Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 4th Floor, Boston, MA 02114, USA.
Radiology. 2010 Jul;256(1):261-9. doi: 10.1148/radiol.10091487.
To compare visualization of subtle normal and abnormal findings at computed tomography (CT) of the chest for diffuse lung disease with images reconstructed with filtered back projection and adaptive statistical iterative reconstruction (ASIR) techniques.
In this HIPAA-compliant, institutional review board-approved study, 24 patients underwent 64-section multi-detector row CT of the chest for evaluation of diffuse lung disease. Scanning parameters included a pitch of 0.984:1 and 120 kVp in thin-section mode, with 2496 views per rotation compared with 984 views acquired for normal mode. The 0.625-mm-thick images were reconstructed with filtered back projection, ASIR, and ASIR high-definition (ASIR-HD) kernels. Two thoracic radiologists independently assessed the filtered back projection, ASIR, and ASIR-HD images for small anatomic details (interlobular septa, centrilobular region, and small bronchi and bronchioles), abnormal findings (reticulation, tiny nodules, altered attenuation, bronchiectasis), image quality (graded by using a six-point scale, where 1 = excellent image quality, and 5 = interpretation impossible), image noise, and artifacts. Data were tabulated for statistical testing.
For visualization of normal and pathologic structures, CT image series reconstructed with ASIR-HD were rated substantially better than those reconstructed with filtered back projection and ASIR (P < .001). ASIR-HD images were superior to filtered back projection images in 15 of 24 (62%) patients for visualization of normal structures and in 24 of 24 (100%) patients for pathologic findings. ASIR-HD was superior to ASIR in three of 24 (12%) images for normal anatomic findings and in seven of 24 (29%) images for pathologic evaluation. None of the images in the three groups were rated as unacceptable for noise (P < .001).
ASIR-HD reconstruction results in superior visualization of subtle and tiny anatomic structures and lesions in diffuse lung disease compared with ASIR and filtered back projection reconstructions.
比较过滤反投影和自适应统计迭代重建（ASIR）技术重建胸部 CT 弥漫性肺部疾病细微正常和异常表现的可视化效果。
本研究符合 HIPAA 规定，并经机构审查委员会批准，24 例患者行 64 层多排 CT 胸部检查，以评估弥漫性肺部疾病。扫描参数包括薄层高分辨模式下的 0.984:1 螺距和 120 kVp，每个旋转 2496 个视野，而正常模式下采集 984 个视野。0.625mm 厚的图像用过滤反投影、ASIR 和 ASIR 高清（ASIR-HD）重建。两位胸部放射科医生独立评估过滤反投影、ASIR 和 ASIR-HD 图像的小解剖细节（小叶间隔、小叶中心区和小支气管和细支气管）、异常发现（网状影、小结节、衰减改变、支气管扩张）、图像质量（使用 6 分制评分，1 分为极好的图像质量，5 分为无法解释）、图像噪声和伪影。数据以表格形式进行统计检验。
对于正常和病理结构的可视化，ASIR-HD 重建的 CT 图像系列明显优于过滤反投影和 ASIR 重建（P<0.001）。在 24 例患者中的 15 例（62%），ASIR-HD 图像在正常结构的显示上优于过滤反投影图像，在 24 例患者中的 24 例（100%），ASIR-HD 图像在病理发现方面优于过滤反投影图像。在 24 例图像中，ASIR-HD 在 3 例（12%）正常解剖发现和 7 例（29%）病理评估中优于 ASIR。三组图像中均无因噪声而被评为不可接受的图像（P<0.001）。
与过滤反投影重建相比，ASIR-HD 重建可更好地显示弥漫性肺部疾病中细微和微小的解剖结构和病变。
