Department of Hepatobiliary and Pancreatic Surgery, National Cancer Center Hospital East, 6-5-1 Kashiwa-no-ha, Kashiwa, 277-8577, Chiba, Japan.
Department of Diagnostic Radiology, National Cancer Center Hospital East, Kashiwa, Japan.
BMC Surg. 2023 Jun 27;23(1):179. doi: 10.1186/s12893-023-02051-1.
Liver-to-spleen signal intensity ratio (LSR) is evaluated by magnetic resonance imaging (MRI) in the hepatobiliary phase and has been reported as a useful radiological assessment of regional liver function. However, LSR is a passive (non-time-associated) assessment of liver function, not a dynamic (time-associated) assessment. Moreover, LSR shows limitations such as a dose bias of contrast medium and a timing bias of imaging. Previous studies have reported the advantages of time-associated liver functional assessment as a precise assessment of liver function. For instance, the indocyanine green (ICG) disappearance rate, which is calculated from serum ICG concentrations at multiple time points, reflects a precise preoperative liver function for predicting post-hepatectomy liver failure without the dose bias of ICG or the timing bias of blood sampling. The aim of this study was to develop a novel time-associated radiological liver functional assessment and verify its correlation with traditional liver functional parameters.
A total of 279 pancreatic cancer patients were evaluated to clarify fundamental time-associated changes to LSR in normal liver. We defined the time-associated radiological assessment of liver function, calculated using information on LSR from four time points, as the "LSR increasing rate" (LSRi). We then investigated correlations between LSRi and previous liver functional parameters. Furthermore, we evaluated how timing bias and protocol bias affect LSRi.
Significant correlations were observed between LSRi and previous liver functional parameters such as total bilirubin, Child-Pugh grade, and albumin-bilirubin grade (P < 0.001 each). Moreover, considerably high correlations were observed between LSRi calculated using four time points and that calculated using three time points (r > 0.973 each), indicating that the timing bias of imaging was minimal.
This study propose a novel time-associated radiological assessment, and revealed that the LSRi correlated significantly with traditional liver functional parameters. Changes in LSR over time may provide a superior preoperative assessment of regional liver function that is better for predicting post-hepatectomy liver failure than LSR using the hepatobiliary phase alone.
磁共振成像（MRI）肝胆期的肝脾信号强度比（LSR）评估已被报道为一种有用的局部肝功能的影像学评估。然而，LSR 是一种被动（非时间相关）的肝功能评估，而不是动态（时间相关）的评估。此外，LSR 存在局限性，如造影剂剂量偏差和成像时间偏差。先前的研究报告了时间相关的肝功能评估的优势，认为其是一种精确的肝功能评估。例如，从多个时间点的血清 ICG 浓度计算得出的吲哚菁绿（ICG）清除率，反映了一种精确的术前肝功能，可预测肝切除术后肝衰竭，而不存在 ICG 的剂量偏差或采血的时间偏差。本研究旨在开发一种新的时间相关的放射性肝功能评估方法，并验证其与传统肝功能参数的相关性。
共评估了 279 例胰腺癌患者，以阐明正常肝脏中 LSR 的基本时间相关变化。我们定义了使用来自四个时间点的 LSR 信息计算的时间相关的肝功能评估，即“LSR 增加率”（LSRi）。然后，我们研究了 LSRi 与先前的肝功能参数之间的相关性。此外，我们评估了时间偏差和方案偏差如何影响 LSRi。
LSRi 与先前的肝功能参数（如总胆红素、Child-Pugh 分级和白蛋白-胆红素分级）之间存在显著相关性（均 P<0.001）。此外，使用四个时间点计算的 LSRi 与使用三个时间点计算的 LSRi 之间存在非常高的相关性（每个 r 值均>0.973），表明成像的时间偏差最小。
本研究提出了一种新的时间相关的放射性评估方法，并显示 LSRi 与传统肝功能参数显著相关。LSR 随时间的变化可能提供一种更好的局部肝功能术前评估，比单独使用肝胆期的 LSR 更能预测肝切除术后肝衰竭。
