Magnetic resonance neurography for the diagnosis of extrapelvic sciatic endometriosis  Mirko Pham, M.D., Claudia Sommer, M.D., Carsten Wessig, M.D., Camelia-Maria Monoranu, M.D., José Pérez, M.D., Guido Stoll, M.D., Martin Bendszus, M.D.  Fertility and Sterility  Volume 94, Issue 1, Pages 351.e11-351.e14 (June 2010) DOI: 10.1016/j.fertnstert.2009.12.046 Copyright © 2010 American Society for Reproductive Medicine Terms and Conditions

Figure 1 Magnetic resonance neurography coronal (A, C, E, G, upper row) and axial (B, D, F, H, lower row) sections through the hip region and proximal thigh. The dotted white reference lines plotted on the T1 weighted images (left column, A, B—T1-w) indicate the respective section planes. The same images facilitate the anatomic delineation of the gluteal muscles on the right side heavily altered by fatty atrophic degeneration (white solid arrows on T1-w, A, B) and the sciatic nerve emerging below the piriform muscle passing through the infrapiriform foramen (white arrowheads, A). In the adjacent column on the right (C, D), contrast-enhanced and fat-saturated images (T1-w +Gd+FS) show intense and diffuse uptake of contrast agent (gadopentetate dimeglumine - Gd-DTPA) centered about the piriformis muscle and extending into the gluteal region. Images of the next column (E, F) were obtained exploiting the T2-w contrast with an inversion recovery technique and fat saturation (TIRM, E, F). As a typical finding in axonal nerve damage, the sciatic nerve is bright on T2-w in its entire course distal to the injury (white arrowheads, E). In addition, gluteal muscles were bright on T2-w MRI as well, indicating involvement of gluteal nerves (white arrow, E, F). On follow-up after 6 months and on initiation of antiestrogenic medication the endometriotic lesion partially regressed on the T2-w image (TIRM, G, H); however, axonal injury and denervation still persisted indicating incomplete regeneration at that date. Fertility and Sterility 2010 94, 351.e11-351.e14DOI: (10.1016/j.fertnstert.2009.12.046) Copyright © 2010 American Society for Reproductive Medicine Terms and Conditions

Figure 2 (A) Islet of endometrium embedded in connective tissue. Endometrial glands with tall columnar epithelial lining are surrounded by cytogenic stroma. Hematoxylin and eosin stain. (B) Strong nuclear expression of estrogen receptor confirming the diagnosis of endometriosis. Immunohistochemistry for estrogen receptor by anti-estrogen receptor rabbit monoclonal primary antibody (Ventana Medical Systems, Illkirch, France). Bar = 50 μm. Fertility and Sterility 2010 94, 351.e11-351.e14DOI: (10.1016/j.fertnstert.2009.12.046) Copyright © 2010 American Society for Reproductive Medicine Terms and Conditions