MR microscopy of the rat lung using projection reconstruction

Projection reconstruction has been implemented with self‐refocused selection pulses on a small bore, 2.0 T MR microscope, to allow imaging of lung parenchyma. Scan synchronous ventilation and cardiac gating have been integrated with the sequence to minimize motion artifacts. A systematic survey of the pulse sequence parameters has been undertaken in conjunction with the biological gating parameters to optimize resolution and signal‐to‐noise (SNR). The resulting projection images with effective echo time of <300 usec allow definition of lung parenchyma with an SNR improvement of ∼15 x over a more conventional 2DFT short echo gradient sequence.

[1]  Paul G. Lauterbur,et al.  Zeugmatography by Reconstruction from Projections , 1980 .

[2]  J B Ra,et al.  Chemical‐shift artifact correction scheme using echo‐time encoding technique , 1985, Magnetic resonance in medicine.

[3]  G. N. Ramachandran,et al.  Three-dimensional reconstruction from radiographs and electron micrographs: application of convolutions instead of Fourier transforms. , 1971, Proceedings of the National Academy of Sciences of the United States of America.

[4]  G H Glover,et al.  Lung parenchyma: magnetic susceptibility in MR imaging. , 1991, Radiology.

[5]  Douglas A. Ortendahl,et al.  A Comparison of the Noise Characteristics of Projection Reconstruction and Two-Dimensional Fourier Transformations in NMR Imaging , 1983 .

[6]  W. Edelstein,et al.  Spin warp NMR imaging and applications to human whole-body imaging. , 1980, Physics in medicine and biology.

[7]  L W Hedlund,et al.  Magnetic resonance microscopy of the rat thorax and abdomen. , 1986, Investigative radiology.

[8]  L. Hedlund,et al.  MR “Microscopy” of the Rat Thorax , 1986, Journal of computer assisted tomography.

[9]  C. Taylor,et al.  Increased lung copper-zinc-superoxide dismutase activity and absence of magnetic resonance imaging-detectable lung damage in copper-deficient rats exposed to hyperoxia. , 1991, The Journal of nutrition.

[10]  L W Hedlund,et al.  A ventilator for magnetic resonance imaging. , 1986, Investigative radiology.

[11]  H. Kundel,et al.  Sodium MRI with coated magnetite: Measurement of extravascular lung water in rats , 1991, Magnetic resonance in medicine.

[12]  J M Pauly,et al.  Lung parenchyma: projection reconstruction MR imaging. , 1991, Radiology.

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

[14]  M. Haida,et al.  Lung cancer: differentiation of tumor, necrosis, and atelectasis by means of T1 and T2 values measured in vitro. , 1988, Radiology.

[15]  G H Glover,et al.  Theoretical Resolution of Computed Tomography Systems , 1979, Journal of computer assisted tomography.

[16]  D. Ailion,et al.  An in vivo NMR imaging determination of multiexponential Hahn T2 of normal lung , 1990, Magnetic resonance in medicine.

[17]  Y. Kimula,et al.  Acute and repair stage characteristics of magnetic resonance relaxation times in oxygen‐induced pulmonary edema , 1988, Magnetic resonance in medicine.

[18]  J. Gore,et al.  Proton relaxation times in bleomycin-induced lung injury. , 1987, Investigative radiology.

[19]  A. Macovski,et al.  Selection of a convolution function for Fourier inversion using gridding [computerised tomography application]. , 1991, IEEE transactions on medical imaging.

[20]  Laurance D. Hall,et al.  Rapid data-acquisition technique for nmr imaging by the projection-reconstruction method , 1984 .