Haubenreisser Holger, Fink Christian, Nance John W, Sedlmair Martin, Schmidt Bernhard, Schoenberg Stefan O, Henzler Thomas
Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany.
Siemens Healthcare, Division CT, Forchheim, Germany.
Eur J Radiol. 2014 Jun;83(6):964-969. doi: 10.1016/j.ejrad.2014.01.026. Epub 2014 Feb 7.
To prospectively compare image quality of cranial computed tomography (CCT) examinations with varying slice widths using traditional filtered back projection (FBP) versus sinogram-affirmed iterative image reconstruction (SAFIRE).
29 consecutive patients (14 men, mean age: 72 ± 17 years) referred for a total of 40 CCT studies were prospectively included. Each CCT raw data set was reconstructed with FBP and SAFIRE at 5 slice widths (1-5mm; 1mm increments). Objective image quality was assessed in three predefined regions of the brain (white matter, thalamus, cerebellum) using identical regions of interest (ROIs). Subjective image quality was assessed by 2 experienced radiologists. Objective and subjective image quality parameters were statistically compared between FBP and SAFIRE reconstructions.
SAFIRE reconstructions resulted in mean noise reductions of 43.8% in the white matter, 45.6% in the thalamus and 42.0% in the cerebellum (p<0.01) compared to FBP on non contrast-enhanced 1mm slice width images. Corresponding mean noise reductions on 1mm contrast-enhanced studies were 45.7%, 47.3%, and 45.0% in the white matter, thalamus, and cerebellum, respectively (p<0.01). There was no significant difference in mean attenuation of any region or slice width between the two reconstruction methods (all p>0.05). Subjective image quality of IR images was mostly rated higher than that of the FBP images.
Compared to FBP, SAFIRE provides significant reductions in image noise while increasing subjective image in CCT, particularly when thinner slices are used. Therefore, SAFIRE may allow utilization of thinner slices in CCT, potentially reducing partial volume effects and improving diagnostic accuracy.
前瞻性比较使用传统滤波反投影（FBP）与正弦图确认迭代图像重建（SAFIRE）技术、不同层厚的头颅计算机断层扫描（CCT）检查的图像质量。
前瞻性纳入29例连续患者（14例男性，平均年龄：72±17岁），共进行40项CCT研究。每个CCT原始数据集均使用FBP和SAFIRE以5种层厚（1 - 5mm；1mm递增）进行重建。使用相同的感兴趣区（ROI），在大脑三个预定义区域（白质、丘脑、小脑）评估客观图像质量。由2名经验丰富的放射科医生评估主观图像质量。对FBP和SAFIRE重建的客观和主观图像质量参数进行统计学比较。
与非增强1mm层厚图像上的FBP相比，SAFIRE重建在白质、丘脑和小脑的平均噪声分别降低了43.8%、45.6%和42.0%（p<0.01）。在1mm增强研究中，白质、丘脑和小脑相应的平均噪声降低分别为45.7%、47.3%和45.0%（p<0.01）。两种重建方法在任何区域或层厚的平均衰减上均无显著差异（所有p > 0.05）。IR图像的主观图像质量大多被评为高于FBP图像。
与FBP相比，SAFIRE在CCT中可显著降低图像噪声，同时提高主观图像质量，尤其是在使用更薄层厚时。因此，SAFIRE可能允许在CCT中使用更薄层厚，潜在地减少部分容积效应并提高诊断准确性。
