Sonographic determination of the position of a levonorgestrel intrauterine device

Abstract

) is not echogenic and may be more difficult to see on ultrasound imaging. Although the vertical stem of the LNG-IUD is not clearly visible, in a sagittal section of the uterus it creates an acoustic shadow of about 2 cm between the echogenic proximal and distal ends of the stem and is seen to extend from above the isthmus to the fundus (Figure 1). Both arms of the crossbars are slightly echogenic and usually visible in a transverse section (Figure 2). The strings hanging at the proximal end are echogenic and may be seen in the cervical canal. Ideally the LNG-IUD should be located high in the uterine cavity, with both arms opened out in the fundus. To determine the location of a LNG-IUD using two-dimensional (2D) ultrasound imaging, we start with a sagittal section followed by a transverse section to identify the landmarks described above. Three-dimensional (3D) ultrasound examination may help and involves the following steps. Starting from the sagittal section, a volume is acquired with the acquisition angle set at 120 • . After reducing the size of the volume box of the region of interest (ROI), the green line of the ROI box is set to cover the IUD. To obtain good visualization of the position of the stem, as well as of both the arms, the ROI of the acquired 3D volume should then be placed just under the level of the uterine cavity in order to render the IUD's shadow (Figures 3-5 and Figures S1-S3 online).The LNG-IUD is a T-shaped device with a polyethylene frame containing barium sulfate. On the 32-mm vertical stem, there is a reservoir containing a mixture of LNG and silicone covered by a silicone membrane. Both arms of the horizontal portion measure 32 mm in total. The LNG-IUD is a highly effective mode of contraception 1,2 and, because it induces hypomenorrhea or amenorrhea, it is also used to treat menorrhagia, dysmenorrhea and adenomyosis 3 -5 .If the LNG-IUD is not visible on ultrasound examination, it has either been expulsed or has perforated the

Three‐dimensional versus two‐dimensional ultrasound for assessing levonorgestrel intrauterine device location: A pilot study

“…Factors previously reported to be associated with malpositioning of IUDs include inexperience of the health professional, insertion of the device within the first 6 months after delivery, nulliparity, a retroflexed uterus, and previous cesarean deliveries . In our study, the use of 3D US confirmed that in all of our participants, the LNG‐IUD was entirely located inside the uterine cavity, but in eight of these women, the device was not aligned with the main axes of the uterus.…”

Levonorgestrel intrauterine system embedded within tubal ectopic pregnancy: a case report

“…However, compared with copper IUDs, the LNG IUS is more likely to be missed by ultrasonography. LNG IUS is compounded with barium sulfate, which makes it radio opaque for X-ray recognition [ 14 ]. A plain X-ray can therefore be used as an adjunctive imaging modality in the case of a lost LNG IUS not seen on ultrasound [ 15 ].…”

Comparison of two- and three-dimensional transvaginal ultrasound in the visualisation of intrauterine devices

“…Other studies have shown that copper IUDs are easier to visualise with ultrasound, whereas imaging of Mirena IUDs is not as accurate and requires higher operator skill. 6,14,15 All of the indeterminately positioned IUDs shown in Figure 2 were Mirena IUDs and were inadequately visualised due to poor echogenicity and partial views of the device. Valsky et al 16 found that the IUD acoustic shadow on the 3D-reconstructed coronal image can give a good clue to its location.…”