Image-based global registration system and method applicable to bronchoscopy guidance

Abstract

A global registration system and method identifies bronchoscope position without the need for significant bronchoscope maneuvers, technician intervention, or electromagnetic sensors. Virtual bronchoscopy (VB) renderings of a 3D airway tree are obtained including VB views of branch positions within the airway tree. At least one real bronchoscopic (RB) video frame is received from a bronchoscope inserted into the airway tree. An algorithm according to the invention is executed on a computer to identify the several most likely branch positions having a VB view closest to the received RB view, and the 3D position of the bronchoscope within the airway tree is determined in accordance with the branch position identified in the VB view. The preferred embodiment involves a fast local registration search over all the branches in a global airway-bifurcation search space, with the weighted normalized sum of squares distance metric used for finding the best match.

Description

REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority from U.S. Provisional Patent Application Ser. Nos. 61 / 299,194, filed Jan. 28, 2010 and 61 / 300,969, filed Feb. 3, 2010, the entire content of both being incorporated herein by reference.GOVERNMENT SUPPORT[0002]This invention was made with government support under Grant No. R01-CA074325. awarded by NIH National Cancer Institute. The government has certain rights in the invention.FIELD OF THE INVENTION[0003]This invention relates generally to bronchoscopy and, in particular, to a global registration system and method useful in image-based bronchoscopy guidance systems and other applications, including other types of endoscopic procedures.BACKGROUND OF THE INVENTION[0004]Bronchoscopy is a medical procedure commonly used in lung-cancer assessment[1]. Lung-cancer assessment involve two main stages[2,3,4]: 1) three-dimensional (3D) multi-detector computed-tomography (MDCT) image assessment; and 2) live bronchoscopy. Du...

AI Technical Summary

Benefits of technology

[0011]This invention resides in a global registration system and method useful in image-based bronchoscopy guidance systems and other applications, including other types of endoscopic procedures. Synchronization is restored by identifying the current branch position, thereby facilitating global, technician-independent bronchoscopy guidance without the need for any external device such as an electromagnetic sensor.

Problems solved by technology

This manually-based route planning procedure proves to be challenging, resulting in errors in bronchoscopy as early as the second airway generation[8,9].

However, metallic objects in the vicinity induce ferromagnetic device interference, leading to distortions in the external EM field[19].

Moreover, the patient's breathing causes chest movement that leads to registration errors[20].

Thus, EM-based bronchoscopy guidance systems implicitly provide global registration, but suffer in local registration.

However, as these methods rely on the bronchoscope video, they are affected by artifacts in bronchoscope video caused by patient coughing or mucous obstruction.

During a live bronchoscopic procedure, the absence of a global registration algorithm leads to increased procedure time and some uncertainty in the bronchoscope position.

This in turn leads to guidance errors.

However, few have worked on the problem of global registration, whereby the branch location of the bronchoscope is established.

However, this method addresses bronchoscope tracking and cannot be used for global registration.

Moreover, it requires manual initialization.

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