Abstract: Adiabatic RF pulses are very useful in MRI when precise flip angles are needed. Unfortunately, adiabatic pulses suffer from a long application time and a high SAR. A new concept to modify the usual adiabatic pulse into a “pseudo-adiabatic” pulse having a shorter application time and lower SAR is introduced. For example, a BIR-4 of 32 ms of application time and a relative SAR of 20 will be transformed into a BIR-4-S1 of 1 ms and relative SAR of 1. The new pulse obtained stays insensitive for a large B1 range but loses its slice selectivity to become a 3D pulse. Experimental results are presented to illustrate the sensitivity to B1 and B0.
Type:
Application
Filed:
May 20, 2003
Publication date:
December 25, 2003
Applicant:
Corporation Du Centre De Recherche Du Centre Hospitalier De L'Universite De Montreal (CHUM)
Abstract: Symptoms of stress such as elevated blood pressure in mammals are treated, and mammalian bodies are preconditioned to manifest reduced adverse reactions to subsequently encountered stresses, by injecting into the mammalian patient a small quantity of the patient's own blood which has been previously extracted and subjected extracorporeally to at least one stressor, such as ultraviolet radiation, an oxidative environment, ozone-oxygen and mild heating, especially infra-red radiation causing mild heating. Particularly beneficial combinations of stressors are simultaneous applications of UV radiation and an ozone-oxygen gas mixture bubbled through the blood sample to provide the oxidative environment, or simultaneous application of UV radiation, ozone-oxygen gas mixtures and mild heating. One specific use of the invention is in preconditioning against ischemic-reperfusion injury e.g. prior to surgery.
Type:
Grant
Filed:
July 14, 2000
Date of Patent:
August 13, 2002
Assignees:
Vasogen Ireland Limited, Centre de Recherche du Centre Hospitalier de l'Universite de
Montreal (CHUM)
Abstract: Symptoms of stress such as elevated blood pressure in mammals are treated, and mammalian bodies are preconditioned to manifest reduced adverse reactions to subsequently encountered stresses, by injecting into the mammalian patient a small quantity of the patient's own blood which has been previously extracted and subjected extracorporeally to at least one stressor, such as ultraviolet radiation, an oxidative environment, ozone-oxygen and mild heating, especially infra-red radiation causing mild heating. Particularly beneficial combinations of stressors are simultaneous applications of UV radiation and an ozone-oxygen gas mixture bubbled through the blood sample to provide the oxidative environment, or simultaneous application of UV radiation, ozone-oxygen gas mixtures and mild heating. One specific use of the invention is in preconditioning against ischemic-reperfusion injury, e.g. prior to surgery.
Type:
Grant
Filed:
September 11, 1998
Date of Patent:
October 24, 2000
Assignees:
Vasogen Ireland Limited, Centre de Recherche du Centre Hospitalier de l'Universite de Montreal (CHUM)