Diagnostic imaging tests

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science

This page was updated on April 29, 2022.

Imaging tests send energy through the body to capture pictures doctors may use to locate and diagnose cancer, to determine whether cancer has spread, and to evaluate whether and to what extent a particular treatment is working. At City of Hope, the diagnostic imaging tests we use include those listed below.

Barium swallow or enema

A barium swallow, or esophagram, is an X-ray test that allows doctors to examine the throat and esophagus. Patients drink a solution containing barium, a chalky, white metallic powder. The solution travels down the digestive tract. A series of X-rays are then taken. The images they produce reveal abnormal areas that doctors may need to examine more closely through an endoscopic procedure or other diagnostic imaging test.

A barium swallow may be performed as part of an upper gastrointestinal series test, which examines the esophagus, stomach and small intestine.

A barium enema is used to take X-rays of the large intestine, which includes the colon and rectum. First, a doctor delivers an enema containing barium through a thin tube inserted through the rectum. The solution travels through the rectum and colon, coating the organs. After the solution has been delivered, air is released through the tube to help the colon expand and make it easier for the doctor to see abnormal growths. A series of X-rays are then taken of the colon and rectum. The X-rays may help the doctor detect polyps and other suspicious tissues that may need to be examined more closely or removed in a colonoscopy.

Bone scan

A bone scan is an imaging test that may detect cancerous cells, evaluate fractures in bones and monitor other bone conditions, such as infections and arthritis. During a bone scan, a small dose of radioactive material is injected into a vein, where it travels through the bloodstream. The material collects in the bones and is detected by a scanner using nuclear imaging to reveal cell activity and function in the bones.

These diagnostic scans may detect cancer that has metastasized to the bone from a different primary site, such as the breast, prostate or lungs.


A colonoscopy is generally used to examine the large intestine (or colon) for the presence of colorectal cancer.

Learn more about colonoscopies

Computed tomography (CT) scan

CT scans (also known as computed tomography or CAT scans) are one of the most commonly used tools for the screening, diagnosis and treatment of cancer, including lung and colorectal cancers.

Learn more about CT scans

Dual-energy X-ray absorptiometry (DEXA) scan

A dual-energy X-ray absorptiometry (DEXA) scan measures bone mineral density, helping doctors evaluate bone health and determine the likelihood of osteoporosis or fractures. While a DEXA scan isn’t typically used to diagnose cancer, it can provide your care team with important information to help them determine whether additional testing is needed.

Using low levels of X-rays, the DEXA scan examines the entire skeleton or specific points on the body, such as the spine or hip. Doctors may perform a baseline DEXA scan before and during treatment to monitor bone health.

Once the scan is complete, the results are detailed by two different scores:

T-Score is the difference between your bone density and that of an average healthy person. This score is used to determine your risk of breaking a bone.

Z-Score is the amount of bone you have compared to other people of the same age, race and gender. A score that is too high or too low may require more testing.


A laparoscopy is useful if you’re experiencing pain in the pelvic region, or if an imaging test has detected a tumor or other abnormality. Most commonly, a laparoscopy is performed to diagnose or treat cancers of the:

  • Colon
  • Kidneys
  • Cervix
  • Ovaries
  • Endometrium

During the procedure, an incision is made near the navel and a laparoscope (a lighted instrument with a lens) is inserted to examine the area, remove a tumor or take a biopsy of a suspicious area.

Learn more about laparoscopies


A mammogram is a tool used to detect breast cancer. Mammography is a specific type of imaging that uses a low-dose X-ray system to examine breast tissue. Radiologists use mammography as a screening tool to identify tumors or abnormal tissue in the breast. Common types of mammography include digital mammography and breast tomosynthesis.

Learn more about mammography

Magnetic resonance imaging (MRI)

MRI is an imaging tool designed to create detailed, cross-sectional pictures of the inside of the body. Using radiofrequency waves, powerful magnets and a computer, MRI systems may distinguish between normal and diseased tissue.

MRI plays an important role in cancer diagnosis, staging and treatment planning. With MRI, we may distinguish between normal and diseased tissue to precisely pinpoint cancerous cells within the body. It also may be useful for revealing metastases. MRI provides greater contrast within the soft tissues of the body than a CT scan. As a result, it is often used for imaging the brain, spine, muscle, connective tissue and the inside of bones.

During an MRI, a patient rests on a table that slides into a scanner. Some exams require that a contrast dye be injected into a vein before the procedure. This helps certain areas show up better on the images. The procedure is painless and typically takes 30 to 60 minutes.

Unlike X-rays and CT scans, an MRI does not use radiation.

Nuclear medicine imaging

Nuclear medicine imaging is used to diagnose and treat certain cancers, such as brain, breast, kidney, bladder, thyroid, liver, lung and bone cancers. In nuclear medicine, small amounts of radioactive material (called radiopharmaceuticals or radiotracers) are administered to a patient by injection, inhalation or pill. The radiopharmaceutical eventually accumulates in a particular organ or area of the body, where it gives off energy in the form of gamma rays.

The energy is detected by a special camera, which produces a series of images on a computer screen or film. This provides details about the structure and function of an organ, tissue or bone in the body. This test also allows for the identification of abnormalities earlier in the disease progression process.

Some types of nuclear medicine tests we offer include:


Also known as a sonogram, an ultrasound is an imaging test that uses high-frequency sound waves to create pictures of internal organs. By capturing images in real time, ultrasound exams reveal the structure and movement of organs, such as the heart, blood vessels, kidneys and liver. Unlike X-rays, ultrasound exams don’t use radiation.

These imaging tests allow your doctors to see tumors in soft tissues that may not appear clearly on X-rays. Although ultrasounds cannot determine whether a tumor is cancerous, they can help your care team distinguish tumors from fluid-filled cysts. They’re also used to help your doctor see where to insert a needle to take a tissue sample during a biopsy.

Learn more about ultrasounds


An X-ray, a type of high-energy electromagnetic radiation, is often used for medical imaging. X-ray technology may be used to examine many parts of the body. This image-guided technology is an important procedure for cancer diagnosis, staging and treatment.

X-rays help doctors detect cancer in the bones as well as in organs such as the stomach, kidneys and lungs. Breast X-rays (called mammograms) can detect breast cancer. X-rays may also be used to find out how well a cancer treatment is working, to help your care team plan for a cancer surgery, and to provide visuals to assist with the placement of catheters and stents used in some cancer treatments.

Below are common types of X-rays.

Upper GI series: An X-ray of the esophagus, stomach and small intestine that is performed after you swallow a barium mixture.

Lower GI series: An X-ray of the colon and rectum that is performed after you’re given a barium enema.

Intravenous pyelogram (IVP): An X-ray of the kidneys, ureters and bladder that is performed after the intravenous injection of a special contrast dye.

Learn more about X-rays

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