High-Resolution Time-Resolved Contrast-Enhanced MR Abdominal and Pulmonary Angiography Using a Spiral- TRICKS Sequence
|
|
- Audrey Merritt
- 5 years ago
- Views:
Transcription
1 High-Resolution Time-Resolved Contrast-Enhanced MR Abdominal and Pulmonary Angiography Using a Spiral- TRICKS Sequence Jiang Du* and Mark Bydder Magnetic Resonance in Medicine 58: (2007) Both high spatial resolution and high temporal resolution are desirable for contrast-enhanced magnetic resonance angiography (CE-MRA) in order to depict the arterial vasculature. In this work a fast MR pulse sequence (spiral time-resolved imaging with contrast kinetics (Spiral-TRICKS)) with spiral readout in-plane and Cartesian slice encoding was developed whereby the slices are partitioned into multiple regions and acquired in the order used with the TRICKS sequence. The combination of highly efficient spiral sampling with TRICKS acquisition significantly reduced imaging time requirements. A unit second temporal reconstructed frame rate could be achieved for threedimensional (3D) CE-MRA without undersampling of the spiral trajectories. Image quality was improved through spiral trajectory measurement and field-map correction. Phantom and volunteer studies were performed to demonstrate the feasibility of this technique. Magn Reson Med 58: , Wiley-Liss, Inc. Key words: gradient distortion; magnetic resonance angiography; spiral trajectories; three-dimensional; time-resolved MRA Three-dimensional (3D) contrast-enhanced magnetic resonance angiography (CE-MRA) has been established as a safe and reliable method for the evaluation of abdominal vasculature. Conventional CE-MRA examinations are typically performed using a single-phase 3D Fourier transform gradient-echo acquisition. It is critical to coordinate the acquisition of central k-space data with contrast arrival to generate arterial phase images and suppress venous contamination (1). Time-resolved acquisition provides contrast dynamics in the vasculature by capturing the passage of the contrast bolus through the artery and vein of interest (2 8). Vascular pathologies with complex enhancement kinetics, such as delayed filling or asymmetric filling, can be assessed on multiple successive phases of contrast bolus (6 8). Therefore, time-resolved acquisition eliminates timing considerations and reduces sensitivity to filling delays between vessels. However, conventional 3D Cartesian acquisition takes about sec to produce good image quality and thus is unable to provide high temporal resolution. To overcome this problem, several techniques have been developed to speed up the acquisition. The time-resolved imaging with contrast kinetics (TRICKS) sequence divides the 3D Cartesian k-space into several subvolumes located at increasing distance from the k-space center and samples the k-space center more often than outer sections to generate a high temporal reconstructed frame rate (6). The spatial resolution is traded for temporal resolution. Using a combination of undersampled projection reconstruction (PR) with TRICKS acquisition allows a high temporal reconstructed frame rate without spatial resolution degradation (7,8). Compared to radial PR, spiral trajectory allows longer sampling intervals and offers more efficient raw data sampling by circular coverage of k-space (9 11). The complete k-space can be covered with fewer excitations without undersampling artifact. Spiral trajectories permit sampling to begin at the k-space center, which significantly reduces the echo time (TE) and provides intrinsic flow compensation. The longer readout of spiral leads to a longer repetition time (TR), which increases the signal-to-noise ratio (SNR) due to more signal recovery and lowers the average specific absorption rate (SAR) delivered to the patient. But the long spiral readout also leads to reduced stationary spin suppression and higher sensitivity to B 0 inhomogeneities, resulting in image blurring (12). Gradient error and eddy-current effects may also contribute to increased image blurring. However, blurring due to B 0 -field inhomogeneities can be reduced by correcting the phase errors through field-map generation (4,12). Gradient distortion and eddy-current effects can be corrected through spiral trajectory measurement (13,14). In this work a fast MR pulse sequence (Spiral-TRICKS) was developed with spiral in-plane readout and Cartesian slice encoding. The 3D k-space was partitioned into multiple regions along the slice-encoding direction and acquired in the order used with the TRICKS sequence. A unit second temporal reconstructed frame rate was achieved for 3D CE-MRA. Gradient distortion and eddy-current effects were reduced through spiral trajectory measurement and field-map correction. Phantom and volunteer studies were performed to demonstrate the feasibility of this technique. MATERIALS AND METHODS Pulse Sequence Department of Radiology, University of California San Diego, San Diego, California, USA. Grant sponsor: Bracco Diagnostic, Inc. *Correspondence to: Jiang Du, Ph.D., Department of Radiology, University of California San Diego, 200 West Arbor Drive, San Diego, CA jiangdu@ucsd.edu Received 1 June 2006; revised 3 April 2007; accepted 8 April DOI /mrm Published online in Wiley InterScience ( Wiley-Liss, Inc. 631 A fast dynamic imaging sequence (spiral-tricks, shown in Fig. 1) was implemented whereby a stack of spiral 3D trajectories is integrated with TRICKS acquisition to provide high-resolution CE-MRA. The Spiral-TRICKS sequence employs spiral readout trajectory in-plane (kx and ky), and conventional Fourier encoding in the slice direction (kz). In each slice-encoding step, 72 (pulmonary MRA) or 48 (abdominal MRA) interleaved spirals were
2 632 Du et al. FIG. 1. a: k-space sampling using a 3D stack of spirals trajectory with kz slices partitioned into four regions (regions A D). b: The interleaved spiral trajectory used for in-plane sampling. c: Schematics of data acquisition. Mask data were acquired for all regions, followed by dynamic data acquisition in the orders used in TRICKS. A sliding-window reconstruction was used to generate high-spatialresolution time-frame images. acquired. The number of spiral interleaves and readout points were chosen as a compromise between spatial resolution, off-resonance blurring, and sampling efficiency. The slice encodings were partitioned into multiple regions (regions A D, with region D being three times the size of regions A C) from low-frequency slice encodings to highfrequency slice encodings and sampled with a TRICKS acquisition scheme (A 1 B 2 A 3 C 4 A 5 D 6 A 7 B 8...), where the subscript refers to the acquisition order (8). Furthermore, spiral interleaves from region A were divided into three subsets of interleaves, with each acquisition of region A covering only one subset of spiral interleaves, a strategy similar to the selective line acquisition mode (SLAM) technique (15). In the slice-encoding direction, asymmetric k-space sampling was employed to