Multi-parametric prostate MRI (mpMRI) is a new technique available to men that assists in the diagnosis of prostate cancer. We pioneered this technique in Australia here at the Wesley Hospital in conjunction with Professor Jelle Barentsz (Rabdoud University, Nijmegen, The Netherlands) who is a world leader in mpMRI. Wesley Medical Imaging is currently one of the most experienced mpMRI centres in the world.
The technique is a non-invasive test that uses a powerful magnetic field to obtain pictures of the prostate gland. The test requires you to lie still on the MRI table and typically takes around 30 minutes to perform. Several images are then taken of the prostate to see if there are any areas that are concerning for cancer.
After the test you will be seen at a follow-up appointment to review your scan. Essentially the scan will either show suspicious areas or not. If suspicious areas are seen, then a biopsy can be arranged and the abnormal areas sampled. This biopsy can be performed in the MRI unit itself (in-gantry), or in the operating theatre where the urologist can target the abnormal areas either by using a mental image of the MRI (cognitive targeting) or by fusing the MRI image with ultrasound in theatre (fusion techniques). In all of these techniques the biopsy involves inserting a needle into the prostate either through the skin between the scrotum and the anus (transperineal) or through the rectum (transrectal).
It is important to note that mpMRI is a new technique and that some cancers can be missed by mpMRI. It is not yet clear how good a negative scan is at excluding prostate cancer. In some cases it may be reasonable to simply observe your PSA level if the scan is negative. However in other cases we may still elect to proceed with a standard prostate biopsy if your PSA tests indicate that there is a moderate to high risk of cancer. Patients often then ask, why do the scan at all if that is the case? The reason is that if the scan is positive, then that will help make any biopsy more accurate because it can clearly demonstrate the abnormal areas that need to be targeted. In summary, a positive scan is useful in identifying that a biopsy is needed and in directing where the needles should go, while a negative scan may allow your PSA to be watched in some cases, while in others a biopsy may still be required.