Why an X-ray instead of an MRI

[anashenwrath, ASN, RN]

Hi all,

First year student here! I was hoping someone could assist me with my care plan and a question my instructor asked regarding my patient.

The patient was a 67 yo male with a history of diabetes and hypertension who presented with chest pains, SOB, and an elevated blood pressure.

He had received a BKA last month, due to vascular disease r/t diabetes. During my rotation, he received an x-ray of the other foot. My instructor wants me to come up with some reasons why he received this x-ray and why an x-ray instead of an MRI.

My thought is that since he had swelling in this leg, they wanted to assess the cause of the swelling and any exacerbation of PVD/risk for PE. But why wouldn't they do an MRI? Is an x-ray better at visualizing fluid buildup around the bone? The only other things I could think of were minor things like cost or patient comfort.

Thanks for any assistance!

[Esme12, ASN, BSN, RN]

Cost isn't minor. MRI's are a HUGE expense. Why did he have the other amputation.....I know you said vascular disease R/T diabeties. Did he have unhealing ulcers, gangarene, osteomylitis, occult fractures?

These can all be seen with diabeties and a simple x-ray will do....

http://en.wikipedia.org/wiki/Osteomyelitis

http://en.wikipedia.org/wiki/Gangrene

[talaxandra]

Can you think of any other advantages of x-rays over MRI? A couple of hints - there are fewer MRI scanners than x-ray machines, and think about what's involved in each test.

Good luck with your homework :)

[anashenwrath, ASN, RN]

Ok, thanks for the feedback! So it's sounding like I'm on the right track thinking it has to do with the nature of the MRI and not something specific with my patient.

I'm not positive what specifically was the cause of the amputation, but he does have ulcers developing on the remaining leg, as well as neuropathy, so I would venture that diabetic ulcers played a role.

I know they have extremity MRIs at my hospital, but I didn't realize just how expensive it could be. I guess that probably is the big reason. It just really seems like the MRI would be the better source for fluid/vascular visualization.

[nurseprnRN, BSN, RN]

what if they're not looking at the fluid? hmmm? bones are well-visualized on x-rays....just sayin' ... look for an orthopedic complication often seen in people who can't feel their feet...

[LadyinScrubs, ASN, RN]

Does your pt have a pacemaker, schrapnal from a war injury, or other metal in his body?

[ckh23, BSN, RN]

Perhaps he does not do well in enclosed spaces.

[xtxrn, ASN, RN]

Does your pt have a pacemaker, schrapnal from a war injury, or other metal in his body?

Interesting comment. (and not sure it applies here- but hey, stuff happens ). Had a guy in LTC who had an irritating mass on his leg...turns out it was 60 year old shrapnel.... WWII. He made the small town news with that one :)