shorten the total acquisition time. Only slices from region A were fully sampled, while slices from regions B D were half sampled. As a result, only 58% of the slice partitions were acquired. Homodyne reconstruction along the slice-encoding direction was carried out to recover the slice resolution (16). The combination of a spiral trajectory, TRICKS acquisition, SLAM technique, and partial slice encoding was expected to significantly improve the temporal reconstructed frame rate of 3D dynamic imaging. Image Reconstruction and Correction A sliding-window reconstruction algorithm was used for dynamic image reconstruction, where data sharing of different regions among neighbor time frames provides high temporal reconstructed frame rate 3D images without spatial resolution degradation (6 8). View sharing will result in temporal resolution blurring, which is regarded as acceptable for dynamic CE-MRA. This reconstruction strategy has been widely used in fluoro-triggering and other dynamic image reconstruction methods (17 19). Spiral acquisition is susceptible to gradient distortion, eddy currents, and off-resonance effects that result in image artifacts such as blurring, distortion, and SNR degradation (9,16). Many algorithms have been developed to address these issues (9,16,20,21). Here a two-step correction algorithm was adopted. First, eddy-current effects and gradient errors were minimized through k-space trajectory measurement (13,14), where the phase difference with and without readout gradients accurately maps the true k-space trajectory. Second, phase error due to off-resonance from B 0 -field inhomogeneities was corrected through field-map acquisition (3,4). A conjugate phase reconstruction was applied to correct the zeroth-order effects of the off-resonance (20,21). Frequency-segmented off-resonance corrections, such as those based on minimizing the imaginary part of the image signal, may offer higher-order correction (4,12), but the reconstruction time will be significantly longer. The entire reconstruction time, including calculating the spiral trajectory and field map, regridding the interleaved spiral interleaves onto Cartesian grids, and fast Fourier transform of the 3D dynamic images (17 time frames) acquired with an eight-channel phased-array coil, took about half an hour on a 3.2 GHz Pentium 4 processor. The multiple coil data were combined using the square root of sum of squares (22). Experimental Methods Phantom and volunteer studies were performed on a standard 1.5T MR scanner (Signa LX; GE Medical System, Waukesha, WI, USA). A phantom was scanned to test the effects of gradient distortion, eddy current, and B 0 -inhomogeneity correction. Time-resolved imaging of the pulmonary and renal vasculature was performed on four volunteers (32 63 years old, kg; two for pulmonary and two for renal MRA) using an eight-element cardiac phasedarray coil (MRI Devices, Milwaukee, WI, USA). The acquisition parameters for pulmonary/renal imaging are were FOV cm, TR 5.1/7.4 ms, TE 0.6/0.8 ms, flip angle 30, BW 125 khz, readout 512/1024 points per interleaf, spiral interleaves 72/48, 36 kz slice encodings in the anterior posterior direction, slice thickness 3.0/2.0 mm, and reconstruction matrix size Region A was updated every sec. Other regions and all of k-space were updated every 7.5 sec. The total scan time was 30 sec, including mask time. The injection of 30 ml Gd-BOPTA (MultiHance ; Bracco Imaging SpA, Mila, Italy) followed by a 20-ml saline flush was applied to each dynamic acquisition. A computer-controlled power injector (Spectris; Medrad, Indianola, PA, USA) was used to ensure a precise injection rate of 3.0 ml/sec for both contrast material and flush. Written informed consent was obtained before the imaging procedures in accordance with institutional review board rules. RESULTS k-space distortion was measured as shown in Fig. 2. Figure 2a shows the ideal and measured trajectories along the kx direction. Figure 2b shows the k-space deviation from the ideal trajectory for both kx and ky directions. As shown in the image, the distortion is nonlinear and thus cannot be corrected through simple gradient delay or k-space shift. The phantom images shown in Fig. 3 demonstrate the
3 Dynamic Imaging Using Spiral-TRICKS 633 FIG. 2. a: Measured and ideal spiral trajectories (only the first 100 of 512 points are displayed for better depiction of the difference). b: k-space deviation of the measured spiral trajectory for the Gx and Gy gradients. efficacy of this k-space distortion correction. Image artifacts were significantly reduced with the measured trajectory instead of the ideal trajectory. Off-resonance correction using a field map further reduced the image artifact. Object details located at the superior and inferior sides of the imaging FOV were recovered through this correction. The Spiral-TRICKS sequence was applied to CE pulmonary imaging (Fig. 4). In total, 17 time frames were generated within 30 sec (including mask), resulting in a high temporal reconstructed frame rate of 1.0 sec/frame, which captured the complete contrast dynamics in the lung, including the arterial, arterial venous transition, and venous phases. The high in-plane spatial resolution of 1.56 mm, which was zero-padded to 0.63 mm, provided an excellent depiction of the pulmonary vessels. Figure 5 shows multiple projections of two consecutive arterial phases of the renal vasculature, which demonstrate the high spatial resolution ( mm 3 ) and rapid renal parenchymal enhancement. A high temporal reconstructed frame rate of 1 sec/frame captured the segmental arteries without parenchymal contamination. DISCUSSION Our preliminary data demonstrate that the spiral-tricks sequence can provide CE-MRA of the abdominal (pulmonary and renal) vasculature with both high spatial resolution and a high temporal reconstructed frame rate. The 4D imaging capability (3D spatial resolution plus 1D temporal resolution) provides detailed contrast enhancement kinetics and a solution for imaging delayed filling or asymmetric filling of the contrast bolus. FIG. 3. Phantom images without any correction (a), with k-space trajectory measurement (b), and k-space trajectory measurement plus B 0 field-map correction (c). The B 0 field map only corrects the phase errors, and k-space distortion was corrected using a spiral trajectory measurement. Eddy-current and gradient distortion was significantly reduced after the trajectory measurement (thick arrows). B 0 field-map correction helps to recover signal at the periphery of the imaging FOV (thin arrows), where B 0 inhomogeneity is most significant. FIG. 4. Complete contrast dynamics of the pulmonary vasculature is depicted through 15 consecutive time-frame maximum intensity projection (MIP) images with a temporal reconstructed frame rate of 1.0 sec/frame. The acquisition FOV of mm 3, spiral readout of 512, and 72 spiral interleaves result in an acquired voxel size of mm 3, which was zero-padded to mm 3 in the reconstruction.
