A Study on the Comparison of VNCa and VMI+ Image Quality and Optimized Method according to kV Modulation of DECT: A Porcine Ankle Ligament Model

Abstract

This study conducted a quantitative and qualitative assessment of the effectiveness of Single-Energy and Dual-Energy Virtual non-calcium imaging, as well as Virtual Monoenergetic Imaging at 55, 65, and 75 keV, for diagnosing ligament conditions with regard to tube voltage modulation. A porcine hindlimb ankle ligament model was utilized for this evaluation. The two widest regions within the ligament model were designated as regions of interest, and measurements of Hounsfield Units, Signal-to-Noise Ratios, and Contrast-to-Noise Ratios were obtained. Quantitative evaluation was then conducted based on the average values. Furthermore, qualitative assessments of ligament diagnosis were carried out by five musculoskeletal radiologists and five radiological technologists, each with over five years of experience in Computed Tomography laboratory work. Following both quantitative and qualitative evaluations, it was observed that the Dual-Energy Virtual non-calcium image obtained at 70/Sn150 kVp and the Virtual Monoenergetic Imaging Plus 65 keV image exhibited superior image quality compared to the Single-Energy CT image. These differences were statistically significant (p<0.05). Moreover, the highest image quality was noted at 65 keV within the Virtual Monoenergetic Imaging Plus energy range. The Dual-Energy Virtual non-calcium image was found to be more suitable for imaging ligaments than the Virtual Monoenergetic Imaging Plus 65 keV image.(p<0.05) Notably, lower tube voltages were associated with improved image quality across all images. Consequently, it was determined that 70/Sn150 kVp Dual-Energy Virtual non-calcium images are more optimized than Single-Energy CT and Virtual Monoenergetic Imaging Plus 65 keV images for diagnosing ligament diseases in patients who present challenges for Magnetic Resonance Imaging and in emergency cases. Additionally, employing Virtual non-calcium Color Coding images for accurately describing ligament thickness or length may enhance the diagnostic value of the images.