What is a Radiology Examination?
A radiology examination combines the technology of imaging and radiology to diagnose various disorders in minimal duration of time. The techniques provide images of internal organs to establish the exact stage of the disease. A radiologist is a medical doctor specializing in the interpretation of the results of the imaging techniques (X-ray, CT-scan, MRI and others).
There are two types of radiology examination: diagnostic and interventional.
Diagnostic Radiology
Diagnostic radiology involves the use of imaging techniques such as X-ray, MRI, CT-scan, Positron Emission Tomography (PET), ultrasound and mammography to obtain images of the internal structures of the body. Below is a brief description of each type of test.
X-Ray
X-ray technology is used for the examination of internal organs, bones, blood vessels, and the progression of diseases such as cancer. It can also detect infection, blockages and foreign objects.
An X-ray procedure typically involves the following steps:
- Lying or standing, or holding a certain position, depending on the part of your body to be imaged.
- A contrast material or dye may be injected into a specific part of your body to obtain a more detailed view.
- The X-ray machine captures an image of the specified region.
Magnetic Resonance Imaging (MRI)
This is a computer-based imaging technique that creates a magnetic field inside your body to obtain images. The images of nerves or soft tissue inside your body are obtained.
This technique is effective in diagnosing cancer, strokes, nerve injury, brain or spinal cord injury, heart problems and abnormalities of the internal organs. It does not use radiation and therefore does not cause any radiation damage.
An MRI imaging procedure involves the following steps:
- You must not wear any metal (as the machine uses a very strong magnet), and you will have to remove hearing aids, wigs, watches, or eyeglasses.
- You may need to swallow a contrast preparation or have an IV line started in your arm if the MRI requires contrast dye. Inform your technician if you have or feel any allergy symptoms such as sneezing or itching.
- You will lie on a table which slides inside the MRI machine.
- It is normal to hear loud tapping sounds during the scan.
Computed Tomography Scan (CT-Scan)
Computerized tomography (CT) scan is an imaging technique that uses a combination of a special X-ray machine and a computer to obtain cross-sectional images of the internal structures of the body. The procedure is done on an outpatient basis and involves the following steps:
- You will wear a hospital gown and lie on a table that is attached to the CT scanner.
- You may need to swallow contrast preparation or have an IV line started in your arm if the CT scan involves contrast dye. Inform your technician if you have or feel any allergy symptoms such as sneezing or itching.
- Speakers inside the scanner enable you to communicate with the technician.
- The table will slide into a large donut-shaped machine which takes images while moving around specific parts of your body, yielding several images or “slices” from different angles. It is normal to hear loud, clicking sounds. A computer will transform the slices into 3-dimensional images for your doctor to view.
- You may be asked to hold your breath for a few seconds during image capturing.
- The IV line is disconnected and you are removed from the scanner once the procedure is completed.
Positron Emission Tomography (PET)
Positron emission tomography scanning, also called PET imaging, is a highly specialized nuclear imaging test that uses small amounts of a radioactive substance called a tracer to produce powerful images of the body’s biological functions. The radionuclides (unstable atoms) used in PET scans are chemical substances such as carbon, glucose, or oxygen used naturally by the organ or tissue to be viewed during its metabolic process. A PET scan is usually painless and non-invasive. PET imaging is used to diagnose the stages of cancer, evaluate brain trauma and assess damage to the heart muscles.
The procedure involves the following steps:
- During the test, an IV line is used to inject the tracer liquid. The liquid may also be swallowed or inhaled. The tracer moves throughout your body, where much of it collects in a specific organ or tissue.
- The tracer gives off tiny positively charged particles called positrons.
- The camera records the positrons and turns the recording into pictures on a computer.
Ultrasound
An ultrasound is an imaging technique commonly used to examine a baby growing in a mother’s uterus but is also used to assess abdominal or pelvic organs, heart, blood vessels, muscles, etc. The directed sound waves bounce off the specific organ or area to be assessed and are processed to create still images.
The procedure involves the following steps:
- You will be lying down and will have a gel applied to the skin over the site to be examined.
- A transducer (handheld instrument) will be gently glided over the gelled area.
- The transducer emits the sound waves and receives them once they bounce off the targeted area. The gel provides lubrication and enhances the passage of the sound waves.
Mammography
Mammography is an imaging technique that uses a low-dose X-ray to take pictures of a woman’s breast structures. The results are recorded onto a computer or on X-ray film. Any changes in the breast tissue or the presence of small lumps in the breast can be viewed on the images by your radiologist.
The procedure involves the following steps:
- You stand in front of an X-ray machine. Your breast is placed on the machine’s plate.
- The upper plastic plate is lowered to compress your breast to flatten it.
- You must be still during the scan. A side-view of your breast may also be taken.
Interventional Radiology
This involves the use of images obtained through X-ray, MRI, CT-Scans and other types of scans to guide certain procedures such as the treatment of blocked arteries and veins. Many diseases are treated by interventional radiology including cancer, uterine fibroids, kidney stones, and blocked heart valves. An interventional radiologist is a doctor with expertise in imaging and interventional techniques. Below is one example of a procedure performed by an interventional radiologist.
Balloon Angioplasty
Balloon angioplasty is indicated in patients suffering from a blocked artery.
The procedure is usually performed under local anesthesia and involves the following steps:
- A small incision is made near your groin or thigh region.
- A catheter is inserted through a large blood vessel and guided towards your heart.
- A contrast dye is injected and photographed via X-ray to visualize the blocked artery.
- A balloon catheter placed over a guidewire is threaded and advanced towards the blockage.
- The balloon is inflated to place a stent that fits the size of the artery to keep it open.
- The catheter is removed, and your surgeon closes the incision near your thigh region.
