Rationale and Objectives
To retrospectively determine the value of magnetic resonance imaging (MRI)-directed breast ultrasonography (US) in the evaluation of indeterminate or suspicious lesions identified on contrast-enhanced, breast MRI.
Materials and Methods
A total of 395 patients presenting for breast MRI during a 4-year period was retrospectively reviewed. Seventy-one patients were recommended for MRI-directed US for further characterization of indeterminate or suspicious breast lesions detected on MRI. Fifty-five patients (all female; age 31–80 years) had US. Their MRI and US were reviewed and tested for correlations with histologic results or long term follow-up. Logistic regression analyses were used to test for associations between MRI lesion characteristics and US detection rate.
Results
US identified 46 of 97 (47%) lesions depicted at MRI from 55 patients (47 [85%] of these patients had histories of breast malignancies). Twelve cancers were found from the 97 lesions (12%). Biopsy was avoidable in 10 lesions (10%). The detection rate with US was slightly higher with “mass” (55% [23/42]) lesions described in MRI than “non–mass” lesions or lymph nodes (42% [23/55]). There was a significant positive association (odd ratio = 1.23: 95% CI = 1.05–1.43, P = .01) between US detection rate and MRI mass lesion size. There was no statistical significance between US detection rate and the presence of malignancies; 42% (5/12) of MRI malignant lesions were not visualized with US.
Conclusions
MRI-directed US reduced the number of biopsies required for indeterminate or suspicious MRI lesions. Nevertheless, the lesions which were biopsied had a low rate of malignancy.
Although the use of contrast-enhanced, breast magnetic resonance imaging (MRI) in the general population has increased exponentially in the past decade ( ), some inherent diagnostic limitations of MRI remain unsolved. The sensitivity of MRI for the detection of breast cancer is high ( ), but its specificity is only moderate, ranging from 37% to 100% ( ). To reduce false-positive rates, the findings of MRI are often tested for correlations with findings from other breast imaging modalities.
When abnormalities detected by MRI are occult on mammograms or are not identified with breast ultrasonography (US) performed before the MRI, a second-look or MRI-directed US is commonly prescribed for further characterization of the MRI findings ( ). The reported sensitivity of MRI-directed US ranged from 23% to 89% ( ). US has many advantages, including wide availability, low cost, and portability. In addition, US may provide guidance for a biopsy when a detected lesion is deemed malignant or suspicious ( ). This option is particularly important in breast imaging centers that are not equipped with the necessary facilities to perform MRI-guided breast biopsies.
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Material and methods
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Patients
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Table 1
Indications for Breast Magnetic Resonance Imaging
Indication Number of Patients (%) Preoperative assessment of disease extent 37 (67) Postoperative assessment of residual disease 4 (7) Past history of breast malignancy Screening 3 (5) Symptomatic 2 (4) Evaluation of response to neoadjuvant therapy 1 (2) Assessment of lesions with benign but discordant pathology 2 (4) Assessment of lesions with high-risk pathology 2 (4) Evaluation of palpable masses (other breast imaging negative) 2 (4) Screening of high-risk patient 1 (2) Search for mammographically occult breast primary 1 (2) Total 55 (100)
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MRI Acquisition
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MRI Interpretation
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MRI-directed Breast US
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Statistical Analysis
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Results
MRI Findings
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Table 2
Characteristics of Lesions Identified on Breast Magnetic Resonance Imaging
Characteristics Number of Lesions (%) Mass lesions Round 13 (13) Oval 13 (13) Lobulated 4 (4) Irregular 12 (12) Non-mass lesions Enhancing focus 31 (32) Non–mass-like enhancement 22 (23) Axillary lymph nodes 2 (2) Total 97 (100)
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MRI-directed US Evaluation
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Reference Standard Examination
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Table 3
Pathology Results for Lesions Identified on Breast Magnetic Resonance Imaging
Pathology Detected on Magnetic Resonance Imaging–directed Ultrasound Yes (%) No (%) Malignant lesion Invasive carcinoma alone 4 (9) 1 (2) In situ carcinoma alone 1 (2) 4 (8) Invasive in situ carcinoma combined 2 (4) 0 High-risk lesion 4 (9) 3 (6) Benign lesion 16 (35) 11 (22) No pathologic correlation 19 (41) 32 (63) Total 46 (100) 51 (100)
Table 4
Correlation of Lesion Characteristics on Breast MRI with Pathology
MRI Lesion Characteristics Malignant (%) Benign (%) Pathology High-risk (%) No Pathology (%) Mass lesion (n = 42) US correlate (n = 23) 6 (26) 7 (30) 3 (13) 7 (30) No US correlate (n = 19) 1 (5) 3 (16) 3 (16) 12 (63) Non-mass lesion (n = 53) US correlate (n = 21) 1 (5) 7 (33) 1 (5) 12 (57) No US correlate (n = 32) 4 (13) 8 (25) 0 20 (63) Axillary lymph node (n = 2) US correlate 0 2 (100) 0 0 No US correlate 0 0 0 0
MRI: magnetic resonance imaging; US: ultrasound.
