Enhancing Soft Tissue Differentiation with Different Dual-Energy CT Systems: A Phantom Study

To quantitatively evaluate the possible advantages of quantifying and differentiating various soft tissues using virtual monochromatic images (VMI) derived from different dual-energy computed tomography (DECT) technologies. This study involved four DECT scanners with different technologies. CIRS phantom images were acquired in single-energy (SECT) and DECT modes with each scanner. The analysis focused on five equivalent soft-tissue inserts: adipose, breast, liver, muscle, and bone (200 mg). The signal-to-noise ratio (SNR) was calculated for each equivalent soft-tissue insert. Finally, the contrasts of tissue pairs between DECT and SECT images were compared using Wilcoxon signed-rank tests adjusted for multiple comparisons. Average CT numbers and noise showed a significant difference pattern between DECT with respect to SECT for each CT scanner. Generally, energy levels of 70 keV or higher led to improved SNR in VMI for most of the equivalent soft-tissue inserts. However, energy levels of 40–50 keV showed significantly higher contrasts in most of the equivalent soft-tissue insert pairs. DECT images at low energies, especially at 40–50 keV, outperform SECT images in discriminating soft tissues across all four DECT technologies. The combined use of DECT images reconstructed at different energy levels provides a more comprehensive set of information for diagnostic and/or radiotherapy evaluation compared to SECT. Some differences between scanners are evident, depending on the DECT acquisition technique and reconstruction method

Where does this image take you? A visual tale from a workshop on geographical imaginations

This work is authored by a group of Ph.D. students and academics who attended a workshop on visual methodologies in the framework of the Scuola di alta formazione in geografia organised by AGeI (Association of Italian Geographers), 2022 edition. By visually reporting the workshop activities we aim at reflecting on the creative power of images in expanding geographical imaginations and its potential in the teaching of geography. The paper is shaped as a visual essay in which images and text do not refer directly to each other but rather aim at creating an imaginative reading flow