Department of Gastroenterology and Hepatology, Yokohama City University, Yokohama 236-0004, Japan.
Department of Diagnostic Radiology, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan.
Tomography. 2024 Oct 7;10(10):1591-1604. doi: 10.3390/tomography10100117.
: The usefulness of dual-energy computed tomography (DECT) for low absorption in the parenchymal phase and contrast effects in the delayed phase for pancreatic cancer is not clear. Therefore, the diagnostic capability of low-KeV images obtained using DECT for pancreatic cancer in the pancreatic parenchymal and delayed phases was evaluated quantitatively and qualitatively. : Twenty-five patients with pancreatic cancer who underwent contrast-enhanced DECT were included. A total of 50 and 70 KeV CT images, classified as low-keV and conventional CT-equivalent images, were produced, respectively. The tumor-to-pancreas contrast (Hounsfield units [HU]) in the pancreatic parenchymal and delayed phases was calculated by subtracting the CT value of the pancreatic tumor from that of normal parenchyma. : The median tumor-to-pancreas contrast on 50 KeV CT in the pancreatic parenchymal phase (133 HU) was higher than that on conventional CT (68 HU) ( < 0.001). The median tumor-to-pancreas contrast in the delayed phase was -28 HU for 50 KeV CT and -9 HU for conventional CT ( = 0.545). For tumors < 20 mm, the tumor-to-pancreas contrast of 50 KeV CT (-39 HU) had a significantly clearer contrast effect than that of conventional CT (-16.5 HU), even in the delayed phase ( = 0.034). : These 50 KeV CT images may clarify the low-absorption areas of pancreatic cancer in the pancreatic parenchymal phase. A good contrast effect was observed in small pancreatic cancers on 50 KeV delayed-phase images, suggesting that DECT is useful for the visualization of early pancreatic cancer with a small tumor diameter.
双能 CT（DECT）在实质期低吸收率和延迟期对比效果方面对胰腺癌的作用尚不清楚。因此，本研究定量和定性评估了 DECT 低 keV 图像在胰腺实质期和延迟期对胰腺癌的诊断能力。
本研究纳入 25 例经增强 DECT 检查的胰腺癌患者。共生成 50 keV 和 70 keV CT 图像，分别归类为低 keV 和常规 CT 等效图像。通过从正常胰腺实质的 CT 值中减去胰腺肿瘤的 CT 值，计算胰腺实质期和延迟期肿瘤与胰腺的对比度（HU）。
50 keV CT 在胰腺实质期的肿瘤与胰腺对比度的中位数（133 HU）高于常规 CT（68 HU）（ < 0.001）。50 keV CT 在延迟期的肿瘤与胰腺对比度为-28 HU，而常规 CT 为-9 HU（ = 0.545）。对于 < 20 mm 的肿瘤，50 keV CT 的肿瘤与胰腺对比度（-39 HU）的对比度效果明显优于常规 CT（-16.5 HU），甚至在延迟期也是如此（ = 0.034）。
这些 50 keV CT 图像可能会使胰腺癌在胰腺实质期的低吸收率区域更清晰。在 50 keV 延迟期图像上，较小的胰腺癌观察到良好的对比度效果，表明 DECT 对显示小肿瘤直径的早期胰腺癌有用。
