Diagnosing injuries, diseases and conditions would be nearly impossible today without the range of methods available to look inside the human body. This guide explains the different techniques, how they work, and what to expect if one of them is ordered for you.
Computed tomography scans, or CT scans, combine X-rays with a computer’s assistance to create cross-sectional images showing more than standard X-rays. Use this section of the guide to learn how CT scans work, why they are used and what to expect during a CT scan.
- CT scans help doctors see the body’s internal organs, such as the brain. The scans help diagnose tumors, lesions and other problems with an organ’s structure.
For an overview of CT scans …
The National Cancer Institute
answers common questions about how CT scans work and what a person can expect during the exam. Though the page also discusses tumors and cancer, the information about CT is applicable to anyone.
For the types of CT scans…
Endoscopy allows doctors to see inside the human body by inserting a narrow tube with an attached camera into various parts of the body. The sites below show you what endoscopy is, when it’s used and what to expect during procedures.
- Endoscopy uses an endoscope, which has many forms. The name changes depending on the body part involved. A laparoscope, for example, is inserted into an incision made in the abdomen, while a bronchoscope goes into the body through the nose or mouth.
For an overview of endoscopy …
The American Cancer Society
explains how endoscopy works. Read a lengthy discussion of endoscopy’s role in detecting and treating cancer. Scroll down to the heading “What Does the Procedure Involve?” to find a table listing each type of test and whether any special preparation is needed, including its length and the kind of anesthesia generally used.
, a consumer health site developed by the insurance company Aetna, offers an overview of endoscopies that explains what to expect through each stage, from preparing for the procedure to post-procedure symptoms.
For endoscopy and children …
Magnetic resonance imaging (MRI) uses magnets, and sub-atomic structures in the body, to look at the soft tissues and organs that X-rays don’t see. Use this section of the guide to learn how MRI works and what to expect during an MRI.
- Because magnetic energy is involved, it’s essential to tell your doctor and the MRI technician if you have any metallic implants, such as a pacemaker, or shrapnel in your body. Without informing them, an MRI could be seriously harmful.
For an overview of magnetic resonance imaging …
has a short video clip that explains, in plain language, what magnetic resonance imaging does.
For what to expect during an MRI …
has an illustrated tutorial that explains what an MRI is and what to expect during the procedure. The information is also available in a printable PDF
For a functional MRI …
describes a slightly different type of imaging called functional MR Imaging (fMRI). Learn what fMRI is, how to prepare for the procedure, how fMRI is performed and more.
Nuclear medicine is primarily used to examine organ function rather than structure. To see how an organ is working, a patient ingests a small amount of radioactive material. By measuring the behavior of the material during a nuclear scan, an assessment can be made. The sites below provide an introduction to nuclear medicine, including how nuclear medicine scans are performed and what to expect during such a scan.
- The amount of radioactive material a person swallows or is injected with for nuclear medicine scans is very small, and usually leaves the body a day or two after the test.
For an overview of nuclear medicine …
For nuclear medicine’s uses …
For what to expect during a nuclear medicine test …
explains how nuclear imaging is different from other radiologic tests, and describes what to expect before, during and after the test.
For a glossary of nuclear medicine terms …
For nuclear medicine and kids …
takes parents step-by-step through what their child can expect during a nuclear medicine study.
Ultrasound is a procedure used to generate images of structures and tissues within the body. Images are generated by sending sound waves into the body and monitoring their reflections. Use this section of the guide to learn about ultrasounds and how they are performed.
- Ultrasounds are often used to look at fetuses in the womb. Though it is safe, the Food and Drug Administration warns parents against having medically unnecessary ultrasounds at storefront places that offer three- and four-dimensional “keepsake” images.
For an overview of ultrasound …
has an illustrated overview of ultrasound that covers how they work and what patients can expect during them. The presentation is also available in a printable PDF
For 3- and 4-dimensional ultrasound …
has an interview with Stephen Smith, a researcher who helped develop the three-dimensional ultrasound technology. Smith talks about how the technology works and its advantages.
National Geographic News
spoke with Professor Stuart Campbell, a leading obstetrician, on four-dimensional ultrasound imagery. Learn how the 4D scans work, their benefits and more.
For what to expect during an ultrasound …
X-ray technology is one of the oldest imaging methods available. Even though there are more advanced ways to see inside the human body, X-rays are still widely used around the world. Use the sites in this section of the guide to learn what X-rays are, when a doctor might order one and what to expect during the procedure.
- X-rays were known as röntgen rays, named for William Conrad Röntgen, who is credited with discovering them in 1885.
For an overview of X-Rays …
explains what X-rays are, why they are performed and how X-ray examinations are provided.
has detailed explanations of the different types of X-Ray studies, such as bone densitometry, mammography, arthrography and others.
For pregnant women and X-rays …
The U.S. Food and Drug Administration
discusses X-rays and pregnancy. Learn the risks posed by X-ray during pregnancy, and why it’s important to tell your doctor if you’re pregnant or think you might be.
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