Prostate cancer is the most common cancer in men worldwide and the second most common cause of cancer death. Prostate exams whether ultrasound or MRI are generally an uncomfortable experience and many men feel embarrassed or completely avoid anything to do with their prostate. It doesn’t have to be like that though. Endorectal coils (ERC) are useful, but now you can get a prostate MRI without any discomfort, and the quality and accuracy is on par with the standard, invasive diagnostic methods.
Endorectal coils – a thing of the past?
Most facilities use an ERC, which is a special coil that is inserted into the rectum through the anus, and is usually covered by a lubricated balloon or condom. Apart from the obvious sensitive nature of the insertion process, the coil has to stay in until the procedure is over. Another important thing to note is that patients are often asked to fast before the procedure and administer an enema so that the lower bowel is empty.
These types of coils would still be the best choice if advancements in medical imaging weren’t possible. Fortunately, MRI machines and coil technology have brought about a change in prostate MRI.
ERCs work well in tandem with the previous generation of 1.5T MRI scanners and are effective because they get as close as possible to the region of interest, the prostate. However, the availability, quality and features of 3T MRI scanners, which have almost two times the SNR (signal-to-noise ratio) of 1.5T, may be the better choice. From a technical perspective, ERCs, because of their shape and technology, can cause anatomical distortion. Surface coils, on the other hand, allow doctors to see prostate anatomy as it is.
Multiparametric software which provides important data on key parameters (T2 weighting, Diffusion Weighting, Dynamic Contrast Enhancement) helps with improving image quality, making accurate diagnoses and for localization and differentiation. Multiple studies have shown that 3T prostate MRI with a body coil is comparable to 1.5T prostate MRI with an ERC, although most of these studies took into account only one imaging parameter. If we take a state-of-the-art 3T machine with multiparametric imaging, it definitely has the ability to surpass anything 1.5T has to offer.
Healthcare facilities are first and foremost interested in making the experience of a prostate MRI more tolerable. With advancing technologies and the availability of modern equipment and software, patient comfort will become aligned with diagnostic accuracy. At this point in time many of these facilities are adopting a body coil approach to image the pelvis, and the results have been extremely promising. Maybe one day we can throw out the lube and breathe freely, without fear and embarrassment, when referred for a prostate MRI.
Jia, G., Shah, Z., Wei, L., & Knopp, M. (2013, May 8). Prostate cancer: Comparing the image quality of endorectal MRI at 1.5T with 3T MRI without the endorectal coil. Retrieved from https://www.auanet.o...meetingID=13SAN