Prostate magnetic resonance imaging (MRI) is a non-invasive medical test that can diagnose and stage prostate cancer, which causes around 3300 deaths in Australian men each year. Prostate cancer is the leading cause of cancer-related deaths in men, and exceeds the number of deaths in women from breast cancer. Until recently, prostate cancer was difficult to image and detect. MRI has emerged as the imaging modality of choice for detection, localisation, grading, staging, and treatment of patients with prostate cancer.
The risk of prostate cancer is:
- Age 40-49 – 1 in 1000
- Age 50-59 – 12 in 1000
- Age 60-69 – 45 in 1000
- Age > 70 – 80 in 1000
Prostate likelihood risk can be determined through digital rectal examination and a simple blood test to measure levels of prostate-specific antigen (PSA), which is a blood protein secreted by prostate cancer.
If either of these tests is abnormal, the patient may be referred to a specialist urologist or for further evaluation, such as ultrasound, MRI or endorectal biopsy. MRI of soft tissue and organs such as the prostate are clearer and more detailed than other imaging methods. MRI enables early diagnosis, as well as accurate evaluation of tumour extent.
If a prostate biopsy is performed, a pathologist analyses tissue samples to determine whether cancer is present. If cancer is found, then further evaluation will determine whether disease is localised or has spread beyond the prostate.
Treatment depends on the extent of spread. MRI can determine If the cancer is completely inside the prostate gland, or has spread to nearby organs such as the bladder or rectum, or has spread to lymph nodes, bones, liver or lungs. For men with intermediate or high probability of spread outside the prostate, MRI improves the accuracy of disease staging.
MRI can also assist surgeons plan cancer resection. Understanding the extent of disease enables a surgeon to preserve delicate arteries and nerves, which are essential for maintaining sexual function and bladder control.
Prostate MRI can also be used to evaluate other prostate problems, such as infection or abscess, prostate enlargement, congenital abnormalities, or complications after pelvic surgery.
MRI uses a very strong magnet, radio frequency waves and a sophisticated computer to generate detailed greyscale images. No x-rays or ionising radiation is used.
For prostate MRI the lower abdomen is placed within a magnet coil that detects shifting signals, which are encoded by the magnetic field gradients that make the loud thumping noises heard during MRI. Finally, powerful computers process the signal to form an image of the area of interest. The magnetic field and radiofrequency waves have not been shown to cause any long-term effects.
South Coast Radiology has MRI at:
Because a strong magnet is used, patients with certain ferromagnetic implanted devices or prostheses should not have MRI scans. When the patient arrives, he will be asked to answer a series of safety questions. Patients with cardiac pacemakers, metal heart valves, some ear implants, certain brain aneurysm clips and various other medically implanted devices should not have MRI because the metal will respond to the strong magnetic field. Also, people with metallic foreign bodies in their eyes, through grinding/welding, are excluded from MRI.
What to expect
The MRI machine combines a doughnut-shaped magnet with a padded couch, which moves through the centre. Throughout the scan, the radiographer will maintain visual and voice contact with the patient. The switching of the magnet creates a lot of loud noise, so the patient will be given hearing protection, which he must wear during the scan.
Scan can take up to 30 minutes depending and during that time the patient must remain relaxed and very still, to avoid a blurred image.
Sometimes, a small dose of gadolinium is injected through the arm vein to temporarily alter the magnetic properties of the body tissue and enhance anatomical detail. Our radiologist will determine whether an injection is needed, at the time of the scan.
MRI is painless and the patient will not feel any after effects, so he can resume normal activity straight away.
As this involves scanning the lower abdomen, the patient will need to fast before the appointment, in order to avoid bowel and stomach movement. Our staff will advise the patient how long to fast for, when he makes the booking.
Patient's who suffer from claustrophobia might not feel comfortable within the magnet for the required time. Please ask the patient to advise our staff so that we can discuss his options.
At South Coast Radiology, we accept MRI referrals from medical specialists, GPs and physiotherapists. GPs have access to a limited number of MRI examinations for both adult and paediatric patients. Medical specialists have access to a larger number of MRI examinations. However, not all MRI examinations attract a Medicare rebate.
Our MRI bookings staff can discuss your options regarding whether a Medicare rebate is available for your scan at the time of booking. Please contact them on 5597 06877, press 1 for bookings.
Please remind the patient to bring any previous relevant x-rays, CT, MRI or ultrasound films, as the radiologist reporting the MRI can review these and possibly improve the quality of the report.
After prostate MRI
One of our radiologists will interpret the MRI and provide you with a comprehensive report about the findings. We will recommend that the patient return to the referring doctor to discuss the MRI result. Processing and reporting of the MRI could take up to two hours.
If you are a registered a referrer you can access your patients’ MRI images and report through our secure online archival system, or view the films we provide. For more information about registering to access patient images visit the Access Medinexus Portal section.
Any hardcopy images and report can generally be delivered to the referrer, by lunchtime on the next working day. If the patient needs to be reviewed on the day of the MRI, the patient can wait for the films and we will fax or email the results.