BREAST MRI. Breast MRI. Sequences and Technique. Equipment. Sequences. When to scan. Equipment Technique BI-RADS Indications Biopsy

Transcription

1 1 2 BREAST MRI Breast MRI Richard Tuft FRCS, FRCR, FFRad(D)(SA) ISRRT Durban 2008 Equipment Technique BI-RADS Indications Biopsy 3 4 Equipment Sequences and Technique 1.5T Minimum 3.0T Ideal Detachable tables Fat saturation Pre contrast STIR (T2 Fat Sat) Pre and post contrast FLASH3D (T1 Fat Sat) Temporal and spatial sequences Subtraction Morphology and Kinetics Scoring (BI-RADS) Chest and upper abdomen staging studies Prosthesis analysis 5 6 When to scan Sequences Pre-menopausal day Months after surgery 12 months after radiotherapy Consider discontinuing HRT for 4-6 weeks Chest and Liver STIR Breast STIR Precontrast 3DFLASH Postcontrast 3D FLASH with timed measurement of Contrast uptake

2 7 8 FAT SATURATION Pre-Contrast STIR with Fat Sat The key Fat sat failure Patient weight T2 Without Fat Sat Axillae Chest wall Cysts 9 10 FLASH 3D High-spatial Resolution: delayed "VIEWS" Pre and Post Contrast Morphology Kinetics Subtraction After dynamic exam. Increased Resolution Thin planes Courtesy of FHDI Multi-modality Approach: The Key MR / Mammo Correlation: Oblique MIP / MLO High-resolution Compound US Mammography Courtesy: Dr. Bruce Porter

3 13 14 Sagittal display: Sagittal display: Multiplanar reconstruction from Dynamic VIEWS Delayed VIEWS Sagittal bilateral acquisition SAG delayed VIEWS Sagittal reconstruction of 90 second Dynamic VIEWS acquisition Courtesy of FHDI Kinetics Angiogenesis 3D fat-saturation dynamic VIEWS Tumour angiogenesis promotes a rich high density network of tumor vessels. > 3mm, malignant infiltration, and metastatic disease. Enhancement quantification (dynamic MR) allows detection of tumors to ~ 3 mm., regardless of their morphology 1 min 2 min Inline dynamic MIP 1 minute subtraction 3 min Pre-contrast 4 min Courtesy of CSMC 5 min Subtraction Kinetics Find enhancing area Apply ROI Assess Kinetics I D Dynamic I I VIBE I

4 19 20 Enhancing Breast Cancer Features of Breast Malignancy: Morphology Kinetics Courtesy: Dr. Bruce Porter BI-RADS Grading BI-RADS Published by ACR Mammography Ultrasound MRI 0 - Incomplete exam 1 - Normal 2 - Benign 3 - Probably Benign 4 Probably Malignant 5 Malignant 6 Biopsy Proven Cancer 1 Normal Benign 2 Benign 3 Probably Benign Imaging follow up or tissue 4 Probably Malignant TISSUE 5 Malignant TISSUE BI-RADS MRI Scoring 23 MRI Scoring System (Gottingen score) 24 MRI Artefact Category Density Type Points Shape - Margins Well -defined Poorly defined Contrast Homogenous Inhomogeneous Ring Initial Inc <50% % >100% Post Initial Increase Plateau Washout

5 25 26 MRI BI-RADS Enhancing Breast Cancer 0 Points 1-2 Points 3 Points 4-5 Points 6-8 Points MRI BI-RADS 1 MRI BI-RADS 2 MRI BI-RADS 3 MRI BI-RADS 4 MRI BI-RADS 5 7 Points = BI-RADS Breast Cancer Breast MRI Indications Screening Assessment and staging of breast cancer Prostheses 1 in 8 women will be diagnosed with breast cancer Assuming a woman lives to the age of MRI Breast Screening MRI Breast Screening NEJM July high risk women Risk > 15%, genetic or familial 358 BRCA1 or BRCA2 positive 52 Tumours 44 Invasive carcinomas 6 DCIS 1 Lymphoma 1 LCIS