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Discussion
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References
1. Beran L., Liang W., Nims T., et. al.: Correlation of targeted ultrasound with magnetic resonance imaging abnormalities of the breast. Am J Surg 2005; 190: pp. 592-594.
2. Lehman C.D., Schnall M.D.: Imaging in breast cancer: magnetic resonance imaging. Breast Cancer Res 2005; 7: pp. 215-219.
3. Latrenta L.R., Menell J.H., Morris E.A., et. al.: Breast lesions detected with MR imaging: utility and histopathology importance of identification with US. Radiology 2003; 227: pp. 856-861.
4. Orel S.G., Schnall M.D.: MR imaging of the breast for the detection, diagnosis, and staging of breast cancer. Radiology 2001; 220: pp. 13-30.
5. Birdwell R.L., Smith D.N.: MR imaging use in breast cancer staging and the assessment of treatment.Feig S.Breast imaging: RSNA categorical course in diagnostic radiology.2005.RSNAOak Brook, IL:pp. 199-207.
6. Lee C.H.: Current status of MR imaging screening for breast cancer.Feig S.Breast imaging: RSNA categorical course in diagnostic radiology.2005.RSNAOak Brook, IL:pp. 209-216.
7. Dershaw D.D.: Magnetic resonance imaging as a clinical tool.Morris E.A.Liberman L.Breast MRI.2005.SpringerNew York:pp. 256-265.
8. Obdeijn I.A., Brouwers-Kuyper E.M., Tilanus-Linthorst M.M., et. al.: MR imaging-guided sonography followed by fine-needle aspiration cytology in occult carcinoma of the breast. AJR Am J Roentgenol 2000; 174: pp. 1079-1084.
9. Hlawatsch A., Teifke A., Schmidt M., et. al.: Preoperative assessment of breast cancer: sonography versus MR imaging. AJR Am J Roentgenol 2002; 179: pp. 1493-1501.
10. Bluemke D.A., Gatsonis C.A., Chen M.H., et. al.: Magnetic resonance imaging of the breast prior to biopsy. JAMA 2004; 292: pp. 2735-2742.
11. Gibbs P., Liney G.P., Lowry M., et. al.: Differentiation of benign and malignant sub-1 cm breast lesions using dynamic contrast enhanced MRI. Breast 2004; 13: pp. 115-121.
12. Liberman L., Morris E.A., Kim C.M., et. al.: MR imaging findings in the contralateral breast of women with recently diagnosed breast cancer. AJR Am J Roentgenol 2003; 180: pp. 333-341.
13. Wiener J.I., Schilling K.J., Adami C., et. al.: Assessment of suspected breast cancer by MRI: a prospective clinical trial using a combined kinetic and morphologic analysis. AJR Am J Roentgenol 2005; 184: pp. 878-886.
14. Lehman C.D., Blume J.D., Thickman D., et. al.: Added cancer yield of MRI in screening the contralateral breast of women recently diagnosed with breast cancer: results from the international breast magnetic resonance consortium (IBMC) trial. J Surg Oncol 2005; 92: pp. 9-16.
15. Langer S.A., Horst K.C., Ikeda D.M., et. al.: Pathologic correlates of false positive breast magnetic resonance imaging findings: which lesions warrant biopsy?. Am J Surg 2005; 190: pp. 633-640.
16. Liberman L., Morris E.A., Dershaw D.D., et. al.: MR imaging of the ipsilateral breast in women with percutaneously proven breast cancer. AJR Am J Roentgenol 2003; 180: pp. 901-910.
17. Sim L.S., Hendriks J.H., Bult P., et. al.: US correlation for MRI-detected breast lesions in women with familial risk of breast cancer. Clin Radiol 2005; 60: pp. 801-806.
18. Agresti A.: Categorical data analysis.2nd ed.2002.John Wiley & SonsNew Jersey
19. American College of Radiology: Breast imaging reporting and data system (BI-RADS).4th ed.2003.Reston, VaAmerican College of Radiology
20. Morris E.A.: Breast MR imaging: performance, reporting with BI-RADS, and pitfalls in interpretation.Feig S.Breast imaging: RSNA categorical course in diagnostic radiology.2005.RSNAOak Brook, IL:pp. 175-784.
21. Stavros A.T.: Introduction to breast ultrasound.2005.Lippincott Williams & WilkinsPhiladelphia, PA:pp. 1-15.
22. Lilienstein J., Daniel B.L., Ikeda D.M.: In vivo sonography through an open MRI breast coil to correlate sonographic and MRI findings. AJR Am J Roentgenol 2005; 184: pp. s49-s52.
23. Quan M.L., Sclafani L., Heerdt A.S., et. al.: Magnetic resonance imaging detects unsuspected disease in patients with invasive lobular cancer. Ann Surg Oncol 2003; 10: pp. 1048-1053.