4 634 Du et al. FIG. 5. Rotation of two consecutive time frames. Frames 4 (a c) and 5(d f) depict the fast parenchyma and venous enhancement in the renal vasculature with high spatial resolution ( mm 3 ) and a high temporal reconstructed frame rate (1 sec/ frame). A spiral trajectory provides higher acquisition efficiency than a Cartesian or radial trajectory, although a quantitative comparison among the three trajectories was not performed in this study. The combination of spiral trajectory with TRICKS acquisition provides a temporal reconstructed frame rate of 1 sec/frame. Conventional multiphase acquisitions typically provide a temporal resolution of 3 6 sec/frame by using a short TR and partial echo, partial slice-encoding acquisition (2,5). In a spiral-tricks acquisition the low spatial frequencies are slightly oversampled, which helps to reduce motion. The high spatial frequencies were sampled according to the Nyquist criteria. Data-sharing was performed in the slice-encoding direction. This differs from the sliding-window reconstruction algorithm used in 3D PR (19), in which view-sharing is performed for high-frequency projection data to suppress undersampling streak artifact. The combination of spiral-tricks with the SLAM technique further improves the frame update rate at the cost of slightly more temporal blurring (15). The major problem associated with spiral-tricks acquisition is its susceptibility to gradient distortion, eddy currents, and B 0 inhomogeneity (3,16). Spiral images typically suffer from blurring, especially at the periphery of the imaging FOV, where B 0 inhomogeneity is substantially higher than that at the center FOV. The two-step correction algorithm used here significantly suppressed these artifacts. Gradient anisotropy leads to different gradient delays along each physical gradient. The k-space trajectory measurement automatically corrects the gradient anisotropy, as well as the effects of eddy currents and gradient nonlinearities. Its combination with field-map correction further improves the image quality, especially at the periphery of the imaging FOV, by correcting both the phase errors due to center frequency offset and linear inhomogeneity (through k-space measurement). In our study a low-spatial-resolution field map was acquired only once before the dynamic image acquisition. Recent studies have shown that the field map may change substantially upon contrast arrival and departure, which may result in residual blurring artifacts when using a global field map correction rather than the actual field map (3). Therefore, it may be necessary to periodically acquire low-spatial-resolution field maps during the dynamic image acquisition. A simpler improvement is to acquire field maps before and after the contrast injection (4). The mask and images before contrast arrival can be corrected using the first field map, while postcontrast images can be corrected using the second field map. In our study the k-space deviation was corrected using the trajectory measurement algorithm (13,14). As shown in Fig. 2, the k-space deviation is nonlinear, which makes correction by a simple k-space shift inadequate. However, a k-space shift can suppress some of the spiral artifact. In summary, we have described a time-resolved 3D spiral-tricks sequence that generates 3D CE-MRA images with both high spatial resolution and a high temporal reconstructed frame rate. REFERENCES 1. Prince MR, Grist TM, Debatin JF. 3D contrast-enhanced MR angiography. New York: Springer-Verlag; Schoenberg SO, Bock M, Knopp MV, Essig M, Laub G, Hawighorst H, Zuna I, Kallinowski F, Kaick G. Renal arteries: optimization of threedimensional gadolinium-enhanced MR angiography with bolus-timingindependent fast multiphase acquisition in a single breath hold. Radiology 1999;211: Amann M, Bock M, Floemer F, Schoenberg SO, Schad LR. Threedimensional spiral MR imaging: application to renal multiphase contrast-enhanced angiography. Magn Reson Med 2002;48: Zhu H, Buck DG, Zhang ZH, Zhang HL, Wang P, Steger VA, Prince MR, Wang Y. High temporal and spatial resolution 4D MRA using spiral data sampling and sliding window reconstruction. Magn Reson Med 2004;52: Carr JC, Laub G, Zheng J, Pereles SF, Finn JP. Time-resolved threedimensional pulmonary MR angiography and perfusion imaging with ultrashort repetition time. Acad Radiol 2002;9: Korosec FR, Frayne R, Grist TM, Mistretta MA. Time-resolved contrastenhanced 3D MR angiography. Magn Reson Med 1996;36: Vigen KK, Peters DC, Grist TM, Block WF, Mistretta CA. Undersampled projection-reconstruction imaging for time-resolved contrast-enhanced imaging. Magn Reson Med 2000;43: Du J, Carroll TJ, Wagner HJ, Vigen KK, Fain SB, Block WF, Korosec FR, Grist TM, Mistretta CA. Time-resolved, undersampled projection reconstruction imaging for high resolution CE MRA of the distal runoff vessels. Magn Reson Med 2002;48: Meyer CH, Hu BS, Nishimura DG, Macovski A. Fast spiral coronary artery imaging. Magn Reson Med 1992;28: Spielman DM, Pauly JM, Meyer CH. Magnetic-resonance fluoroscopy using spirals with variable sampling densities. Magn Reson Med 1995; 34: King K, Foo TKF, Crawford CR. Optimized gradient waveforms for spiral scanning. Magn Reson Med 1995;34: Noll DC, Pauly JM, Meyer CH, Nishimura DG, Macovski A. Deblurring for non-2d Fourier transform magnetic resonance imaging. Magn Reson Med 1992;25: Duyn JH, Yang YH, Frank JA, Veen JW. Simple correction method for k-space trajectory deviations in MRI. J Magn Reson 1998;132: Zhang Y, Hetherington HP, Stokely EM, Mason GF, Twieg DB. A novel k-space trajectory measurement technique. Magn Reson Med 1998;39: Rehwald WG, Kim RJ, Simonetti OP, Laub G, Judd RM. Theory of high-speed MR imaging of the human heart with the selective line acquisition mode. Radiology 2001;220: Noll D, Nishimura D, Makovski A. Homodyne detection in magnetic resonance imaging. IEEE Trans Med Imaging 1991;10: Riederer SJ, Tasciyan T, Farzaneh F, Lee JN, Wright RG, Herfkens RJ. MR fluoroscopy: technical feasibility. Magn Reson Med 1988;8:1 15.
5 Dynamic Imaging Using Spiral-TRICKS Foo TKF, Bernstein MA, Aisen AM, Hernandez RJ, Collick BD, Bernstein T. Improved ejection fraction and flow velocity estimates with use of view sharing and uniform repetition time excitation with fast cardiac techniques. Radiology 1995;195: Du J, Carroll TJ, Brodsky E, Lu AM, Mistretta CA, Block WF. Contrast enhanced peripheral magnetic resonance angiography using time-resolved vastly undersampled isotropic projection reconstruction. J Magn Reson Imaging 2004;20: Irarrazabal P, Meyer CH, Nishimura DG, Macovski A. Inhomogeneity correction using an estimated linear field map. Magn Reson Med 1996; 35: Kadah YM, Hu XP. Simulated phase evolution rewinding (SPHERE): a technique for reducing B 0 inhomogeneity effects in MR images. Magn Reson Med 1997;38: Roemer PB, Edelstein WA, Hayes CE, Souza SP, Mueller OM. The NMR phased array. Magn Reson Med 1990;16:
Module 5: Dynamic Imaging and Phase Sharing. (true-fisp, TRICKS, CAPR, DISTAL, DISCO, HYPR) Review. Improving Temporal Resolution.
