Magnetic field interactions of copper-containing intrauterine devices in 3.0-Tesla magnetic resonance imaging: in vivo study

An in-vivo study of the safety of copper-containing intrauterine devices in 3.0 Tesla magnetic resonance imaging

PURPOSE

The aim of this study is to prospectively evaluate whether women with copper-containing intrauterine devices (Cu-IUD), currently listed as MR conditional, can safely undergo 3.0 Tesla (3 T) magnetic resonance imaging (MRI).

METHODS

73 women, age 18-54 years old, with a Cu-IUD who were undergoing MRI for any reason were included consecutively. Pre- and post-MRI standard pelvic ultrasound examinations were completed to determine the appropriate pre- and post-MRI positioning of the Cu-IUD. Displaced IUDs were defined by IUD crossbars not in the fundal portion of the endometrial cavity, a visualized tip in the mid or lower uterus, any part of the device located in the cervical canal or outside of the endometrial canal, a fractured device, or a non-visualized IUD. Additionally, a questionnaire was completed by participants to determine the level of pre- and post-MRI pelvic pain.

RESULTS

There were zero observed displaced Cu-IUDs on post-MRI pelvic ultrasounds (p = 0/70, 95% CI 0, .043). Three participants were dropped from the study due to malpositioned IUDs on pre-MRI pelvic ultrasound. Six patients reported new or worsening pelvic pain/discomfort during or after their MRI examination.

CONCLUSION

Our results suggest that performing 3 T MRI using a low SAR setting does not cause displacement of Cu-IUDs, with zero out of 70 patients demonstrating IUD displacement.

Case series demonstrating in vivo MR safety of stainless steel (Chinese/Ring) IUDs

Intrauterine devices (IUDs) are one of the most common forms of long-term contraception used by patients around the world. Many studies have been performed over the past few decades demonstrating the safety of many common hormonal and metallic intrauterine devices in Magnetic Resonance (MR) imaging; however, the stainless steel ring IUD (often termed the “Chinese” IUD) is still considered MR Unsafe. This device was used in the 1980s and 1990s in China, where as many as 60 million women in China were using an IUD by 1988, and approximately 90% of those were stainless steel ring IUDs. In a major metropolitan area hospital such as ours with a large immigrant population, we encounter females with this ring IUD several times a year. As this population ages, the need for medical care (and concomitantly, MR imaging) is projected to increase. The purpose of this case review is to examine the imaging and clinical course of patients with stainless-steel ring intrauterine devices who safely received 1.5T Brain MR scans at our institution for clinically necessary diagnostic imaging.

Risk assessment of copper-containing contraceptives: the impact for women with implanted intrauterine devices during clinical MRI and CT examinations

OBJECTIVES

To assess the risks for implant users with copper-containing intrauterine devices (IUDs) during MR and CT examinations.

METHODS

A tissue-mimicking phantom suitable for all experiments within this study was developed. Seven different types of copper IUDs were evaluated. Heating and dislocation of each IUD were investigated at two clinically relevant positions in 1.5 T and 3 T MR scanners. Artifacts in the field of view caused by each tested IUD were determined for clinical MR and CT imaging.

RESULTS

No significant heating of any tested IUD was detected during MR measurements. The temperature increase was less than 0.6 K for all IUDs. Neither angular deflection nor translation of any IUD was detected. Artifacts in MR images were limited to the very vicinity of the IUDs except for one IUD containing a steel-visualizing element. Streaking artifacts in CT were severe (up to 75.5%) in the slices including the IUD.

CONCLUSION

No significant risk possibly harming the patient was determined during this phantom study, deeming MR examinations safe for women with an implanted copper IUD. Image quality was more impaired for CT than for MR imaging and needs careful consideration during diagnosis.

KEY POINTS

• Risk assessment of copper-containing IUDs with regard to heating, dislocation, and artifacts during MR and CT imaging. • Neither significant heating nor dislocation was determined in MR; image quality was more impaired for CT than for MR imaging and needs careful consideration during diagnosis. • The tested IUDs pose no additional risks for implant users during MR and CT examinations.

Safety of intrauterine devices in MRI

Objectives

The paucity of safety information on intrauterine devices (IUD) for magnetic resonance imaging (MRI) examinations is clinically relevant. The aim of this study is to evaluate the MRI safety of clinically used IUDs composed of copper/gold and stainless steel at 1.5T and 3.0T.

Materials and methods

We assessed and compared the displacement force, torque effects, presence of imaging artifacts and heating of IUDs composed of copper/gold (western IUDs) and stainless steel (China) on 1.5 and 3.0T MRI systems.

