Imaging Ferromagnetic Tracers With An Ac Biosusceptometer

The aim of this work was to study the feasibility of obtaining images of the distribution of ferromagnetic tracers using an ac biosusceptometer (ACB). The images were generated by mapping the response of the ACB at short distances due to the presence of a ferrite powder dispersed in a planar gel matrix with different shapes. The ACB was scanned over the sample and the voltages generated by the variation in ferrite concentration were sampled. Methods to render and image the distribution of ferromagnetic particles were studied. The generalized Wiener parametric method gave the best results. The system has a potential to be used in functional images of the gastrointestinal tract where a moderate resolution is required. We conclude that this biomagnetic method can be successfully used to generate planar functional images of magnetic particles in the near field. © 2000 American Institute of Physics.71625322538Erol, R.A., Cherian, P., Smallwood, R.H., Brown, B.H., Bardhan, K.D., (1996) Physiol. Meas., 17, pp. A141Ikeya, M., Ishii, H., (1990) J. Magn. Reson., 88, p. 130Smith, C.M., Stevens, A.D., (1994) Br. J. Radiol., 67, p. 1186Roth, B.J., Sepulveda, N.G., Wikswo J.P., Jr., (1989) J. Appl. Phys., 65, p. 361Moreira, M., Murta, L.O., Baffa, O., (1994) Phys. Med. Biol., 39 A, p. 633Miranda, J.R.A., Baffa, O., Oliveira, R.B., Matsuda, N.M., (1992) Med. Phys., 19, p. 445Baffa, O., Oliveira, R.B., Miranda, J.R., Troncon, L.E.A., (1995) Med. Biol. Eng. Comput., 33, p. 353Oliveira, R.B., Baffa, O., Troncon, L.E.A., Miranda, J.R.A., Cambrea, C.R., (1996) Eur. J. Gastroent. Hepatol., 8, p. 491Miranda, J.R.A., Oliveira, R.B., Sousa, P.L., Braga, F.J.H., Baffa, O., (1997) Phys. Med. Biol., 42, p. 1791Daghastanli, N.A., Braga, F.J.H.N., Oliveira, R.B., Baffa, O., (1998) Physiol. Meas., 19, p. 413Forsman, M., Hultin, L., Abrahamsson, H., (1995) Biomagnetism: Fundamental Research and Clinical Applications. Studies in Applied Electromagnetics and Mechanics, 7, p. 739. , edited by C. Baumgartner, L. Deecke, G. Stroink, and S. J. Williamson Elsevier, AmsterdamBasile, M., Neri, M., Carriero, A., Casciardi, S., Comani, S., Del Gratta, C., Donate, L.G., Romani, G.L., (1992) Dig. Dis. Scie., 37, p. 1537Bruno, A.C., (1997) J. Appl. Phys., 82, p. 1Cruvinel, P.E., Cesareo, R., Crestana, S., Mascarenhas, S., (1990) IEEE Trans. Instrum. Meas., 39, p. 745Lim, J.S., (1990) Two-Dimensional Signal and Image Processing, , Prentice-Hall, Englewood Cliffs, NJJ. P. Wikswo, Jr., N. G. Sepulveda, and I. M. Thomas, Ref. 11, p. 789Tan, S., Ma, Y.P., Smith, I.M., Wikswo J.P., Jr., (1996) IEEE Trans. Magn., 32, p. 230Weber, E., (1951) Electromagnetic Fields: Theory and Applications, Mapping of Magnetic Fields, 1. , Wiley, New YorkSpiegel, M.R., (1990) Mathematical Handbook of Formulas and Tables, , McGraw-Hill, New YorkBruno, A.C., Costa Ribeiro, P., Von Der Wied, J.P., Symko, O., (1986) J. Appl. Phys., 59, p. 2584Vrba, J., Fife, A.A., Burbank, M., Weinberg, H., Bricket, P.A., (1982) Can. J. Phys., 60, p. 106