Intussusception – ultrasound is extremely sensitive in detecting…
Intussusception – ultrasound is extremely sensitive in detecting intestinal intussusception and several different sonographic ‘signs’ are described.
When bowel telescopes into itself concentric rings are seen creating the target sign (left image) also known as the doughnut sign. The appearance is not only due to three bowel walls paralleling each other, but is also due to each wall itself demonstrating the normal striation of echogenic mucosa, hypoechoic submucosa and echogenic muscularis.
When a large portion of mesenteric fat is incorporated within the intussusception then an additional echogenic crescent may be seen creating the crescent within a doughnut sign.
Finally, the combination of intussusception and adjacent enlarged mesenteric lymph nodes may simulate the appearance of a kidney creating the pseudokidney sign (right image) where hypoechoic lymph nodes appear like renal medullary pyramids.
from our tumblr blog: http://radiologysigns.tumblr.com/post/26825013177