Site Editors
Shaji K. Kumar, MD
Prashant Kapoor, MD, FACP
Shaji K. Kumar, MD
Prashant Kapoor, MD, FACP
Posted: Wednesday, December 7, 2022
Findings from Radiology suggest that photon-counting detector (PCD) CT and deep learning noise reduction may improve spatial resolution at lower radiation doses compared with energy-integrating detector (EID) CT. According to Francis I. Baffour, MD, of the Mayo Clinic, Rochester, Minnesota, and colleagues, PCD CT imaging improved radiologists’ visualization of multiple myeloma features over conventional EID CT.
“In whole-body low-dose CT, the primary clinical need is to improve the evaluation of skeletal findings while maintaining an acceptably low radiation dose,” the researchers explained. “Use of the ultra–high-resolution PCD CT scan mode enables improved spatial resolution without a noise or dose penalty.”
In the 27-patient study, participants underwent EID and PCD CT scans at matched radiation doses, reconstructed with Br44 and Br64 kernels at a section thickness of 2.0 mm. The PCD images were also reconstructed with Br44 and Br76 kernels at a 0.6-mm thickness and denoised with a convolutional neural network. To compare image quality, the investigators quantified noise texture and spatial resolution differences between the two methods. Additionally, two radiologists blindly scored images with a 5-point Likert scale.
In phantom and patient images, the PCD CT reconstructions resulted in less noise and higher lesion contrast than EID CT. Differences in quality were pronounced at lower spatial frequencies, and the 0.6-mm PCD images showed the strongest noise reduction. Lytic lesions (median score = 1.0), intramedullary lesions (median score = 0.5), and fat attenuation (median score = 0.5) were more clearly viewed on the 2.0-mm PCD images than the 2.0-mm EID images (P < .001). So too were the thinner 0.6-mm images, which were given median Likert scores of 2.0, 0.5, and 1.0 for lytic lesions, intramedullary lesions, and fat attenuation, respectively (P < .001). In 21 of 27 patients, one or more additional lytic lesions were detected from the 0.6-mm PCD images compared with the 2.0-mm EID CT images (median score = 1.5; P < .001).
Disclosure: For full disclosures of the study authors, visit pubs.rsna.org.
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