Anyone can get breast cancer BREAST MRI KATE Datin Dr Fatimah Moosa Sunway Medical Centre DATIN SERI ENDON KYLIE SIZE DOES NOT MAKE A DIFFERENCE BREAST CANCER The incidence of getting breast cancer is 1:19 in Malaysia Breast cancer - commonest cancer in all ethnic groups Year 2003-3738 breast cancer cases were reported 31.0 % of newly diagnosed cases. Y mi voz Junto a las demás 1
MR Imaging for Breast Cancer Detection, Diagnosis, and Staging At the present time, mammography is the only imaging modality with proved efficacy for the detection of early, clinically occult breast cancer screening. Limitations in both the specificity and sensitivity of mammography have stimulated exploration into adjunctive imaging modalities which includes MRI breast Advances in surface coil technology, development of new imaging protocols and introduction of contrast enhanced MR imaging show promising tool for breast imaging modality MR Imaging for Breast Cancer Detection, Diagnosis, and Staging For MR imaging to be a viable modality for breast imaging, it must be demonstrated that this technology can provide clinically valuable information that cannot be obtained with conventional imaging methods Several clinical studies have now demonstrated the potential of MR imaging for greater specificity and sensitivity than is possible with mammography, ultrasound and physical examination Benefits of Breast MRI Can image breast implants and ruptures Highly sensitive to small abnormalities Used effectively in dense breast Can evaluate inverted nipples for evidence of cancer Can evaluate the extent of breast cancer multicenteric or multifocal lesions Sensitivity and Specificity of Examinations for Breast Cancer in a High Risk Population* Sensitivity Specificity Clinical Examination 18% 98% Mammography 40% 95% MRI 71% 90% *Women with genetic or familial predisposition to breast cancer Benefits of Breast MRI Can determine what type of surgery in indicated ( lumpectomy vs. mastectomy) May help detect breast recurrences, residual tumours from scar tissue after lumpectomy Can locate primary tumour in women whose cancer has spread to axillary LN Can spot or characterise small abnormalities misses by mammography Maybe useful in screening women at high risk for breast cancer Limitations of Breast MRI MRI takes 30-60 min compared to 10-15 min for screening mammography Cost of MRI is several times the cost of mammography MRI pt must tolerate claustrophobia MRI can be non specific, often cannot distinguish between cancerous and non-cancerous lesions 2
Limitations of Breast MRI Minimally invasive breast biopsy techniques need sofisticated software and techniques Cannot image micro calcifications Advanced MRI techniques are often not available at most centres Cannot always produce results cited in research studies Technical Requirements No universally accepted standard or optimal technique Multitude of imaging variables including magnetic field strength (high vs low), breast surface coil configuration, and imaging parameters ( i.e., two-dimentional vs. three-dimentional acquisition, imaging matrix, FOV, TOA and unilateral vs. bilateral examination Suggested Protocol Axial SE/FSE T1: Acts as localiser.thickslices/gap throught both breasts Sagital SE /FSE/PD/T2: Prescribed through the breast include the axillae Axial gradient echo T1 with contrast: dynamic pre and post contrast.use FAT SAT to distinguish enhancing pathology from fat Additional sequences: Sagital/coronal SE/FSE T1 post contrast STIR: coronal or axial Image Optimisation: Technical Issues Increase SNR due to recent developments in coil technology Phase array coils return highest and most uniform signal. Others can give glare at nipple and signal fall of nearer the chest FSE is a great advantage as it facilitates the acquisition of very fine matrices in relatively short scan times. Smallest FOV, thin slices and small gaps used to maintain spatial resolution further FAT SAT and other fat suppression tech. are useful in pts with fatty breast to distinguish lesion from surrounding breast tissue Artefact Problems Respiratory artefact: reduced in prone position Cardiac motion and flow within the mammillary vessels are often troublesome, hence swapping the phase encoding axis to S to I on sagital images and R to L on axial removes the artifact from the breast, but it can interfere with the breast. FC also reduces flow artifact but it increases the signal in vess. And the minimum TE available, not usually beneficial in T1W seq. SAT(presaturation pulse) brought into FOV and placed posteriorly over the heart are useful in reducing motion artefact 3
