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Instrumentation for NMR spin-warp imaging
Magnetic Resonance Imaging 0 Volume 1, Number 2, 1982
112
density images and T, images of a transverse section of the head obtained by using this coil are also given. Phys. Med. Biol. 27: 443; 1982
Instrumentation G. Johnson,
for NMR Spin-Warp
J. M. S. Hutchison,
Imaging
and L. M. Eastwood
Department of Biomedical Physics and Bioengineering, University of Aberdeen, Foresterhill, Aberdeen AB9 2ZD. Scotland The authors describe some modifications in the electronics used in a new imaging technique developed by the Aberdeen NMR Imaging group. This paper in particular describes (i) the microprocessor control of the various gradient pulse waveforms and timing, (ii) the design of the Y gradient driver, and (iii) the adiabatic fast passage generator required for the spin population inversion in this technique. The performance of this imaging technique with these modifications has been tested with a phantom made up of an array of bottles containing MnClz solution and the image of a section through the thorax of one of the authors (LME). With these modifications incorporated in the Aberdeen machine, the instrument is now capable of producing clinically useful images of proton density and spin-lattice relaxation time T,. J. Phys. E: Sri. tnstrum. 1.5: 74; I982
Magnetic Field Gradient Coils for NMR Imaging
phantom made up of an octagonal filled with doped water.
array of test tubes
J. Ph ys. E: Sci. Instrum. i5: 235; I982
A Phase Coherent Pulsed NMR Spectrometer P. Narasimha
Reddy and B. P. Nagi Reddy
Department of Physics, Sri Venkateswara University, Tirupati-517502, India The authors describe the design and construction of a pulsed NMR spectrometer working at 12.4 MHz. The typical pulse width for a ~12 pulse is 4.8 pus and the receiver recovery time is 12 vs. The instrument is useful for the measurement of relaxation times of protons in biological systems and may be for studies in some solids with longer Tz. The design is simple and inexpensive and can be built easily for clinical work in tissues. J. Phys. E: Sci. Instrum. 15: 448: 1982
IN VIVO IMAGING NMR Imaging of Forearms in Healthy Volunteers and Patients with Giant-Cell Tumor of Bone Thomas J. Brady, MD, Mark C. Gebhardt, MD, Ian L. Pykett, PhD, Ferdinand0 S. Buonanno, MD, Jeffrey H. Newhouse, MD, C. Tyler Burt, PhD, Richard J. Smith, MD, Henry J. Mankin, MD, J. Philip Kistler, MD, Mark R. Goldman, MD, Wlado S. Hinshaw, PhD, Gerald M. Pohost, MD
V. Bangert and P. Mansfield* Department of Physics, University of Nottingham, University Park, Nottingham NC7 ZRD, UK (*author to whom correspondence should be addressed) The authors describe a new gradient coil system for diffusions and flow measurements and NMR imaging. The coils are especially suitable for applications where the field gradients have to be switched on and off rapidly. The special features of this design are linearity over larger region (-3.3 m) and low inductance and hence especially suitable for whole body NMR imaging. Full theoretical details in the design of the coils are given. The measured values of the gradient field produced by the gradient coils built according to this design are within 2% of the calculated values on the average. The performance of the gradient coil system in producing an NMR image has been tested with a
Departments of Radiology (I.L.P., T.J.B., C. T.B.. W.S.H., J.H.N.). Orthopaedic Surgery (M.C.G., R.J.S., H.J.M.), Medicine (M.R.G., G.M.P.), and Neurology (F.S.B., J.B.K.), Massachusetts General Hospital, Boston, MA Proton NMR images were obtained on four normal male subjects and four patients (two men, two women) with giant cell tumor of the distal radius using an NMR imaging device (Technicare Corporation, Solon, OH) at a frequency of 61.4 MHz. Serial NMR images were obtained using steady-state-free-precession technique (SSFP). Data acquisition time for each image was 2.3 min. NMR images of excellent resolution and soft-tissue contrast have been obtained for all subjects. In all four patients with giant cell tumor, NMR images revealed bone marrow replacement by tumor, cortical bone thinning and cortical bone destruction. The