MRES 7005 - Fast Imaging Techniques Module 5: Dynamic Imaging and Phase Sharing (true-fisp, TRICKS, CAPR, DISTAL, DISCO, HYPR) Review Improving Temporal Resolution True-FISP (I) True-FISP (II) Keyhole
More informationK-Space Trajectories and Spiral Scan
K-Space and Spiral Scan Presented by: Novena Rangwala nrangw2@uic.edu 1 Outline K-space Gridding Reconstruction Features of Spiral Sampling Pulse Sequences Mathematical Basis of Spiral Scanning Variations
More informationOutline: Contrast-enhanced MRA
Outline: Contrast-enhanced MRA Background Technique Clinical Indications Future Directions Disclosures: GE Health Care: Research support Consultant: Bracco, Bayer The Basics During rapid IV infusion, Gadolinium
More informationModule 4. K-Space Symmetry. Review. K-Space Review. K-Space Symmetry. Partial or Fractional Echo. Half or Partial Fourier HASTE
MRES 7005 - Fast Imaging Techniques Module 4 K-Space Symmetry Review K-Space Review K-Space Symmetry Partial or Fractional Echo Half or Partial Fourier HASTE Conditions for successful reconstruction Interpolation
More informationDynamic Contrast enhanced MRA
Dynamic Contrast enhanced MRA Speaker: Yung-Chieh Chang Date : 106.07.22 Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan 1 Outline Basic and advanced principles of Diffusion
More informationDynamic Autocalibrated Parallel Imaging Using Temporal GRAPPA (TGRAPPA)
Magnetic Resonance in Medicine 53:981 985 (2005) Dynamic Autocalibrated Parallel Imaging Using Temporal GRAPPA (TGRAPPA) Felix A. Breuer, 1 * Peter Kellman, 2 Mark A. Griswold, 1 and Peter M. Jakob 1 Current
More informationFast Imaging Trajectories: Non-Cartesian Sampling (1)
Fast Imaging Trajectories: Non-Cartesian Sampling (1) M229 Advanced Topics in MRI Holden H. Wu, Ph.D. 2018.05.03 Department of Radiological Sciences David Geffen School of Medicine at UCLA Class Business
More informationMRI Physics II: Gradients, Imaging
MRI Physics II: Gradients, Imaging Douglas C., Ph.D. Dept. of Biomedical Engineering University of Michigan, Ann Arbor Magnetic Fields in MRI B 0 The main magnetic field. Always on (0.5-7 T) Magnetizes
More informationMR Advance Techniques. Vascular Imaging. Class III
MR Advance Techniques Vascular Imaging Class III 1 Vascular Imaging There are several methods that can be used to evaluate the cardiovascular systems with the use of MRI. MRI will aloud to evaluate morphology
More informationk-space Interpretation of the Rose Model: Noise Limitation on the Detectable Resolution in MRI
k-space Interpretation of the Rose Model: Noise Limitation on the Detectable Resolution in MRI Richard Watts and Yi Wang* Magnetic Resonance in Medicine 48:550 554 (2002) Noise limitation on the detected
More informationField Maps. 1 Field Map Acquisition. John Pauly. October 5, 2005
Field Maps John Pauly October 5, 25 The acquisition and reconstruction of frequency, or field, maps is important for both the acquisition of MRI data, and for its reconstruction. Many of the imaging methods
More informationMagnetic Resonance Angiography
Magnetic Resonance Angiography Course: Advance MRI (BIOE 594) Instructors: Dr Xiaohong Joe Zhou Dr. Shadi Othman By, Nayan Pasad Phase Contrast Angiography By Moran 1982, Bryan et. Al. 1984 and Moran et.
More informationEvaluations of k-space Trajectories for Fast MR Imaging for project of the course EE591, Fall 2004
Evaluations of k-space Trajectories for Fast MR Imaging for project of the course EE591, Fall 24 1 Alec Chi-Wah Wong Department of Electrical Engineering University of Southern California 374 McClintock
More informationSources of Distortion in Functional MRI Data
Human Brain Mapping 8:80 85(1999) Sources of Distortion in Functional MRI Data Peter Jezzard* and Stuart Clare FMRIB Centre, Department of Clinical Neurology, University of Oxford, Oxford, UK Abstract:
More informationClinical Importance. Aortic Stenosis. Aortic Regurgitation. Ultrasound vs. MRI. Carotid Artery Stenosis
Clinical Importance Rapid cardiovascular flow quantitation using sliceselective Fourier velocity encoding with spiral readouts Valve disease affects 10% of patients with heart disease in the U.S. Most
More informationAccelerated MRI Techniques: Basics of Parallel Imaging and Compressed Sensing
Accelerated MRI Techniques: Basics of Parallel Imaging and Compressed Sensing Peng Hu, Ph.D. Associate Professor Department of Radiological Sciences PengHu@mednet.ucla.edu 310-267-6838 MRI... MRI has low
More informationRole of Parallel Imaging in High Field Functional MRI
Role of Parallel Imaging in High Field Functional MRI Douglas C. Noll & Bradley P. Sutton Department of Biomedical Engineering, University of Michigan Supported by NIH Grant DA15410 & The Whitaker Foundation
More information(a Scrhon5 R2iwd b. P)jc%z 5. ivcr3. 1. I. ZOms Xn,s. 1E IDrAS boms. EE225E/BIOE265 Spring 2013 Principles of MRI. Assignment 8 Solutions
EE225E/BIOE265 Spring 2013 Principles of MRI Miki Lustig Assignment 8 Solutions 1. Nishimura 7.1 P)jc%z 5 ivcr3. 1. I Due Wednesday April 10th, 2013 (a Scrhon5 R2iwd b 0 ZOms Xn,s r cx > qs 4-4 8ni6 4
More informationFast Isotropic Volumetric Coronary MR Angiography Using Free-Breathing 3D Radial Balanced FFE Acquisition
Fast Isotropic Volumetric Coronary MR Angiography Using Free-Breathing 3D Radial Balanced FFE Acquisition C. Stehning, 1 * P. Börnert, 2 K. Nehrke, 2 H. Eggers, 2 and O. Dössel 1 Magnetic Resonance in
More informationCompressed Sensing for Rapid MR Imaging
Compressed Sensing for Rapid Imaging Michael Lustig1, Juan Santos1, David Donoho2 and John Pauly1 1 Electrical Engineering Department, Stanford University 2 Statistics Department, Stanford University rapid
More informationLab Location: MRI, B2, Cardinal Carter Wing, St. Michael s Hospital, 30 Bond Street
Lab Location: MRI, B2, Cardinal Carter Wing, St. Michael s Hospital, 30 Bond Street MRI is located in the sub basement of CC wing. From Queen or Victoria, follow the baby blue arrows and ride the CC south
More informationTOF-MRA Using Multi-Oblique-Stack Acquisition (MOSA)
JOURNAL OF MAGNETIC RESONANCE IMAGING 26:432 436 (2007) Technical Note TOF-MRA Using Multi-Oblique-Stack Acquisition (MOSA) Ed X. Wu, PhD, 1,2 * Edward S. Hui, BEng, 1,2 and Jerry S. Cheung, BEng 1,2 Purpose:
