Probably Benign Lesions Detected on Breast MR Imaging

Identification of the Benignity and Malignancy of BI-RADS 4 Breast Lesions Based on a Combined Quantitative Model of Dynamic Contrast-Enhanced MRI and Intravoxel Incoherent Motion

The aim of this study was to explore whether intravoxel incoherent motion (IVIM) combined with a dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative model can improve the ability to distinguish between benign and malignant BI-RADS 4 breast lesions. We enrolled 100 patients who underwent breast MRI at our institution and extracted the quantitative parameters of lesions with a post-processing workstation. Statistical differences in these parameters between benign and malignant BI-RADS 4 lesions were assessed using a two independent samples t-test or a Mann-Whitney U test. Binary logistic regression analysis was performed to establish five diagnostic models (model_{_ADC}, model_{_IVIM}, model_{_DCE}, model_{_DCE+ADC}, and model_{_DCE+IVIM}). Receiver operating characteristic (ROC) curves, leave-one-out cross-validation, and the Delong test were used to assess and compare the diagnostic performance of these models. The model_{_DCE+IVIM} showed the highest area under the curve (AUC) of 0.903 (95% confidence interval (CI): 0.828-0.953, sensitivity: 87.50%, specificity: 85.00%), which was significantly higher than that of model_{_ADC} (p = 0.014) and model_{_IVIM} (p = 0.033). The model_{_ADC} had the lowest diagnostic performance (AUC = 0.768, 95%CI: 0.672-0.846) but was not significantly different from model_{_IVIM} (p = 0.168). The united quantitative model with DCE-MRI and IVIM could improve the ability to evaluate the malignancy in BI-RADS 4 lesions, and unnecessary breast biopsies may be obviated.

Image-guided Procedure Versus 2-year Follow-up for a BI-RADS 3 Probably Benign Lesion: A Cost Comparison Analysis

OBJECTIVE

Perform a comparison between the costs of image-guided breast procedures versus 2-year imaging follow-up for findings classified as BI-RADS assessment category 3-probably benign.

METHODS

The national payment amount costs at non-facility locations were obtained from the Centers for Medicare and Medicaid Services physician fee schedule for breast imaging-related Current Procedural Terminology codes. Total costs were calculated and compared for management algorithms of 2-year imaging follow-up of a BI-RADS 3 lesion from 2018 through 2019 versus performing an image-guided procedure of the lesion in 2018 after the initial diagnostic imaging.

RESULTS

Two-year mammographic follow-up of a BI-RADS 3 finding costs $484. This was less than a stereotactic-guided breast biopsy, which cost at least $1055. Two-year follow-up for a probably benign US finding cost $615 compared to $1173 for the least expensive US-guided breast biopsy scenario. For breast MRI, 2-year imaging follow-up cost $1510, which was also less than most MRI-guided breast biopsy scenarios. The one exception in which biopsy costs less than 2-year imaging follow-up was in the setting of an MRI-guided biopsy in the average-risk population without a post-benign biopsy follow-up breast MRI; in this setting, MRI biopsy cost $1235.

CONCLUSION

In 2018-2019, 2-year imaging follow-up of a BI-RADS 3 finding continues to be less costly than an immediate procedure, except for MRI-guided breast biopsy in the average-risk population without a post-benign biopsy follow-up MRI.

Usefulness of abbreviated breast MRI screening for women with a history of breast cancer surgery

PURPOSE

We investigated the usefulness of abbreviated breast MRI (AB-MRI), including fat-suppressed T2-weighted imaging, pre- and postcontrast image acquisition, and subtracted maximum-intensity projection imaging, for the screening of women with a history of breast cancer surgery.

METHODS

Between October 2014 and March 2016, a total of 799 AB-MRI examinations were performed for 725 women with a history of breast cancer surgery. The image acquisition time was 8.5 min. Screening mammography, ultrasound, and AB-MRI were generally performed around the same time. The cancer detection rate, positive predictive values for recall and biopsy, sensitivity and specificity of screening MRI, and rate of malignancy belonging to each breast imaging reporting and data system (BI-RADS) category were assessed.

RESULTS

AB-MRI detected 12 malignancies in 12 women (15.0 cancers per 1000 cases). Seven of these 12 malignancies were initially invisible on ultrasound and mammography, although subsequent targeted ultrasound revealed lesions corresponding to the MRI-detected lesions. The positive predictive values for recall and biopsy and sensitivity and specificity values for screening MRI were 12.4, 61.5, 100, and 89.2%, respectively. The rates of malignancies belonging to categories 1, 2, 3, and 4 of the BI-RADS were 0, 0, 4.8, and 57.1%, respectively.