Aurora 1.5T Dedicated Breast MRI Differences 1 st FDA approved designed specifically for breast, dedicated and integrated with propriety CAD and biopsy capability Superior image at 4.5T quality and clearness Ability to see full coverage of both breast,chest wall and axillae in a single scan Feet first entry,patient comfort and greater access to breast for biopsy intervention Aurora Dedicated Breast MRI with 3-D Bilateral SpiralRODEO A more efficient manner for acquiring data 3X signal to noise, and 4 X resolution SpiralRODEO encodes signal acquisition during 46% of the scan time High resolution fat-suppressed imaging thru water excitation Magnetization transfer contrast (ductal tissue suppression) Faster scan times five 3 minute sequences Increased Temporal Resolution with the first time point at 90 seconds Isotropic Resolution 1.1 mm slice thickness for better detection of Ductal Carcinama In-Situ Dedicated Breast MRI System 3-D Image Acquisition Matrix 360x360x128 _ 3-D Image Reconstruction Matrix 512x512x160 slices _ 1mm 1.1mm slice thickness; no gap between slices _ Less than 3 minutes per scan _ Post-contrast time points obtained at 90-second, 4.5-minute, 7.5-minute and 10.5-minute intervals Importance of good Fat Suppression (to avoid snowman in snowstorm effect) A picture is worth a thousand words 4
Poor magnetic field homogeneity: hot spots Why Shim? Ellipsoid homogeneous field and image driven shimming provide homogeneous fat suppression of breasts and axillary regions Lesion Visibility: Suppression of Fat Signal In contrast to mammography, where lesion detectability is increased in a fatty background, on MR an enhancing lesions may not be detected because it becomes isointense to fat following contrast Hence signal from fat need to be eliminated Lesion Visibility: Suppression of Fat Signal One method is by post processing image subtraction (subtracting the precontrast from the post contrast sequences) Alternatively, fat suppression techniques use of a variation of chemical selective fat suppression where an extra RF pulse is used produces images of enhancing lesions that are easily identified on a dark background without any significant increase in imaging time 5
Fat suppression Sequences Breast MR Imaging for Lesion Characterisation One of the major limitations of mammogram is the overlap in the appearance of benign and malignant lesions MR imaging in the characterisation of mammographically and clinically detected lesions have reported improved specificity with MR imaging using differences in enhancement kinetics and morphologic features between malignant and benign lesions Breast MR Imaging for Lesion Characterisation Reported specificities of MR have been variable ranging from 37% to 97% This wide range is reflective of multiple factors including differences in magnetic field strength, imaging parameters, pt selection criteria, image interpretation, and histologic variation of benign and malignant lesions 6-10% of benign lesion do enhance Enhancement kinetics can be used to differentiate malignant lesions from benign, where malignant lesions demonstrate rapid increase in signal intensity followed by a wash-out of contrast in delayed images, whereas benign lesion exhibit a slower, progressive rise in signal intensity without wash-out of contrast 6
Malignant enhancement pattern 7
Breast MR Image-Guided Interventional System Allow largest access area to the breast for MRI-Interventional procedures Accommodate core biopsy or vacuum assisted biopsy devices Large apeture allows for increase access to breast for both medial and lateral approaches Core/Mammotome with MR Fast and simple set-up Hand held use Visual Targeting Z-lock and Imageable Aperture Grid System Maximize Breast Access Position the Cube Insert Targeting Set Note: Clean and anesthetize skin before making skin nick for targeting set insertion. Remove obturator and insert probe for biopsy Biopsy Take sample Activate Rotate 8
Mark Biopsy Site Breast implants MR imaging of Breast Implants Intracapsular Rupture- contained by fibrous capsule with linguine sign(arrows) Extracapsular tear With collapse of the silicone shell Extensive Gel Bleed with focal rupture without complete collapse of implant shell- inverted teardrop sign Summary MR imaging has proved to be excellent imaging modality in locating free silicone and evaluating an implant rupture, with a sensitivity of approximately 94% and specificity of 97% The most reliable findings for detection of rupture include identification the collapse implant shell (linguine sign) and free silicone within breast parenchyma 9
Conclusion While MRI is en effective problemsolving technology, it has limitations as a screening tool for breast cancer MRI s limited availability, expense, and frequent non-specificity has slowed its widespread acceptance However there is a potential role for screening in young women with dense breast in the high risk group THANK YOU 10