CT brain scan v MRI for memory loss dx

[whatwouldyoudoifisangoutofkey]

Following memory clinic appointment friend referred for brain scan.
Unable to have MRI due to metal pin placed long ago in leg.
Could anyone comment on difference to understanding what is going on with my friends brain? She has severe short term memory loss but her cognitive skills seem fine.

MRI scans and PET both give a picture of the structure and function of the brain. MRI pictures are a bit clearer and don't involve any radiation so the doctors prefer them if possible. But both can give the information needed for a diagnosis.

A metal pin in leg from years ago wouldn’t contraindicate an MRI scan. The CT would be quicker - does your friend understand the situation and would they be able to lie still for the scan? Just thinking that maybe that’s why the dr thought a CT may be better?

My dad had short term memory loss, after the memory nurse appointment he was referred for a head CT scan and diagnosed with Alzheimer’s. CT scans are usually used for dementia diagnosis.

If your friend can’t have an MRI though it’s not right to assume it’s this though.

I hope it works out well for them.

@parietal , thanks.
She's having a CT scan not PET or MRI.
I thought PET scans were used to detect cancer ?

@DiamondLily, friend would be fine about lying still.
Consultant said that because metal pin was placed over 10 years ago they couldn't be sure of its composition and therefore a MRI not possible.
We thought odd , especially as leg somewhat distant from the area being scanned.

@TimeForATerf , thanks. It is short term memory loss
Did the Alzheimer's dx lead to any useful intervention?
Was any medication or support from professionals offered?

The older the metal, it's true the less likely they are to know exactly what it is. Ditto if it was put in abroad.

Pins can also be pretty long - what we think of as a pin can be larger than expected.

Distance from site of scan can be ok but it also depends on strength of scanner. A 1.5T scanner may be ok, but a 3T or more, less so. The radiographer will have made a judgment call.

My mum just had a CT for the same dx reasons. Seems normal.

My parent had CT scan as there was the possibility of metal in their body so MRI not advisable. My understanding was that it is more to define the type and location of the brain disease, so which lobe(s) and what type of lesions/plaque is forming.

"to define the type and location of the brain disease, so which lobe(s) and what type of lesions/plaque is forming.''
that's really interesting , thank you @unsync

@Borgonzola thank you that's interesting.
I'm not being critical, it's great she's had an appointment and is having investigations,just wanting to understand.
It was a UK pin ( !! ) and has been recently x rayed.
The gerontology consultant referred for a CT scan ,I think probably following protocol if there's an old metal pin. So it didn't feel like it was the radiologist's call.
The consultant , for instance, couldn't request that the advice re date of appointment be copied by email to a NOK ( because friend misses texts, forgets phone calls , buries letters) as it was a different department that would be contacting friend.

I have metal rods in me from over 30 years ago. Was assured that MRI was safe. Still scared the living shit out of me but was fine.

Thanks @Awrite , good to know .
Might be relevant to question if at some point , maybe for something different, a MRI would be preferred scan .
To be fair the pin was put in 60 years ago , at the hospital she's still attending.
Not that I expect records to go back that far !

Ah @whatwouldyoudoifisangoutofkey we could go down a rabbit hole about metal pins and scans, but the important thing to note is that both CT and MRI can be helpful in to diagnosing dementia ( and rule other causes of the symptoms out). There are more specialised scans as another pp has said, but remember any referrals should be based on how it will affect the management of the patient. Of course you want a diagnosis, but unless there is a different type of medication they could take for example, then they don’t need lots of specialised tests. As for appt letters etc, that’s another avenue to explore - does anyone have power of attorney for them, and if not are they still sufficiently able to set this up? I hope all of this is useful, and I don’t sound heartless - it’s such a difficult time and I wish you and your friend all the best 💐

@DiamondLily absolutely agree about rabbit holes.
I'm that sort of person who likes to understand and it wouldn't have been appropriate to delve into this at the busy clinic.
I am more interested in how the departments interact and an IT system which I suspect made it difficult for the consultant to communicate about preferred methods of communication to patients.
Yes H& W LPA in place but held solely by a solicitor.

I completely understand @whatwouldyoudoifisangoutofkey , everyone wants the best for their friends and relatives and gathering all the information needed to make the best decisions is part of that. PALS may be able to help or direct you with communication and contacts, or the NOK may be able to access information via the NHS app?

Good point about NHS app.
I tried to help the person in question sign up but to say that it did not go well would be an understatement🙂
However , if at first you don't succeed...

Basically mum was put in touch with Alzheimer’s Association for support, informed about Attendance Allowance, and given medication to slow down the condition.

The AA support may work for some people but it didn’t work for our family.

In later years, dad was given other anti depressant type medication which mellowed the aggression which was not my dad.

I hope it doesn’t turn out to be this for your friend x

@TimeForATerf thank you , it's definitely something 😞