Performance of a handheld point of care ultrasonography to assess IUD position compared to conventional transvaginal ultrasonography

Abstract

Objective

To compare the performance of the abdominal handheld point-of-care ultrasonography (POCUS) Butterfly-iQ to gold standard transvaginal ultrasonography (US) in identifying the position of intrauterine devices (IUDs) in the hands of a medical doctor specialised in ultrasonography.

Methods

In this diagnostic accuracy study, a single operator conducted abdominal POCUS followed by conventional transvaginal US. Seventy patients utilising copper or hormonal IUDs were assessed between June 2021 and October 2022. IUDs were categorised as entirely within the uterine cavity or malpositioned. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for detecting malpositioned IUDs, with conventional US results serving as the reference standard. Concordance rate and Kappa coefficient were computed to assess the agreement between the two ultrasound modalities.

Results

Among the 70 patients, 46 (65.7%) used copper IUDs, and 24 (34.3%) used hormonal IUDs. Conventional transvaginal US showed IUDs entirely within the uterine cavity in 56 (80%) patients and 14 (20%) IUDs were malpositioned. Of the 14 malpositioned IUDs seen by conventional US, POCUS identified 13 demonstrating a sensitivity of 92.9% (66.1–99.8). Of the 56 IUDs entirely within the uterine cavity shown by conventional US, only two cases were considered malpositioned by POCUS demonstrating a specificity of 96.4% (87.7–99.6). The concordance rate was 95.7%, and the Kappa value was 0.87 in differentiating between IUDs entirely within the uterine cavity and those that were malpositioned.

Conclusion

Abdominal POCUS using Butterfly-iQ, when administered by an imaging specialist, exhibited excellent performance in confirming IUDs entirely within the uterine cavity.

SHORT CONDENSATION

Through a smartphone-based handheld point-of-care ultrasonography it was possible to correctly evaluate the position of intrauterine devices (IUDs) in a sample of 70 patients (46 using copper and 24 using hormonal IUDs).

摘要

目的

比较专业超声医师应用经腹手持床旁即时超声(PICUS) Butterfly-iQ与金标准经阴道超声(US)在确定宫内节育器(IUD)位置方面的表现。

方法

在这项诊断准确性研究中, 同一操作者先进行经腹POCUS检查, 然后进行传统的经阴道超声检查。在2021年6月至2022年10月期间, 对70名带含铜或激素的宫内节育器的患者进行了评估。宫内节育器的位置分为完全在宫腔内或移位。计算检测宫内节育器移位的敏感度、特异度、阳性预测值(PPV)、阴性预测值(NPV)和准确度, 以传统US结果作为参考标准。计算一致性指数和Kappa系数以评估两种超声方法之间的一致性。

结果

70例患者中, 46例(65.7%)应用含铜宫内节育器, 24例(34.3%)应用释放激素的宫内节育器。常规经阴道超声显示56例(80%)患者宫内节育器完全位于宫腔内, 14例(20%)宫内节育器移位。在传统经阴道超声发现的14例移位宫内节育器中, POCUS确定了13例, 敏感性为92.9%(66.1-99.8)。传统经阴道超声显示完全位于宫腔内的56个宫内节育器中, 仅2例被POCUS确定为宫腔移位, 其特异度为96.4%(87.7-99.6)。完全位于宫腔内的宫内节育器与移位宫内节育器的一致性指数为95.7%, Kappa值为0.87。

结论

在由影像专家进行经腹超声时, 应用Butterfly-iQ确认完全位于宫腔内的宫内节育器具有很好的效果。

Keywords:

• Point-of-care
• ultrasonography
• intrauterine device
• contraceptive IUD
• gynaecology

Acknowledgments

KGA was supported by Coordination of Improvement of Higher Education Personnel - Brazil (Capes) - 88887.372719/2019-00. National Council for Scientific and Technological Development (CNPq) supported SD and LOS, grants numbers 304544/2022-1 and 308871/2021-9, respectively. We would like to thank Prof. Dr. Rodrigo Menezes Jales, director of medical imaging at Prof. José Aristodemo Pinotti Women’s Hospital, CAISM, University of Campinas, Unicamp, for his kind support in carrying out this study.

Disclosure statement

The authors declare that they have no competing interests. The institution and the authors did not receive any payment or benefit from the ultrasound machines or smartphone companies cited in this study.