Encapsulated gas or partial vacuum ct contrast material

Patent metadata

Field	Value
Publication number	US-2024237959-A1
Application number	US-202418434667-A
Country	US
Kind code	A1
Filing date	Feb 6, 2024
Priority date	Apr 20, 2015
Publication date	Jul 18, 2024
Grant date	—

Abstract

The present invention provides an encapsulated gas or partial vacuum particle contrast media for use in CT imaging. In an exemplary embodiment, the invention provides an enteric contrast medium formulation. An exemplary formulation comprises, (a) an enteric contrast medium comprising a encapsulated gas or partial vacuum particle suspended in water. Exemplary encapsulated gas or partial vacuum particle has a specific gravity between 0.2 and 1.5. In various embodiments, the encapsulated gas or partial vacuum particle is suspended in aqueous media by an agent compatible with enteric administration of the formulation to a subject in need of such administration. In an exemplary embodiment, the contrast material is incorporated into a pharmaceutically acceptable carrier in which the material is suspended homogeneously. In an exemplary embodiment, the encapsulated gas or partial vacuum particle comprises 5% or more of the weight of the contrast material formulation. The invention also provides methods for imaging of the abdomen by dual energy CT or spectral CT contemporaneously with the delivery of the encapsulated gas or partial vacuum particle contrast material into the bowel lumen with or without the delivery of a second complementary contrast material into the blood vessels or other body compartments. The invention also provides methods for the digital separation of CT signal produced by the contrast media of the invention from the CT signal produced by other contrast media or bodily tissues to generate multiple resultant CT images with the contrast medium of the invention subtracted or highlighted.

First claim

What is claimed is:

1 . An enteric contrast medium formulation which is formulated for oral delivery to a subject contemporaneous with a medical imaging procedure performed on the abdomen of said subject, said formulation comprising:
an enteric contrast medium comprising a suspension of one encapsulated gas or partial vacuum particle (e.g., hollow borosilicate microsphere) and an aqueous vehicle component, with said aqueous component which is a pharmaceutically acceptable aqueous vehicle, wherein said particle comprises a shell defining an interior void, said shell formed of a material contributing at least about 30 Hounsfield Units (HU) to the CT number of said contrast medium formulation or of a body cavity in which said contrast medium is distributed during said medical imaging procedure.

2 . An enteric contrast medium formulation which is formulated for oral delivery to a subject contemporaneous with a medical imaging procedure performed on the abdomen of said subject, said formulation comprising an encapsulated gas or partial vacuum particle.

3 . The enteric contrast medium formulation of any preceding claim , wherein said formulation is a unit dosage formulation comprising a diagnostically effective amount of said enteric contrast medium.

4 . The enteric contrast medium formulation of any preceding claim , wherein said formulation is a unit dosage formulation of from about 800 mL to about 1500 mL per adult human dose, which may be divided into smaller containers such as 400 mL to 500 mL in volume.

5 . The enteric contrast medium formulation of any preceding claim wherein said formulation is a unit dosage formulation of from about 50 to about 100 mL in volume.

6 . The enteric contrast medium formulation of any preceding claim wherein formulation is a unit dosage formulation of from about 100 mL to about 800 mL in volume.

7 . The enteric contrast medium formulation of any preceding claim , wherein said encapsulated gas or partial vacuum particle is stable at room or body temperature (e.g., hollow borosilicate microspheres, gas impregnated silicone rubber, coated silica gel particles, heat-sealed silica gel particles, barium impregnated heat sealed silica gel particles, gas and barium impregnated silicone rubber, ceramic hollow microparticles).

8 . The enteric contrast medium formulation of any preceding claim , wherein said formulation comprises at least about 5% weight/weight percentage of said encapsulated gas or partial vacuum particle (from about 5% to about 95% in terms of weight/weight percentage).

9 . The enteric contrast medium formulation of any preceding claim , wherein said formulation comprises at least about 10% weight/weight percentage of said encapsulated gas or partial vacuum particle (from about 10% to about 95% in terms of weight/weight percentage).

10 . The enteric contrast medium formulation of any preceding claim , wherein said suspension agent is selected from xanthan gum, guar gum, hydroxypropylmethyl cellulose, hydroxypropyl cellulose, polyvinyl pyrrolidone, alginates, polyethylene glycol chains, and sodium carboxylmethylcellulose.

