(HealthDay News) — Levonorgestrel-releasing intrauterine contraceptive devices (LNG-IUDs) seem to have systemic effects on the body, resulting in increased background enhancement on breast magnetic resonance imaging (MRI), according to a study presented at the annual meeting of the Radiological Society of North America, held from Nov. 28 to Dec. 2 in Chicago.
Luisa Huck, M.D., from RWTH Aachen University in Germany, and colleagues examined the association between LNG-IUD use and background parenchymal enhancement (BPE) in breast MRI as an established imaging biomarker of hormonal stimulation.
Forty-eight premenopausal women without a personal history of breast cancer or hormone or antihormone intake who had undergone standardized dynamic contrast-enhanced breast MRI for screening at least twice, with and without an IUD in place, were identified.
Half of the included women had their first MRI without the IUD in place, and the other half had their first MRI with the IUD in place. There was a median of 27 months between the two studies. The degree of BPE was assessed based on American College of Radiology (ACR) categories.
The researchers found that the ACR categories did not change with versus without IUD in 24 of 48 women. In 23 patients, the ACR category was higher with versus without IUD; in one woman, the ACR category was lower. The change in ACR category according to the presence or absence of IUD was highly significant.
“Use of an IUD leads to hormonal stimulation of the breast that is detectable by MRI,” Huck said in a statement. “The increased enhancement also has implications for the diagnostic accuracy of breast MRI in women using hormonal IUDs.”