Echogenic foci mimicking adenomyosis presumably due to air intravasation into the myometrium during sonohysterography

PURPOSE: To report the radiological findings of a pseudolesion in the myometrium mimicking adenomyosis presumably due to air intravasation during sonohysterography (SHG). MATERIALS AND METHODS: We searched magnetic resonance imaging (MRI) and transvaginal ultrasound (TVUS) examination results before and after SHGs, in which echogenic foci were found suggesting adenomyosis in the myometrium, and found 7 female cases. MRI and TVUS findings were compared to the SHG findings to assess the persistence of echogenic foci seen with SHG and other imaging modalities, and to exclude the possibility of pseudolesions secondary to saline-air intravasation into the myometrium during SHG. RESULTS: Ages of the 7 patients ranged from 27 to 60 years; 2 of them were postmenopausal. SHG examinations showed solitary or multiple echogenic foci measuring 4-15 mm, with acoustic shadowing, which were adjacent to the endometrium and consistent with adenomyosis. Only 1 of the patients underwent both MRI and TVUS, 2 of them had TVUS after SHG, and 1 had TVUS before SHG; the 3 remaining patients had TVUS as a baseline examination prior to SHG. None of these TVUS or MRI examinations confirmed the echogenic foci found with SHG. CONCLUSION: In order to differentiate echogenic myometrial pseudolesions from true adenomyosis lesions, a detailed preliminary TVUS is essential before any SHG procedure. If such lesions are encountered despite meticulous care to avoid the inadvertent introduction of air into the endometrial cavity, TVUS findings should be reviewed and a pelvic MRI is recommended in cases with heterogeneous myometrium.