• endometrial tissue in myometrium
  • secondary smooth muscle hypertrophy and hyperplasia
  • diffuse or focal
clinical presentation
  • dysmenorrhea
  • dysfunctional uterine bleeding
  • enlarged, globular uterus
  • myometrial heterogeneity
  • echogenic myometrial nodules
  • subendometrial echogenic linear striations
  • 2-6 mm subendometrial cysts
  • endometrial pseudowidening: poor definition of endomyometrial junction
  • rain shower appearance: multiple fine areas of attenuation throughout the lesion
  • doppler: speckled pattern of increased vascularity within heterogeneous area
  • areas of low myometrial signals in T2
  • focal or diffuse thickening of junctional zone
Junctional zone
> 12 mm high accuracy of diagnosis
8-12 mm needs other criteria
a: high signal intensity striations extending out from endometrium into myometrium
b: high signal intensity in T1 representing endometrial rests or punctate hemorrhages
< 8 mmexcludes disease with high accuracy