More informationACQUIRING AND PROCESSING SUSCEPTIBILITY WEIGHTED IMAGING (SWI) DATA ON GE 3.0T
ACQUIRING AND PROCESSING SUSCEPTIBILITY WEIGHTED IMAGING (SWI) DATA ON GE 3.0T Revision date: 12/13/2010 Overview Susceptibility Weighted Imaging (SWI) is a relatively new data acquisition and processing
More informationWhite Pixel Artifact. Caused by a noise spike during acquisition Spike in K-space <--> sinusoid in image space
White Pixel Artifact Caused by a noise spike during acquisition Spike in K-space sinusoid in image space Susceptibility Artifacts Off-resonance artifacts caused by adjacent regions with different
More informationSpiral keyhole imaging for MR fingerprinting
Spiral keyhole imaging for MR fingerprinting Guido Buonincontri 1, Laura Biagi 1,2, Pedro A Gómez 3,4, Rolf F Schulte 4, Michela Tosetti 1,2 1 IMAGO7 Research Center, Pisa, Italy 2 IRCCS Stella Maris,
More informationPartial k-space Reconstruction
Chapter 2 Partial k-space Reconstruction 2.1 Motivation for Partial k- Space Reconstruction a) Magnitude b) Phase In theory, most MRI images depict the spin density as a function of position, and hence
More informationPartial k-space Recconstruction
Partial k-space Recconstruction John Pauly September 29, 2005 1 Motivation for Partial k-space Reconstruction a) Magnitude b) Phase In theory, most MRI images depict the spin density as a function of position,
More informationSampling, Ordering, Interleaving
Sampling, Ordering, Interleaving Sampling patterns and PSFs View ordering Modulation due to transients Temporal modulations Slice interleaving Sequential, Odd/even, bit-reversed Arbitrary Other considerations:
More informationM R I Physics Course
M R I Physics Course Multichannel Technology & Parallel Imaging Nathan Yanasak, Ph.D. Jerry Allison Ph.D. Tom Lavin, B.S. Department of Radiology Medical College of Georgia References: 1) The Physics of
More informationMotion Artifacts and Suppression in MRI At a Glance
Motion Artifacts and Suppression in MRI At a Glance Xiaodong Zhong, PhD MR R&D Collaborations Siemens Healthcare MRI Motion Artifacts and Suppression At a Glance Outline Background Physics Common Motion
More informationIMAGE reconstruction in conventional magnetic resonance
IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 24, NO. 3, MARCH 2005 325 Conjugate Phase MRI Reconstruction With Spatially Variant Sample Density Correction Douglas C. Noll*, Member, IEEE, Jeffrey A. Fessler,
More informationAdvanced Imaging Trajectories
Advanced Imaging Trajectories Cartesian EPI Spiral Radial Projection 1 Radial and Projection Imaging Sample spokes Radial out : from k=0 to kmax Projection: from -kmax to kmax Trajectory design considerations
More informationFast Imaging UCLA. Class Business. Class Business. Daniel B. Ennis, Ph.D. Magnetic Resonance Research Labs. Tuesday (3/7) from 6-9pm HW #1 HW #2
Fast Imaging Daniel B. Ennis, Ph.D. Magnetic Resonance Research Labs Class Business Tuesday (3/7) from 6-9pm 6:00-7:30pm Groups Avanto Sara Said, Yara Azar, April Pan Skyra Timothy Marcum, Diana Lopez,
More informationSampling, Ordering, Interleaving
Sampling, Ordering, Interleaving Sampling patterns and PSFs View ordering Modulation due to transients Temporal modulations Timing: cine, gating, triggering Slice interleaving Sequential, Odd/even, bit-reversed
More informationConstrained Reconstruction of Sparse Cardiac MR DTI Data
Constrained Reconstruction of Sparse Cardiac MR DTI Data Ganesh Adluru 1,3, Edward Hsu, and Edward V.R. DiBella,3 1 Electrical and Computer Engineering department, 50 S. Central Campus Dr., MEB, University
More informationZigzag Sampling for Improved Parallel Imaging
Magnetic Resonance in Medicine 60:474 478 (2008) Zigzag Sampling for Improved Parallel Imaging Felix A. Breuer, 1 * Hisamoto Moriguchi, 2 Nicole Seiberlich, 3 Martin Blaimer, 1 Peter M. Jakob, 1,3 Jeffrey
More informationParallel Imaging. Marcin.
Parallel Imaging Marcin m.jankiewicz@gmail.com Parallel Imaging initial thoughts Over the last 15 years, great progress in the development of pmri methods has taken place, thereby producing a multitude
More informationReferenceless Interleaved Echo-Planar Imaging
Referenceless Interleaved Echo-Planar Imaging Magnetic Resonance in Medicine 41:87 94 (1999) Scott B. Reeder, 1 Ergin Atalar, * Anthony Z. Faranesh, 1 and Elliot R. McVeigh 1, Interleaved echo-planar imaging
More informationCHAPTER 9: Magnetic Susceptibility Effects in High Field MRI
Figure 1. In the brain, the gray matter has substantially more blood vessels and capillaries than white matter. The magnified image on the right displays the rich vasculature in gray matter forming porous,
More informationSparse sampling in MRI: From basic theory to clinical application. R. Marc Lebel, PhD Department of Electrical Engineering Department of Radiology
Sparse sampling in MRI: From basic theory to clinical application R. Marc Lebel, PhD Department of Electrical Engineering Department of Radiology Objective Provide an intuitive overview of compressed sensing
More informationCorrection for EPI Distortions Using Multi-Echo Gradient-Echo Imaging
Correction for EPI Distortions Using Multi-Echo Gradient-Echo Imaging Nan-kuei Chen and Alice M. Wyrwicz* Magnetic Resonance in Medicine 41:1206 1213 (1999) A novel and effective technique is described
More informationMotion Artifact Suppression in MRI Using k-space Overlap Processing ABSTRACT
C04 1 Motion Artifact Suppression in MRI Using k-space Overlap Processing Yasser M. Kadah Biomedical Engineering Department, Cairo University, Egypt (E-mail: ymk@k-space.org) ABSTRACT Starting from the
More informationImproved Spatial Localization in 3D MRSI with a Sequence Combining PSF-Choice, EPSI and a Resolution Enhancement Algorithm
Improved Spatial Localization in 3D MRSI with a Sequence Combining PSF-Choice, EPSI and a Resolution Enhancement Algorithm L.P. Panych 1,3, B. Madore 1,3, W.S. Hoge 1,3, R.V. Mulkern 2,3 1 Brigham and
More informationSlide 1. Technical Aspects of Quality Control in Magnetic Resonance Imaging. Slide 2. Annual Compliance Testing. of MRI Systems.
