Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Eur Radiol. 2019 Jul;29(7):3606-3616. doi: 10.1007/s00330-019-06090-2. Epub 2019 Mar 22.
To systematically evaluate the effects of virtual tube current reduction and sparse sampling on image quality and vertebral fracture diagnostics in multi-detector computed tomography (MDCT).
In routine MDCT scans of 35 patients (80.0% females, 70.6 ± 14.2 years, 65.7% showing vertebral fractures), reduced radiation doses were retrospectively simulated by virtually lowering tube currents and applying sparse sampling, considering 50%, 25%, and 10% of the original tube current and projections, respectively. Two readers evaluated items of image quality and presence of vertebral fractures. Readout between the evaluations in the original images and those with virtually lowered tube currents or sparse sampling were compared.
A significant difference was revealed between the evaluations of image quality between MDCT with virtually lowered tube current and sparse-sampled MDCT (p < 0.001). Sparse-sampled data with only 25% of original projections still showed good to very good overall image quality and contrast of vertebrae as well as minimal artifacts. There were no missed fractures in sparse-sampled MDCT with 50% reduction of projections, and clinically acceptable determination of fracture age was possible in MDCT with 75% reduction of projections, in contrast to MDCT with 50% or 75% virtual tube current reduction, respectively.
Sparse-sampled MDCT provides adequate image quality and diagnostic accuracy for vertebral fracture detection with 50% of original projections in contrast to corresponding MDCT with lowered tube current. Thus, sparse sampling is a promising technique for dose reductions in MDCT that could be introduced in future generations of scanners.
• MDCT with a reduction of projection numbers of 50% still showed high diagnostic accuracy without any missed vertebral fractures. • Clinically acceptable determination of vertebral fracture age was possible in MDCT with a reduction of projection numbers of 75%. • With sparse sampling, higher reductions in radiation exposure can be achieved without compromised image or diagnostic quality in routine MDCT of the spine as compared to MDCT with reduced tube currents.
系统评估虚拟管电流降低和稀疏采样对多探测器 CT（MDCT）中图像质量和椎骨骨折诊断的影响。
在 35 名患者（80.0%为女性，70.6±14.2 岁，65.7%显示椎骨骨折）的常规 MDCT 扫描中，通过虚拟降低管电流并应用稀疏采样，分别考虑 50%、25%和 10%的原始管电流和投影来回顾性模拟降低辐射剂量。两位读者评估了图像质量和椎骨骨折的存在情况。比较原始图像与虚拟降低管电流或稀疏采样的评估之间的读取。
在 MDCT 中虚拟降低管电流和稀疏采样的图像质量评估之间存在显著差异（p<0.001）。只有原始投影的 25%稀疏采样数据仍显示出良好到非常好的整体图像质量和对比度，以及最小的伪影。在投影减少 50%的稀疏采样 MDCT 中没有遗漏骨折，并且在投影减少 75%的 MDCT 中可以进行可接受的骨折年龄确定，与相应的管电流减少 50%或 75%的 MDCT 相比。
与相应的管电流降低的 MDCT 相比，稀疏采样 MDCT 以原始投影的 50%提供足够的图像质量和诊断准确性，用于检测椎骨骨折。因此，稀疏采样是一种有前途的 MDCT 剂量减少技术，可在未来几代扫描仪中引入。
MDCT 以减少 50%的投影数量仍显示出高诊断准确性，没有任何遗漏的椎骨骨折。
在 MDCT 中以减少 75%的投影数量可以进行可接受的椎骨骨折年龄确定。
与管电流降低的 MDCT 相比，稀疏采样可在常规 MDCT 脊柱成像中实现更高的辐射暴露减少，而不会影响图像或诊断质量。
