An automated A-value measurement tool for accurate cochlear duct length estimation.
An automated A-value measurement tool for accurate cochlear duct length estimation.
复制标题
一个自动的A值测量工具，用于精确的耳蜗长度估计。
DOI：
10.1186/s40463-018-0253-3
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发表时间：
2018-01-22
期刊：
影响因子：
--
通讯作者：
Agrawal SK
中科院分区：
文献类型：
--
作者：
Iyaniwura JE;Elfarnawany M;Ladak HM;Agrawal SK
耳蜗导管长度（CDL）在术前人工耳蜗电极选择和术后生成患者特定频率图方面重新受到关注。CDL可以通过测量A值来估计，A值被定义为圆窗与基弯上最远点之间的长度。不幸的是，当这些测量在临床上进行时，存在显著的观察者内和观察者间变异性。本研究的目的是开发一种自动化的A值测量算法，以提高准确性和消除观察者的变异性。收集20例尸体耳蜗标本的临床和显微CT图像。选择一个样本的micro-CT作为图谱，并将A值基准点放置在该图像上。图像配准（刚性仿射和非刚性B样条）之间的图集和19个剩余的临床CT图像。将配准变换应用于A值基准点，然后自动计算每个标本的A值。使用相同19个标本的高分辨率显微CT图像测量金标准A值，以与手动和自动方法进行比较。该配准算法在图谱和目标图像之间具有良好的定性重叠。自动化方法消除了观察员的可变性和专家的系统低估。与微型CT相比，临床CT上A值的手动测量的平均误差为9.5 ± 4.3%，使用自动算法时，误差改善为2.7 ± 2.1%。自动和手动方法均与金标准micro-CT A值显著相关（分别为r = 0.70，p < 0.01和r = 0.69，p < 0.01）。成功开发并验证了一种使用基于图谱的配准方法的自动A值测量工具。与专家手动测量相比，自动化方法消除了观察者的可变性并提高了准确性。这种开源工具有可能在未来使人工耳蜗植入者受益。
There has been renewed interest in the cochlear duct length (CDL) for preoperative cochlear implant electrode selection and postoperative generation of patient-specific frequency maps. The CDL can be estimated by measuring the A-value, which is defined as the length between the round window and the furthest point on the basal turn. Unfortunately, there is significant intra- and inter-observer variability when these measurements are made clinically. The objective of this study was to develop an automated A-value measurement algorithm to improve accuracy and eliminate observer variability. Clinical and micro-CT images of 20 cadaveric cochleae specimens were acquired. The micro-CT of one sample was chosen as the atlas, and A-value fiducials were placed onto that image. Image registration (rigid affine and non-rigid B-spline) was applied between the atlas and the 19 remaining clinical CT images. The registration transform was applied to the A-value fiducials, and the A-value was then automatically calculated for each specimen. High resolution micro-CT images of the same 19 specimens were used to measure the gold standard A-values for comparison against the manual and automated methods. The registration algorithm had excellent qualitative overlap between the atlas and target images. The automated method eliminated the observer variability and the systematic underestimation by experts. Manual measurement of the A-value on clinical CT had a mean error of 9.5 ± 4.3% compared to micro-CT, and this improved to an error of 2.7 ± 2.1% using the automated algorithm. Both the automated and manual methods correlated significantly with the gold standard micro-CT A-values (r = 0.70, p < 0.01 and r = 0.69, p < 0.01, respectively). An automated A-value measurement tool using atlas-based registration methods was successfully developed and validated. The automated method eliminated the observer variability and improved accuracy as compared to manual measurements by experts. This open-source tool has the potential to benefit cochlear implant recipients in the future.
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DOI：
10.1186/s40463-017-0194-2
发表时间：
2017-03-07
期刊：
Journal of otolaryngology - head & neck surgery = Le Journal d'oto-rhino-laryngologie et de chirurgie cervico-faciale
影响因子：
--
作者：
Koch RW;Ladak HM;Elfarnawany M;Agrawal SK
通讯作者：
Agrawal SK
影响因子：
9.8
作者：
Gerber, Nicolas;Reyes, Mauricio;Gonzalez Ballester, Miguel A.
通讯作者：
Gonzalez Ballester, Miguel A.
影响因子：
2.4
作者：
Fu, QJ;Shannon, RV;Galvin, JJ
通讯作者：
Galvin, JJ
影响因子：
2.7
作者：
Fukumitsu N;Nitta K;Terunuma T;Okumura T;Numajiri H;Oshiro Y;Ohnishi K;Mizumoto M;Aihara T;Ishikawa H;Tsuboi K;Sakurai H
通讯作者：
Sakurai H
影响因子：
2.5
作者：
Fedorov, Andriy;Beichel, Reinhard;Kalpathy-Cramer, Jayashree;Finet, Julien;Fillion-Robin, Jean-Christophe;Pujol, Sonia;Bauer, Christian;Jennings, Dominique;Fennessy, Fiona;Sonka, Milan;Buatti, John;Aylward, Stephen;Miller, James V.;Pieper, Steve;Kikinis, Ron
通讯作者：
Kikinis, Ron