Multiphase photon counting detector CT data sets - Which combination of contrast phase and virtual non-contrast algorithm is best suited to replace true non-contrast series in the assessment of active bleeding?

Purpose: Aim of this study was to determine which virtual non-contrast (VNC) reconstruction algorithm, applied to which contrast phase of computed tomography angiography, best matches true non-contrast (TNC) images in the assessment of active bleeding.

Method: Patients who underwent a triphasic scan (pre-contrast, arterial, portal venous contrast) on a photon-counting detector CT (PCD-CT) (120 kV, image quality level 68) with suspected active (tumor, postoperative, spontaneous or other) bleeding were retrospectively included in this study. Conventional (VNC) and a calcium-preserving VNC algorithm (VNC) were derived from both arterial (art) and portal venous (pv) contrast scans, and analyzed quantitatively and qualitatively by two independent and blinded raters.

Spectral metal artifact reduction after posterior spinal fixation in photon-counting detector CT datasets.

Purpose: To investigate the usefulness of virtual monoenergetic image (VMI) reconstructions derived from scans on a novel photon-counting detector CT (PCD-CT) for artifact reduction in patients after posterior spinal fixation.

Methods: This retrospective cohort study included 23 patients status post posterior spinal fixation. Subjects were scanned on a novel PCD-CT (NAEOTOM Alpha, Siemens Healthineers, Erlangen, Germany) as part of routine clinical care.

Artifact Reduction From Dental Material in Photon-Counting Detector Computed Tomography Data Sets Based on High-keV Monoenergetic Imaging and Iterative Metal Artifact Reduction Reconstructions-Can We Combine the Best of Two Worlds?

Objective: The aim of this study was to compare the effectiveness of common strategies for artifact reduction of dental material in photon-counting detector computed tomography data sets.

Materials And Methods: Patients with dental material who underwent clinically indicated CT of the neck were enrolled. Image series were reconstructed using a standard and sharp kernel, with and without iterative metal artifact reduction (IMAR) (Qr40, Qr40 IMAR , Qr60, Qr60 IMAR ) at different virtual monoenergetic imaging (VMI) levels (40-190 keV).

Non-specific effects of MMR vaccines on infectious disease related hospitalizations during the second year of life in high-income countries: a systematic review and meta-analysis.

Children who had received MMR as the most recent vaccine had a pooled 35% (95%CI: 12-53%) lower risk for hospitalization due to any infectious disease, compared to children who had received DTaP as the most recent vaccine (three studies, 1,919,192 children). The effect was stronger for respiratory tract infections than for gastrointestinal infections. Two studies investigated MMR alone, compared to concurrent administration of MMR and DTaP vaccines.