Armed Forces Institute of Pathology.

Transcription

1 Armed Forces Institute of Pathology

2 Armed Forces Institute of Pathology Breast Disease

3 Armed Forces Institute of Pathology Interpretation of Breast MRI Leonard M. Glassman MD FACR American College of Radiology Breast Imaging Scientist Armed Forces Institute of Pathology Washington DC Washington Radiology Associates, PC Washington DC

4 Why MRI? Mammography is imperfect Ultrasound is limited New technologies have limited data Positron emission mammography Breast scintigraphy

5 Indications Problem Solving Screening High risk groups General population?? Cost Availability

6 Breast Implants

7 Breast Implants

8 Problem Solving Pretreatment staging Residual disease Recurrence after breast conservation Problem patient/mammogram/sonogram Metastatic disease with unknown primary Usually for enlarged axillary or supraclavicular nodes Response to chemotherapy

9 Pretreatment Staging MRI changes treatment in 15-30% Multifocal/multicentric disease Lumpectomy to mastectomy in 15% Larger area for lumpectomy than indicated by mammography or sonography Chest wall involvement 2-3% have cancer in the opposite breast

10 Preoperative Multiple Sites

11 Preoperative Larger Lumpectomy

12 Preoperative Both Breasts

13 Residual Disease Postoperative residual disease Postlumpectomy preradiation Used if margins positive or close

14 Residual Disease

15 Recurrence After Breast 10% recurrence at 10 years MRI usually positive for at least 2 years after completion of treatment Abnormal findings after 2 years are suspicious Conservation

16 Problem Patient/Mammogram/Sonogram Symptomatic patient with negative mammogram/sonogram Unknown primary MRI positive in 50% Asymmetries Global or focal Abnormality in 1 view Multiple rounded solid masses

17 Problem Mammogram/Sonogram Pathologic nipple discharge MR ductogram Calcifications 85% or less negative predictive value Not good enough

18 Response to Chemotherapy Effectiveness of treatment (metabolic response to treatment) Change in size Routine contrast (change in kinetic curve) Diffusion weighted (free interstitial water diffusion rate) MR spectroscopy (choline peak change) Can predict response after days or weeks of treatment, not months

19 Response to Chemotherapy

20 Screening High risk women Average risk women??

21 High Risk Screening American Cancer Society Guidelines MRI and annual mammograms beginning at age 30 20% or more lifetime risk (double the general risk) BRCA 1 or 2 Parent, sibling or child with BRCA 1 or 2 Radiation treatment to chest between ages 10 and 30 Begin 10 years after treatment Significant positive family history

22 Significant Positive Family History One first degree relative with breast cancer before age 50 doubles risk (to 20%) Mother, sister, daughter Father, brother, son

23 High Risk Syndromes Li-Fraumeni Multiple cancers Cowden (Multiple Hamartoma Syndrome) Multiple cancers (breast and thyroid) Bannayan-Riley-Ruvalcaba Similar to Cowden Syndrome

24 Minimum Technical Specifications 1.5 T or greater Bilateral breast coil Resolution 1mm or less in plane Contrast enhancement Active fat suppression or subtraction on contrast sequences Biopsy availability

25 CAD Motion registration Multiplanar reconstruction Subtraction Automated kinetics Curves Peak enhancement Measurement package Kinetics only

26 CAD

27 Temporal vs. Spatial Resolution Initially temporal very important Now temporal less important Good spatial resolution more important Temporal resolution can be sacrificed for better spatial resolution

28 Type 1 Continued enhancement in delayed part of slope 6% malignant

29 Type 3 Rapid or medium initial phase Washout delayed phase 29-77% malignant

30 Type 2 Plateau in delayed part of slope 10% variance allowed from horizontal

31 Sequences

32 T1 Pre-contrast Not fat suppressed Central high signal Lymph node Fat necrosis Fresh and chronic Hamartoma

33 T2 Fat Suppressed High signal Cysts Colloid carcinoma Myxoid fibroadenoma Lymph node Fat necrosis Fresh and chronic Cysts

34 T2 Fat Suppressed High Signal Fibroadenoma Colloid carcinoma

35 T2 Fat Suppressed Moderate signal Invasive lobular carcinoma DCIS Fibrocystic change Low signal Invasive ductal carcinoma Sclerotic fibroadenoma Scar

36 T1-weighted Dynamic Contrast Enhanced 3D T1-weighted fat suppressed spoiled gradient-echo sequence typically Multiple runs over 5-8 minutes Each run <2 minutes for kinetics Gadolinium 0.1 mmol/kg bolus

