Prototype Ultrahigh-Resolution Computed Tomography for Chest Imaging: Initial Human Experience

OBJECTIVE: The objective of this study was to evaluate a prototype, ultrahigh-resolution computed tomography offering higher reconstruction matrix (1024 x 1024) and spatial resolution (0.15 mm) for chest imaging. METHODS: Higher (1024) matrix reconstruction enabled by ultrahigh-resolution computed tomography scanner (128-detector rows; detector width, 0.25 mm; spatial resolution, 0.15 mm) was compared with conventional (512) reconstruction with image quality grading on a Likert scale (1, excellent; 5, nondiagnostic) for image noise, artifacts, contrast, small detail, lesion conspicuity, image sharpness, and diagnostic confidence. Image noise and signal-to-noise ratio were quantified. RESULTS: Diagnostic image quality was achieved for all scans on 101 patients. The 1024 reconstruction demonstrated increased image noise (20.2 +/- 4.0 vs 17.2 +/- 3.8, P < 0.001) and a worse noise rating (1.98 +/- 0.63 vs 1.75 +/- 0.61, P < 0.001) but performed significantly better than conventional 512 matrix with fewer artifacts (1.37 +/- 0.43 vs 1.50 +/- 0.48, P < 0.001), better contrast (1.50 +/- 0.56 vs 1.62 +/- 0.57, P < 0.001), small detail detection (1.06 +/- 0.19 vs 2.02 +/- 0.22, P < 0.001), lesion conspicuity (1.08 +/- 0.23 vs 2.02 +/- 0.24, P < 0.001), sharpness (1.09 +/- 0.24 vs 2.02 +/- 0.28, P < 0.001), and overall diagnostic confidence (1.09 +/- 0.25 vs 1.18 +/- 0.34, P < 0.001). CONCLUSIONS: Ultrahigh-resolution computed tomography enabled a higher reconstruction matrix and improved image quality compared with conventional matrix reconstruction, with a minor increase in noise.