Fig. 14. Simple ovarian cyst. Longitudinal image through the pelvis show a well-defined, unilocular, anechoic lesion (indicated by the calipers) with posterior acoustic enhancement behind the urinary bladder (B). A small amount of normal ovarian parenchyma (arrow) is noted posterior to the cyst.
Pelvic inflammatory disease The term ‘‘pelvic inflammatory disease’’ refers to a sexually transmitted infection of the upper genital tract. It is an ascending infection that begins in the vagina and cervix and may extend to the endometrium, fallopian tubes, ovaries, and peritoneal cavity. The common causative organisms are Neisseria gonorrhoeae, Chlamydia trachomatis, and endogenous anaerobic organisms. The presenting signs and symptoms include lower quadrant or pelvic pain and tenderness. The diagnosis usually is established clinically, but sonography can have a role in establishing disease extent and the presence of complications.
Sonography may be normal in patients who have minimal inflammatory disease. In the early stage of disease, an enlarged ill-defined uterus (‘‘indefinite uterus’’sign) may be seen. Later, if pyosalpinx develops, it appears as a thick-walled, tubular structure containing low-level echoes (Fig. 16). Ovarian involvement initially presents as a poorly defined, solid adnexal mass (tubo-ovarian complex) (Fig. 17). Later, when necrosis and liquefaction occur, an abscess is seen, appearing as a uni- or multilocular mass with thickened walls and internal debris. Color Doppler imaging shows hyperemia of the involved structures.73