Slide 1 Technical Aspects of Quality Control in Magnetic Resonance Imaging Slide 2 Compliance Testing of MRI Systems, Ph.D. Department of Radiology Henry Ford Hospital, Detroit, MI Slide 3 Compliance Testing
More informationClassification of Subject Motion for Improved Reconstruction of Dynamic Magnetic Resonance Imaging
1 CS 9 Final Project Classification of Subject Motion for Improved Reconstruction of Dynamic Magnetic Resonance Imaging Feiyu Chen Department of Electrical Engineering ABSTRACT Subject motion is a significant
More informationRedundancy Encoding for Fast Dynamic MR Imaging using Structured Sparsity
Redundancy Encoding for Fast Dynamic MR Imaging using Structured Sparsity Vimal Singh and Ahmed H. Tewfik Electrical and Computer Engineering Dept., The University of Texas at Austin, USA Abstract. For
More informationADVANCED RECONSTRUCTION TECHNIQUES IN MRI - 2
ADVANCED RECONSTRUCTION TECHNIQUES IN MRI - 2 Presented by Rahil Kothari PARTIAL FOURIER RECONSTRUCTION WHAT IS PARTIAL FOURIER RECONSTRUCTION? In Partial Fourier Reconstruction data is not collected symmetrically
More informationApplications Guide for Interleaved
Applications Guide for Interleaved rephase/dephase MRAV Authors: Yongquan Ye, Ph.D. Dongmei Wu, MS. Tested MAGNETOM Systems : 7TZ, TRIO a Tim System, Verio MR B15A (N4_VB15A_LATEST_20070519) MR B17A (N4_VB17A_LATEST_20090307_P8)
More informationParallel Magnetic Resonance Imaging (pmri): How Does it Work, and What is it Good For?
Parallel Magnetic Resonance Imaging (pmri): How Does it Work, and What is it Good For? Nathan Yanasak, Ph.D. Chair, AAPM TG118 Department of Radiology Georgia Regents University Overview Phased-array coils
More informationBreast MRI Accreditation Program Clinical Image Quality Guide
Breast MRI Accreditation Program Clinical Image Quality Guide Introduction This document provides guidance on breast MRI clinical image quality and describes the criteria used by the ACR Breast MRI Accreditation
More informationdesign as a constrained maximization problem. In principle, CODE seeks to maximize the b-value, defined as, where
Optimal design of motion-compensated diffusion gradient waveforms Óscar Peña-Nogales 1, Rodrigo de Luis-Garcia 1, Santiago Aja-Fernández 1,Yuxin Zhang 2,3, James H. Holmes 2,Diego Hernando 2,3 1 Laboratorio
More informationView-Ordering in Radial Fast Spin-Echo Imaging
View-Ordering in Radial Fast Spin-Echo Imaging Rebecca J. Theilmann, 1,3 Arthur F. Gmitro, 1 3 Maria I. Altbach, 1 and Theodore P. Trouard 1,2 * Magnetic Resonance in Medicine 51:768 774 (2004) Radial
More informationPartially Parallel Imaging With Localized Sensitivities (PILS)
Partially Parallel Imaging With Localized Sensitivities (PILS) Magnetic Resonance in Medicine 44:602 609 (2000) Mark A. Griswold, 1 * Peter M. Jakob, 1 Mathias Nittka, 1 James W. Goldfarb, 2 and Axel Haase
More informationAn Accurate, Robust, and Computationally Efficient Navigator Algorithm for Measuring Diaphragm Positions #,z
JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE 1 Vol. 6, No. 2, pp. 483 490, 2004 TECHNIQUE An Accurate, Robust, and Computationally Efficient Navigator Algorithm for Measuring Diaphragm Positions #,z Yiping
More information3D Radial Undersampling 7/19/2012. Artifact Removal SNR Restoration-- HYPR. Background: Time Resolved MR Angiography 4D DSA AND 4D FLUOROSCOPY:
4D DSA AND 4D FLUOROSCOPY: Accelerated Applications using Undersampled Acquisition and Constrained Reconstruction Background: Time Resolved MR Angiography During the past 12 years we have been investigating
More informationSteen Moeller Center for Magnetic Resonance research University of Minnesota
Steen Moeller Center for Magnetic Resonance research University of Minnesota moeller@cmrr.umn.edu Lot of material is from a talk by Douglas C. Noll Department of Biomedical Engineering Functional MRI Laboratory
More informationOverlapped k-space Acquisition and Reconstruction Technique for Motion Artifact Reduction in Magnetic Resonance Imaging
RESEARCH ARTICLE Copyright 2011 American Scientific Publishers All rights reserved Printed in the United States of America Journal of Medical Imaging and Health Informatics Vol. 1, 1 5, 2011 Overlapped
More information8/11/2009. Common Areas of Motion Problem. Motion Compensation Techniques and Applications. Type of Motion. What s your problem
Common Areas of Motion Problem Motion Compensation Techniques and Applications Abdominal and cardiac imaging. Uncooperative patient, such as pediatric. Dynamic imaging and time series. Chen Lin, PhD Indiana
More informationDevelopment of fast imaging techniques in MRI From the principle to the recent development
980-8575 2-1 2012 10 13 Development of fast imaging techniques in MRI From the principle to the recent development Yoshio MACHIDA and Issei MORI Health Sciences, Tohoku University Graduate School of Medicine
More informationBasic fmri Design and Analysis. Preprocessing
Basic fmri Design and Analysis Preprocessing fmri Preprocessing Slice timing correction Geometric distortion correction Head motion correction Temporal filtering Intensity normalization Spatial filtering
More informationHigh dynamic range magnetic resonance flow imaging in the abdomen
High dynamic range magnetic resonance flow imaging in the abdomen Christopher M. Sandino EE 367 Project Proposal 1 Motivation Time-resolved, volumetric phase-contrast magnetic resonance imaging (also known
More informationFaster 3D Vocal Tract Real-time MRI Using Constrained Reconstruction
Faster 3D Vocal Tract Real-time MRI Using Constrained Reconstruction Yinghua Zhu 1, Asterios Toutios 1, Shrikanth Narayanan 1,2, Krishna Nayak 1 1 Department of Electrical Engineering, University of Southern
More informationHigh Spatial Resolution EPI Using an Odd Number of Interleaves
Magnetic Resonance in Medicine 41:1199 1205 (1999) High Spatial Resolution EPI Using an Odd Number of Interleaves Michael H. Buonocore* and David C. Zhu Ghost artifacts in echoplanar imaging (EPI) arise
More informationInitial Experience of Applying TWIST Dixon with Flexible View Sharing in Breast DCE-MRI
Initial Experience of Applying TWIST Dixon with Flexible View Sharing in Breast DCE-MRI Yuan Le PhD 1, Hal D. Kipfer MD 1, Dominik M. Nickel PhD 2, Randall Kroeker PhD 2, Brian Dale PhD 2, Stephanie P.
