Three-dimensional metric, perfusion and metabolic compartment spectroscopy phantom

Claim 2

A precisely measurable three-dimensional Cartesian grid for calibrating an NMR imaging device, said grid including materials selected so that cross-sections of said grid provide NMR grid images defined by contrasting light and dark areas, in a plurality of planes at angles which are arbitrary with respect to one another and with respect to said grid.

Claim 3

The apparatus of claim 1 comprising: a plurality of blocks of known sizes stacked in layers to form said three-dimensional grid; and means for holding said blocks in said three-dimensional grid.

Claim 4

The apparatus of claim 2 wherein said blocks are substantially identical parallelepipeds with square bases.

Claim 5

The apparatus of claim 3 wherein each of said blocks defines a hollow interior for retaining a fluid.

Claim 6

The apparatus of claim 4 wherein each of said blocks comprises a top, four walls, and a bottom, the bottoms of said blocks being open to communicate with said hollow interior, the tops of said blocks having protrusions for inserting into said bottoms so that a first block may be selectably fixed to the top of at least one second block, in a known alignment.

Claim 7

The apparatus of claim 5 wherein said alignment comprises the walls of the first block being in planes parallel to but offset from the planes of the walls of the second block; and said first block is fixed to the tops of at least two second blocks, said protrusions holding adjacent walls of said second blocks in such close contact that fluid flow is substantially impaired therebetween.

Claim 8

The apparatus of claim 6 wherein the tops of a subset of said blocks define holes positioned so that said holes in conjunction with said walls of said blocks form at least one path for fluid flow between the layers of said apparatus.

Claim 9

The apparatus of claim 7 comprising a plurality of said paths which diverge from a top of said apparatus toward a bottom of said apparatus.

Claim 10

The apparatus of claim 7 comprising a plurality of said paths which converge toward a bottom of said apparatus.

Claim 11

The apparatus of claim 7 comprising a plurality of entries on at least one outside surface of said apparatus; a plurality of said paths coupled to said entries, said paths being disposed so that distinct fluids inserted through distinct ones of said entries mix at predetermined places and in predetermined ratios inside said apparatus.

Claim 12

The apparatus of claim 4 wherein a subset of said blocks define holes which allow fluid to flow between said layers of said blocks.

Claim 13

The apparatus of claim 2 wherein said blocks are immersed in at least one fluid.

Claim 14

The apparatus of claim 12 wherein said fluid is an aqueous solution of one of: copper sulfate, Cu2 + ions, Cr3 + ions, Fe3 + ions, Mn2 + ions, and Gd3 + ions.

Claim 15

The apparatus of claim 13 wherein the ion concentration is between 10 -5 and 10 -1 mol/liters.

Claim 16

The apparatus of claim 12 comprising a sealed plastic container for retaining said blocks and said fluid.

Claim 17

The apparatus of claim 2 comprising approximately 300 said blocks and wherein said three-dimensional grid is of approximately the same size as a human head.

Claim 18

The apparatus of claim 2 wherein said blocks are LEGO® Duplo® blocks, of dimensions approximately 2 cm×2 cm×1.8 cm.

Claim 19

The apparatus of claim 17 comprising (a) five layers of twenty-five blocks, each of said five layers arranged in a square grid having five columns and five rows; (b) four layers of thirty-six blocks, each of said four layers being arranged in a square grid having six columns and six rows; (c) said four and five layers being stacked in an alternating arrangement so that first, third, fifth, seventh, and ninth layers are five-by-five, and second, fourth, sixth, and eighth layers are six-by-six and so that centers of said four layers are in vertical alignment with centers of said five layers; (d) said first and ninth layers defining holes in the centers of the tops of the following blocks: ______________________________________ column row A B C D E ______________________________________ I none none none none none II none center none center none III none none center none none IV none center none center none V none none none none none ______________________________________ (e) said third and seventh layers defining holes in the center of the tops of the following blocks: ______________________________________ column row A B C D E ______________________________________ I none none none none none II none center center center none III none center center center none IV none center center center none V none none none none none ______________________________________ (f) said second and eighth layers defining holes in the top of the following positions of the following blocks: ______________________________________ column row A B C D E F ______________________________________ I none none none none none none II none none none none none none III none none NW,SE SW,NE none none IV none none SW,NE NW,SE none none V none none none none none none VI none none none none none none ______________________________________ (g) said fifth layer defining holes in the following positions of the following blocks: ______________________________________ column row A B C D E ______________________________________ I SE SW,SE SW,SE SW,SE SW II NE,SE center center center NW,SW III NE,SE center center center NW,SW IV NE,SE center center center NW,SW V NE NW,NE NW,NE NW,NE NW ______________________________________ (h) said fourth and sixth layers defining holes in the following positions of the following blocks: ______________________________________ column row A B C D E F ______________________________________ I none none none none none none II none NW,SE NW,NE NW,NE SW,NE none SE SW III none NW,SW NW,SE SW,NE NE,SW none SE SE IV none NW,NE NE,SW NW,SE NW,NE none SW SE V none NE,SW NE,SW NW,SW NW,SE none SE SE VI none none none none none none ______________________________________ (i) an aqueous copper sulfate solution in which said blocks are immersed; (j) a sealed container of internal dimensions approximately 19.7 cm×19.7 cm×19.7 cm retaining said solution and said blocks; and (k) five closable tubes inserted into said holes in said first and ninth layers, whereby fluids may be injected into and drained from said apparatus along a plurality of paths defined by all of said holes and said walls of said blocks, said paths diverging from a top face of said apparatus and converging to a bottom face of said apparatus.

