Size difference in tumor between ultrasound and MRI...

kec1972

Hi everyone,

So I just got my MRI results back. When I had my ultrasound/biopsy a couple of weeks ago, my tumor size was shown to be 13mmx10mmx9mm. On MRI it was shown to be only 9mmx8mmx8mm....wondering which would show the more accurate measurements? It seems like a big size discrepancy.

Salamandra

Was your ultrasound before or after the biopsy?

I was told that the biopsy can make the tumor look bigger. My biopsy called my tumor 1.3cm, and on the MRI it looked more like 3-4cm. Surgery found 1.8cm. The surgeon said that she does not trust post-biopsy imaging for size. And of course the biopsy wasn't quite accurate either. I think you can't really know until they take it out.

kec1972

My ultrasound measurements were taken before my biopsy; MRI was post-biopsy. I guess I find it strange because I've read that MRI often overestimates tumor size. The radiologist even wrote in my results that it was very unusual to find such a smaller measurement on MRI. I'm eager to see what the actual size is after my lumpectomy!

Skwashie

I raised this one with my BC surgeon after my surgery. He advised that an US tends to undersize a tumour. Remember sound waves are being used to estimate the dimensions. Magnetic resonance imaging is a different technology, which results in different sizings (not always accurate again).

Like someone has already said, you won't find out the true size and character of the tumour until it has been removed and tested. It is however quite typical that during this journey we try to make sense of what is happening; with each piece of additional information. The mind is quite literally trying to find homeostasis so that we can live lives that aren't in perpetual trauma. We also start to exhibit survivor characteristics by rationalising our experiences ... it's a good thing to do, just remember that the journey is somewhat unpredictable and getting used to that is in fact the wave that we ride.

Good luck with the next stage and wishing you healing and gentleness.

coraleliz

The explanation I was given: The tumor is pliable. When you lay on your back for the ultrasound, the tumor spreads itself out differently than when you lay on you stomach for a MRI.

jessie123

I can feel my tumor -- before biopsy it was really hard to find - needle core ultrasound measured 1.3 cm. After biopsy it was really easy to find. I mentioned this to the surgeon and she said that it's because the tumor is swollen from the biopsy trauma. I just had my MRI which is a month after the biopsy. The swelling has gone down so I'll be curious what size it measured. Will let you know.

kec1972

yes Jessie please do! I’m interested. Hug

Rah2464

I will echo what others have said, you won't know the exact size until the tumor is removed. My mass on imaging (which didn't show on mammogram or ultrasound, only MRI) was over 2cm. But wonderfully at surgical removal was 1.3 cm

Cin17

jessie123, same here. Mine was difficult to find before biopsy. After biopsy it feels larger and is easier to find. It went from 2.7 cm on ultrasound to 4.9 cm on MRI. Fingers crossed it isn't any bigger when it's removed next week.

Beesy_The_Other_One

My tumor was HER2 positive and was clearly exploding in growth at the time of diagnosis, but did it really grow from 1.5 cm to 7 cm in two weeks? Note below that in December I had an ultrasound on the 10th and an MRI on the 13th. The ultrasound measured the tumor's largest dimension as 8 mm and the MRI three days later measured it at 1.3 cm. My oncologist did the original MRI in August because he wanted me to qualify for Perjeta. Boy, did I! He looked pretty ashen the next time I saw him. Suddenly I not only qualified for Perjeta, but also radiation! I would say that, in my experience, based on the December imaging, MRI exaggerates.

8/15/18 Biopsy Ultrasound---1.5 x 1 x 1 cm

8/30/18 MRI----------------------7 x 2 x 3.4 cm (!!!!)

11/12/18 Ultrasound-----------1.1 x 0.6 x 0.4 cm

12/10/18 Ultrasound------------0.8 x 0.7 x 0.3 cm

12/13/18 MRI---------------------1.3 cm at largest point (radiologist did not record other 2 measurements)

mammalou

my MRI was approx 1 cm. Final pathology 3.6cm idc plus 1.2 cm DCIS. I think it depends on your breast tissue. I am very dense even on MRI so imaging is obscured.