This is Dr. David
yes, an ultrasound can look into your knee. and can check for fluid.
but the resolution of an ultrasound is not as fine as an MRI scan.
and small tears in the meniscus can be missed on ultrasound.
but it is a good first scan choice for the knee.
here is a good study comparing ultrasounds vs MRI scans for meniscal tears
Ultrasound was found to be correct in 25 (86.2%) of the 29 meniscal tears and incorrect in four menisci. As a result, ultrasound yielded 86.2% sensitivity for meniscal tears, 84.9% specificity, 85.4% accuracy, 75.8% positive predictive value, and 91.8% negative predictive value.
That,is interesting thank you . I will go to the hospital this afternoon. Thank you.