Claim 20

The apparatus of claim 1, wherein the apparatus defines a coordinate system and comprises at least one subunit selectably positioned, in a non-redundant manner, with respect to the coordinate system.

Claim 21

The apparatus of claim 19 wherein said at least one subunit comprises at least one block of known size.

Claim 22

The apparatus of claim 20 wherein said at least one block is selectably attachable to a plurality of precisely defined positions on a baseplate.

Claim 23

The apparatus of claim 20 comprising at least one second subunit comprising at least one second block of known size which is selectably attachable to said at least one subunit.

Claim 24

The apparatus of claim 22 wherein said at least two subunits are hollow and sealed and contain respective distinct NMR signal-producing fluids having respective distinct NMR measurable properties, whereby small localized volumes having said respective distinct NMR measurable properties are created.

Claim 25

The apparatus of claim 23 wherein said respective distinct NMR measurable properties are respective distinct T 1 and T 2 relaxation times.

Claim 26

The apparatus of claim 23 wherein said respective distinct NMR measurable properties are respective distinct NMR spectra.

Claim 27

The apparatus of claim 20 wherein said at least one block is hollow and sealed and contains an NMR signal-producing fluid.

Claim 28

The apparatus of claim 24 comprising means for removing and replacing said NMR signal-producing fluid, so that said at least one block is sealed after said NMR signal-producing fluid is replaced.

Claim 29

The apparatus of claim 20 wherein said at least one block is hollow and defines at least one external hole, whereby an NMR signal-producing fluid is selectably introduced into said at least one block through said at least one hole.

Claim 30

The apparatus of claim 19 wherein said at least one subunit comprises at least two substantially identical blocks, stacked with one on top of the other.

Claim 31

The apparatus of claim 29 wherein said at least two identical blocks are hollow, one of said at least two blocks being sealed and containing an NMR signal-producing fluid, and another of said at least two blocks defining at least one external hole, whereby said other block is made flow-through to an NMR signal-producing fluid.

Claim 32

The apparatus of claim 19 wherein said at least one subunit comprises a plurality of substantially identical blocks, said blocks being hollow and sealed, at least two of said blocks containing respective distinct NMR signal-producing fluids having respective distinct NMR measurable properties.

Claim 33

The apparatus of claim 19 wherein said at least one subunit comprises a plurality of substantially identical blocks, said blocks being hollow and sealed, and intercommunicating internally to form intercommunicating chambers.

Claim 36

The method of claim 33 comprising: introducing at least one second fluid into at least one entry in a first face of an outside of said phantom, said entry communicating with at least one fluid pathway inside said phantom; draining said at least one second fluid from at least one exit in a second face of said outside of said phantom, said exit communicating with said pathway; second imaging said three-dimensional grid at said planes at at least one subsequent time, whereby a profile of fluid flow through said phantom is obtained.

Claim 37

The method of claim 34 comprising pumping said second fluid through said phantom.

Claim 38

The method of claim 34 comprising introducing said second fluid, said second and said first fluids being the same.

Claim 39

The method of claim 34 comprising introducing at least two distinct said second fluids into said entries.

Claim 40

The method of claim 37 comprising: taking a plurality of images during a time when said second fluids are moving through said phantom; and measuring a gradation of T1 and T2 using said plurality of images.

Claim 41

The method of claim 37 comprising taking a plurality of images during a time when said second fluids are moving through said phantom, and measuring spectra at a plurality of locations in a plurality of planes in order to obtain a gradation of regional spectroscopy.

Claim 42

The method of claim 34 comprising measuring a spatial gradation of fluid from images produced in the imaging steps.

Claim 43

The method of claim 34 comprising measuring a spatial gradation of fluid flow from images produced in the imaging steps.

Claim 44

The method of claim 34 comprising measuring a spatial gradation of change in fluid flow from images produced in the imaging steps.