Next Generation Cone Beam CT with Improved Contrast Resolution and Added Spectral Imaging Functionality

ABSTRACT
Cone beam Computed Tomography (CBCT) with a digital flat panel detector (FPD) is the primary imaging
workhorse for image-guided interventions. By rotating the tube-detector assembly around the patient, 3D cone
beam CT (CBCT) data can be acquired to supplement 2D x-ray imaging and improve disease diagnosis,
treatment planning, and treatment execution in medical procedures. Despite its volumetric coverage and high
spatial resolution, FPD-based CBCT does not provide the necessary soft-tissue contrast resolution for
intraoperative hemorrhage monitoring, gray-white matter differentiation, or the detection of other low-contrast
lesions in a variety of imaging tasks. In addition, quantitative imaging capabilities that are much desired by
physicians are lacking in the current CBCT technology. The overarching objective of this project is to
develop an integrated PCD-FPD CBCT imaging platform by adding an x-ray photon counting detector
(PCD) to the current CBCT system, enabling users to freelyswitch between the new PCD-CBCT imaging
mode and the existing FPD-based imaging without interference between the two components. This new
imaging platform offers the same soft-tissue contrast resolution and z-coverage as those of MDCT, but
without requiring additional room space to house both MDCT and CBCT in the same suite. Additionally,
the proposed system offers quantitative spectral CT imaging functionality at reduced radiation and contrast dose
for image-guided interventions. To develop the integrated PCD-FPD CBCT imaging system and to explore its
added value to medical diagnosis, three specific aims are planned. Aim #1 is designed to construct and calibrate
a prototype PCD-CBCT system; Aim #2 is dedicated to the development of the novel correction algorithms
needed to achieve artifact-free PCD-CBCT images; Aim #3 is dedicated to clinical feasibility studies using in vivo
canine subjects and human subjects. Upon the completion of these aims, a prototype for the next-generation
CBCT imaging system will have been constructed, calibrated, and evaluated; the system will be capable of
consistently producing nearly artifact-free PCD-CBCT images with spectral imaging functionality and MDCT-like
low-contrast detectability; the benefits and potential clinical applications of the integrated PCD-FPD CBCT
imaging system will have been demonstrated.

Grant Number: 5R01EB034011-03
NIH Institute/Center: NIH
Principal Investigator: Guang-Hong Chen