Endometrial color flow/image-directed Doppler imaging: Negative predictive value for excluding ectopic pregnancy

Abstract

Purpose Visualization of an intrauterine pregnancy with transvaginal ultrasound virtually excludes an ectopic pregnancy. However, findings that might lower patients' risk for ectopic pregnancy have not been extensively investigated. We prospectively performed transvaginal color flow/image‐directed Doppler imaging of the endometrium to determine the predictive value of endometrial blood flow for excluding ectopic pregnancy. Materials and Methods From April 1994 to August 1995, 211 consecutive women underwent transvaginal ultrasound examinations to exclude an ectopic pregnancy. Color flow/image‐directed Doppler imaging of the endometrium was performed on each patient. Flow was considered to be present only if a Doppler signal could be obtained with the cursor located completely within the endometrium. All Doppler imaging parameters were optimized for each patient. Resistive indices were obtained if arterial signal was present, and receiver operator characteristic curves were constructed for RI and peak systolic velocity. Findings were correlated with surgical and pathology results. Results Of 211 total patients, there were 55 ectopic pregnancies (52 diagnosed for a sensitivity of 95%), 89 incomplete spontaneous abortions, 40 completed spontaneous abortions, and 27 intrauterine pregnancies. Of 55 ectopic pregnancies diagnosed with real time imaging, 9 had areas of endometrial blood flow (6 venous, 3 arterial), and 46 did not. Of the 156 patients that did not have an ectopic pregnancy, 107 had arterial blood flow within the endometrium, and 49 had no flow. Using only cases with arterial signal, the negative predictive value of endometrial blood flow for excluding an ectopic pregnancy was 97% (107/107 + 3). The optimal cutoff values (5% false‐positive rate) for peak systolic velocity and refractive index (RI) were 15 cm/s and 0.55. Conclusions Arterial blood flow within the endometrium lowers the risk for ectopic pregnancy even when other findings that might indicate a high risk are present. Venous flow within the endometrium does not exclude an ectopic pregnancy. © 1997 John Wiley & Sons, Inc. J Clin Ultrasound 25: 103–109, 1997.

The Ectopic Pregnancy: A Well-Deserved Review

“…In the past, and currently, there have been several studies on low-resistance endometrial arterial flow to confirm or exclude the presence of an intrauterine pregnancy to aid in the diagnosis of an ectopic pregnancy. 4,7,20 The efficacy of this technique in early pregnancy in relation to ALARA principles has not been fully investigated. In general, in any situation where there is a potential diagnosis of an ectopic pregnancy, the benefits would outweigh the risks, although specific studies in the future might provide further information on this issue.…”

Low‐resistance endometrial arterial flow in the exclusion of ectopic pregnancy revisited.

“…The technique for obtaining such signals has been reported previously. 20,21 Such flow was defined as having been obtained with a cursor completely within the endometrium and having a resistive index (RI) of less than 0.6. 21 Each waveform was obtained at least twice.…”

“…18 J Ultrasound Ectopic pregnancies have been shown to have endometrial blood flow; however, usually the RI is greater than 0.55, and the peak systolic velocity is less than 15 cm/s. 9,20,21 Because of doubts regarding non-angle-corrected Doppler velocimetry measurements, we chose not to include such data in this analysis. Only 1 of our study patients who had an ectopic pregnancy had documented low-resistance arterial flow in the endometrium (RI = 0.30).…”

“…In summary, the detection of a low-resistance, low-velocity Doppler signal within the peritrophoblastic tissue has a high (97%) negative predictive value in the exclusion of ectopic pregnancy, which confirms earlier work. 9,20,21 Although this finding does not always preclude the need for clinical and laboratory follow-up, it can on occasion change treatment. Its presence can also make the interpreting physician more comfortable with the exclusion of ectopic pregnancy in the setting of nondiagnostic gray scale ultrasonographic findings.…”