Imaging services

At HCA Houston Healthcare Medical Center, we know the importance of imaging in the diagnosis of medical conditions. That is why we provide advanced imaging technology, allowing for fast, accurate results so our physicians can start your treatment as soon as possible. We offer a range of services from mammography to nuclear medicine. All imaging exams are performed by our certified radiologists who provide expert, comforting care for all our patients.


HCA Houston Healthcare Medical Center’s centralized scheduling department will be happy to help schedule your imaging examination and obtain any necessary pre-authorizations. They will also let you know about any financial obligations for which you may be responsible. Our centralized scheduling department is available Monday to Friday from 7:30 a.m. to 5:00 p.m.

To schedule your imaging appointment today, please call (713) 285-1890.


Magnetic resonance imaging (MRI) is one of the most advanced diagnostic tools for today’s physicians. MRI allows your physician to see inside your body without surgery or the use of ionizing radiation. MRI machines use a power magnet, low-intensity radio waves and computer technology to create detailed images of the soft tissues, muscles, nerves and bones in your body.

How does an MRI scanner work?

The main component of an MRI scanner is a magnet that allows your body to receive radio signals from the magnetic resonance system. Your body reacts by sending its own radio signals back to the machine. The radio frequency is then computer-processed and turned into detailed images.

Preparing for your MRI

Because MRI uses a strong magnetic field, metal objects will interfere with the scan. For your convenience, we provide lockers to store your metal objects like barrettes, jewelry and/or credit cards. We ask that you wear comfortable, loose-fitting clothing, but you may be asked to change into a hospital gown.

You cannot be examined by an MRI if you have any of the following:

  • Pacemaker
  • Aneurysm clip in the brain
  • Inner ear implants
  • Metal fragments in one or both eyes
  • Implanted spinal cord stimulator
  • If you are pregnant or think you might be pregnant
  • If you are breastfeeding
  • If you have anemia or any diseases that affect red blood cells
  • If you have asthma or other allergic respiratory disorders

If you have questions about whether or not you are eligible to receive an MRI, please contact your physician.

Contrast media

Certain types of MRI scans require the use of a paramagnetic agent or contrast media. This contrast media, which is given intravenously before the exam, highlights certain body parts. When needed, it will be discussed in detail with eligible patients. Tell your physician before your exam if you have ever had an adverse reaction to contrast media.


Ultrasound is an imaging test that uses high-frequency sound waves beyond human hearing capability to produce high-quality images of soft tissues and motion within the body. Ultrasound imaging involves no X-rays and may give doctors medical information that in the past may have required surgery.

Ultrasound imaging is used to find health conditions like aneurysms, blood clots, damaged heart tissue, abnormal growths and diseased tissue. Additionally, ultrasound is used throughout pregnancy to track a baby’s size, weight, position and physical condition. Ultrasound is also used to detect muscle injuries and some joint problems.

How does an ultrasound work?

An ultrasound test is simple and painless. A hand-held device, putting off silent, high frequency sound waves, is placed against the body and is slowly passed over the area being checked. The sound waves pass through the skin and into the body. The returning sound waves or echoes are picked up by the handle and changed into a picture form. Advanced equipment will create images on a video screen and then on paper or film.

Preparing for your ultrasound

Most ultrasound exams require little or no preparation. In some cases, you may be asked to avoid gas producing foods for one to two days, drink specific types and amounts of fluids, go to the bathroom or follow other instructions stated by your doctor.

You will be asked to lie on a comfortable table while your technologist applies a gel to your skin to allow the sound waves to travel through. The technologist will then gently pass the handle of the ultrasound over the certain body area several times.

CT scan

A CT scan, or computed tomography, is an advanced diagnostic test that uses X-rays, a special scanner and a computer to produce detailed images of an area of your body. These images can give your physicians a 3D view of your body.

How does a CT scanner work?

A CT scanner is made up of a ring containing an X-ray tube and a receptor mounted opposite of each other. This ring encircles you and rotates around you. With each rotation the tube sends X-rays absorbed during each rotation of the ring. The computer then transforms these measurements into a visual image. This image, or slice of information, is viewed on a video screen during the exam and later converted into a photograph for your doctor or the radiologist to study.

Preparing for your CT scan

Be sure to tell your doctor and technologist if you are pregnant, think you might be pregnant or if you are breastfeeding. Also inform them if you are allergic to, or have ever had any reaction to, iodine, contrast media or shellfish.

Wear comfortable, loose-fitting clothing. You may be asked to change into a hospital gown. Remove hairpins, barrettes, earrings or other objects that will interfere with your CT scan. Some CT scans require the use of contrast media, which are substances given intravenously or orally to highlight areas of your body. The contrast may cause you to feel warm, and you may experience a metallic taste in your mouth. Tell your technologist immediately if you begin to itch, feel short of breath or experience discomfort.

Your technologist will help you onto the CT table, and when you are ready, the table will slide into the ring of the scanner. Your technologists will conduct the test from an adjacent room. You will be able to speak to your technologist through the patient intercom system during the entire exam.

Nuclear medicine

Nuclear medicine is a diagnostic test that uses a small amount of radioactive material, called isotopes, and a special camera, which measures radioactivity in the form of images. Nuclear medicine is a broad term that describes a variety of tests used to detect abnormalities of the thyroid, lungs, heart, liver and bones. It can also be used to treat some forms of diseases such as thyroid disease.

What are isotopes and how do they work?

Isotopes have been specifically formulated for human use, and the amount needed when performing nuclear imaging is very small. The isotope used for the exam is specific to the area of your body being examined and travels through the bloodstream to the target organ. Once the isotope has been moved to the target area of the body, pictures are taken with a special camera. The isotope is eliminated from your body within one to two days.

Isotopes are administered in capsule form, or through an injection in your vein. You are then required to wait for a specified amount of time before the scan can begin. This is because the isotopes take time to work their way through your system and become concentrated in the area to be examined.

Preparing for your nuclear medicine test

Before your test, you will be given specific instructions by your physician’s office or from our imaging center. You will also need to tell your doctor and technologist if:

  • You are pregnant
  • Think you might be pregnant
  • Are breastfeeding
  • You have any history of allergies
  • You have had a previous nuclear medicine scan or radiation therapy

Imaging services at HCA Houston Healthcare

Imaging services refers to the performance of imaging exams for better visualization and treatment of medical conditions. Different exams allow radiologists and physicians to view structures and activity within the body. Imaging exams are vital for diagnosis and there are a wide range of tests that can be performed.

Learn about Imaging services