Prezzi D, Goh V, Virdi S, Mallett S, Grierson C, Breen D J
Division of Imaging Sciences & Biomedical Engineering, King's College London, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, United Kingdom.
Institute of Applied Health Research, University of Birmingham, United Kingdom.
Eur J Radiol Open. 2017 Jun 1;4:69-74. doi: 10.1016/j.ejro.2017.05.003. eCollection 2017.
To determine the effect of Adaptive Statistical Iterative Reconstruction (ASIR) on perfusion CT (pCT) parameter quantitation and image quality in primary colorectal cancer.
Prospective observational study. Following institutional review board approval and informed consent, 32 patients with colorectal adenocarcinoma underwent pCT (100 kV, 150 mA, 120 s acquisition, axial mode). Tumour regional blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were determined using identical regions-of-interests for ASIR percentages of 0%, 20%, 40%, 60%, 80% and 100%. Image noise, contrast-to-noise ratio (CNR) and pCT parameters were assessed across ASIR percentages. Coefficients of variation (CV), repeated measures analysis of variance (rANOVA) and Spearman' rank order correlation were performed with statistical significance at 5%.
With increasing ASIR percentages, image noise decreased by 33% while CNR increased by 61%; peak tumour CNR was greater than 1.5 with 60% ASIR and above. Mean BF, BV, MTT and PS differed by less than 1.8%, 2.9%, 2.5% and 2.6% across ASIR percentages. CV were 4.9%, 4.2%, 3.3% and 7.9%; rANOVA values: 0.85, 0.62, 0.02 and 0.81 respectively.
ASIR improves image noise and CNR without altering pCT parameters substantially.
确定自适应统计迭代重建（ASIR）对原发性结直肠癌灌注CT（pCT）参数定量及图像质量的影响。
前瞻性观察性研究。经机构审查委员会批准并获得知情同意后，32例结肠腺癌患者接受了pCT检查（100 kV，150 mA，采集120秒，轴向模式）。使用相同的感兴趣区域，针对ASIR百分比分别为0%、20%、40%、60%、80%和100%的情况，测定肿瘤区域血流量（BF）、血容量（BV）、平均通过时间（MTT）和通透表面积乘积（PS）。在不同ASIR百分比下评估图像噪声、对比噪声比（CNR）和pCT参数。进行变异系数（CV）、重复测量方差分析（rANOVA）以及Spearman等级相关分析，以5%作为统计学显著性水平。
随着ASIR百分比增加，图像噪声降低33%，而CNR增加61%；当ASIR为60%及以上时，肿瘤峰值CNR大于1.5。在不同ASIR百分比下，平均BF、BV、MTT和PS的差异分别小于1.8%、2.9%、2.5%和2.6%。CV分别为4.9%、4.2%、3.3%和7.9%；rANOVA值分别为0.85、0.62、0.02和0.81。
ASIR可改善图像噪声和CNR，而不会显著改变pCT参数。
