【摘 要】
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Objective To evaluate the image quality and feasibility of low-dose 80 kVp pulmonary CT angiography (PCTA) with iterative model reconstruction technique in patients with BMI >= 25 kg/m2. Methods Fifte
【出 处】
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中华放射学学术大会2016、中华医学会第23次全国放射学学术大会暨中华医学会第24次全国影像技术学术大会
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Objective To evaluate the image quality and feasibility of low-dose 80 kVp pulmonary CT angiography (PCTA) with iterative model reconstruction technique in patients with BMI >= 25 kg/m2. Methods Fifteen patients (25 ≤ BMI < 30) with clinical suspicion of pulmonary embolism underwent PCTA were prospectively enrolled. PCTA was performed using 80 kV tube voltage and xxx tube current with automatic modulation. The images were reconstructed by filtered back projection (FBP), hybrid iterative reconstruction (HID) and Iterative Model Reconstruction (IMR) technique. The image quality parameters: image noise, signal-to-noise (SNR), contrast-to-noise ratio (CNR) and subjective image score (1, 2,non-diagnostic, 5, excellent) were measured and compared among 3 reconstruction techniques. The effective dose was calculated using a conversion factor of 0.017.. Results The image noise, SNR and CNR were 144.1±29.3, 3.8±1.2and 9.0 ± 4.1 for FBP, 79.8± 15.4,7.0,±2.3 and 10.4 ± 4.1 for HID and 44.2 ± 6.8, 12.0 ± 2.9 and 20.2 ± 10.5 for IMR images. The image quality in terms of noise, SNR and CNR was significantly better for IMR images than those for iDose or FBP (all P < 0.05). The subjective image score was 2.3 ± 0.6, 2.9 ± 0.5 and 4.4 ± 0.6 for FBP, HID and IMR images. The IMR images received significantly higher score (p < 0.05) and all achieved diagnostic image quality. The diagnosable rate was 50.0%,78.6% and 100% for FBP, HID and IMR images. The effective dose was 0.5 ± 0.1 mSv. Conclusion The IMR technique significantly improved the image noise, SNR, CNR and subjective image score in low dose 80 kVp CT pulmonary angiography for overweight patients, compared with FBP and HID technique.
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