Barash Hila, Gross Eitan, Edrei Yifat, Pappo Orit, Spira Gadi, Vlodavsky Israel, Galun Eithan, Matot Idit, Abramovitch Rinat
The Goldyne Savad Institute of Gene Therapy, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
Hepatology. 2008 Oct;48(4):1232-41. doi: 10.1002/hep.22394.
Liver diseases and regeneration are associated with hemodynamic changes denoting pathological alterations. Determining and monitoring physiological and pathological liver changes is essential for diagnostic and therapeutic objectives. Our aim was to determine the feasibility of functional magnetic resonance imaging (fMRI) during hypercapnia and hyperoxia for monitoring liver pathology. Liver fMRI images were acquired in rodents following acute bleeding, partial hepatectomy, and fibrosis. Results were quantitated and confirmed by histology. Changes induced by hyperoxia and hypercapnia following hemorrhage significantly correlated with the percentage of blood loss, reflecting lower liver perfusion and diminished vessel responsiveness to gas saturation. Hepatectomy resulted in an early decline in signal intensity changes due to hyperoxia, suggesting a decrease in liver perfusion and blood content. Following hepatectomy, signal intensity changes due to hypercapnia increased, signifying a change in liver perfusion from a mainly portal to a more arterial source. Two weeks after induction of fibrosis, signal intensity changes due to hypercapnia became much lower and those due to hyperoxia were much higher than those in normal livers, reflecting the increased perfusion due to the inflammatory process as confirmed by histologic analysis. With fibrosis progression, signal intensity changes induced by hypercapnia and hyperoxia were gradually attenuated, indicating structural and functional alterations of the liver vasculature during fibrosis.
In various liver pathologies, fMRI response to hypercapnia and hyperoxia is sensitive to changes in liver hemodynamic status involved in hepatic damage or recovery; thus, this technique may offer an additional noninvasive diagnostic tool for evaluation and follow-up of liver diseases by means of examining perfusion-related alterations.
肝脏疾病与再生与表示病理改变的血流动力学变化相关。确定和监测肝脏的生理和病理变化对于诊断和治疗目标至关重要。我们的目的是确定在高碳酸血症和高氧血症期间功能磁共振成像（fMRI）监测肝脏病理的可行性。在啮齿动物中，于急性出血、部分肝切除和肝纤维化后采集肝脏fMRI图像。结果进行定量分析并通过组织学证实。出血后高氧血症和高碳酸血症引起的变化与失血量百分比显著相关，反映出肝脏灌注降低以及血管对气体饱和度的反应性减弱。肝切除导致高氧血症引起的信号强度变化早期下降，提示肝脏灌注和血容量减少。肝切除后，高碳酸血症引起的信号强度变化增加，表明肝脏灌注从主要的门静脉来源转变为更多的动脉来源。诱导肝纤维化两周后，高碳酸血症引起的信号强度变化变得比正常肝脏低得多，而高氧血症引起的变化则比正常肝脏高得多，这反映了组织学分析证实的炎症过程导致的灌注增加。随着肝纤维化进展，高碳酸血症和高氧血症引起的信号强度变化逐渐减弱，表明肝纤维化过程中肝脏血管系统的结构和功能改变。
在各种肝脏疾病中，fMRI对高碳酸血症和高氧血症的反应对肝脏损伤或恢复过程中涉及的肝脏血流动力学状态变化敏感；因此，该技术可能通过检查与灌注相关的改变，为肝脏疾病的评估和随访提供一种额外的非侵入性诊断工具。
