2002
On the use of bang gel polymer in the commission of a conical collimator for the treatment of trigeminal neuralgias with radiosurgery
M. Martin-Landrove, J. E. Davila, R Martin
Proc. Intl. Soc. Mag. Reson. Med. 10 (2002)
The techniques employed in the treatment of both benign and malignant diseases include the use of ionizing radiation. For trigeminal neuralgias, the principal constraint is the approach to sensitive areas in the central nervous system where a margin is nor possible and accuracy is the most important requirement. To improve accuracy a method for transverse relaxation rate distribution rendering was considered [l]. There were three compartments in the observed spectrum, the one related to protons in the polymer formed by the radiation action [2], is correlated to the absorbed dose. In spite to the presence of noise, this component can be studied easily and it offers a real potential for an accurate dose spatial distribution.
Effect of verapamil administration on human brain fetuses in high risk pregnancy after Lactate detection by 1H magnetic resonance spectroscopy (1HMRS)
A. Alvarado, R. Ortega, F. Mayobre, N. Hernández, M . Martín, F. Guevara, S. Siurana, F. Paseta, J. Guitian
Proc. Intl. Soc. Mag. Reson. Med. 10 (2002)
The purpose of this study was to evaluate the effect of verapamil administration on Human Fetuses in High Risk Yregnancies (FHRP) by 'HMRS after Lactate identification. Two HMRS studies was performed on a 1.5 Tesla system using the body RF coil: the first one was done between 30-31 weeks of gestation and the second between 34-35 weeks after verapamil administration. The results obtained in the second 'HMRS study show a significant decrease in Lactate signal in FHRP compared with the first study. This reduction could be related to a more oxygen offer due to verapamil vasodilator effect in FHRP.
Choline signal changes after choline-inositol plus fish oils oral administration in attention deficit disorder (ADD). 1H magnetic resonance spectroscopy (1HMRS) follow up study
A. Alvarado, L. Díaz, Z. Sucre, G. Zapata, F. Mayobre, M. Martín, A. Guitian', A. Robaina, N. lsava, R. Pérez, G. Veraecoechea, M. Hernández
Proc. Intl. Soc. Mag. Reson. Med. 10 (2002)
This study was designed to investigate the possible effect of oral choline bitartrate administration in the 'HMRS profile of ADD children. 'HMRS was performed in the Frontal Lobe at the beginning of the study and six months after choline therapy using a 1.5 Tesla MR system. The results demonstrate a 15 % increase in the signal intensities of Choline-containing compounds and a significant raise in Choline/Creatine ratio after six months of therapy in ADD children. 'HMRS could be a useful tool to evaluate Frontal Lobe function in ADD.
Long-range interactions of solitons in a double chain
Jorge A. González, Miguel Martín-Landrove
Physics Letters A 292 (2002) 256–262
We investigate the soliton solutions of the Yakushevich equations (Phys. Lett. A 136 (1989) 413). Analytical expressions for some solutions of the exact model are obtained. Special attention is paid to the stability of the solutions and the character of the interactions between the solitons, which turned out to be long-range. The periodically perturbed equations can have chaotic attractors. Power-law behaviors found in the dynamics are discussed.
Use of electrical impedance tomography (EIT) for the assessment of unilateral pulmonary function
JRoberto E Serrano, Bruno de Lema, Oscar Casas, Teresa Feixas,Nuria Calaf, Valle Camacho, Ignasi Carrió, Pere Casan, J Sanchis, Pere J Riu
Physiol. Meas. 23 (2002) 211–220
We describe a fully automatable quantification process for the assessment of unilateral pulmonary function (UPF) by means of EIT and propose a measurement protocol for its clinical implementation. Measurements were performed at the fourth and sixth intercostal levels on a first group of ten healthy subjects (5M, 5F, ages 26–48 years) to define the proper protocol by evaluating the most common postures and ventilation modes. Several offline processing tools were also evaluated, including the use of digital filters to extract the respiratory components from EIT time series. Comparative measures were then carried out on a second group consisting of five preoperatory patients with lung cancer (4M, 1F, ages 25–77 years) scheduled for radionuclide scanning. Results show that measurements were best performed with the subject sitting down, holding his arms up and breathing spontaneously. As regards data processing, it is best to extract Fourier respiratory components. The mean of the healthy subject group leads to a left–right division of lung ventilation consistent with literature values (47% left lung, 53% right lung). The comparative study indicates a good correlation (r = 0.96) between the two techniques, with a mean difference of (−0.4 ± 5.4)%, suggesting that the elimination of cardiac components from the thoracic transimpedance signal leads to a better estimation of UPF.