More information2/5/2006 8:26 PM TOPICS
TOPICS 2/5/2006 8:26 PM Key Hole Acquisition Block Regional Interpolation Scheme for K-space (BRISK) Time Resolved Imaging of Contrast Kinetics (TRICKS) Real Time Imaging Introduction 2/5/2006 8:26 PM
More informationSPM8 for Basic and Clinical Investigators. Preprocessing. fmri Preprocessing
SPM8 for Basic and Clinical Investigators Preprocessing fmri Preprocessing Slice timing correction Geometric distortion correction Head motion correction Temporal filtering Intensity normalization Spatial
More informationImaging Notes, Part IV
BME 483 MRI Notes 34 page 1 Imaging Notes, Part IV Slice Selective Excitation The most common approach for dealing with the 3 rd (z) dimension is to use slice selective excitation. This is done by applying
More informationRemoval of EPI Nyquist Ghost Artifacts With Two- Dimensional Phase Correction
Removal of EPI Nyquist Ghost Artifacts With Two- Dimensional Phase Correction Nan-kuei Chen 1,5 and Alice M. Wyrwicz 4 * Magnetic Resonance in Medicine 51:147 153 (004) Odd even echo inconsistencies result
More informationEPI Data Are Acquired Serially. EPI Data Are Acquired Serially 10/23/2011. Functional Connectivity Preprocessing. fmri Preprocessing
Functional Connectivity Preprocessing Geometric distortion Head motion Geometric distortion Head motion EPI Data Are Acquired Serially EPI Data Are Acquired Serially descending 1 EPI Data Are Acquired
More informationFunctional MRI in Clinical Research and Practice Preprocessing
Functional MRI in Clinical Research and Practice Preprocessing fmri Preprocessing Slice timing correction Geometric distortion correction Head motion correction Temporal filtering Intensity normalization
More informationMultiprocessor Scheduling Implementation of the Simultaneous Multiple Volume (SMV) Navigator Method
Magnetic Resonance in Medicine 52:362 367 (2004) Multiprocessor Scheduling Implementation of the Simultaneous Multiple Volume (SMV) Navigator Method Vladimir Kolmogorov, 1 Thanh D. Nguyen, 2 Anthony Nuval,
More informationImage Acquisition Systems
Image Acquisition Systems Goals and Terminology Conventional Radiography Axial Tomography Computer Axial Tomography (CAT) Magnetic Resonance Imaging (MRI) PET, SPECT Ultrasound Microscopy Imaging ITCS
More informationVD-AUTO-SMASH Imaging
Magnetic Resonance in Medicine 45:1066 1074 (2001) VD-AUTO-SMASH Imaging Robin M. Heidemann, Mark A. Griswold, Axel Haase, and Peter M. Jakob* Recently a self-calibrating SMASH technique, AUTO-SMASH, was
More informationHST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis Fall 2008
MIT OpenCourseWare http://ocw.mit.edu HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.
More information3D MAGNETIC RESONANCE IMAGING OF THE HUMAN BRAIN NOVEL RADIAL SAMPLING, FILTERING AND RECONSTRUCTION
3D MAGNETIC RESONANCE IMAGING OF THE HUMAN BRAIN NOVEL RADIAL SAMPLING, FILTERING AND RECONSTRUCTION Maria Magnusson 1,2,4, Olof Dahlqvist Leinhard 2,4, Patrik Brynolfsson 2,4, Per Thyr 2,4 and Peter Lundberg
More information2D spatially selective excitation pulse design and the artifact evaluation
EE 591 Project 2D spatially selective excitation pulse design and the artifact evaluation 12/08/2004 Zungho Zun Two-dimensional spatially selective excitation is used to excite a volume such as pencil
More informationLucy Phantom MR Grid Evaluation
Lucy Phantom MR Grid Evaluation Anil Sethi, PhD Loyola University Medical Center, Maywood, IL 60153 November 2015 I. Introduction: The MR distortion grid, used as an insert with Lucy 3D QA phantom, is
More informationDiffusion MRI Acquisition. Karla Miller FMRIB Centre, University of Oxford
Diffusion MRI Acquisition Karla Miller FMRIB Centre, University of Oxford karla@fmrib.ox.ac.uk Diffusion Imaging How is diffusion weighting achieved? How is the image acquired? What are the limitations,
More informationGeneralized Autocalibrating Partially Parallel Acquisitions (GRAPPA)
Magnetic Resonance in Medicine 47:1202 1210 (2002) Generalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) Mark A. Griswold, 1 * Peter M. Jakob, 1 Robin M. Heidemann, 1 Mathias Nittka, 2 Vladimir
More informationXI Signal-to-Noise (SNR)
XI Signal-to-Noise (SNR) Lecture notes by Assaf Tal n(t) t. Noise. Characterizing Noise Noise is a random signal that gets added to all of our measurements. In D it looks like this: while in D
More informationSuper-resolution Reconstruction of Fetal Brain MRI
Super-resolution Reconstruction of Fetal Brain MRI Ali Gholipour and Simon K. Warfield Computational Radiology Laboratory Children s Hospital Boston, Harvard Medical School Worshop on Image Analysis for
More informationTOPICS 2/5/2006 8:17 PM. 2D Acquisition 3D Acquisition
TOPICS 2/5/2006 8:17 PM 2D Acquisition 3D Acquisition 2D Acquisition Involves two main steps : Slice Selection Slice selection is accomplished by spatially saturating (single or multi slice imaging) or
More informationAdvanced MRI Techniques (and Applications)
Advanced MRI Techniques (and Applications) Jeffry R. Alger, PhD Department of Neurology Ahmanson-Lovelace Brain Mapping Center Brain Research Institute Jonsson Comprehensive Cancer Center University of
