In a new study utilizing the Kaiser score for breast magnetic resonance imaging (MRI) analysis, researchers found that T2WI hyperintensity, an absence of ipsilateral breast hypervascularity and lesion size < 1 cm are significantly associated with false negatives.
For the retrospective study, recently published in the European Journal of Radiology, researchers utilized the Kaiser score to assess preoperative breast MRI findings in 1,058 patients. The study authors noted that 859 breast lesions were malignant and 199 were benign.
Researchers found that the Kaiser score correctly identified 95.6 percent of true-positive cases of breast cancer but only 70.9 percent of true-negative cases. They also noted common factors that contributed to false-negative and false-positive findings with breast MRI.
Lesion size < 1 cm had a nearly 3.7 times likelihood of being associated with false-negative findings, according to the study authors. They also noted that the lack of ipsilateral breast hypervascularity had a threefold likelihood of being associated with false-negative cases.
“ … Among the 859 breast cancer patients in our study, tumors with ipsilateral breast hypervascularity were larger on average (493 patients; mean tumor diameter, 32.2 mm) than lesions without ipsilateral breast hypervascularity (367 patients; mean tumor diameter, 22.3 mm). Therefore, radiologists should carefully evaluate breast lesions with small diameters and insufficient evidence of increased blood supply to reduce misdiagnosis of breast cancer,” wrote lead study author Bing Zhang, M.D., who is affiliated with the Department of Radiology at the Second Affiliated Hospital of Xi’an Jiao Tong University in Shaanxi, China, and colleagues.
The researchers pointed out that non-mass enhancement had an approximately 4.7-fold likelihood of association with false-positive findings. Moderate or high background parenchymal enhancement (BPE) had a 2.4 times likelihood of contributing to false-positive diagnoses, according to the study authors.
Hyperintensity on T2W1 MRI is particularly challenging as the researchers found this factor had a nearly threefold likelihood of contributing to false-positive cases and a 2.4 times likelihood of association with false-negative diagnoses.
Three Key Takeaways
1. Significant factors for false-negative findings. Lesion size < 1 cm and the absence of ipsilateral breast hypervascularity were significantly associated with false-negative findings, with lesion size having a 3.7 times likelihood and the lack of hypervascularity having a threefold likelihood of association.
2. Challenges with T2WI hyperintensity. T2WI hyperintensity posed challenges in diagnosis, with a nearly threefold likelihood of contributing to false-positive cases and a 2.4 times likelihood of association with false-negative diagnoses. Understanding the imaging characteristics of both benign and malignant T2 hyperintense lesions can be key for accurate diagnosis.
3. High rate of true-positive identification. The Kaiser score accurately identified 95.6 percent of true-positive breast cancer cases but was less effective for true-negative cases, identifying only 70.9 percent.
Fibroadenomas, cysts and inflammatory lesions such as granulomatous mastitis represent common benign masses found on T2 MRI, according to the study authors. They pointed out that malignant findings such as papillary breast cancer, mucinous carcinoma and breast lesions with central necrosis have high T2 signals.
“Understanding the imaging findings of these benign and malignant T2 hyperintense lesions facilitates accurate diagnosis while ensuring the identification of suspicious lesions,” noted Zhang and colleagues. “We believe that an assessment of the morphology and enhancement pattern of T2 high-signal masses can help to differentiate between benign and malignant lesions. For instance, the finding of thickened or irregularly enhancing margins around cystic structures, enhancing nodules within cysts, or inhomogeneous internal enhancement within a T2 high-signal mass suggests the possibility of malignancy and may require biopsy.”
(Editor’s note: For related content, see “Study: Use of Preoperative MRI 46 Percent Less Likely for Black Women with Breast Cancer,” “Can AI Facilitate Effective Triage for Supplemental Breast MRI After Negative Mammography Screening?” and “Mammography and Breast MRI: Is it Time to Evaluate Strategies as Opposed to Modalities?”)
Beyond the inherent limitations of a retrospective single-center study, the authors acknowledged a small number of benign lesions and a lack of grading for high signal on T2-weighted MRI scans. The researchers also noted the reviewed imaging was entirely comprised of DCE-MRI images.
