English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Purpose: Photon counting (PC) computed tomography (CT) can provide materialselective CT imaging at lowest patient dose but it suffers from suboptimalcount rate. A dynamic beam attenuator (DBA) can help with count rate bymodulating x-ray beam intensity such that the low attenuating areas of thepatient receive lower exposure, and detector behind these areas is notoverexposed. However, DBA may harden the beam and cause artifacts and errors.This work investigates positive and negative effects of using DBA in PCCT.Methods: A simple PCCT with single energy bin, spectroscopic PCCT with 2 and 5energy bins, and conventional energy integrating CT with and without DBA weresimulated and investigated using 120kVp tube voltage and 14mGy air dose. TheDBAs were modeled as made from soft tissue (ST) equivalent material, iron (Fe),and holmium (Ho) K-edge material. A cylindrical CT phantom and chest phantomwith iodine and CaCO3 contrast elements were used. Image artifacts andquantification errors in general and material decomposed CT were determined.Results: Simple PCCT exhibited major image artifacts and quantification errorswhen DBAs were used. The artifacts and errors were decreased with 2binspectroscopic PCCT and nearly eliminated with 5bin spectroscopic CT. The photonstarvation noise did present with Fe-DBA due to strong absorption of lowerenergy photons. The 5bin PCCT with ST-DBA and Ho-DBA were nearly free ofartifacts and photon starvation noise. The Ho-DBA better preserved low energyphotons and decreased beam hardening artifacts, and improved materialdecomposition. Also, the Ho-DBA was also miniature having 1.4mm thickness and2cm length, much smaller than Fe-DBA. Conclusion: DBA fabricated from K-edgematerial such as Ho can address count rate problem of PCCT and provideminiature size, minimal image artifacts, and improved material decomposition atlowest patient dose.

Photon counting spectroscopic CT with dynamic beam attenuator