SWIFT MRI for Breast Imaging Curtis A. Corum, John C. Benson, Djaudat Idiyatullin, Angela Styczynski-Snyder, Diane Hutter, Lenore Everson, Lynn Eberly, Michael T. Nelson and Michael Garwood University of Minnesota Minneapolis, MN, USA RSNA 2012, VSBR51-04

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging2 What is SWIFT? SWeep Imaging with Fourier Transform Developed 2006 at University of Minnesota, Center for Magnetic Resonance Research

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging3 What is SWIFT? ISMRM 2009 ISMRM 2010 JOE 2011

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging4 Motivation Make more efficient use of scan time for Breast MRI by simultaneously obtaining: High Spatial Resolution Morphological Images and High Temporal Resolution DCE Images.

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging5 Goals Optimize SWIFT sequence and protocol for Breast MRI at 4 T. Scan a pilot cohort of diagnostic patients. BI-RADS 4-5 Acquire simultaneously DCE and Morphological images. Optimize view sharing* based reconstruction. * Dougherty et al., (2007). High frame-rate simultaneous bilateral breast DCE-MRI., Magn Reson Med 57 :

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging6 SWIFT SWeep Imaging with Fourier Transform Always Acquiring - Fast and Efficient short dead time - short T2 sensitive (2-6 μs)(preserve off-resonance) Smooth Gradient - Quiet and PNS free (peripheral nerve stimulation)

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging7 SWIFT, Non-Cartesian... K-space Sampling Radial 3D, Center-Out 2 sec per 512 view sphere 3 sec with interleaved FS View Ordering (and gradient co-ordinate) One interleaved sphere (of many)

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging8 SWIFT, Non-Cartesian....but... No gradient timing errors (group delay)......because gradient already ramped. Minimal eddy currents and thermal issues......because of small, smooth ramps. No special timing or k-space calibrations......either per scan or maintenance, or in post-processing.

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging9 SWIFT Diagnostic Breast Protocol On Research Scanner, Agilent Console, Siemens Gradients, Oxford 4 T Magnet *** in progress, replace list slide

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging10 SWIFT Diagnostic Breast Protocol 2 minshimming, pre-scan, scout 20 secSWIFT pre-scans, phase reference and gain 1-2 minSWIFT FOV check, FS (2-4 min)(optional) Double Angle Method GRE B1 map (2-4 min)(optional) SWIFT Variable Flip Angle T1 map 2-6 minSWIFT DCE FS, pre-contrast (Magnavist TM 0.1 mM/kg at 2 cc/s) 6 minSWIFT DCE FS post-contrast, (optional) further SWIFT test scans min Minimum total time On Research Scanner, Agilent Console, Siemens Gradients, Oxford 4 T Magnet

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging11 SWIFT Cases #AgeBI-RADSInitialPath Breast History 1194aUSFAL painless lump in left breast at 4:00 position 2314USFAR Palpable lump in the right breast at 9: MamFAL Generalized breast lumpiness 4444MamDCIS, crib, necrR Right breast lump, with hx of breast augmentation 5404MamFAR Had recent mammo with Bi-rads MamFCCL History of left breast pain, burning, nodules. 7484USFAR Probably benign mass in the right breast prev. 8534MamIDCL Persistent nipple discharge, amber/green in color 9555MamDCISL Left breast lump. Sister, mother w/breast cancer MamDCISL Previous bi-rads MamFAL Physician feels palpable lesion med. to the nipple 12255USFAR Patient feels small sup. Lump 11: near the nipple MamIDCR Right inverted nipple, injury to the right breast 6 months ago, right axillary lump 14394USFAL Left breast lump. Patient reports bilateral non spontaneous greenish colored nipple discharge.

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging12 SWIFT Cases, subtraction MIPs 3D images on sized SWIFT compatible transmit/recieve single breast coils 256^3 matrix, isotropic < 1mm resolutionOR 384^3 matrix, isotropic < 0.67 mm resolution (for more recent scans 10-14)

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging13 Case 4, Mass Like DCIS 256^3 matrix, isotropic < 1mm (using all available data) Reformat to arbitrary slice without loss of image quality

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging14 Case 4, Mass Like DCIS Clinical 1.5 T subtraction MIP High Resolution post contrast image is not at Maximum enhancement (DCE image is available) SWIFT 4 T Subtraction MIP High Resolution image at any time point is available

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging 15 Case 4, Mass Like DCIS MIP at each time point 6 sec frames MIP of all time points (maximum enhancement)

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging16 Case 4, Mass Like DCIS DCE ROI 6 sec frames DCE ROI intensity 6 sec frames

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging17 Case 12, FA 384^3 matrix, isotropic < 0.67mm (using all available data) Again, reformat to arbitrary slice without loss of image quality

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging18 Case 13, IDC 384^3 matrix, isotropic < 0.67mm (using all available data) Again, reformat to arbitrary slice without loss of image quality

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging 19 Conclusion Demonstrated simultaneous high spatial resolution isotropic morphological and DCE Breast MRI with SWIFT.

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging20 Breast SWIFT (near) Future... Dual Breast Coil Compressed Sensing Reconstruction Parallel Acceleration Siemens Research sequence implementation

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging21 Acknowledgements We gratefully acknowledge NIH R21 CA139688, P41 RR008079, S10 RR023730, S10 RR027290, and the Minnesota Medical Foundation for grant support. Thanks to S. Suddarth and A. Rath of Agilent, B. Hannah, J. Strupp, and P. Anderson of CMRR for software and hardware support. Also thanks to Mike Tesch for assistance with the SWIFT distribution package, Jinjin Zhang for help with patients, and Carl Snyder and Gregor Adriany for assistance with coil modifications and design.

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging 22 SWIFT Parameters TR 4.4 ms, 62 kHz, 4.1 ms HS1, Flip 8-16 deg, 256 points Fat Suppression (FS) 1/8 views, 4 ms Gauss, Flip 120 deg, offset -625 Hz 3d Radial Isotropic Vieworder Sorted Halton** sequence, 512 views per k-space sphere 128 full spheres per 4.5 min acquisition (6 min with FS) 65,536 views total before restarting * 10 ms HS4 R20 pulse for dual fat and silicone suppression ** Wong TT, Sampling with Hammersley and Halton Points, J Graph Tools archive, Volume 2, Issue 2, Chan RW et al., MRM 2010.

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging23 NMR and Convolution * = h(t) r(t) spin impulse response x(t) RF pulse system response NMR and Convolution The fundamental basis of SWIFT signal processing is that a frequency modulated pulse alters the system response away from the familiar hard pulse impulse response. In the small flip angle limit the relationship is convolution. Practically it works well up to 90°.

Thursday, Nov 29, 9:10 AMRSNA2012 VSBR51-04 Corum et al. SWIFT MRI for Breast Imaging24 SWIFT and Correlation = x(t) RF pulse Recovering a standard FID by correlation SWIFT produces an FID if the raw data (system reposnse) is correlatied with the complex RF pulse shape as a post processing step. In practice this is performed in the frequency domain by multiplication with the complex conjugate of the complex pulse profile. r(t) system response h(t) spin impulse response