Ohnesorge B, Flohr T, Fischbach R, Kopp A F, Knez A, Schröder S, Schöpf U J, Crispin A, Klotz E, Reiser M F, Becker C R
Siemens Medical Solutions, Division CT, CTS C, Siemensstrasse 1, 91301 Forchheim, Germany.
Eur Radiol. 2002 Jun;12(6):1532-40. doi: 10.1007/s00330-002-1394-2. Epub 2002 Apr 19.
High reproducibility is a key requirement for coronary calcium scoring in follow-up examinations. We investigated the inter-examination reproducibility of calcium scoring with retrospectively ECG-gated multisection spiral CT (MSCT). Fifty patients were examined twice with MSCT. Slices were reconstructed with retrospective ECG gating in the diastolic phase with 3-mm slice width and up to 125-ms temporal resolution. We calculated the Agatston score, calcium volume with and without isotropic interpolation, and calcium mass, and derived the mean and median variability. We investigated the change of variability with use of 3-mm non-overlapping and overlapping increments (2, 1.5, 1 mm). Use of overlapping increment results in considerably reduced interscan variability. We observed a minimum mean variability of 12% and a minimum median variability of 9% for the Agatston score. For volume and mass quantification we obtained a minimum mean variability of 7.5% and a minimum median variability of 5%. Multisection spiral CT enables coronary calcium quantification with high reproducibility in follow-up examinations mainly founded on image data with reduced partial-volume errors due to overlapping increment.
高重复性是随访检查中冠状动脉钙化评分的一项关键要求。我们采用回顾性心电图门控多层螺旋CT（MSCT）研究了钙化评分的检查间重复性。50例患者接受了两次MSCT检查。在舒张期采用回顾性心电图门控重建图像，层厚3mm，时间分辨率高达125ms。我们计算了阿加斯顿评分、有无各向同性插值的钙体积以及钙质量，并得出均值和中位数变异性。我们研究了使用3mm非重叠和重叠增量（2、1.5、1mm）时变异性的变化。使用重叠增量可显著降低扫描间变异性。我们观察到阿加斯顿评分的最小均值变异性为12%，最小中位数变异性为9%。对于体积和质量定量，我们获得的最小均值变异性为7.5%，最小中位数变异性为5%。多层螺旋CT能够在随访检查中实现高重复性的冠状动脉钙化定量，这主要基于因重叠增量而减少了部分容积误差的图像数据。