CONCLUSIONS

The diagnostic performance of screening AB-MRI for women with a history of breast cancer surgery is acceptable, with the advantages of short examination and interpretation times and low costs. Thus, it could be used as a main screening modality that may replace conventional imaging in breast cancer survivors.

Management for BI-RADS category 3 lesions detected in preoperative breast MR imaging of breast cancer patients

OBJECTIVE

To retrospectively evaluate characteristics of and determine appropriate follow-up recommendations for BI-RADS category 3 lesions detected in preoperative MRI of breast cancer patients.

METHODS

BI-RADS category 3 assessments were identified from the breast MRI database for 5,110 consecutive breast cancer patients who had undergone preoperative MRI and surgery. Patient and lesion characteristics, malignancy rate, and interval between lesion detection and cancer diagnosis were analysed. Histopathological results or imaging at or after 2-year follow-up were used as reference standards.

RESULTS

Of the 626 lesions, morphological features included a single focus in 26.5% (n = 166), multiple foci in 47.1% (n = 295), mass in 21.7% (n = 136) and non-mass enhancement in 4.6% (n = 29). Cancer was found in 0.8% (5/626) at a median interval of 50 months (range, 29-66 months). Malignancy rate according to morphological feature was: 1.8% (3/166) in a single focus, 0.7% (1/136) in mass and 3.4% (1/29) in non-mass enhancement. All detected cancers were stage 0 or IA.

CONCLUSIONS

Annual follow-up might be adequate for BI-RADS category 3 lesions detected at preoperative MRI because of the 0.8% (5/626) malignancy rate, long interval between lesion detection and cancer diagnosis, and early stage of diagnosed cancers.

KEY POINTS

• BI-RADS category 3 lesions on preoperative MRI had 0.8% malignancy rate. • All cancer diagnoses from BI-RADS 3 occurred after 24-month follow-up. • Annual follow-up might be adequate for BI-RADS 3 detected on preoperative MRI.

Probably benign breast MRI lesions: frequency, lesion type, and rate of malignancy

PURPOSE

To determine the frequency, malignancy rate, and imaging characteristics of BI-RADS (Breast Imaging Reporting and Data System) 3 MRI detected lesions.

MATERIALS AND METHODS

A total of 4370 consecutive contrast-enhanced breast MRI exams from March 1, 2004, to March 1, 2009, were retrospectively reviewed. The study was HIPAA (Health Insurance Portability Accountability Act) compliant and Institutional Review Board approved. The frequency of BI-RADS 3 MRI interpretations and lesion type, as well as malignancy rate at follow-up were calculated.

RESULTS

There were 348/4370 (8%) BI-RADS 3 exams performed on 345 patients. There were 125 foci (35.9%), 52 non-masslike enhancements (14.9%), and 171 masses (49.1%). There were 207 lesions with biopsy or imaging follow-up of at least 24 months (mean, 32 months; range, 6-77 months) of the BI-RADS 3 lesion. Five of these 207 (2.4%) lesions were found to be malignant.

CONCLUSION

Rate of malignancy among BI-RADS 3 MRI exams with follow-up was 2.4%. Types of lesions assigned as probably benign were 35.9% foci, 14.9% non-masslike enhancements, and 49.1% masses.

Utility of targeted sonography in management of probably benign breast lesions identified on magnetic resonance imaging

OBJECTIVES

The purpose of this study was to determine the utility of targeted sonography in the management of probably benign breast lesions detected on magnetic resonance imaging (MRI).

METHODS

A total of 4370 consecutive contrast-enhanced breast MRI examinations from March 1, 2004, to March 1, 2009, were retrospectively reviewed. The study was Health Insurance Portability and Accountability Act compliant and Institutional Review Board approved. When targeted sonography was recommended for a Breast Imaging Reporting and Data System (BI-RADS) category 3 examination, results of the sonography and any subsequent breast pathologic examinations were recorded. The frequency of identifying the MRI-detected lesions and the rate at which the BI-RADS category was changed by sonography were calculated for mass and non-mass-like lesions.

RESULTS

Of the 4370 examinations, 349 (8%) had BI-RADS 3 findings in 346 patients. One hundred eighteen lesions underwent targeted sonography for evaluation of 85 masses and 33 areas of non-mass-like enhancement. Of these 118 lesions, 54 (46%) were seen on sonography. No cancers were detected on sonography in the areas of non-mass-like enhancement. Two of the 85 masses (2.4%) evaluated with targeted sonography had a malignant diagnosis before initiation of follow-up.

CONCLUSIONS

Selective use of targeted sonography, particularly in masses, may help identify some malignancies before initiating short-interval follow-up for MRI-detected BI-RADS 3 lesions.