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OBJECTIVES: The aim of this study was to investigate the impact of virtual monoenergetic imaging (VMI+) and dual-energy computed tomography perfusion maps (DECT-PMs) on reader confidence and diagnostic accuracy in dual-energy computed tomography pulmonary angiography (DE-CTPA) studies with suboptimal contrast attenuation, compared with standard linearly blended reconstruction series. MATERIALS AND METHODS: Dual-energy computed tomography pulmonary angiography examinations with suboptimal contrast attenuation of 68 patients with suspected pulmonary embolism (PE) were included in this institutional review board-approved retrospective study. Virtual monoenergetic imaging series at 40 keV, DECT-PM, and linearly blended images (M₀. 6, 60% 90-kV spectrum) were reconstructed. Contrast-to-noise ratio and signal-to-noise ratio within the pulmonary trunk were calculated. Four independent radiologists assessed the presence of PE and their diagnostic confidence using 3 DE-CTPA reconstruction protocols: protocol 1, M₀. 6 images; protocol 2, M₀. 6 series and DECT-PM; and protocol 3, M₀. 6, DECT-PM, and VMI+ series. Receiver operating characteristic (ROC) analysis was performed. RESULTS: Fourteen patients showed central and 29 segmental PE. Greater contrast-to-noise ratio and signal-to-noise ratio values were measured in VMI+ series at 40 keV in comparison to M₀. 6 images (P < 0. 001). Diagnostic accuracy for segmental PE detection was as follows: protocol 1 (69. 1%) ; protocol 2 (86. 8%) ; and protocol 3 (92. 6%). Protocol 3 resulted in a significantly greater area under the curve for diagnosing segmental PE (0. 991, P ≤ 0. 033), compared with protocol 1 and 2 (0. 897 and 0. 951, respectively), and provided the highest diagnostic confidence (P < 0. 001). CONCLUSIONS: A reconstruction protocol including 40-keV VMI+ series and DECT-PM improves reader confidence and diagnostic accuracy for segmental PE detection compared with standard M₀. 6 images in DE-CTPA with suboptimal contrast attenuation.
Leithner et al. (Wed,) studied this question.