Skornitzke Stephan, Mayer Philipp, Kauczor Hans-Ulrich, Stiller Wolfram
Diagnostic and Interventional Radiology (DIR), Heidelberg University Hospital, Heidelberg, Germany.
Heliyon. 2023 Mar 22;9(4):e14726. doi: 10.1016/j.heliyon.2023.e14726. eCollection 2023 Apr.
By using bolus tracking with an appropriate acquisition delay dual-energy computed tomography (DECT) iodine maps might serve as a replacement of CT perfusion maps at reduced radiation exposure. This study aimed to evaluate the optimal acquisition delays of DECT for the replacement of parameter maps calculated with the Patlak model in pancreatic adenocarcinoma by corresponding iodine maps.
Dual-source dynamic DECT acquisitions at 80 kV/Sn140 kV of 14 patients with pancreatic carcinoma were used to calculate CT perfusion maps of blood volume and permeability with the Patlak model. DECT iodine maps were generated from individual DECT acquisitions, matching acquisition times relative to prior bolus-triggered three-phase CT acquisitions for investigating different acquisition delays. Correlation between perfusion parameters and iodine concentrations was determined for acquisition delays between -6 s and 33 s.
Correlation between iodine concentrations and perfusion parameters ranged from -0.05 to 0.63 for blood volume and from -0.05 to 0.71 for permeability, depending on potential trigger delay. The correlation was significant for potential acquisition delays above 1.5 s for blood volume and above 9.0 s for permeability (both p < 0.05). Maximum correlation occurred at an acquisition delay of 15.0 s for blood volume (r = 0.63) and at 25.5 s for permeability (r = 0.71), with significantly lower iodine concentrations in carcinoma (15.0 s: 1.3 ± 0.5 mg/ml; 22.5 s: 1.4 ± 0.7 mg/ml) than in non-neoplastic pancreatic parenchyma (15.0 s: 2.3 ± 0.8 mg/ml; 22.5 s: 2.4 ± 0.6 mg/ml; p < 0.05).
In the future, well-timed DECT iodine maps acquired with bolus tracking could provide an alternative to permeability and blood volume maps calculated with the Patlak model.
通过使用团注追踪并设置合适的采集延迟，双能计算机断层扫描（DECT）碘图或许可以在降低辐射剂量的情况下替代CT灌注图。本研究旨在评估DECT的最佳采集延迟，以便用相应的碘图替代胰腺腺癌中用Patlak模型计算的参数图。
对14例胰腺癌患者进行80 kV/Sn140 kV的双源动态DECT采集，以用Patlak模型计算血容量和通透性的CT灌注图。从个体DECT采集中生成DECT碘图，使其采集时间与先前团注触发的三相CT采集时间相匹配，以研究不同的采集延迟。确定了-6秒至33秒采集延迟下灌注参数与碘浓度之间的相关性。
根据潜在触发延迟，碘浓度与灌注参数之间的相关性，血容量为-0.05至0.63，通透性为-0.05至0.71。血容量在潜在采集延迟高于1.5秒时相关性显著，通透性在潜在采集延迟高于9.0秒时相关性显著（均p<0.05）。血容量在采集延迟15.0秒时相关性最大（r=0.63），通透性在采集延迟25.5秒时相关性最大（r=0.71），癌组织中的碘浓度（15.0秒：1.3±0.5mg/ml；22.5秒：1.4±0.7mg/ml）显著低于非肿瘤性胰腺实质（15.0秒：2.3±0.8mg/ml；22.5秒：2.4±0.6mg/ml；p<0.05）。
未来，通过团注追踪适时获取的DECT碘图可以替代用Patlak模型计算的通透性和血容量图。
