cancer, CT is used to detect a tumor, provide information about the extent of the disease, help plan treatment, and determine whether the cancer is responding to treatment

  6. A CT scan uses slightly more radiation than a chest x-ray, but the benefits generally outweigh the risks • During a CT scan, the person lies very still on a table. The table slowly passes through the center of a large x-ray machine. The person might hear whirring sounds during the procedure. People may be asked to hold their breath at times, to prevent blurring of the pictures. • Often, a contrast agent, or “dye,” may be given by mouth or injected into a vein before the CT scan is done. The contrast dye can highlight specific areas inside the body, resulting in a clearer picture.

  7. Magnetic Resonance Imaging (MRI) • MR imaging uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. The images can then be examined on a computer monitor or printed. MRI does not use ionizing radiation (x-rays).

  8. In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the following implants cannot be scanned and should not enter the MRI area: • internal (implanted) defibrillator • cochlear (ear) implant • clips used on brain aneurysms

  9. Positron Emission Tomography A PET scan, unlike a normal X-ray, can detect cancer before organ or gland enlargement occurs. Here a normal X-ray of the chest (left) is compared with a PET scan of the chest producing normal results (top right) and a PET scan revealing cancer that's spread to the lymph nodes (bottom right).

  10. Advantages of digital imaging • No developing process • Copies are as good as originals • Viewed on computer screen • Can be transmitted over telephone lines • Less radiation • More flexible • Can be highlighted or enhanced

  11. X-rays are most frequently used in orthopedics and dentistry • As with many of mankind's monumental discoveries, X-ray technology was invented completely by accident. In 1895, a German physicist named Wilhelm Roentgen made the discovery while experimenting with electron beams in a gas discharge tube. Roentgen noticed that a fluorescent screen in his lab started to glow when the electron beam was turned on. This response in itself wasn't so surprising -- fluorescent material normally glows in reaction to electromagnetic radiation -- but Roentgen's tube was surrounded by heavy black cardboard. Roentgen assumed this would have blocked most of the radiation.

  12. Roentgen placed various objects between the tube and the screen, and the screen still glowed. Finally, he put his hand in front of the tube, and saw the silhouette of his bones projected onto the fluorescent screen. Immediately after discovering X-rays themselves, he had discovered their most beneficial application

  13. Mammography is a traditional x-ray • Mammography is a low-powered x-ray technique that captures a picture of the internal structure of the breast. Additional angles and magnified views are taken of suspicious areas. • A mammogram may help in the diagnosis of breast problems, including cancer. • It is recommended a woman have a baseline mammogram at age 40, followed by a mammogram every couple of years until age 50. After 50, a woman should have a mammogram every year.

  14. Ultrasound can distinguish between cysts and tumors • It is used along with mammograms • Does not use radiation but high frequency sound waves

  15. Computer Tomography • Uses x-rays and digital technology to produce a cross-sectional image of the body. (Enhanced CT’s use dye)

  16. Magnetic Resonance Imaging • Produces images of soft tissue within the body • The image is produced by a computer with a magnetic field that is 25,000 times stronger than the earth’s magnetic field

  17. Positron Emission Tomography (PET) • Scans can be two or three dimensional • Used in the study of Alzheimer’s and Parkinson’s disease • They produce pictures of activity and function

  18. Interventional Radiology • Treats an ever-widening range of conditions inside the body from outside the body by inserting various small instruments or tools, such as catheters or wires, with the use of various x-ray and imaging techniques (i.e., CT scanners, MRI scanners, ultrasound scanners). • Interventional radiology offers an alternative to the surgical treatment of many conditions and can eliminate the need for hospitalization, in some cases • Surgical biopsies have now been replaced with needle biopsies

  19. Stereotactic Radiosurgery • Stereotactic radiosurgery (SRS) treats brain disorders with a precise delivery of a single, high dose of radiation in a one-day session. Focused radiation beams are delivered to a specific area of the brain to treat abnormalities, tumors or functional disorders. • Is the very precise delivery of radiation to a brain tumor with sparing of the surrounding normal brain.

  20. Stereotactic Radiosurgery cont. • Uses a gamma knife which is a painless device • The gamma knife uses multiple beams of radiation converging in three dimensions to focus precisely on a small volume, such as a tumor, permitting intense doses of radiation to be delivered to that volume safely.

  21. Focused ultrasound surgery • Uses sound waves which create a powerful ultrasonic beam • High-intensity ultrasound energy focused on a small target volume raises the tissue temperature high enough to destroy it. This is similar to the manner in which sunlight focused by a magnifying glass can create sufficient heat to start a fire. The use of heat to destroy tissue is called thermal ablation

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