RSNA 2020

Abstract Archives of the RSNA, 2020


SSCH07-05

First Clinical Trial of a Photon-counting Surface Detector Insert in a Whole-body CT Scanner to Provide Resolution in Chest Scans Beyond the Scanner's Hardware Limits

All Day Room: NA



FDA Discussions may include off-label uses.

Participants
Han Wen, PHD, Bethesda, MD (Presenter) Nothing to Disclose
TJ Vongkovit, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Eric Bennett, MS, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Dumitru Mazilu, PhD, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Amir Hasani, MS, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Shirley Rollison, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Amanda M. Jones, RN, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Patricia Julien-Williams, RN, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Tatyana A. Worthy, RN, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Babak Saboury, MD, MPH, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Marcus Y. Chen, MD, Bethesda, MD (Abstract Co-Author) Nothing to Disclose
Joel Moss, MD,PhD, Bethesda, MD (Abstract Co-Author) Nothing to Disclose

For information about this presentation, contact:

han.wen@nih.gov

PURPOSE

The ultimate goal is to achieve near microscopic resolution in body CT scans in targeted areas in order to reduce invasive biopsy procedures. This trial specifically evaluates an add-on hybrid technology to whole-body CT scanners which can be readily disseminated to clinical scanners.

METHOD AND MATERIALS

This trial included 8 patients suspected of lymphangioleiomyomatosis (LAM) (all female, age 33 to 64). Similar to the high sensitivity of surface coils in MRI due to their proximity to the body, in a CT scanner the proximity effect is exploited to overcome the resolution limit imposed by the x-ray focal spot penumbra. A surface panel detector insert (SDI) is placed in a foam frame on the scanner bed, in direct contact with the patient's body (Fig. 1). This minimizes the focal spot penumbra on the SDI. The SDI acquired data at 1000 Hz for 0.35 sec concurrent with the CT's own detector. The method was previously tested in phantoms with a photon-counting SDI of 100 Ám pixels and 2048x256 matrix (Larsen et al., TOMOGRAPHY, 2:233-238, 2019). Axial-mode chest scans of 2 cm z length were performed. Data from the SDI and the CT's detector were combined in a prototype tomosynthesis software to produce a coronal image stack of 50 Ám pixels and 0.1 mm slice spacing. System resolutions were measured by scanning tungsten wires.

RESULTS

Examples of structural details provided by the SDI hybrid scan (Fig.1) include bronchioles down to 0.6 mm diameter with walls of 0.15 to 0.35 mm thickness; air-filled lung cysts down to 1.1 mm size, some with walls down to 0.20 mm thickness; blood vessels down to 0.20 mm diameter; endplate micro fractures in thoracic vertebrae down to 0.10 mm scale. A first in vivo observation was made of a 0.35 mm diameter bronchiole that appears to terminate in a round cyst of 2.4 mm diameter with a distinct wall, offering clues to the mechanism of cyst formation in LAM. System resolutions and MTFs of scans with and without the SDI are summarized in Fig. 1.

CONCLUSION

Initial patient trial of an add-on surface detector in a whole-body CT scanner provided structural details in chest scans beyond the resolution limit of the scanner hardware. Current work focuses on data fusion methods for true 3D reconstruction.

CLINICAL RELEVANCE/APPLICATION

Initial trial of an add-on surface detector to a whole-body CT scanner demonstrates structural details in the chest scans of patients with LAM beyond the resolution limit of the scanner.

Printed on: 03/01/22