Journal of Ultrasound in Medicine, Vol 20, Issue 1 27-31, Copyright © 2001 by American Institute of Ultrasound in Medicine
Comparison of tubal ring and corpus luteum echogenicities: a useful differentiating characteristic
M. C. Frates, A. Visweswaran and F. C. Laing
Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
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
improved detection of early ectopic pregnancy. In patients with ectopic
pregnancy diagnosed at sonography on the basis of the presence of an
adnexal tubal ring, echogenicity of the ring was compared with the
echogenicity of the ovarian parenchyma. Twenty-six patients with tubal
rings containing either a yolk sac or cardiac activity were included.
Twenty-three (88%) of the 26 tubal rings had echogenicity equal to or
greater than that of ovarian parenchyma. 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 echogenic than the ovary
in only 3 (7%). The tubal ring of an ectopic pregnancy is usually more
echogenic than ovarian parenchyma, and the corpus luteum 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 from a corpus
luteum.
