A majority of community hospitals comply with two common sets of guidelines for high-quality breast MRI acquisition, despite the absence of uniform standards for breast MRI in the U.S., according to a survey of community hospitals published in the November edition of the Journal of the American College of Radiology.
Breast MRI's high specificity offers several advantages over mammography and ultrasound as a modality for breast cancer screening. The American Cancer Society and the National Comprehensive Cancer Network have both recommended that women at high-risk for breast cancer undergo yearly breast MRI on top of annual mammography screening, while the National Comprehensive Cancer Network recommends that women recently diagnosed with breast cancer consider pre-operative breast MRI, the authors noted. As a result, the use of breast MRI has grown significantly.
"As its use has expanded, breast MRI has been adopted by community practice facilities, at which most women undergo breast imaging in this country. However, little is known about the technical quality of MRI performed at U.S. community facilities," Wendy B. DeMartini, MD, of the University of Washington Medical Center in Seattle, wrote with co-authors. "[S]ignificant deviation from minimum technical specifications is a concern because it could compromise patient outcomes compared with those demonstrated in carefully controlled clinical trials."
Of the 98 community hospital members in the Breast Cancer Surveillance Consortium (BCSC) responding to the authors' queries, 23 responded that they performed breast MRI and 14 were willing to fill out the questionnaire about the hospital's acquisition techniques, filling out information for a total of 16 MRI scanners. With these respondents, the authors evaluated MRI equipment and acquisition techniques across several parameters to determine compliance with minimum breast MRI standards, as specified by the ACRIN 6667 Trial and the European Society of Breast Imaging (EUSOBI).
"[W]e found that adherence to minimum standards for breast MRI equipment across community practice facilities was excellent, with 94 percent of scanners having 1.5T field strength, and all scanners used dedicated breast coils, as recommended by both ACRIN and the EUSOBI," DeMartini and colleagues wrote.
On the other hand, the authors found that the "results regarding imaging parameters were varied and illustrate the heterogeneous nature of breast MRI acquisition." ACRIN recommends unilateral or bilateral acquisition coverage and EUSOBI suggests only bilateral. Fifteen of the eighteen scanners acquired bilateral images. Seventy-eight percent of respondents reported fulfilling ACRIN's recommendation that image slices measure under three mm (EUSOBI has no standard for this parameter). For ACRIN's field of view metrics, 67 percent fulfilled the dedicated unilateral and 78 percent met the dedicated bilateral guidelines for fewer than 20 and 36 mm, respectively.
Finally, all community hospitals met EUSOBI's contrast dose recommendations of .1 mmol/kg, while 10 of 16 hospitals fulfilled ACRIN'S suggestion for initial postcontrast sequencing completion within four minutes of contrast administration.
The researchers noted several limitations to the study. Despite this being the first investigation of community hospitals' breast MRI techniques, the research was a pilot study consisting of just 14 hospitals and 16 scanners. In addition, the authors pointed out that they did not assess MR images for quality or inquire as to whether hospitals performed MRI-guided biopsy, "an important standard for a quality breast MRI practice."
The authors concluded that the "[s]tudy provides important information for understanding the quality of breast MRI that is taking place in community practice in the United States. Adherence to minimum technical standards is key to achieve the clinical outcomes that have been demonstrated in research trials."