At a major hospital in Israel, one with a very extensive emergency department, they do not have an MRI for the ED. Why? The payment for an emergency room visit is a flat rate, and a low one at that, regardless of diagnosis. While they have X-Rays and CT scanners, they cannot justify the cost of an MRI. Besides, noted my host, "How often do you really need an MRI for an emergency room visit?"
What a contrast with the US, where an MRI in each hospital's ED is de rigueur. But the same question could be asked, "How often do you really need an MRI for an emergency room visit?" Not, how often is one used? This article, for example, shows a tripling of MRI and CT usage in the ten years after 1998. The JAMA abstract is here. (It doesn't separate the two modalities.) During this same time period, there was a small increase in the prevalence of life-threatening conditions; but there was no change in prevalence of visits during which patients were either admitted to the hospital or to an intensive care unit. Visits during which CT or MRI was obtained lasted 126 minutes longer than those for which CT or MRI was not obtained.
So, how often is an MRI really needed? At what cost to society?