The high flexibility of C-arm flat-detector computed tomography (FDCT) is used in a volume of interest (VOI) imaging
method to handle the challenges of increasing spatial resolution, reducing noise and saving dose.
A low-dose overview scan of the object and a high-dose scan of an arbitrary VOI are combined. The first scan is
adequate for orientation to select the VOI and the second scan assures high image quality in the VOI. The combination is
based on a forward projection of the reconstructed overview volume and the measured VOI data in the raw data domain.
Differences in the projection values are matched before a standard Feldkamp-type reconstruction is performed. In
simulations, spatial resolution, noise and contrast detectability were evaluated. Measurements of an anthropomorphic
phantom were used to validate the proposed method for realistic application. In Monte Carlo dose simulations the dose
reduction potential was investigated.
By combination of the two scans an image is generated which covers the whole object and provides the actual VOI at
high image quality. Spatial resolution was increased whereas noise was decreased from outside to inside the VOI, e.g. for
the simulations from 0.8 lp/mm to 3.0 lp/mm and from 39 HU to 18 HU, respectively. Simultaneously, the cumulative
dose for this two-scan procedure was significantly reduced in comparison to a conventional high dose scan, e.g. for the
performed simulations and measurements by about 95 %.
The proposed VOI approach offers significant benefits with respect to high-resolution and low-contrast imaging of a
VOI at reduced dose.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.