Not All Bores Are Created Equal
There’s a lot of confusion when it comes to the various types of MRI. Centers toss around terms like “open” and “closed” and “wide open” and expect patients to take them at their word and understand what the differences are. We can’t tell whether the machine is the type it’s supposed to be. We’re not the experts. But with a little help, we can get a better understanding of the differences in each type of MRI so that later down the line, when we finally have to take that trip into a medical center for our first MRI, we know what to be looking for.
There are three types of MRI bores: closed, open, and wide. The term “bore” simply refers to the opening that the patient is placed in (it’s that tube you’re quite familiar with), and MRI types are determined by the size of the scanner’s bore.
Closed MRI’s have closed bores. Closed bores usually have a higher magnetic strength (somewhere between 1.0T and 3.0T), and a bore diameter of somewhere around 60 cm. Generally speaking the rule with MRI’s is that the smaller the bore, the greater the image clarity, so even though closed MRI’s are ranked lower for patient comfort, they’re definitely the best option if you need a high-clarity study.
As far as the other two types of MRI’s, this is where it gets a bit confusing, partly because machines with “open bores” and machines with “wide bores” are in many cases both referred to as “Open MRI machines”. This is how we like to differentiate between the two:
The Open MRI bore is completely different from a closed. Instead of the bore being like a tube that completely encircles the patient, it’s got two flat magnets above and below a large space where the patient lies. You’re not closed in, so if you’re claustrophobic or just enjoy having some extra space, then this is the MRI scan for you. We like to refer to machines with the open bore as “truly open MRI’s”.
Machines with the wide bore are what we call “sort of open MRI’s”, and they’re exactly what they sound like: a middle ground between open MRI’s and closed MRI’s. The wide bore is slightly larger than the closed bore, coming in at around 70cm, so patients get a little more space than they would in a traditional closed bored. Although wide bore machines are more “open” than closed bore machines, they still don’t provide patients with the amount of space necessary to classify as a “truly open” machine.
So when you’re looking at a center that advertises an Open MRI, be sure to ask them about their machines bore.