Comparison of tubal ring and corpus luteum echogenicities - A useful differentiating characteristic

The purpose of this report is to compare the echogenicity of the tubal ring of an ectopic pregnancy and the corpus luteum with that of the ovary for i mproved detection of early ectopic pregnancy. In patients with ectopic preg nancy diagnosed at sonography on the basis of the presence of an adnexal tu bal ring, echogenicity of the ring was compared with the echogenicity of th e ovarian parenchyma. Twenty-six patients with tubal rings containing eithe r a yolk sac or cardiac activity were included. Twenty-three (88%) of the 2 6 tubal rings had echogenicity equal to or greater than that of ovarian par enchyma. In 13 patients with ectopic pregnancy diagnosed on the basis of an empty tubal ring, 10 rings (77%) were more echogenic than the ovary. In 45 control patients with intrauterine pregnancy, the corpus luteum was more e chogenic than the ovary in only 3 (7%). The tubal ring of an ectopic pregna ncy is usually more echogenic than ovarian parenchyma, and the corpus luteu m is usually equal to or less echogenic than the ovary. Echogenicity of an adnexal mass may help distinguish the tubal ring of an ectopic pregnancy fr om a corpus luteum.