Nickel-Doped Agarose Gel Phantoms in MR Imaging

A method for the production of a tissue-mimicking phantom material for MR imaging is described. The material consists of a nickel-doped agarose gel. The T1 and T2 values of the gel can be varied independently by changing the relative amounts of nickel and agarose. Practically any T1 and T2 combination of clinical interest can be obtained. The long-term stability was studied and found to be good. The relaxation times were estimated using an MR analyzer. The accuracy and the reproducibility of these measurements were evaluated and found to be reassuring. Gel phantoms were also scanned in an MR unit. The signal strength of an inversion recovery sequence was evaluated using the gel phantoms in order to verify their usefulness. These measurements were compared to theory with good agreement. Furthermore, tissue-equivalent phantoms were made. Gels resembling gray matter, white matter, and CSF were scanned. Comparisons with clinical in vivo scans, as well as calculated levels were made. It is anticipated that the gel phantoms described here will be useful in quality assurance as well as in pulse sequence optimization.

[1]  L. Olsson,et al.  A new dosimeter based on ferrous sulphate solution and agarose gel , 1991 .

[2]  Simulation of Biologic Tissues by Using Agar Gels at Magnetic Resonance Imaging , 1989 .

[3]  S. Ablett,et al.  A test material for tissue characterisation and system calibration in MRI. , 1989, Physics in medicine and biology.

[4]  E. Madsen,et al.  Tissue-mimicking gelatin-agar gels for use in magnetic resonance imaging phantoms. , 1988, Medical physics.

[5]  F. Howe.  Relaxation times in paramagnetically doped agarose gels as a function of temperature and ion concentration. , 1988, Magnetic resonance imaging.

[6]  N. Schneiders.  Solutions of two paramagnetic ions for use in nuclear magnetic resonance phantoms. , 1988, Medical physics.

[7]  P. Fatouros,et al.  An MRI phantom material for quantitative relaxometry , 1987, Magnetic resonance in medicine.

[8]  M. Daube-Witherspoon,et al.  A silicone gel phantom suitable for multimodality imaging. , 1987, Investigative radiology.

[9]  B Maraviglia,et al.  Biological tissue simulation and standard testing material for MRI , 1987, Magnetic resonance in medicine.

[10]  I Mano,et al.  New polyvinyl alcohol gel material for MRI phantoms , 1986, Magnetic resonance in medicine.

[11]  A Hemmingsson,et al.  Improved formulae for signal amplitudes in repeated NMR sequences: Applications in NMR imaging , 1986, Magnetic resonance in medicine.

[12]  L. Axel,et al.  Agarose as a tissue equivalent phantom material for NMR imaging. , 1986, Magnetic resonance imaging.

[13]  R. Vré,et al.  The use of agar gel as a basic reference material for calibrating relaxation times and imaging parameters , 1985, Magnetic resonance in medicine.

[14]  T. Foster,et al.  A review of normal tissue hydrogen NMR relaxation times and relaxation mechanisms from 1-100 MHz: dependence on tissue type, NMR frequency, temperature, species, excision, and age. , 1984, Medical physics.

[15]  J R MacFall,et al.  Mechanisms of Contrast in NMR Imaging , 1984, Journal of computer assisted tomography.

[16]  E. Madsen,et al.  Prospective tissue-mimicking materials for use in NMR imaging phantoms. , 1982, Magnetic resonance imaging.