Results

Gold/Copper IUDs can show small deflection angles of 7° ± 7° in the worst-case field gradient of 40T/m (equivalent to magnetic force of 0.5 mN), while the stainless steel IUD experienced significant magnetic force and deflection (Force > 7.5 N; deflection angle 90° ± 1°). Manual rotation and suspension method show no torque effects on gold/copper IUDs but high torque effects were observed by manual rotation on the stainless steel IUD. Heating measurements showed a temperature increase (rescaled to a wbSAR of 4 W/kg) of 1.4°C at 1.5T / 3.4°C at 3.0 T (stainless steel IUD), 3.2°C at 1.5 T / 3.8°C at 3 T (copper/gold IUD), 3.3°C at 1.5 T / 4.8°C at 3 T (copper 1), 3.8°C at 1.5 T / 4.8°C at 3 T (copper 2). The visible imaging artifacts of the copper and gold IUDs at 3 T MRI reach a diameter of 4 mm ± 1 mm, while the stainless steel IUD resulted in artifacts measuring 200mm ± 10 mm when using gradient echo pulse sequences.

Conclusions

Standard IUDs (copper/gold) can be considered as conditional for MR safety at 1.5 T and 3.0 T, demonstrating at wbSAR up to 4W/kg and a magnetic field gradient of up to 40T/m with minimal imaging artifacts. The stainless steel IUD, however, induces unacceptable artifacts and is potentially harmful to patients during MRI due to high magnetic dislocation forces and torque (MR unsafe).

Contraception concerns, utilization and counseling needs of women with a history of breast cancer: a qualitative study

Introduction

Reproductive-aged women who have had breast cancer face unique challenges when it comes to making decisions about contraception. Clinical guidelines indicate that patients should avoid pregnancy during cancer treatment, however the extent of contraception counseling and utilization after diagnosis has not been well studied.

Methods

We conducted three focus groups and one semi-structured interview with women between the ages of 18 and 50 years old diagnosed with breast cancer within the last 5 years. We used clinic- and population-based recruitment methods to identify participants. Participants were asked a series of open-ended questions regarding their contraception decision-making and concerns at the time of their diagnosis, during treatment and afterward. We analyzed data to identify themes among participant responses.

Results

A total of 10 women participated. We identified the following themes: 1) doctors treating cancer do not focus on reproductive health issues; 2) there is misinformation and lack of information on contraceptive options and risks; 3) women fear unintended pregnancy but have limited guidance on prevention; 4) peers are a trusted source of contraception information; and 5) information about contraception should be provided soon after diagnosis.

Conclusion

Reproductive-aged breast cancer survivors have unique contraceptive concerns and may not be adequately informed about their contraceptive options. The results of this study may help guide and improve contraceptive counseling services for breast cancer survivors.

Ureteric erosion and obstruction: A rare but dreaded complication of intrauterine contraceptive device

Though intrauterine contraceptive device (IUCD) is a safe and most frequently used long-term contraceptive method, it has some complications. Uterine perforation and intra-abdominal migration have been reported often, but a retroperitoneal migration is exceptional. Here, we are reporting an IUCD which perforated the uterus and migrated to the retroperitoneum; impinging into and obstructing left ureter causing severe hydroureteronephrosis due to the development of the left lower ureteric stricture.

Ultrasonography of intrauterine devices

The intrauterine device (IUD) is gaining popularity as a reversible form of contraception. Ultrasonography serves as first-line imaging for the evaluation of IUD position in patients with pelvic pain, abnormal bleeding, or absent retrieval strings. This review highlights the imaging of both properly positioned and malpositioned IUDs. The problems associated with malpositioned IUDs include expulsion, displacement, embedment, and perforation. Management considerations depend on the severity of the malposition and the presence or absence of symptoms. Three-dimensional ultrasonography has proven to be more sensitive in the evaluation of more subtle findings of malposition, particularly side-arm embedment. Familiarity with the ultrasonographic features of properly positioned and malpositioned IUDs is essential.

Sigmoid colocolic fistula caused by intrauterine device migration: a case report

Introduction

The intrauterine device is a form of contraception with a long duration of action and few systemic side effects. Migration into the abdominal cavity may occur early or years after insertion giving rise to bowel obstruction, perforation, ischemia, mesenteric injury, strictures or fistulae. Colocolic fistula formation is a rare but serious complication of intrauterine device migration, which may lead to difficulties in diagnosis and device retrieval.

Case presentation

We report the case of a 29-year-old Sri Lankan woman who became pregnant 5 years after intrauterine device insertion. The device could not be located during pregnancy. She was asymptomatic and defaulted follow up during the antenatal period. She had an uncomplicated vaginal delivery. A subsequent laparotomy for device retrieval failed due to technical difficulties. A repeat laparotomy identified a sigmoid colocolic fistula with adhesions to the fallopian tube. The device was removed and colonic defects primarily closed following which the patient made an uneventful recovery.

Conclusions

All translocated intrauterine devices should be removed regardless of type and location. This case illustrates that they may cause complex bowel lesions leading to serious technical difficulties during retrieval. With the increasing use of minimally invasive approaches for intrauterine device retrieval, a low threshold for open surgery in complicated cases is advocated.