Method of magnetic resonance imaging of the liver and spleen

Claim 1

The method of imaging a tumor in the liver or spleen of a human subject, comprising: (a) parenterally administering to the human subject prior to magnetic resonance imaging (MRI) examination an aqueous suspension composed essentially of 1.5 to 8 micron diameter microspheres, said microspheres having a biodegradeable matrix with a contrast agent dispersed therein selected from the group consisting of paramagnetic and ferromagnetic contrast agents, the quantity of said microspheres administered being effective to appreciably reduce the T 2 relaxation time of the subject's liver and/or spleen; (b) delaying the examination until the microspheres have been segregated by the reticuloendothelial system and are concentrated in the liver and spleen; and then (c) carrying out an MRI examinaiton of the liver and/or spleen by T 2 imaging or mixed T 1 and T 2 imaging to obtain an image in which the normal liver or spleen tissues appear dark and the tumor appears light with distinct margins therebetween.

Claim 2

The method of imaging a tumor in the liver or spleen of a human subject, comprising: (a) parenterally administering to the human subject prior to magnetic resonance imaging (MRI) examination an aqueous suspension composed essentially of 1.5 to 8 micron diameter microspheres, said microspheres having a biodegradeable matrix with a contrast agent dispersed therein selected from the group consisting of paramagnetic and ferromagnetic contrast agents, the quantity of said microspheres administered being effective to appreciably reduce the T 2 relaxation time of the subject's liver and/or spleen; (b) delaying the examination until the microspheres have been segregated by the reticuloendothelial system and are concentrated in the liver and spleen; and then (c) carrying out an MRI examinaiton of the liver and/or spleen by T 2 imaging or mixed T 1 and T 2 imaging to obtain an image in which the normal liver or spleen tissues appear dark and the tumor appears light with distinct margins therebetween.

Claim 8

The method of imaging a tumor in the liver or spleen of a human subject, comprising: (a) intravenously administering to the human subject prior to magnetic resonance imaging (MRI) examination an aqeuous suspension composed essentially of microspheres having an average size of from 2 to 5 microns diameter, said microspheres being composed of a biodegradable matrix having a ferromagnetic contrast agent dispersed therein, the quantity of said microspheres administered being effective to appreciably reduce the T 2 relaxation time of the subject's liver and/or spleen; (b) delaying the examination until the microspheres have been segregated by the reticuloendothelial system and are concentrated in the liver and spleen; and then (c) carrying out an MRI examination of the liver and/or spleen by T 2 imaging or mixed T 1 and T 2 imaging to obtain an image in which the normal liver or spleen tissues appear dark and the tumor appears light with distinct margins therebetween.

Claim 9

The method of imaging a tumor in the liver or spleen of a human subject, comprising: (a) intravenously administering to the human subject prior to magnetic resonance imaging (MRI) examination an aqeuous suspension composed essentially of microspheres having an average size of from 2 to 5 microns diameter, said microspheres being composed of a biodegradable matrix having a ferromagnetic contrast agent dispersed therein, the quantity of said microspheres administered being effective to appreciably reduce the T 2 relaxation time of the subject's liver and/or spleen; (b) delaying the examination until the microspheres have been segregated by the reticuloendothelial system and are concentrated in the liver and spleen; and then (c) carrying out an MRI examination of the liver and/or spleen by T 2 imaging or mixed T 1 and T 2 imaging to obtain an image in which the normal liver or spleen tissues appear dark and the tumor appears light with distinct margins therebetween.

Claim 14

The method of imaging a tumor in the liver or spleen of a human subject, comprising: (a) intravenously administering to the human subject prior to magnetic resonance imaging (MRI) examination an aqueous suspension composed essentially of 1.5 to 8 micron diameter microspheres, said microspheres having a matrix of human serum albumin with magnetite particles dispersed therein, the quantity of said micropsheres administered being effective to appreciably reduce the T 2 relaxation time of the subject's liver and/or spleen; (b) delaying the examination until the microspheres have been segregated by the reticuloendothelial system and are concentrated in the liver and spleen; and then (c) carrying out an MRI examination of the liver and/or spleen by T 2 imaging or mixed T 1 and T 2 imaging to obtain an image in which the normal liver or spleen tissues appear dark and the tumor appears light with distinct margins therebetween.

Claim 15

The method of imaging a tumor in the liver or spleen of a human subject, comprising: (a) intravenously administering to the human subject prior to magnetic resonance imaging (MRI) examination an aqueous suspension composed essentially of 1.5 to 8 micron diameter microspheres, said microspheres having a matrix of human serum albumin with magnetite particles dispersed therein, the quantity of said micropsheres administered being effective to appreciably reduce the T 2 relaxation time of the subject's liver and/or spleen; (b) delaying the examination until the microspheres have been segregated by the reticuloendothelial system and are concentrated in the liver and spleen; and then (c) carrying out an MRI examination of the liver and/or spleen by T 2 imaging or mixed T 1 and T 2 imaging to obtain an image in which the normal liver or spleen tissues appear dark and the tumor appears light with distinct margins therebetween.