³¹P MR spectroscopic imaging detects regenerative changes in human liver stimulated by portal vein embolization

Abstract

Purpose First, to evaluate hepatocyte phospholipid metabolism and energetics during liver regeneration stimulated by portal vein embolization (PVE) using proton-decoupled 31P-magnetic resonance spectroscopic imaging (31P-MRSI). Second, to compare the biophysiologic differences between hepatic regeneration stimulated by PVE and by partial hepatectomy. Materials and Methods Subjects included 6 patients with hepatic metastases from colorectal cancer who were scheduled to undergo right PVE before definitive resection of right-sided tumor. 31P-MRSI was performed on the left liver lobe prior to PVE and 48 hours following PVE. Normalized quantities of phosphorus-containing hepatic metabolites were analyzed from both visits. In addition, MRSI data at 48 hours following partial hepatectomy were compared with the data from the PVE patients. Results At 48 hours after PVE, the ratio of phosphomonoesters to phosphodiesters in the non-embolized lobe was significantly elevated. No significant changes were found in NTP and Pi values. The PME to PDE ratio in regenerating liver 48 hours after partial hepatectomy was significantly greater than PME/PDE 48 hours after PVE. Conclusion 31P-MRSI is a valid technique to noninvasively evaluate cell membrane metabolism following PVE. The different degree of biochemical change between PH and PVE indicates that hepatic growth following these two procedures does not follow the same course.

Liver regeneration — mechanisms and models to clinical application

“…Noninvasive measurements during liver regeneration in patients should be particularly insight ful in the future. Modern functional imaging tech niques, such as magnetic resonance spectro scopy [65][66][67] , in which distinct meta bolic signatures are seen in patients with regenerating livers, should have an effect on the trans lational gap. Likewise, proteomic analy sis of patient's blood during liver regeneration seems an obvious future development; studies in mice have already shown a distinct proteomic signature in plasma following hepatectomy and during liver regeneration that were strongly associ ated to metabolism 68 .…”

Multinuclear magnetic resonance evaluation of tumor tissue

“…Due to the high level of water soluble Cho metabolites in cancer tissue, 31 P MRS is often used to monitor the synthesis of PCho (Katz-Brull et al, 2002). Recently, 31 P MR was used to study metabolite profiles of several types of cancer including glioblastoma (Al-Saffar et al, 2014), ovarian (Abramov et al, 2012), prostate (Kobus et al, 2012), liver (Qi et al, 2011), colorectal (Silberhumer et al, 2009), human extremity sarcomas (Sijens, 1998), non-Hodgkin's lymphomas (Negendank et al, 1995) and focal hepatic malignancies (Cox et al, 1992).…”

<sup>31</sup>P MR Spectroscopy with 3D Chemical-Shift Imaging Detects Changes in Levels of Phosphorus Metabolites Due to Saliva Secretion in Human Parotid Glands

“…MRS can be used to identify information such as the type of metabolite, its concentration, and the relaxation time. Phosphorus magnetic resonance spectroscopy ( 31 P-MRS) is a non-invasive technique that provides useful information regarding the metabolic and phosphoenergetic status of human tissue, in both physiological and pathological conditions [2] [3]. In addition to the information contained within static spectra, dynamic 31 P-MRS has been used to assess changes in the levels of phosphorus metabolites…”