11 . The enteric contrast medium formulation of any preceding claim , wherein said formulation is a unit dosage formulation and it contains more than about 20 g of said encapsulated gas or partial vacuum particle.

12 . The enteric contrast medium formulation of any preceding claim , wherein said suspension agent comprises xanthan gum.

13 . The enteric contrast medium formulation of any preceding claim , wherein said pharmaceutically acceptable vehicle further comprises an additive to retard dehydration of said formulation in the bowel, a flavoring agent, a thickening agent, a flow agent, a pH buffer, a laxative, an osmolality-adjusting agent, and a combination thereof.

14 . The enteric contrast medium formulation of any preceding claim , wherein said enteric contrast medium has an 80:140 kVp CT number ratio of greater than about 2.1

15 . The enteric contrast medium formulation of any preceding claim , wherein said enteric contrast medium has an 80:140 kVp CT number ratio of from about 0.6 to about 0.8.

16 . The enteric contrast medium formulation of any preceding claim , wherein said enteric contrast medium has an 80:140 kVp CT number ratio of from about 0.3 to about 0.5.

17 . The enteric contrast medium formulation of any preceding claim , wherein said enteric contrast medium has an 80:140 kVp CT number ratio below 0.3, including ratios below zero.

18 . The enteric contrast medium formulation of any preceding claim wherein the encapsulated gas or partial vacuum particle has a specific gravity similar to that of water (e.g., from about 0.7 to about 1.2 g/cc).

19 . The enteric contrast medium formulation of any preceding claim wherein the encapsulated gas or partial vacuum particle a specific gravity from about 0.2 to about 0.8.

20 . The enteric contrast medium formulation of any preceding claim wherein the encapsulated gas or partial vacuum particle has a mean diameter of from about 5 to about 60 micrometers.

21 . The enteric contrast medium formulation of any preceding claim wherein the encapsulated gas or partial vacuum particle has a mean diameter of from about 60 to about 200 micrometers.

22 . The enteric contrast medium formulation of any preceding claim wherein the encapsulated gas or partial vacuum particle has a mean diameter of from about 0.5 to about 5 micrometers.

23 . The enteric contrast medium formulation of any preceding claim wherein said enteric contrast medium is provided in powdered or other concentrated form to be mixed with water or other said acceptable pharmaceutical aqueous vehicle near the time of administration for CT scanning, together with instructions for preparing an administrable enteric contrast medium and, optionally, one or more device for administering said administratble enteric contrast medium to a subject.

24 . The enteric contrast medium formulation of any preceding claim , wherein the encapsulated gas or partial vacuum particle makes up 5% or more of the weight of the formulation.

25 . A method of acquiring contrast enhanced X-ray or computed tomography or dual energy computed tomography or spectral computed tomography projection data of a subject, said method comprising: administering to said subject a diagnostically effective amount of said enteric contrast medium formulation of any preceding claim ; and acquiring said projection data of said subject.

26 . The method according to claim 25 , wherein said X-ray or computed tomography or dual energy computed tomography or spectral computed tomography projection data is reconstructed into a computed tomography image.

27 . The method of any of claims 25-26 , wherein said contrast agent is imaged using a dual energy or spectral CT scanner with X-ray filters of different material or thickness (including zero) that modify the energy spectra of the X-ray beams. Example materials to filter the energy spectra of the X-ray beams include but are not limited to aluminum, copper, gold, or tin

28 . The method according to claims 25-27 , wherein said X-ray or computed tomography or dual energy computed tomography or spectral computed tomography projection data are used for 2-material, 3-material, or multi-material decomposition and reconstructed into CT images.

2

Assignees

• Univ California
• The United Sttes Government As Represented By Th E Dept Of Veterans Affairs

Inventors

• Yeh Benjamin M
• Fu Yanjun

Classifications

• A61B6/032

  Transmission computed tomography [CT] · CPC title

• A61K49/0419 Primary

  Microparticles, microbeads, microcapsules, microspheres, i.e. having a size or diameter higher or equal to 1 micrometer · CPC title

• A61K9/10

  Dispersions; Emulsions · CPC title

• A61B6/03 Primary

  Computed tomography [CT] · CPC title

• A61K9/50

  Microcapsules {having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals (A61K9/2081 takes precedence; particles with a single coating comprising drug A61K9/167)} · CPC title