Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.
Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany.
Magn Reson Med. 2017 Oct;78(4):1496-1505. doi: 10.1002/mrm.26526. Epub 2016 Nov 18.
To compare low-pass imaging dynamic acquisitions (LIDA) approach in combination with a group-oriented registration (GOREG) scheme with conventional Fourier decomposition (FD).
Dynamic images of six healthy volunteers and one chronic obstructive pulmonary disease (COPD) patient were acquired on a 1.5 Tesla scanner using a spoiled gradient echo sequence. For the volunteers each slice was acquired during regular (RB) and irregular breathing (IB). For conventional registration (CR), all images were directly registered to the intermediate respiratory position. For the group-oriented registration (GOREG) a group-based step-by-step scheme was used. The registered datasets were evaluated with FD and LIDA. The image quality was assessed by image sharpness metric and parenchyma-vessel contrast. The GOREG+LIDA and CR+FD results were compared with computed tomography (CT) in a patient with COPD. To show feasibility of the presented method at 3 Tesla (T), a healthy volunteer was included, who was scanned at 1.5T and 3T on the same day.
Improved image sharpness (predominantly by GOREG, P < 0.0125) and contrast (predominantly by LIDA, P < 0.0125) were obtained for RB and IB. Synergetic improvements were found for GOREG+LIDA. Hypoventilated regions in the COPD patient calculated with GOREG+LIDA showed a good agreement with emphysema identified by CT.
GOREG+LIDA can be used to calculate quantitative ventilation images with improved image quality, which is an important step toward clinical translation of this method. The presented method is also feasible at 3T. Magn Reson Med 78:1496-1505, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
比较低通成像动态采集（LIDA）方法与面向组的配准（GOREG）方案结合常规傅里叶分解（FD）的效果。
使用扰相梯度回波序列在 1.5T 扫描仪上获取 6 名健康志愿者和 1 名慢性阻塞性肺疾病（COPD）患者的动态图像。对于志愿者，每个切片在规则呼吸（RB）和不规则呼吸（IB）期间获取。对于常规配准（CR），所有图像都直接配准到中间呼吸位置。对于面向组的配准（GOREG），使用基于组的逐步方案。使用 FD 和 LIDA 评估配准后的数据集。使用图像锐度度量和实质-血管对比度评估图像质量。在 COPD 患者中，将 GOREG+LIDA 和 CR+FD 结果与 CT 进行比较。为了在 3T（T）上展示所提出方法的可行性，我们纳入了一名健康志愿者，他在同一天分别在 1.5T 和 3T 上进行了扫描。
对于 RB 和 IB，GOREG 主要提高了图像锐度（P < 0.0125），LIDA 主要提高了对比度（P < 0.0125）。GOREG+LIDA 还具有协同改善效果。使用 GOREG+LIDA 计算 COPD 患者的低通气区域与 CT 识别的肺气肿具有良好的一致性。
GOREG+LIDA 可用于计算具有改善图像质量的定量通气图像，这是该方法向临床转化的重要步骤。该方法在 3T 上也是可行的。磁共振医学 78:1496-1505, 2017。© 2016 国际磁共振学会。
