Bier Georg, Bongers Malte Niklas, Hempel Johann-Martin, Örgel Anja, Hauser Till-Karsten, Ernemann Ulrike, Hennersdorf Florian
Department of Diagnostic and Interventional Neuroradiology, Eberhard Karls University Tuebingen, 72076, Tuebingen, Germany.
Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, 72076, Tuebingen, Germany.
Neuroradiology. 2017 Jul;59(7):649-654. doi: 10.1007/s00234-017-1855-6. Epub 2017 Jun 3.
This paper aims to evaluate a new iterative metal artifact reduction algorithm for post-interventional evaluation of brain tissue and intracranial arteries.
The data of 20 patients that underwent follow-up cranial CT and cranial CT angiography after clipping or coiling of an intracranial aneurysm was retrospectively analyzed. After the images were processed using a novel iterative metal artifact reduction algorithm, images with and without metal artifact reduction were qualitatively evaluated by two readers, using a five-point Likert scale. Moreover, artifact strength was quantitatively assessed in terms of CT attenuation and standard deviation alterations.
The qualitative analysis yielded a significant increase in image quality (p = 0.0057) in iteratively processed images with substantial inter-observer agreement (ĸ = 0.72), while the CTA image quality did not differ (p = 0.864) and even showed vessel contrast reduction in six cases (30%). The mean relative attenuation difference was 27% without metal artifact reduction vs. 11% for iterative metal artifact reduction images (p = 0.0003).
The new iterative metal artifact reduction algorithm enhances non-enhanced CT image quality after clipping or coiling, but in CT-angiography images, the contrast of adjacent vessels can be compromised.
本文旨在评估一种用于脑组织和颅内动脉介入后评估的新型迭代金属伪影减少算法。
回顾性分析20例颅内动脉瘤夹闭或栓塞术后接受随访头颅CT和头颅CT血管造影的患者数据。使用一种新型迭代金属伪影减少算法对图像进行处理后，由两名阅片者采用五点李克特量表对有无金属伪影减少的图像进行定性评估。此外，从CT衰减和标准差变化方面对伪影强度进行定量评估。
定性分析显示，迭代处理后的图像质量显著提高（p = 0.0057），观察者间一致性较高（ĸ = 0.72），而CTA图像质量无差异（p = 0.864），甚至有6例（30%）出现血管对比度降低。未进行金属伪影减少时平均相对衰减差异为27%，而迭代金属伪影减少图像为11%（p = 0.0003）。
新型迭代金属伪影减少算法可提高夹闭或栓塞术后非增强CT图像质量，但在CT血管造影图像中，相邻血管的对比度可能会受到影响。
