[Use of 3-dimensional ultrasound for assessment of intrauterine device position].

AIM OF THE STUDY

The purpose of our prospective study was to assess the accuracy of measuring and visualizing different types of IUDs with three dimensional ultrasound (3D) and two dimensional ultrasound (2D).

METHODS

Ultrasound investigation was carried out in 147 patients 6 weeks after insertion of the IUD; in 127 cases a copper IUD was inserted, in 20 cases a Levonorgestrel-containing (LNG) IUD. Correct measurement was defined as the distance between top of the IUD and inner endometrium as well as IUD and myometrium (fundus) in the longitudinal plane (2D) plus the frontal plane (3D). The possibility to visualize the complete IUD was evaluated in the frontal plane and in the transparent mode after volume rendering.

RESULTS

The distance measurement between copper IUD and myometrium or endometrium with 2D and 3D did not differ significantly (19.54 mm +/- 6.13 vs. 19.48 +/- 6.39, 5.58 +/- 4.57 vs. 5.21 +/- 4.57). There was no difference in the distance between LNG IUD and myometrium between the two ultrasound investigations (17.75 +/- 3.70 vs. 16.80 +/- 4.65), whereas the distance between LNG IUD and endometrium was significantly different (5.00 +/- 2.81 vs. 4.30 +/- 3.06, p = 0.03). The imaging of the LNG IUD was very clear with the 3D facilities, especially in the transparent mode. Furthermore, congenital anomalies of the uterus, like an arcuate uterus, were clearly detectable in the frontal plane (3D).

CONCLUSION

Distance measurement can be obtained equal as well by 2D or 3D ultrasound. The 3D ultrasound offers the advantage of better visualization of LNG IUD and the assessment of anomalies of the uterine cavity.