Cancer Imaging Tests

You asked if there was a comprehensive cancer imaging test.

The answer is yes, no, sort of.

Cancer imaging tests range from x-rays to nuclear medicine tests to various scopes inserted into your body. This article introduces you to some of these tests and how they are used to assist your doctor in identifying if you have cancer.

As we discussed in the first article of this series (Read: Is There a Cancer Test?), there are many cancer tests, but not every test is used exclusively to find cancer.

In this article though, we will look at cancer imaging tests used specifically to detect cancer along with a brief explanation of each test.

Please note that:

·         I am not an expert in cancer imaging tests

·         This is not a complete list of cancer imaging tests

·         Imaging tests can also be used to diagnose health conditions other than cancer

The first types of cancer imaging tests we will look at are radiology tests.

  X-ray = radiograph

• This test looks at the bones, chest, and abdomen

• For this test, you stand in front of the x-ray screen and the radiology tech takes the x-ray which is a single snapshot. The tech will help you get into position, then they will go behind a leaded barrier to snap the x-ray. You may need to move into different positions if more than one x-ray is taken.

  CT scan = computed tomography scan

• This cancer imaging test takes multiple images from different angles, then the computer processes the images. Imagine your body being a loaf of bread with your head at one end of the loaf and your feet at the other end. The CT scan looks at slices of your body like slices of bread. Don’t worry, you won’t be sliced up, but the images will look like that.

•  For this test, you will lie on a table that slides into the machine with openings on each end. When the test is completed, the tech will slide you back out.

 The next cancer imaging test is an MRI = magnetic resonance imaging

 This test is like a CT scan, but instead of using x-rays, this test uses magnetic fields and radio waves to form the images.

      Again, you will lie on a table and slide into the machine. Some MRI machines are closed at one end, and some are open.

        CAUTION:  you cannot wear any clothing with metal on it or wear any metal jewelry. The magnet will attract the metal. Let the MRI tech know if you have any metal implanted in your body, like an artificial joint, or any medical devices inside you such as a pacemaker. Some medical devices are safe to go into an MRI but not all are.

A special kind of MRI images your breasts if your doctor is concerned you may have breast cancer. For this MRI, you lie face down and your breasts hang down through holes cut in the table. (Read: The Day I Met Cancer in the Mirror).

The final cancer imaging test in this group is the mammogram.

• This test takes images of the breasts. This test can be done on men as well as women. Unfortunately, men get breast cancer too, but not as often as women.

• To get the proper image, the mammography technician will position one of your breasts onto the plate of the machine and adjust the machine to apply pressure to your breast to flatten out the tissue for improved imaging.

The next category of cancer imaging tests we will look at are some nuclear medicine scans.

PET scan = Positron Emission Tomography

• This test looks for areas of high metabolism in your tissues also called hot spots. Cancer shows up on this test because it has a higher metabolism than the surrounding tissue.

• For this test, you will have a radioactive tracer injected into an IV in your arm. You will sit quietly in a room for about 30 minutes before your PET scan while the tracer is absorbed into your tissues. For the test itself, you just lie still on a table that is slowly rolled into the machine.

• For several days before this test, you will not be allowed to do any heavy physical exertion such as exercise. Areas of trauma in your body will have a higher metabolic rate as the area heals. This could be mistaken for cancer.

The next cancer imaging test is a bone scan.

This is similar to a PET scan except that this test looks at your bones instead of tissues and organs.

This is not the same test as a bone density test or a Dexa scan. A Dexa scan looks at the density of your bones to find any weakened areas of osteopenia or osteoporosis.

A thyroid scan is another nuclear medicine cancer imaging test.

For this scan, a radioactive iodine tracer is injected into an IV in your arm. Next, images are taken of your thyroid to see how the tracer was absorbed and to see if there are any areas where more of the tracer was absorbed.

Another nuclear medicine cancer imaging test is a gallium scan.

In this test, a small amount of gallium, which is a radioactive material is injected into your vein. You lie on a table that is then rolled into the imaging machine. This is another test that looks for rapidly dividing cells. Cancer is one cause of rapidly dividing cells in the body, but not the only one.

The next category of cancer imaging tests we will look at are endoscopies.

To perform an endoscopy, your physician will insert an endoscope, which is a long flexible tube inside you. Once inside, the physician can look around, take photos, or even use a special instrument to snatch a piece of tissue for a biopsy.

Here are ten different scopes and the body part each examines:

Bronchoscopy: bronchos = air tube, scopy = scope

For a bronchoscopy, your physician inserts a lighted tube (scope) into your mouth or nose and continues to insert the tube to look at structures of the airways including the trachea = windpipe, larynx = voice box,  bronchi = right and left bronchus which are the two main branches of airway off of the trachea, and bronchioles = small airways which continue to branch off of the bronchi.

