Department of Neuroradiology, University of Erlangen- Nuremberg, Schwabachanlage 6, 91052, Erlangen, Germany,
Eur Radiol. 2015 Feb;25(2):428-35. doi: 10.1007/s00330-014-3411-7. Epub 2014 Oct 17.
After deployment of flow-diverting stents (FDS), complete aneurysm occlusion is not predictable. This study investigated whether parametric colour coding (PCC) could allow in vivo visualization of flow alterations induced by FDS and identify favourable or adverse flow modulations.
Thirty-six patients treated by FDS were analyzed. Preinterventional and postinterventional DSA-series were postprocessed by PCC and time-density curves (TDCs) were calculated. The parameters aneurysmal inflow, outflow, and relative time-to-peak (rTTP) were calculated. Preinterventional and postinterventional values were compared and related to occlusion rate.
Postinterventional inflow showed a mean reduction of 37%, outflow of 51%, and rTTP a prolongation of 82%. Saccular aneurysm occlusion occurred if a reduction of at least 15% was achieved for inflow and 35% for outflow (sensitivity: 89%, specificity: 82%). Unchanged outflow and a slightly prolonged rTTP were associated with growth in one fusiform aneurysm.
PCC allows visualization of flow alterations after FDS treatment, illustrating "flow diverting effects" by the TDC shape and indicating mainly aneurysmal outflow and lesser inflow changes. Quantifiable parameters (inflow, outflow, rTTP) can be obtained, thresholds for predicting aneurysm occlusion determined, and adverse flow modulations assumed. As a rapid intraprocedural tool, PCC might support the decision to implant more than one FDS.
• After deployment of a flow-diverting stent, complete aneurysm occlusion is unpredictable. • Parametric colour coding offers new options for visualizing in vivo flow alterations non-invasively. • Quantifiable parameters, i.e., aneurysmal inflow/outflow can be obtained allowing prognostic stratification. • Rapid, intraprocedural application allows treatment monitoring, potentially contributing to patient safety.
血流导向装置（FDS）置入后，完全闭塞动脉瘤的情况无法预测。本研究旨在探讨参数彩色编码（PCC）是否可用于活体可视化 FDS 引起的血流变化，并确定有利或不利的血流调节。
分析了 36 例行 FDS 治疗的患者。对术前和术后的 DSA 系列进行 PCC 后处理，并计算时间密度曲线（TDC）。计算了动脉瘤流入、流出和相对达峰时间（rTTP）等参数。比较了术前和术后的值，并与闭塞率相关联。
术后流入量平均减少 37%，流出量减少 51%，rTTP 延长 82%。如果流入量减少至少 15%，流出量减少 35%，则可实现囊状动脉瘤闭塞（敏感性：89%，特异性：82%）。未改变的流出量和略微延长的 rTTP 与一个梭形动脉瘤的生长有关。
PCC 可在 FDS 治疗后可视化血流变化，通过 TDC 形状说明“血流转向效应”，并主要表明动脉瘤流出量和较小的流入量变化。可获得可量化的参数（流入量、流出量、rTTP），确定预测动脉瘤闭塞的阈值，并假设不利的血流调节。作为一种快速的术中工具，PCC 可能有助于决定植入多个 FDS。
FDS 置入后，完全闭塞动脉瘤的情况无法预测。
参数彩色编码提供了一种新的非侵入性活体可视化血流变化的方法。
可获得可量化的参数（如动脉瘤的流入和流出），允许进行预后分层。
快速的术中应用允许治疗监测，可能有助于患者安全。