37 Subtraction/Fat Suppression Must use active fat suppression or subtraction Patient motion limits usefulness of subtraction CAD software can help with motion Both is best

38 Sensitivity and Specificity Sensitivity % for invasive disease Specificity % for invasive disease

39 False negatives Poor enhancement pattern 16% DCIS and 3% invasive carcinoma Invasive lobular carcinoma Metastatic breast carcinoma Low grade DCIS Well differentiated invasive breast cancer Colloid carcinoma MRI dense breast High background enhancement Colloid carcinoma

40 Normal Examination Background enhancement Usually progressive over time Diffuse Hormonal enhancement Image between day 5 and 12

41 Hormonal Effects Luteal phase day 22 (Subtraction) Follicular phase phase day 10 (Subtraction)

42 MRI Dense Breast

43 Focus and Foci Enhancements < 5mm Too small to characterize Stable on follow-up usually Chance of malignancy extremely low

44 Benign Lesions Fibroadenoma Cysts Lymph nodes Fat necrosis Hamartoma Cysts (Post gad)

45 Cysts

46 Is MRI Definitive for Benign Lesions? Cyst Fibroadenoma Benign spatial characteristics Nonenhancing septations Type 1 curve Fatty lesions Hamartoma Lipoma Fat necrosis Lymph node Benign spatial characteristics Fatty hilum Benign lesions often hyperintense on T2

47 Fibroadenoma Benign spatial characteristics Nonenhancing septations Type 1 curve

48 Nonenhancing septations Fibroadenoma

49 Fatty Lesions Hamartoma Hamartoma

50 Mass 3D lesion Evaluate shape, margins and internal enhancement

51 Mass Shape Round Oval Lobulated Irregular 32% cancer Irregular (Angiosarcoma)

52 Mass Shape Oval (Juvenile fibroadenoma) Lobulated (Fibroadenoma)

53 Mass Margins Smooth Spiculated 80% cancer Irregular Smooth (Epidermal inclusion cyst)

54 Spiculated (Invasive ductal carcinoma) Mass Margins

55 Mass Margins Irregular (Adenoid cystic carcinoma)

56 Mass Internal Enhancement Pattern Homogeneous Heterogeneous Rim Cancer, fat necrosis, cyst with inflammation 40% cancer Dark internal septations Enhancing septations Central enhanced nidus or septations Homogeneous (Invasive ductal carcinoma)

57 Mass Internal Enhancement Pattern Heterogeneous (Invasive lobular carcinoma) Rim enhancement (Invasive ductal carcinoma)

58 Mass Internal Enhancement Pattern Dark septations (Fibroadenoma) Enhancing septations (Invasive ductal carcinoma)

59 Change Over Time

60 Non-mass Enhancement Enhancement without 3D characteristics Distribution Internal enhancement pattern Symmetry or asymmetry

61 Distribution Non-mass Focal < 25% of a quadrant Ductal 60% cancer Linear Not ductal orientation 31% cancer Segmental Multiple ducts 78% cancer Regional Not ductal or segmental 21% cancer Diffuse Focal (DCIS)

62 Distribution Non-mass Ductal (DCIS) Linear (Stromal fibrosis)

63 Distribution Non-mass Segmental (DCIS) Regional (DCIS)

64 Internal Enhancement Pattern Non-mass Homogeneous Heterogeneous Punctate Foci 25% cancer Clumped 60% cancer Reticular Homogeneous (DCIS)

65 Internal Enhancement Pattern Non-mass Heterogeneous (Invasive ductal carcinoma)

66 Internal Enhancement Pattern Non-mass Clumped (DCIS) Clumped (DCIS)

67 Associated Findings Skin or nipple involvement Signal void Muscle or chest wall invasion Dilated ducts Adenopathy

68 Associated Findings Chest wall invasion Adenopathy

69 DCIS Curves not useful Many cases of DCIS show no washout Usually cases with slow initial enhancement Non-mass enhancement Clumped, ductal, linear, segmental

70 DCIS

71 DCIS

72 Sarcoma Angiosarcoma Sarcoma with osseous differentiation

73 Conclusion MRI is a powerful tool in cancer diagnosis Can find cancer not seen on other imaging Problem solving High risk screening Can monitor chemotherapy better than other imaging

74 Conclusion Changes treatment plan in 15 30% of cases Larger lumpectomy or prelumpectomy chemotherapy Mastectomy But rate of change to mastectomy is greater than recurrence rate if MRI is not done