112
density images and T, images of a transverse section of the head obtained by using this coil are also given. Phys. Med. Biol. 27: 443; 1982
Instrumentation G. Johnson,
for NMR Spin-Warp
J. M. S. Hutchison,
Imaging
and L. M. Eastwood
Department of Biomedical Physics and Bioengineering, University of Aberdeen, Foresterhill, Aberdeen AB9 2ZD. Scotland The authors describe some modifications in the electronics used in a new imaging technique developed by the Aberdeen NMR Imaging group. This paper in particular describes (i) the microprocessor control of the various gradient pulse waveforms and timing, (ii) the design of the Y gradient driver, and (iii) the adiabatic fast passage generator required for the spin population inversion in this technique. The performance of this imaging technique with these modifications has been tested with a phantom made up of an array of bottles containing MnClz solution and the image of a section through the thorax of one of the authors (LME). With these modifications incorporated in the Aberdeen machine, the instrument is now capable of producing clinically useful images of proton density and spin-lattice relaxation time T,. J. Phys. E: Sri. tnstrum. 1.5: 74; I982
Magnetic Field Gradient Coils for NMR Imaging
phantom made up of an octagonal filled with doped water.
array of test tubes
J. Ph ys. E: Sci. Instrum. i5: 235; I982
A Phase Coherent Pulsed NMR Spectrometer P. Narasimha
Reddy and B. P. Nagi Reddy
Department of Physics, Sri Venkateswara University, Tirupati-517502, India The authors describe the design and construction of a pulsed NMR spectrometer working at 12.4 MHz. The typical pulse width for a ~12 pulse is 4.8 pus and the receiver recovery time is 12 vs. The instrument is useful for the measurement of relaxation times of protons in biological systems and may be for studies in some solids with longer Tz. The design is simple and inexpensive and can be built easily for clinical work in tissues. J. Phys. E: Sci. Instrum. 15: 448: 1982
IN VIVO IMAGING NMR Imaging of Forearms in Healthy Volunteers and Patients with Giant-Cell Tumor of Bone Thomas J. Brady, MD, Mark C. Gebhardt, MD, Ian L. Pykett, PhD, Ferdinand0 S. Buonanno, MD, Jeffrey H. Newhouse, MD, C. Tyler Burt, PhD, Richard J. Smith, MD, Henry J. Mankin, MD, J. Philip Kistler, MD, Mark R. Goldman, MD, Wlado S. Hinshaw, PhD, Gerald M. Pohost, MD
V. Bangert and P. Mansfield* Department of Physics, University of Nottingham, University Park, Nottingham NC7 ZRD, UK (*author to whom correspondence should be addressed) The authors describe a new gradient coil system for diffusions and flow measurements and NMR imaging. The coils are especially suitable for applications where the field gradients have to be switched on and off rapidly. The special features of this design are linearity over larger region (-3.3 m) and low inductance and hence especially suitable for whole body NMR imaging. Full theoretical details in the design of the coils are given. The measured values of the gradient field produced by the gradient coils built according to this design are within 2% of the calculated values on the average. The performance of the gradient coil system in producing an NMR image has been tested with a
Departments of Radiology (I.L.P., T.J.B., C. T.B.. W.S.H., J.H.N.). Orthopaedic Surgery (M.C.G., R.J.S., H.J.M.), Medicine (M.R.G., G.M.P.), and Neurology (F.S.B., J.B.K.), Massachusetts General Hospital, Boston, MA Proton NMR images were obtained on four normal male subjects and four patients (two men, two women) with giant cell tumor of the distal radius using an NMR imaging device (Technicare Corporation, Solon, OH) at a frequency of 61.4 MHz. Serial NMR images were obtained using steady-state-free-precession technique (SSFP). Data acquisition time for each image was 2.3 min. NMR images of excellent resolution and soft-tissue contrast have been obtained for all subjects. In all four patients with giant cell tumor, NMR images revealed bone marrow replacement by tumor, cortical bone thinning and cortical bone destruction. The