Imaging scans

You will usually have at least one of the following imaging scans:

• Ultrasound
• CT scan
• MRI scan
• Radioisotope bone scan
• PET Scan

Ultrasound 

In an ultrasound, soundwaves are used to produce pictures of your internal organs. These might show if there is a tumour in your kidney.

For this scan, you will lie down and a gel will be  spread over your abdomen or back. A small device called a transducer is passed over the area. The transducer sends out soundwaves that echo when they meet something dense, like an organ or tumour. An ultrasound is painless and takes about 15–20 minutes.

CT scan 

A CT (computerised tomography) scan uses x-ray beams to take many pictures of the inside of your body and then a computer compiles them into one detailed, cross-sectional picture.

If kidney cancer is suspected on an ultrasound, your doctor will usually recommend a CT scan. This will help find any tumours in the kidneys, and provide information about the size, shape and position of a tumour. The scan also helps check if a cancer has spread to nearby lymph nodes or to other organs and tissues.

CT scans are usually done at a hospital or radiology clinic. You may be asked to fast (not eat or drink) for several hours before the scan to make the pictures clearer and easier to read.

Before the scan, a dye may be injected into a vein in your arm. This dye, known as contrast, helps make the pictures clearer. It travels through your bloodstream to the kidneys, ureters, bladder and other organs. The dye might make you feel flushed and hot for a few minutes and you could feel like you need to pass urine. These effects won’t last long.

For the scan, you will lie flat on a table that moves in and out of the CT scanner, which is large and shaped like a doughnut. This painless test takes about 30–40 minutes.

MRI scan 

An MRI (magnetic resonance imaging) scan uses a powerful magnet and radio waves to create detailed, cross-sectional pictures of the inside of your body. Only a few people with kidney cancer need an MRI, but it might be used to check whether cancer has spread from the kidney to the renal vein or spinal cord.

Let your medical team know if you have a pacemaker, as the magnet in an MRI scanner can interfere with some pacemakers. As with a CT scan, a dye might be injected into your veins before an MRI scan. An MRI without dye may be used instead of a CT scan if you have pre-existing kidney problems and cannot have the dye.

During the scan, you will lie on an examination table that slides into a large metal tube that is open at both ends. Lying within the noisy, narrow machine makes some people feel anxious or claustrophobic. If you think you may become distressed, mention this beforehand to your medical team. You may be given a mild sedative to help you relax, and you will usually be offered headphones or earplugs. The MRI scan may take between 30 and 90 minutes.

Radioisotope bone scan 

Also called a nuclear medicine bone scan or simply a bone scan, a radioisotope scan can look for changes in the bones. It’s used only if you have bone pain or blood tests results show high levels of alkaline phosphatase. These may be a sign that the cancer has spread to the bones. If cancer is found in the bones, the scan can also used be used to check how the cancer is responding to treatment.

A radioisotope bone scan uses a very small amount of a radioactive solution. Before you have the scan, the solution is injected into a vein, usually in your arm. You will need to wait for a few hours while the solution moves through your bloodstream to your bones. Your body will be scanned with a machine that detects radioactivity. A larger amount of radioactivity will show up in any areas of bone affected by cancer cells.

Precautions to take

Radioisotope bone scans generally do not cause any side effects. After the scan, you need to drink plenty of fluids to help remove the radioactive substance from your body through your urine.

You should avoid contact with young children and pregnant women for the rest of the day. Your treatment team will discuss these precautions with you.

PET Scan

A PET (positron emission tomography) scan is a specialised imaging test. It uses an injection of a small amount of radioactive solution to help cancer cells show up brighter on the scan. A PET scan is useful for some cancers, but kidney cancer does not always show up well on a standard PET scan. Newer solutions are currently being studied and a PET scan may be used to look for kidney cancer in the future.

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