6 31 32 MRI Breast Screening MRI Breast Screening Sensitivity Clinical 17.9 Mammography 33.3 MRI 79.5 Specificity Clinical 98.1 Mammography 95.0 MRI American Cancer Society Guidelines for Breast Screening with MRI as an Adjunct to Mammography March 2007 Screening MRI is recommended: for women with an approximately 20 25% or greater lifetime risk of breast cancer, including women with a strong family history of breast or ovarian cancer and women who were treated for Hodgkin disease. Non-Screening Clinical Indications for Contrast Breast MR Lobular Cancer Occult Breast Cancer Close or positive surgical margins Post-operative scar vs. tumor recurrence Neo-adjuvant chemotherapy or brachytherapy Suspected multiple or bilateral cancers Implants and known or suspected cancer Problematic Mammogram Assessment of all diagnosed breast cancers MRI in unilateral breast cancer MRI in diagnosed breast cancer NEMJ March with diagnosis of unilateral breast cancer Other breast normal clinically and mammo Occult cancer in second breast 3.1% April 2008 European Breast Cancer Conference in Germany 249 patients who had malignancy on biopsy had MRI Altered management in 13% 20 additional cancers 8% Better than mammo or US in assessing tumour size We would like to see MRI become a standard preoperative treatment for breast cancer, along with biopsy, mammography, and ultrasound

7 37 38 Analysis Unilateral vs. Bilateral Cancers are bilateral in up to 10% Multiple lesions Infiltrating ductal Ca Fibroadenoma Exclusion of contra-lateral tumor is of great clinical and personal value Courtesy: Dr. Bruce Porter Courtesy of FHDI DCIS

8 43 44 Pathology with prostheses Prostheses with pathology Extent of Tumour Lobular carcinoma larger than Mammo or US Incomplete Excision Neo-adjuvant Chemotherapy: Monitoring Post-chemo Courtesy of FHDI

9 49 50 Contrast-enhanced Breast MR: Accuracy Staging Varies significantly with technique and experience. Sensitivity: > % Negative Predictive Value: > 95 % Specificity: % Positive Predictive Value: ~ % For DCIS sensitivity is lower, especially for low or intermediate grades; also for some lobular, low grade, or less angiogenic invasive carcinomas. Courtesy: Dr. Bruce Porter Chest STIR: Aids in cancer staging MR - guided breast biopsies Look for highest positive lymph node Use body coil, supine placement Some lesions are not visible with mammography or ultrasound (US) After identified with MR (diagnosis) Many lesions can be found using US US is interactive, cheaper, faster MR-guided BB needed for those lesions which cannot be seen in retrospect on US or mammaography Courtesy of FHDI MRI Breast Biopsy Device Breast Biopsy Lateral and medial access Needle or wire placement (core, fna) Vacuum assisted biopsy extraction Software controlled guidance Comfortable patient support

10 55 56 Spectroscopy - MRS MRS monitoring of Chemotherapy Early results show specificity > 95% Choline peak at 3.6 ppm Single voxel studies Before Chemotherapy 1 st cycle 2 nd cycle 3 rd cycle MRS monitoring of Chemotherapy Silicone Implant Rupture MRI MR is the definitive exam for implant assessment. Non-contrast unless a question of cancer. 4 th cycle 5 th cycle 6 th cycle Silicone Courtesy of FHDI and USCD Implant rupture Conclusion MRI is the gold standard if resources are available. Combined approach with Mammogaphy and Ultrasound. Should be used for screening high risk cases. Should be used to assess all diagnosed breast cancer. Use scoring system and BI-RADS You will get false positives No false negatives Don t screen unless you can biopsy.

11 61 Thank you! Richard Tuft FRCS, FRCR, FFRad(D)(SA) ISRRT Durban 2008