Clearly I should stick to the bones and most definitely not look at bowel….especially bowel contents! (I deal with way too much of it in the day to day, I will stop looking at it)
I mistakenly assumed that bright T1 bowel "contents" implied steatorrhea. I gather this is a normal appearance.
Regardless of the normal signal, I believe it caught my attention because of the degree of distention.
I have learned that she is consulting a gastroenterologist for symptoms of constipation and malabsorption.
My colleague told me :
Often in people with anorexia, constipation is a sequela of laxative abuse (chronic laxative abuse leads to decreased muscle tone in gut which leads to constipation). But I think they can get constipation for other reasons as well.
Bruno Vende Berg, who authored the seminal articles on serous atrophy wrote:
very common findings. Same findings for other tissue (like cartilage) in these patients at knee mri on T1.. (cartilage may have a high SI at knee MRI on T1)
my explanation is that it is due to the automatic dynamic of the signal at MRI. The "viewing" softwares need a maximum and a minimum and then spread all tissues in between.
Air and cortical bone yield for minimum value.
Which tissue will play the role of the maximum if no residual fat ? Propably some protein rich tissue which might have a signal a bit higher than the other tissues on T1. Therefore it will receive a high intensity and the SI of the other tissues will be spread between min and max.
On T2, fluid will get the highest SI.
This a purely hypothetic explanation withoutproof
Dr. Vande Berg shared a fascinating set of images, with dramatic normalization after weight gain:
T1 WI of same patient when sick and then few weeks later with 10 kg more
Cartilage has a high signal on T1 and then has a low SI when fat is back
And for those of you who have not seen the single best published MSK image, Dr. Vande Berg shared this….a very dramatic comparison of his own leg interposed between the legs of the affected patient (I would have liked to have seen the companion photograph…the logistics of that must have been fascinating)
On Thu, Apr 25, 2024 at 3:26 PM hilary umans <hilary.umans> wrote:
There is uniform Dark T1, Bright T2 (these images are actually PDFS) marrow signal with almost no body fat in this case….minimal body fat in PDFS images is bright, like the marrow.These changes are typical of SEROUS MARROW ATROPHY , which can start more focally and becomes confluent with increased severity of underlying anorexia or cachexia.
This patient is a 30 year old female runner who is 5 foot 2 inches and weighs 80 lbs
She has had previous stress fractures, but there is no fracture at this time
I had assumed she was an anorectic runner, but I am confused by the bright T1 distention of her colon….I don’t know if there is abnormality of the gut lining or if she is eating and not absorbing nutrients….I don’t recall seeing this. I don’t know anything about gut imaging.
In the axial plane it seems like she might have dilation of both colon and small bowel?
What do you think?
Hilary
