Grieser Christian, Denecke Timm, Rothe Jan-Holger, Geisel Dominik, Stelter Lars, Cannon Walter Thula, Seehofer Daniel, Steffen Ingo G
Klinik für Strahlenheilkunde, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, Germany
Klinik für Strahlenheilkunde, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, Germany.
Acta Radiol. 2015 Dec;56(12):1419-27. doi: 10.1177/0284185114558975. Epub 2014 Nov 18.
Despite novel software solutions, liver volume segmentation is still a time-consuming procedure and often requires further manual optimization. With the high signal intensity of the liver parenchyma in Gd-EOB enhanced magnetic resonance imaging (MRI), liver volume segmentation may be improved.
To evaluate the practicability of threshold-based segmentation of the liver volume using Gd-EOB-enhanced MRI including a customized three-dimensional (3D) sequence.
A total of 20 patients examined with Gd-EOB MRI (hepatobiliary phase T1-weighted (T1W) 3D sequence [VIBE]; flip angle [FA], 10° and 30°) were enrolled in this retrospective study. The datasets were independently processed by two blinded observers (O1 and O2) in two ways: manual (man) and threshold-based (thresh; study method) segmentation of the liver each followed by an optimization step (man+opt and thresh+opt; man+opt [FA10°] served as reference method). Resulting liver volumes and segmentation times were compared. A liver conversion factor was calculated in percent, describing the non-hepatocellular fraction of the total liver volume, i.e. bile ducts and vessels.
Thresh+opt (FA10°) was significantly faster compared to the reference method leading to a median volume overestimation of 4%/8% (P < 0.001). Using thresh+opt (FA30°), segmentation was even faster (P < 0.001) and even reduced median volume deviation of 0%/2% (O1/O2; both P > 0.2). The liver conversion factor was found to be 10%.
Threshold-based liver segmentation employing Gd-EOB-enhanced hepatobiliary phase standard T1W 3D sequence is accurate and time-saving. The performance of this approach can be further improved by increasing the FA.
尽管有新颖的软件解决方案，但肝脏体积分割仍然是一个耗时的过程，并且通常需要进一步的手动优化。在钆塞酸二钠增强磁共振成像（MRI）中，肝脏实质具有高信号强度，这可能会改善肝脏体积分割。
使用钆塞酸二钠增强MRI（包括定制的三维（3D）序列）评估基于阈值的肝脏体积分割的实用性。
本回顾性研究纳入了20例接受钆塞酸二钠MRI检查的患者（肝胆期T1加权（T1W）3D序列[VIBE]；翻转角[FA]，10°和30°）。数据集由两名盲法观察者（O1和O2）以两种方式独立处理：手动（man）和基于阈值（thresh；研究方法）的肝脏分割，每种方法之后都进行优化步骤（man+opt和thresh+opt；man+opt [FA10°]用作参考方法）。比较所得的肝脏体积和分割时间。计算肝脏转换因子的百分比，描述肝脏总体积的非肝细胞部分，即胆管和血管。
与参考方法相比，thresh+opt（FA10°）明显更快，导致中位体积高估4%/8%（P < 0.001）。使用thresh+opt（FA30°），分割甚至更快（P < 0.001），并且中位体积偏差甚至降低了0%/2%（O1/O2；两者P > 0.2）。发现肝脏转换因子为10%。
采用钆塞酸二钠增强肝胆期标准T1W 3D序列进行基于阈值的肝脏分割准确且省时。通过增加翻转角可以进一步提高这种方法的性能。