More informationSPM8 for Basic and Clinical Investigators. Preprocessing
SPM8 for Basic and Clinical Investigators Preprocessing fmri Preprocessing Slice timing correction Geometric distortion correction Head motion correction Temporal filtering Intensity normalization Spatial
More informationNuts & Bolts of Advanced Imaging. Image Reconstruction Parallel Imaging
Nuts & Bolts of Advanced Imaging Image Reconstruction Parallel Imaging Michael S. Hansen, PhD Magnetic Resonance Technology Program National Institutes of Health, NHLBI Declaration of Financial Interests
More informationMotion artifact reduction technique for dual-contrast FSE imaging
Magnetic Resonance Imaging 20 (2002) 455 462 Motion artifact reduction technique for dual-contrast FSE imaging Eugene G. Kholmovski a, *, Alexei A. Samsonov a, Dennis L. Parker a,b a Department of Physics,
More informationG Practical Magnetic Resonance Imaging II Sackler Institute of Biomedical Sciences New York University School of Medicine. Compressed Sensing
G16.4428 Practical Magnetic Resonance Imaging II Sackler Institute of Biomedical Sciences New York University School of Medicine Compressed Sensing Ricardo Otazo, PhD ricardo.otazo@nyumc.org Compressed
More informationAutomatic Correction of Echo-Planar Imaging (EPI) Ghosting Artifacts in Real-Time Interactive Cardiac MRI Using Sensitivity Encoding
JOURNAL OF MAGNETIC RESONANCE IMAGING 27:239 245 (2008) Technical Note Automatic Correction of Echo-Planar Imaging (EPI) Ghosting Artifacts in Real-Time Interactive Cardiac MRI Using Sensitivity Encoding
More informationExam 8N080 - Introduction MRI
Exam 8N080 - Introduction MRI Friday January 23 rd 2015, 13.30-16.30h For this exam you may use an ordinary calculator (not a graphical one). In total there are 6 assignments and a total of 65 points can
More informationWhat is pmri? Overview. The Need for Speed: A Technical and Clinical Primer for Parallel MR Imaging 8/1/2011
The Need for Speed: A Technical and Clinical Primer for Parallel MR Imaging Nathan Yanasak, Ph.D. Chair, AAPM TG118 Assistant Professor Department of Radiology Director, Core Imaging Facility for Small
More informationUnaliasing by Fourier-Encoding the Overlaps Using the Temporal Dimension (UNFOLD), Applied to Cardiac Imaging and fmri
1999 ISMRM YOUNG INVESTIGATORS MOORE AWARD PAPERS Magnetic Resonance in Medicine 42:813 828 (1999) Unaliasing by Fourier-Encoding the Overlaps Using the Temporal Dimension (UNFOLD), Applied to Cardiac
More informationGE Healthcare CLINICAL GALLERY. Discovery * MR750w 3.0T. This brochure is intended for European healthcare professionals.
GE Healthcare CLINICAL GALLERY Discovery * MR750w 3.0T This brochure is intended for European healthcare professionals. NEURO PROPELLER delivers high resolution, motion insensitive imaging in all planes.
More informationANALYSIS OF PULMONARY FIBROSIS IN MRI, USING AN ELASTIC REGISTRATION TECHNIQUE IN A MODEL OF FIBROSIS: Scleroderma
ANALYSIS OF PULMONARY FIBROSIS IN MRI, USING AN ELASTIC REGISTRATION TECHNIQUE IN A MODEL OF FIBROSIS: Scleroderma ORAL DEFENSE 8 th of September 2017 Charlotte MARTIN Supervisor: Pr. MP REVEL M2 Bio Medical
More informationA Transmission Line Matrix Model for Shielding Effects in Stents
A Transmission Line Matrix Model for hielding Effects in tents Razvan Ciocan (1), Nathan Ida (2) (1) Clemson University Physics and Astronomy Department Clemson University, C 29634-0978 ciocan@clemon.edu
More informationMRI Imaging Options. Frank R. Korosec, Ph.D. Departments of Radiology and Medical Physics University of Wisconsin Madison
MRI Imaging Options Frank R. Korosec, Ph.D. Departments of Radiolog and Medical Phsics Universit of Wisconsin Madison f.korosec@hosp.wisc.edu As MR imaging becomes more developed, more imaging options
More informationNew Technology Allows Multiple Image Contrasts in a Single Scan
These images were acquired with an investigational device. PD T2 T2 FLAIR T1 MAP T1 FLAIR PSIR T1 New Technology Allows Multiple Image Contrasts in a Single Scan MR exams can be time consuming. A typical
More informationSparse MRI: The Application of Compressed Sensing for Rapid MR Imaging
Magnetic Resonance in Medicine 58:1182 1195 (2007) Sparse MRI: The Application of Compressed Sensing for Rapid MR Imaging Michael Lustig, 1 David Donoho, 2 and John M. Pauly 1 The sparsity which is implicit
More informationAbbie M. Diak, PhD Loyola University Medical Center Dept. of Radiation Oncology
Abbie M. Diak, PhD Loyola University Medical Center Dept. of Radiation Oncology Outline High Spectral and Spatial Resolution MR Imaging (HiSS) What it is How to do it Ways to use it HiSS for Radiation
More informationGRAPPA Operator for Wider Radial Bands (GROWL) with Optimally Regularized Self-Calibration
GRAPPA Operator for Wider Radial Bands (GROWL) with Optimally Regularized Self-Calibration Wei Lin,* Feng Huang, Yu Li, and Arne Reykowski Magnetic Resonance in Medicine 64:757 766 (2010) A self-calibrated
More informationCOBRE Scan Information
COBRE Scan Information Below is more information on the directory structure for the COBRE imaging data. Also below are the imaging parameters for each series. Directory structure: var/www/html/dropbox/1139_anonymized/human:
More information