Contrast resolution tissue mimicking phantoms for nuclear magnetic resonance imaging with stable NMR properties

An NMR phantom for testing NMR imaging apparatus, which is stable in dimensions and NMR properties over time, comprising:

• (a) a container formed of walls enclosing an interior space, the walls formed of a material which does not impede the NMR imaging;
• (b) a base tissue mimicking material within the enclosed volume of the container, the tissue mimicking material comprising a solidified gel, the gel solidified from a mixture of agar, water and at least another gelling agent;
• and
• (c) at least one inclusion of selected shape within and in contact with the base tissue mimicking material, the inclusion formed of a solidified gel of the same mixture as that forming the base tissue mimicking material except differing in the dry weight concentration of agar so as to result in a contrast difference between the inclusion and the base tissue mimicking material when the phantom is imaged by NMR imaging apparatus wherein the contrast difference between the inclusion and the base tissue mimicking material is substantially stable over time.

A method of producing tissue mimicking material for NMR phantoms comprising the steps of:

• (a) mixing agar, water, and glycerol together and heating to form a molten agar gelling liquid in which the ratio of the quantity of glycerol to water is at a selected value;
• (b) mixing animal hide gelatin, water and glycerol together and heating to form a molten animal hide gelling liquid, the rate of glycerol to water bearing the same value as the ratio of glycerol to water in the agar gelling liquid;
• (c) mixing together selected quantities of the agar gelling liquid and the animal hide gelling liquid while in the molten liquid state to form a uniformly mixed gelling liquid;
• (d) adding a cross-linking agent to the mixture of the agar gelling liquid and the animal hide gelling liquid which will cause the animal hide gel to cross link, and then cooling the mixture to cause gelling and cross linking to thereby form a solidified gel having NMR T.sub.1 and T.sub.2 properties which are stable over time.