Liang Hongwei, Zhou Yang, Zheng Qiao, Yan Gaowu, Liao Hongfan, Du Silin, Zhang Xiaohui, Lv Fajin, Zhang Zhiwei, Li Yong-Mei
Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, 400016, China.
Department of Radiology, Suining Central Hospital, Suining, 629000, China.
Insights Imaging. 2022 Sep 24;13(1):153. doi: 10.1186/s13244-022-01297-2.
To evaluate the value of monoenergetic images (MEI [+]) and iodine maps in dual-source dual-energy computed tomography (DECT) for assessing pancreatic ductal adenocarcinoma (PDAC), including the visually isoattenuating PDAC.
This retrospective study included 75 PDAC patients, who underwent contrast-enhanced DECT examinations. Conventional polyenergetic image (PEI) and 40-80 keV MEI (+) (10-keV increments) were reconstructed. The tumor contrast, contrast-to-noise ratio (CNR) of the tumor and peripancreatic vessels, the signal-to-noise ratio (SNR) of the pancreas and tumor, and the tumor diameters were quantified. On iodine maps, the normalized iodine concentration (NIC) in the tumor and parenchyma was compared. For subjective analysis, two radiologists independently evaluated images on a 5-point scale.
All the quantitative parameters were maximized at 40-keV MEI (+) and decreased gradually with increasing energy. The tumor contrast, SNR of pancreas and CNRs in 40-60 keV MEI (+) were significantly higher than those in PEI (p < 0.05). For visually isoattenuating PDAC, 40-50 keV MEI (+) provided significantly higher tumor CNR compared to PEI (p < 0.05). The reproducibility in tumor measurements was highest in 40-keV MEI (+) between the two radiologists. The tumor and parenchyma NIC were 1.28 ± 0.65 and 3.38 ± 0.72 mg/mL, respectively (p < 0.001). 40-50 keV MEI (+) provided the highest subjective scores, compared to PEI (p < 0.001).
Low-keV MEI (+) of DECT substantially improves the subjective and objective image quality and consistency of tumor measurements in patients with PDAC. Combining the low-keV MEI (+) and iodine maps may yield diagnostically adequate tumor conspicuity in visually isoattenuating PDAC.
评估双源双能量计算机断层扫描（DECT）中的单能量图像（MEI[+]）和碘图在评估胰腺导管腺癌（PDAC）（包括视觉上等密度的PDAC）方面的价值。
这项回顾性研究纳入了75例接受对比增强DECT检查的PDAC患者。重建了常规多能量图像（PEI）和40 - 80 keV的MEI（+）（以10 keV递增）。对肿瘤对比度、肿瘤与胰腺周围血管的对比噪声比（CNR）、胰腺和肿瘤的信噪比（SNR）以及肿瘤直径进行了量化。在碘图上，比较了肿瘤和实质中的归一化碘浓度（NIC）。对于主观分析，两名放射科医生独立地以5分制对图像进行评估。
所有定量参数在40 keV的MEI（+）时达到最大值，并随着能量增加而逐渐降低。40 - 60 keV的MEI（+）中的肿瘤对比度、胰腺SNR和CNR显著高于PEI中的（p < 0.05）。对于视觉上等密度的PDAC，40 - 50 keV的MEI（+）与PEI相比，提供了显著更高的肿瘤CNR（p < 0.05）。在两名放射科医生之间，40 keV的MEI（+）在肿瘤测量中的可重复性最高。肿瘤和实质的NIC分别为1.28±0.65和3.38±0.72 mg/mL（p < 0.001）。与PEI相比，40 - 50 keV的MEI（+）提供了最高的主观评分（p < 0.001）。
DECT的低keV MEI（+）显著提高了PDAC患者的主观和客观图像质量以及肿瘤测量的一致性。结合低keV MEI（+）和碘图可能在视觉上等密度的PDAC中产生诊断上足够的肿瘤清晰度。
