The aims of this study were to quantitatively assess two new scan modes on a photon-counting detector computed tomography
system, each designed to maximize spatial resolution, and to qualitatively demonstrate potential clinical impact using patient data.
Materials and Methods
This Health Insurance Portability Act–compliant study was approved by our institutional review board. Two high–spatial-resolution scan modes (Sharp
) were evaluated using phantoms to quantify spatial resolution and image noise, and results were compared with the standard mode (Macro
). Patients were scanned using a conventional energy-integrating detector scanner and the photon-counting detector
scanner using the same radiation dose. In first patient images, anatomic details were qualitatively evaluated to demonstrate potential clinical impact.
modes had a 69% and 87% improvement in in-plane spatial resolution, respectively, compared with Macro
mode (10% modulation-translation-function values of 16.05, 17.69, and 9.48 lp/cm, respectively). The cutoff spatial frequency of the UHR
mode (32.4 lp/cm) corresponded to a limiting spatial resolution of 150 μm. The full-width-at-half-maximum values of the section sensitivity profiles were 0.41, 0.44, and 0.67 mm for the thinnest image thickness for each mode (0.25, 0.25, and 0.5 mm, respectively). At the same in-plane spatial resolution, Sharp
images had up to 15% lower noise than Macro
images. Patient images acquired in Sharp
mode demonstrated better delineation of fine anatomic structures compared with Macro
Phantom studies demonstrated superior resolution and noise properties for the Sharp
modes relative to the standard Macro
mode and patient images demonstrated the potential benefit of these scan modes for clinical practice.