In the competitive industry of diagnostic
imaging, MRI appears to be doing well at least according to my
Google search that produced 49.1 million results in 0.12 seconds.
Seven of these results told me that I could receive an MRI at seven
different locations just miles from where I work in Cincinnati, OH.
I wonder how each of these seven centers remain profitable with all
of the competition in such a close proximity? They must provide
great patient service, be competent, abreast of all the latest
technology, and practice safety. Right? I enjoy exploring Google and
discovering what services MRI centers believe that they are the
“best” or “safest” at performing. I am most fascinated by the
rationale behind their claims of grandeur. I believe that the
marketing tactics used by some centers and institutions is like
reading the funnies in the newspaper. I understand that a center or
institution wants to highlight their positive attributes while down
playing less desirable aspects of their operation, but how far
should the marketing go? At what point does the marketing stop being
funny and start being false or misleading? The center discussed in
this article will remain nameless as I wish to extend a professional
courtesy throughout this article. This center stresses the
importance of being the safest center in their area with the
strongest magnet. To support this claim they have written an article
titled “3T MRI is twice as strong as any other MRI unit”.
The first sentence of the article states, “The increased magnet strength gives us many benefits at no additional expense.” MRI is very much a give and take modality. Rarely have I encountered a benefit in MRI without an expense. In this instance, I will assume that they are comparing a 1.5T MRI unit to a 3.0T MRI unit. This increase in field strength will increase specific absorption rates (SAR). SAR is a term that is used to describe the absorption of RF radiation. It is measured in watts per kilogram and is usually designated as a whole body average. Frank Shellock, Ph.D. states, “Many MR systems now operate at a static magnetic field strength of 3-Tesla, several operate at 4-Tesla and 7-Tesla, one operates at 9.4-Tesla. These very-high-field MR systems are capable of depositing RF power that exceed those associated with a 1.5T MR system” (13). In my opinion, this is not a benefit without an additional expense. SAR should be taken seriously as it affects the thermoregulatory system of patients, which may already be compromised due to other physiologic conditions. Additionally, the technologist should try to manage SAR levels with the use of a longer TR, reduced number of slices, pulse sequence order, time between sequences, and the use of gradient echoes. I guess if I multiply 1.5T by two my answer is 3.0T, but this does not necessarily equal a better imaging solution. There are also many other factors that must be managed at 3.0T in order to provide best patient care. 3.0T is more prone to chemical shift artifacts in areas where fat and water interface in the frequency direction. This can be seen as a bright or dark band at the edge of anatomy and could be mistaken for pathology by the inexperienced eye. However, the increase in chemical shift artifact can be helpful in terms of spectroscopy. It is also important to mention the increase in diamagnetic susceptibility artifacts at 3.0T. This will definitely affect the imaging of patients with dental braces or other ferromagnetic implants, but it is wonderful for susceptibility weighted imaging. I believe that all of the above mentioned facts are trade-offs that one encounters at 3.0T. Therefore, it is not accurate to make the statement that there are many benefits at no expense.
A large, secondary theme of the article discusses how safe the center is and how the use of a 3.0T MRI unit helps them to achieve this unsurpassable level of safety for their patients. The unknown author explains, “It (the use of 3.0T) gives us extra contrast enhancement. When you get an injection of contrast on a 3T MRI unit you get twice the enhancement you would get at a lower field strength. This means renal failure patients get a safer study with less risk of NSF.” The author then briefly discusses the molecular composition of the “safest” contrast (as if the average reader would understand this chemical phenomenon). The truth that should be known by all MRI technologists is that the T1 time of tissues is longer at 3.0T than at 1.5T, and one can administer less contrast. It is also safe to say that if a patient has renal insufficiency, the technologist and radiologist should work together to limit the dose. Gadolinium is bonded with a ligand molecule to make it safer when administered to humans, and those with poor renal function run the risk of having the gadolinium ion dissociate from the ligand. Additionally, when interviewed by Radiology Today about the association between gadolinium-based contrast agents and NSF Emanuel Kanal, MD states, “…There have been some pretty strong associations made between the administration of gadolinium-based MR contrast agents and the subsequent development of NSF. This is the case only in patients with severe or, especially, end-stage renal disease or those with acute kidney injury.” Dr. Kanal further explains that there are five gadolinium based MR contrast agents. I do not dispute the fact that reducing the amount of contrast administered to those with renal insufficiency is a safe practice. I disagree with the way the information is presented to the average consumer. The static magnetic field at 3.0T is not what makes contrast enhanced studies at this institution safer than any other institution. I also disagree with the commercial plug of a specific contrast that is in fact gadolinium based. Therefore, it is not necessarily the “safest”. It is only safe if those who work in the institution administer it correctly.
On multiple occasions that author of the article states that 3.0T is faster, clearer, shows more detail, and is a more diagnostic MRI. These are pretty heavy claims for one piece of equipment. Does this mean that it will correctly diagnose more disease? Does this mean that the technologist behind the scanner console has a firm grasp on how to speed up scan times or adjust parameters without comprising data? Does this mean that all of their protocols are optimized for a 3.0T and not just copied from their old 1.5T? Is “clearer” the perfect mix of resolution and signal to noise? Does this mean that a 1.5T can’t do any of these things appropriately? Well, if I were the average reader in need of an MRI, I would believe that this center is the place to go for my diagnostic imaging needs. I would also believe that the technologist would know exactly what to do when sitting behind the console. They would also understand the Mona Lisa picture that we are all shown at every conference that we have ever attended. I would think that 1.5T technology is totally obsolete and basically useless. Lastly, I would believe that the number of phase encodings, NSA, and TR doesn’t really effect the scan time and that the static magnetic field does.
In a revenue driven imaging industry, marketing is crucial for the success of imaging centers and institutions. However, we must ask ourselves how far should marketing go to reach consumers while concurrently conveying accurate information? Consumers can be overwhelmed and sometimes confused with options and must make a choice about what is best for their healthcare. I believe that as professionals in our industry we must convey the most accurate information possible. The article that I have referenced is an example of marketing gone awry. It may highlight its strengths, but it masks many facts.