BREAST MRI. VASILIKI FILIPPI RADIOLOGIST CT MRI & PET/CT Departments Hygeia Hospital, Athens, Greece

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1 BREAST MRI VASILIKI FILIPPI RADIOLOGIST CT MRI & PET/CT Departments Hygeia Hospital, Athens, Greece

2 Breast ΜR Imaging (MRM) Breast MR imaging is an extremely powerful diagnostic tool, that when used in specific clinical scenarios can be used for problem solving, with regard to equivocal mammographic and/or US findings

3 No Radiation ΜR Mammography (MRM): advantages Very sensitive for Cancer More sensitive than Mx & US in women with dense breast, previous surgery, implants

4 High cost ΜR Mammography (MRM): disadvantages Availability, Expertise Misses 6-10% of Ca (mainly DCIS) seen on Mx only as suspicious Microcalcifications Moderate specificity benign lesions that can mimic Ca

5 MRM: PLANNING THE EXAMINATION Higher field, higher accuracy Clinical history & examination Good quality Mammography and/or US Premenopausal: 7-13 day of m.c. Post-menopausal: stop HRT for 6-8 w. After Breast Surgery: after 3-6 months Recent Radiotherapy: after months Check contraindications, claustrofobia

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7 PERFORMING MRM Patient preparation: 10 minutes Examination time: ~15 minutes

8 Dynamic Contrast-Enhanced (DCE)- MRM Information about tissue vascularity Kinetics & Morphology of Contrast Enhancement (CE) can determine the likelihood of malignancy

9 EVALUATION OF AN ENHANCING Morphology LESION Shape: Regular (round, oval, lobular) Irregular (linear, dendritic, stellate) Margin: well- or ill-defined Homogeneity of contrast enhancement Signal intensity on T2-w images

10 EVALUATION OF AN ENHANCING LESION Kinetics: Signal-to-time Curve Persistent Plateau Wash-out Curve type 1 -mostly benign -up to 6% of Ca Curve type 2 -non specific -benign lesions % of Ca Curve type 3 -most Ca -30% fibroadenomas -sclerosing adenosis, apocrine metaplasia

11 TYPICAL APPEARANCE OF BENIGN LESION Focal lesion with regular shape, smooth margins and type 1 curve Dark septa pathognomonic of fibroadenoma

12 TYPICAL APPEARANCE OF CANCER Focal lesion with irregular shape and ill-defined margins Intense inhomogeneous contrast enhancement Type 3 curve

13 Typical MRM appearance of an IDC

14 DCIS: DIAGNOSIS IS BASED MOSTLY ON MORPHOLOGY OF CE No standard pattern of neoangiogenesis 10-20%: no contrast enhancement! 22%: progressive CE (curve type 1)! 30%: moderate CE 44%: intense early CE, curve type 2 or 3

15 DCIS Asymmetric non masslike enhancement that follows the ductal system Clumped internal enhancement

16 DCIS Clinical situations where MRM is NOT sufficient: Suspicious Microcalcifications on Mx MRM has a ~85% sensitivity for detecting DCIS seen only as microcalcifications on Mx: Decision for biopsy should rely on Mx findings! Usefulness of MRM: detection/exclusion of underlying infiltrative BC detection of the full extent of a probable DCIS: Mx & MRM are COMPLEMENTARY!

17 BI-RADS: Sensitivity 92% (95% for invasive) Specificity 92% Fischer U et al, Radiology 1999 (231), Baum F et al, Eur Radiol 2002

18 MRM INDICATIONS Inconclusive or suspicious conventional imaging findings! If a lesion is equivocal it is probably more efficient to offer imaging guided biopsy

19 MRM INDICATIONS D.D. scarring vs tumor recurrence: better >3-6 m. post surgery & >12-18 m. post RT Inadequate tumor resection: MRM within days!

20 RT lumpectomy+rt (ended 16 months ago) +ChT Recurrence or Scar?

21 ΜRΜ: Scar 3D MIP of substracted images Τ1-w Substraction, post IVC

22 MRM INDICATIONS Preoperative local staging (dense breasts): extent, multifocality/multicentricity ΜRΜ detects additional cancerous sites, missed with palpation/mx/us, in 15-27%

23 38-y. o. palpable lesion in LT breast with (+) FNA

24 MRM: Invasive Ca+Extensive Intraductal Component (EIC)

25 RT breast: ill defined lesion with microcalcifications (BI-RADS 4)

26 ΜRΜ: IDC on the RT, DCIS on the LT RT: lesion BI-RADS 5 LT: regional enhancement (BI-RADS 4)

27 42-y.o. woman, reporting nodular sense at her RT Breast

28 42 y.o. woman, reporting nodular sense at her RT Breast

29 lesion 1 lesion 2 ΜRM: 3 highly suspicious lesions in the RT breast. Probable diagnosis: multicentric infiltrative cancer (confirmed at Mastectomy) lesion 3

30 MRM INDICATIONS Monitor neo-adjuvant Chemotherapy

31 Evaluation of response to neoadjuvant ChemoT: MRM is recommended by the RECIST 1.1 Guidelines (2009) Before therapy After 4 cycles of neoadjuvant ChT

32 MRM INDICATIONS High-risk women with dense breasts

33 54-y.o. familial history of Breast Cancer Clinical Examination & Mammogram: negative

34 Histology: IDC

35 38-y.o. high-risk woman. Very dense breasts US: solid hypo echoic lesion in the LT breast

36 Τ1 + C MRM: Typical Fibroadenoma Τ2-w

37 Annual Breast Ca Screening with ΜRI: Guidelines of American Cancer Society- ACS ( ) Women with life-time risk of Breast Ca>20%: -carriers of BRCA 1 or 2 gene mutations -1 st degree relative carrier of BRCA 1 or 2 -risk calculated on the basis of familial history of Breast & Ovary Cancers Women with previous RT of Thorax, at age years (e.g. for Hodgkin s disease) Women with detected or probable mutation in TP53 or PTEN genes (syndromes: Li- Fraumeni, Cowden, Bannayan-Riley-Ruvalcaba) Saslow D, et al. CA Cancer J Clin 2007;57:75-89

38 MRM INDICATIONS Implants: diagnosis of rupture -extracapsular: accuracy % -intracapsular: accuracy 74-90% Inflammation around implant: accuracy > 90% Evaluate breast parenchyma adjacent to implant

39 Implants Intracapsular rupture Extracapsular rupture

40 MRM NOT RECOMMENDED! Screening average-risk patients Suspicious lesions & microcalcifications accessible for Mx- or US-guided percutaneous wire localization or biopsy Pregnancy, lactation Breast inflammation

41 MR-guided Breast Wire Localization & Core Biopsy If a suspicious lesion is identified with MRM and has no correlate on either mammogram or second-look targeted US, MR guidance for biopsy is needed

42 MR-guided Breast Wire Localization & Core Biopsy

43 CONCLUSIONS MRM is a very sensitive method for supplementing Mammography Moderate specificity To be used when indicated! Not to be used solely or without Mammographic correlation! Ideally, should be performed at facilities that follow technical & diagnostic guidelines and can perform MR-guided biopsies (ACR Guidelines 2007)

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