Forward Projected Model-Based Iterative Reconstruction Solution (FIRST) for Target Scan
andTarget Reconstruction in Temporal Bone CT Image
WANG Tianjiao1，WANG Yun1，MA Zhuangfei2，CHEN Yu1，LIAO Kai1，FU Haihong1，JIN Zhengyu1
1. Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijng 100730, China丨
2. Canon Medical System (China) Co., Ltd., Beijing 100015, China
摘要目的 评估全模型迭代重建算法（Forward Projected Model-Based Iterative Reconstruction Solution，FIRST）对于靶扫描
颞骨图像的应用价值。方法 回顾性收集了36例行颞骨靶扫描检查的病人，分别使用FIRST BODY、FIRST BODY SHARP、
FIRST BONE和滤波反射投影（Filtered Back Projection，FBP）四种方式进行颞骨图像重建。将重建后的图像从客观和主
观两方面进行图像质量分析。客观图像质量分析采用在横断位图像上测量图像的CT值及噪声标准差（Standard Deviation，
SD）值，并计算信号噪声比（Signal to Noise Ratio，SNR）和对比噪声比（Contrast to Noise Ratio，CNR）。主观图像质量
分析采用主观盲法对图像质量进行打分。结果 在耳后肌肉处、前庭处和耳前皮下脂肪处，四种重建方法的CT值无统计学
差异，P值分别为0.966、0.205和0.441。在锤砧关节处、耳后肌肉处、前庭处和耳前皮下脂肪处，与FIRST BODY SHARP、
FIRST BONE和FBP对比，FIRST BODY重建方法图像的SNR、CNR最高，SD值最低，并具有统计学差异（P均<0.001）。
四种重建方法的图像都能够满足于临床诊断。结论 相比于FIRST BODY SHARP、FIRST BONE和FBP，FIRST BODY重建
方法可以降低图像噪声，提高SNR和CNR，并且在主观上可以满足于临床诊断。
Abstract：Objective To evaluate the application value of the forward projected model-based iterative reconstruction solution (FIRST)
for target scanning temporal bone images. Methods A total of 36 patients with the same scanning parameters were selected and used
FIRST BODY, FIRST BODY SHARP, FIRST BONE and filtered back projection (FBP) to reconstruct temporal bone images. The
reconstructed image was analyzed for image quality from objective and subjective aspects. Objective image quality was analyzed
by measuring the CT value and standard deviation (SD) value of the image on the transverse image and calculating the signal to
noise ratio (SNR) and contrast to noise ratio (CNR). Subjective image quality was analyzed by using subjective blindness to score
image quality. Results There was no statistical difference in the CT values of the four reconstruction methods at the muscles behind
the ear, the vestibule and subcutaneous fat of the ear (P values were 0.966, 0.205 and 0.441, respectively). Compared with FIRST
BODY SHARP, FIRST BONE and FBP at the hammer-anvil joint, muscles behind the ear, vestibule and subcutaneous fat of the ear,
the FIRST BODY reconstruction method had the highest SNR, CNR and the lowest SD value with statistical differences (P<0.001).
The images of the four reconstruction methods can be satisfied with clinical diagnosis. Conclusion Compared with FIRST BODY
SHARP, FIRST BONE and FBP, the FIRST BODY reconstruction method can reduce image noise, improve SNR and CNR, and
subjectively can be satisfied with clinical diagnosis.
