Huber Adrian, Landau Julia, Ebner Lukas, Bütikofer Yanik, Leidolt Lars, Brela Barbara, May Michelle, Heverhagen Johannes, Christe Andreas
Department of Diagnostic, Interventional and Paediatric Radiology, University Hospital Inselspital Bern, CH-3010, Bern, Switzerland.
Department of Polyvalent and Oncological Radiology, University Hospital Pitié-Salpêtrière, Paris, France.
Eur Radiol. 2016 Oct;26(10):3643-52. doi: 10.1007/s00330-015-4192-3. Epub 2016 Jan 26.
To investigate the detection rate of pulmonary nodules in ultralow-dose CT acquisitions.
In this lung phantom study, 232 nodules (115 solid, 117 ground-glass) of different sizes were randomly distributed in a lung phantom in 60 different arrangements. Every arrangement was acquired once with standard radiation dose (100 kVp, 100 references mAs) and once with ultralow radiation dose (80 kVp, 6 mAs). Iterative reconstruction was used with optimized kernels: I30 for ultralow-dose, I70 for standard dose and I50 for CAD. Six radiologists examined the axial 1-mm stack for solid and ground-glass nodules. During a second and third step, three radiologists used maximum intensity projection (MIPs), finally checking with computer-assisted detection (CAD), while the others first used CAD, finally checking with the MIPs.
The detection rate was 95.5 % with standard dose (DLP 126 mGycm) and 93.3 % with ultralow-dose (DLP: 9 mGycm). The additional use of either MIP reconstructions or CAD software could compensate for this difference. A combination of both MIP reconstructions and CAD software resulted in a maximum detection rate of 97.5 % with ultralow-dose.
Lung cancer screening with ultralow-dose CT using the same radiation dose as a conventional chest X-ray is feasible.
• 93.3 % of all lung nodules were detected with ultralow-dose CT. • A sensitivity of 97.5 % is possible with additional image post-processing. • The radiation dose is comparable to a standard radiography in two planes. • Lung cancer screening with ultralow-dose CT is feasible.
研究超低剂量CT扫描中肺结节的检出率。
在本肺部模型研究中，232个不同大小的结节（115个实性结节、117个磨玻璃结节）以60种不同排列方式随机分布于肺部模型中。每种排列方式分别采用标准辐射剂量（100 kVp，100参考mAs）和超低辐射剂量（80 kVp，6 mAs）各扫描一次。采用迭代重建技术并使用优化内核：超低剂量扫描采用I30内核，标准剂量扫描采用I70内核，计算机辅助检测（CAD）采用I50内核。6名放射科医生对1mm层厚的轴位图像进行实性和磨玻璃结节检查。在第二步和第三步中，3名放射科医生先使用最大密度投影（MIP），最后使用计算机辅助检测（CAD）；而其他医生则先使用CAD，最后使用MIP进行检查。
标准剂量扫描（剂量长度乘积[DLP]为126 mGycm）时的检出率为95.5%，超低剂量扫描（DLP为9 mGycm）时的检出率为93.3%。额外使用MIP重建或CAD软件可弥补这一差异。MIP重建和CAD软件联合使用时，超低剂量扫描的最大检出率为97.5%。
采用与传统胸部X线相同的辐射剂量进行超低剂量CT肺癌筛查是可行的。
• 超低剂量CT扫描可检出93.3%的肺结节。• 额外的图像后处理可使敏感度达到97.5%。• 辐射剂量与两个平面的标准X线摄影相当。• 超低剂量CT肺癌筛查是可行的。
