Böning G, Kahn J F, Kaul D, Rotzinger R, Freyhardt P, Pavel M, Streitparth F
1 Department of Radiology Charité, Humboldt-University Medical School, Berlin, Germany.
2 Department of Radiation Oncology Charité, Humboldt-University Medical School, Berlin, Germany.
Acta Radiol. 2018 May;59(5):517-526. doi: 10.1177/0284185117726101. Epub 2017 Aug 8.
Background Frequent computed tomography (CT) follow-ups involve significant radiation related risks for patients with low-grade neuroendocrine tumors (NETs). Contrast agent (CA) application is essential for diagnostic evidence and has additional risks especially in patients with limited renal function. Purpose To investigate if a combination of dose and contrast agent (CA) reduction affects image quality and diagnostic evidence in neuroendocrine tumor (NET) patients. Material and Methods A total of 51 NET patients were enrolled in the study and 153 CT scans were analyzed. Patients underwent a baseline CT scan (A = 120 kVp, filtered back projection [FBP]) and two follow-up CTs (B = 120 kVp, adaptive statistical iterative reconstruction [ASIR] 40%; C1 = 100 kVp, ASIR 40%; C2 = 100 kVp, ASIR 60%; the latter two protocols were applied with a 30% reduction in CA volume). We evaluated image quality and applied dose. Results In C1/2, the combination of low kV (100 kVp) with ASIR 40%/60% reduced the mean applied dose significantly by 28% compared to B and by 57% compared to A. Signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNR) of tumor to liver/muscle were significantly increased by using C1/2 compared to B and A. With respect to subjective image quality, a slight loss of diagnostic confidence in C1 could be counterbalanced by the higher ASIR blending in C2. Conclusion Combined dose reduction techniques can be used to reduce radiation dose and CA volume without sacrificing image quality and diagnostic confidence in staging CT of NET patients.
背景 对于低度神经内分泌肿瘤（NET）患者，频繁的计算机断层扫描（CT）随访存在与辐射相关的重大风险。造影剂（CA）的应用对于诊断证据至关重要，并且存在额外风险，尤其是在肾功能有限的患者中。目的 研究剂量和造影剂（CA）减少的组合是否会影响神经内分泌肿瘤（NET）患者的图像质量和诊断证据。材料与方法 共有51例NET患者纳入本研究，分析了153次CT扫描。患者接受了一次基线CT扫描（A = 120 kVp，滤波反投影[FBP]）和两次随访CT扫描（B = 120 kVp，自适应统计迭代重建[ASIR] 40%；C1 = 100 kVp，ASIR 40%；C2 = 100 kVp，ASIR 60%；后两种方案的CA体积减少30%）。我们评估了图像质量并应用了剂量。结果 在C1/2中，与B相比，低千伏（100 kVp）与ASIR 40%/60%的组合使平均应用剂量显著降低了28%，与A相比降低了57%。与B和A相比，使用C1/2时肿瘤与肝脏/肌肉的信噪比（SNR）和对比噪声比（CNR）显著增加。关于主观图像质量，C1中诊断信心的轻微下降可以通过C2中更高的ASIR混合来抵消。结论 联合剂量减少技术可用于减少NET患者分期CT中的辐射剂量和CA体积，而不牺牲图像质量和诊断信心。
