Fast Variance Prediction for Iteratively Reconstructed CT Images With Locally Quadratic Regularization

Predicting noise properties of iteratively reconstructed CT images is useful for analyzing reconstruction methods; for example, local noise power spectrum (NPS) predictions may be used to quantify the detectability of an image feature, to design regularization methods, or to determine dynamic tube current adjustment during a CT scan. This paper presents a method for fast prediction of reconstructed image variance and local NPS for statistical reconstruction methods using quadratic or locally quadratic regularization. Previous methods either require impractical computation times to generate an approximate map of the variance of each reconstructed voxel, or are restricted to specific CT geometries. Our method can produce a variance map of the entire image, for locally shift-invariant CT geometries with sufficiently fine angular sampling, using a computation time comparable to a single back-projection. The method requires only the projection data to be used in the reconstruction, not a reconstruction itself, and is reasonably accurate except near image edges where edge-preserving regularization behaves highly nonlinearly. We evaluate the accuracy of our method using reconstructions of both simulated CT data and real CT scans of a thorax phantom.

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:36

Enthalten in:

IEEE transactions on medical imaging - 36(2017), 1 vom: 02. Jan., Seite 17-26

Sprache:

Englisch

Beteiligte Personen:

Schmitt, Stephen M [VerfasserIn]
Goodsitt, Mitchell M [VerfasserIn]
Fessler, Jeffrey A [VerfasserIn]

Links:

Volltext

Themen:

Journal Article

Anmerkungen:

Date Completed 21.12.2017

Date Revised 02.12.2018

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1109/TMI.2016.2593259

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM262714183