Continuous radial data acquisition for dynamic MRI

Since image acquisition times in MRI have been reduced considerably over recent years, several new important application areas of MRI have appeared. In addition to pure static anatomic information, the evolution of a dynamic process may be visualized by a sequence of temporal snapshots of the process acquired within a short time period. This makes applications like interactive or interventional MRI as well as the acquisition of additional functional information feasible. For high temporal resolution, all these applications require a quasi real‐time image acquisition during the time the interaction or dynamic process evolves. We present an approach to realtime imaging using a continuous radial acquisition scheme. The intrinsic advantages of radial or projection reconstruction (PR) techniques are used to minimize motion‐related image distortions. Modifications of the acquisition scheme as well as dedicated reconstruction techniques are used to further reduce the temporal blurring due to the finite acquisition time of one entire data set in our approach. So far we have used this technique for the visualization of active joint motion.

[1]  X Hu,et al.  Continuous Update with Random Encoding (CURE): A New Strategy for Dynamic Imaging , 1995, Magnetic resonance in medicine.

[2]  D. Twieg.  The k-trajectory formulation of the NMR imaging process with applications in analysis and synthesis of imaging methods. , 1983, Medical physics.

[3]  C. Lai,et al.  Reconstructing NMR images from projections under inhomogeneous magnetic field and non-linear field gradients. , 1983, Physics in medicine and biology.

[4]  D G Nishimura,et al.  On the nature and reduction of the displacement artifact in flow images , 1991, Magnetic resonance in medicine.

[5]  J N Lee,et al.  MR fluoroscopy: initial clinical studies. , 1989, Radiology.

[6]  D. Feinberg,et al.  GRASE (Gradient‐and Spin‐Echo) imaging: A novel fast MRI technique , 1991, Magnetic resonance in medicine.

[7]  S. Ljunggren.  A simple graphical representation of fourier-based imaging methods , 1983 .

[8]  F G Shellock,et al.  Patellofemoral joint: identification of abnormalities with active-movement, "unloaded" versus "loaded" kinematic MR imaging techniques. , 1993, Radiology.

[9]  J. Cuppen,et al.  Very fast MR imaging by field echoes and small angle excitation. , 1985, Magnetic resonance imaging.

[10]  M Heller,et al.  Patellar tracking patterns during active and passive knee extension: evaluation with motion-triggered cine MR imaging. , 1993, Radiology.

[11]  Z H Cho,et al.  Reduction of flow artifacts in NMR diffusion imaging using view‐angle tilted line‐integral projection reconstruction , 1991, Magnetic resonance in medicine.

[12]  G H Glover,et al.  Projection Reconstruction Techniques for Reduction of Motion Effects in MRI , 1992, Magnetic resonance in medicine.

[13]  E M Haacke,et al.  Reducing motion artifacts in two-dimensional Fourier transform imaging. , 1986, Magnetic resonance imaging.

[14]  J N Lee,et al.  MR fluoroscopy: Technical feasibility , 1988, Magnetic resonance in medicine.

[15]  F G Shellock,et al.  Patellofemoral joint: evaluation during active flexion with ultrafast spoiled GRASS MR imaging. , 1991, Radiology.

[16]  A Briguet,et al.  Projection‐reconstruction methods: Fast imaging sequences and data processing , 1994, Magnetic resonance in medicine.

[17]  A. C. Riddle,et al.  Inversion of Fan-Beam Scans in Radio Astronomy , 1967 .

[18]  A. Zwinderman,et al.  Preparation of the colon for single- and double-contrast barium enema examination: a simplified method. , 1993, Radiology.

[19]  J. J. van Vaals,et al.  “Keyhole” method for accelerating imaging of contrast agent uptake , 1993, Journal of magnetic resonance imaging : JMRI.