Walk-in lab test for lung morphometry characterization

Patent metadata

Field	Value
Publication number	US-12257093-B2
Application number	US-202017769333-A
Country	US
Kind code	B2
Filing date	Oct 13, 2020
Priority date	Oct 15, 2019
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

The present invention relates to a method for estimating lung morphometry based on aerosol deposition characteristics using an imaging means such as a gamma camera to scan the lungs. An adaptive image threshold technique is used to determine the ratio of deposition in central to peripheral region of the lung (C/P ratio). The morphometric parameters such as length and diameter of distal lung airways (P 8 and P 9 respectively) and mean alveolar diameter (d alv ) are determined from aerosol retention data and clearance data.

First claim

We claim:

1. A method for estimating lung morphometry comprising of:
delivering radio-aerosol in a subject;
generating a plurality of images of lungs of said subject post-inhalation of the radio-aerosol using an imaging means,
wherein said images are obtained from imaging at t=0 hours and upto t=24 hours post-inhalation of said radio-aerosol;
applying an adaptive image threshold technique to draw a Region of Interest (ROI) on said images of the lungs for determining a Central region (C) of said ROI, and a Peripheral region (P) of said ROI, and determining ratio of radio-aerosol deposition in the Central region (C) to radio-aerosol deposition in the Peripheral region (P) of the lungs (C/P ratio) based on characteristics of said radio-aerosol deposition post-inhalation in the Central region (C) and the Peripheral region (P),
wherein said adaptive image threshold technique comprises of:
i) converting said images obtained from imaging at t=0 hours and upto t=24 hours post-inhalation of said radio-aerosol to gray scale images;
ii) cropping said gray scale images to make right lung as the only focus and obtain uniform dimensions of said gray scale images for said subject;
iii) calculating right lung boundary from said gray scale images by extracting said right lung boundary at a given threshold value through an automated iterative procedure until said threshold value for obtaining maximum said right lung boundary is achieved;
iv) obtaining right lung area by superimposing said right lung boundary over first image obtained from imaging at t=0 hours post-inhalation of said radio-aerosol;
(v) calculating the C/P ratio from the ratio of the area of the central region to the area of the peripheral region,
wherein said ratio of the area of the central region to the area of the peripheral region is obtained based on image intensities of said gray scale images in the central region (C) and the peripheral region (P); and

vi) shrinking said right lung area to create an area ratio obtained in step (v), using an iterative procedure,
wherein said iterative procedure comprises calculating and recalculating boundaries of said central and said peripheral regions based on said threshold value and said image intensities of said gray scale images until the central region is shrunk to one-third of said right lung boundary; and

determining parameters of lung morphometry based on said C/P ratio through an optimization procedure comprising minimizing an error function,
wherein said parameters of lung morphometry include length (P 8 ) and diameter (P 9 ) of the 17 th generation lung airway to the 23 rd generation lung airway, and mean alveolar diameter (d alv ) of said lung airways.

2. The method for estimating lung morphometry according to claim 1 , wherein said radio-aerosol is delivered to the lungs using any oral or nasal compliance.

3. The method for estimating lung morphometry according to claim 1 , wherein the imaging means is selected from a gamma imaging camera, CT scan, SPECT, and PET scan.

4. The method for estimating lung morphometry according to claim 1 , wherein the characteristics of said radio-aerosol deposition in said Central region (C) and said Peripheral region (P) include retention data and clearance data of radio-aerosol in the lungs.

5. The method for estimating lung morphometry according to claim 4 , wherein said retention data and said clearance data of said radio-aerosol in the lungs include time, volume, or percentage of said radio-aerosol in the lungs.

6. The method for estimating lung morphometry according to claim 1 , wherein said minimizing an error function is a normed difference between numerical predictions of (C/P) m ratio and experimentally determined values C/P ratio.

Assignees

• Indian Institute Of Tech Madras
• Sri Venkateswara Inst Of Medical Sciences Svims

Inventors

• Panchagnula Mahesh V
• G Karthiga Devi S
• Alladi Mohan

Classifications

• A61B6/5217

  extracting a diagnostic or physiological parameter from medical diagnostic data · CPC title

• A61B6/481

  involving the use of contrast agents · CPC title

• G06T2207/30061

  Lung · CPC title

• G06T7/0012

  Biomedical image inspection · CPC title

• A61B5/004

  adapted for image acquisition of a particular organ or body part (A61B5/0082 takes precedence; arrangements for optical scanning A61B5/0062) · CPC title