Mediastinoscopy: the mediastinum is the area in the center of the chest between the lungs.

Within the mediastinum are the trachea, heart, the thoracic aorta and vena cava, which are the largest artery and vein in the body, and nerves.

Your physician will make a small incision just above the sternum = breastbone, and insert a thin, flexible scope to look around and possibly removed tissue to biopsy.

Laryngoscopy: larynx = voice box, scopy = scope

Depending on which type of scope is used, either rigid or flexible, your physician will insert the scope into your mouth or nose and then into your voice box to look at your vocal cords and the structure of your throat.

Thoracoscopy: thorax = chest, scopy = scope

This time, instead of looking at the structures in between your lungs, your doctor is looking at the lungs themselves. For this test, your doctor will make three small incisions and insert the scope into the lung area. When he/she uses video equipment in the procedure, the test is called a video-assisted thoracoscopy or VATS.

EGD

Esophagogastroduodenoscopy: esophago = esophagus or food tube, gastro = stomach, duodenum = the first part of the small intestine which is where food goes when it leaves your stomach for further digestion, scopy = scope. This test is called an EGD for short.

-         For this test, the doctor inserts a scope into your mouth, down your esophagus, into and through your stomach, and into the duodenum.

Colonoscopy: colon = large or lower intestines, scopy = scope

-         An EGD is an upper endoscopy because it looks at the upper end of your digestive tract. A colonoscopy is a lower endoscopy because it looks at the lower end of your digestive tract.

-         Your doctor does a colonoscopy by inserting the scope into your anus, through your rectum, and into the colon.

Sigmoidoscopy: sigmoid = the section of intestines above to colon, scopy = scope

-         A sigmoidoscopy is done the same way as a colonoscopy, but this time the doctor inserts the scope higher into your colon into the sigmoid colon.

Laparoscopy: Laparo = wall of the abdomen, scopy = scope

-         A laparoscopy is performed by your doctor by making a small incision into your abdomen and inserting the scope to look at the organs of your abdomen.

Hysteroscopy: hyster = uterus, scopy = scope

-         Your doctor performs a hysteroscopy by inserting a scope into your uterus.

Cystoscopy: cysto = urinary bladder (not gallbladder), scopy = scope

-         For a cystoscopy, your doctor inserts the scope up the urethra (pee tube) and then into the bladder.

Ureteroscopy: ureter = the tube connecting a kidney to the bladder, scopy = scope

-         This test is done the same way as a cystoscopy, except that the doctor inserts the scope into and through the bladder into the ureter.

The cancer imaging tests mentioned above each require different preparations. Some require you to be NPO = nothing per os (mouth), which means you cannot eat or drink anything for eight or more hours before your procedure. Other tests require that you be NPO and take medicine to clean out your colon (medicine to give you diarrhea). Follow your doctor’s pre-procedure instructions closely.

For instance, even though it is no fun having diarrhea, this step is necessary to clear your colon of solid matter (poop) so your doctor can see the colon walls clearly for tests like a colonoscopy or sigmoidoscopy.

And do not eat or drink anything before your test according to your doctor’s instructions. Even though you will be thirsty, if you have something in your stomach when they put you to sleep, you could vomit this material while you are unconscious for your test, and it will go down your lungs. This can cause still further problems like pneumonia.

For some tests, you may need to stop taking certain medicines or supplements for a given period prior to your test. Be sure to ask about this when you are given instructions for your test.

But keep this in mind, the tests mentioned above are cancer imaging tests the doctor uses to specifically look for cancer. These tests can also be used for reasons other than diagnosing cancer though.

So, unless your doctor tells you that they are specifically trying to determine if you have cancer by doing one or more of these tests on you, do not assume by reading this article that you have cancer if your doctor orders these tests. Doctors use diagnostic imaging tests to look for things other than cancer, as well as look for cancer.

For further reading about cancer imaging tests, go to these sites:

https://www.cancer.org/treatment/understanding-your-diagnosis/tests/imaging-radiology-tests-for-cancer.html

https://www.mskcc.org/cancer-care/diagnosis-treatment/diagnosing/role-imaging

Comment below on how this article has helped you better understand cancer imaging tests.

Wishing you all the best,

Kelly

 Are your cancer screenings up to date?

Yes, I am a nurse. No, I am not your nurse. The medical topics discussed in this, or any article on this site, are intended to be issues for you to discuss with your medical team if you feel they apply to you. None of the information you are about to read in this article is treatment advice for you from me. I do not have that authority.