Abstract：
OBJECTIVE: To assess image quality and radiation dose of ultra-high-pitch CT pulmonary angiography (CTPA) with free-breathing technique for diagnosis of pulmonary embolism using a photon-counting detector (PCD) CT compared to matched energy-integrating detector (EID)-based single-energy CTPA.
METHODS: Fifty-one PCD-CTPAs were prospectively compared to 51 CTPAs on a third-generation dual-source EID-CT. CTPAs were acquired with an ultra-high-pitch protocol with free-breathing technique (40 mL contrast medium, pitch 3.2) at 140 kV (PCD) and 70-100 kV (EID). Iodine maps were reconstructed from spectral PCD-CTPAs. Image quality of CTPAs and iodine maps was assessed independently by three radiologists. Additionally, CT attenuation numbers within pulmonary arteries as well as signal-to-noise and contrast-to-noise ratios (SNR, CNR) were compared. Administered radiation dose was compared.
RESULTS: CT attenuation was higher in the PCD-group (all P < 0.05). CNR and SNR were higher in lobar pulmonary arteries in PCD-CTPAs (P < 0.05), whereas no difference was ascertained within the pulmonary trunk (P > 0.05). Image quality of PCD-CTPA was rated best by all readers (excellent/good image quality in 96.1% of PCD-CTPAs vs. 50.9% of EID-CTPAs). PCD-CT produced no non-diagnostic scans vs. three non-diagnostic (5.9%) EID-CTPAs. Radiation dose was lower with PCD-CT than with EID-CT (effective dose 1.33 ± 0.47 vs. 1.80 ± 0.82 mSv; all P < 0.05).
CONCLUSIONS: Ultra-high-pitch CTPA with free-breathing technique with PCD-CT allows for superior image quality with significantly reduced radiation dose and full spectral information. With the ultra-high pitch, only PCD-CTPA enables reconstruction of iodine maps containing additional functional information.
METHODS: Fifty-one PCD-CTPAs were prospectively compared to 51 CTPAs on a third-generation dual-source EID-CT. CTPAs were acquired with an ultra-high-pitch protocol with free-breathing technique (40 mL contrast medium, pitch 3.2) at 140 kV (PCD) and 70-100 kV (EID). Iodine maps were reconstructed from spectral PCD-CTPAs. Image quality of CTPAs and iodine maps was assessed independently by three radiologists. Additionally, CT attenuation numbers within pulmonary arteries as well as signal-to-noise and contrast-to-noise ratios (SNR, CNR) were compared. Administered radiation dose was compared.
RESULTS: CT attenuation was higher in the PCD-group (all P < 0.05). CNR and SNR were higher in lobar pulmonary arteries in PCD-CTPAs (P < 0.05), whereas no difference was ascertained within the pulmonary trunk (P > 0.05). Image quality of PCD-CTPA was rated best by all readers (excellent/good image quality in 96.1% of PCD-CTPAs vs. 50.9% of EID-CTPAs). PCD-CT produced no non-diagnostic scans vs. three non-diagnostic (5.9%) EID-CTPAs. Radiation dose was lower with PCD-CT than with EID-CT (effective dose 1.33 ± 0.47 vs. 1.80 ± 0.82 mSv; all P < 0.05).
CONCLUSIONS: Ultra-high-pitch CTPA with free-breathing technique with PCD-CT allows for superior image quality with significantly reduced radiation dose and full spectral information. With the ultra-high pitch, only PCD-CTPA enables reconstruction of iodine maps containing additional functional information.
摘要：
目的：与基于匹配能量积分探测器（EID）的单能量CTPA相比，使用光子计数探测器（PCD）CT评估具有自由呼吸技术的超高螺距CT肺动脉造影（CTPA）诊断肺栓塞的图像质量和辐射剂量。
方法：在第三代双源EID-CT上对51个PCD-CTPA进行了前瞻性比较。CTPAs是通过具有自由呼吸技术的超高螺距方案获得的（40mL造影剂，间距3.2)在140kV(PCD)和70-100kV(EID)。从光谱PCD-CTPAs重建碘图谱。CTPAs和碘图的图像质量由三名放射科医生独立评估。此外,肺动脉内的CT衰减数以及信噪比和对比噪声比(SNR，CNR）进行了比较。比较施用的辐射剂量。
结果：PCD组的CT衰减较高（均P<0.05）。PCD-CTPAs大叶肺动脉CNR和SNR较高(P<0.05),而肺动脉干内无差异(P>0.05)。PCD-CTPA的图像质量被所有读者评为最佳(96.1%的PCD-CTPA与50.9%的EID-CTPAs）。PCD-CT没有产生非诊断扫描与三个非诊断性（5.9％）EID-CTPA。PCD-CT的辐射剂量低于EID-CT（有效剂量1.33±0.47vs.1.80±0.82mSv；所有P<0.05）。
结论：采用PCD-CT自由呼吸技术的超高螺距CTPA可获得优异的图像质量，同时显著降低辐射剂量和完整的光谱信息。随着超高的音调，只有PCD-CTPA能够重建包含额外功能信息的碘图谱.
方法：在第三代双源EID-CT上对51个PCD-CTPA进行了前瞻性比较。CTPAs是通过具有自由呼吸技术的超高螺距方案获得的（40mL造影剂，间距3.2)在140kV(PCD)和70-100kV(EID)。从光谱PCD-CTPAs重建碘图谱。CTPAs和碘图的图像质量由三名放射科医生独立评估。此外,肺动脉内的CT衰减数以及信噪比和对比噪声比(SNR，CNR）进行了比较。比较施用的辐射剂量。
结果：PCD组的CT衰减较高（均P<0.05）。PCD-CTPAs大叶肺动脉CNR和SNR较高(P<0.05),而肺动脉干内无差异(P>0.05)。PCD-CTPA的图像质量被所有读者评为最佳(96.1%的PCD-CTPA与50.9%的EID-CTPAs）。PCD-CT没有产生非诊断扫描与三个非诊断性（5.9％）EID-CTPA。PCD-CT的辐射剂量低于EID-CT（有效剂量1.33±0.47vs.1.80±0.82mSv；所有P<0.05）。
结论：采用PCD-CT自由呼吸技术的超高螺距CTPA可获得优异的图像质量，同时显著降低辐射剂量和完整的光谱信息。随着超高的音调，只有PCD-CTPA能够重建包含额外功能信息的碘图谱.
