The Relationship Of In Vivo 31P Mr Spectroscopy to Histology in Chronic Hepatitis C

Abstract

Liver biopsy remains the gold standard for characterizing diffuse liver disease and is associated with significant morbidity and, rarely, mortality. Our aim was to investigate whether a noninvasive technique, in vivo phosphorus 31 ( 31 P)-magnetic resonance spectroscopy (MRS), could be used to assess the severity of hepatitis C virus (HCV)-related liver disease. Fifteen healthy controls and 48 patients with biopsy-proven HCV-related liver disease were studied prospectively. Based on their histologic fibrosis (F) and necroinflammatory (NI) scores, patients were divided into mild hepatitis (F < 2/6, NI < 3/18), moderate/severe hepatitis (3 < F < 6 or NI > 4/18), and cirrhosis (F ‫؍‬ 6/6). Hepatic 31 P MR spectra were obtained using a 1.5-T spectroscopy system. Quantitation of the 31 P signals was performed in the time domain using the Advanced MAgnetic RESonance algorithm. There was a monotonic increase in the mean ؎ 1 standard error phosphomonoester (PME) to phosphodiester (PDE) ratios for the control, mild disease, moderate disease, and cirrhosis groups: 0.15 ؎ 0.01, 0.18 ؎ 0.02, 0.25 ؎ 0.02, 0.38 ؎ 0.04, respectively (ANOVA, P < .001). An 80% sensitivity and specificity was achieved when using a PME/PDE ratio less than or equal to 0.2 to denote mild hepatitis and a corresponding ratio greater than or equal to 0.3 to denote cirrhosis. No other significant spectral changes were observed. In conclusion, 31 P MRS can separate mild from moderate disease and these 2 groups from cirrhosis. The ability to differentiate these populations of patients has therapeutic implications and 31 P MRS, in some situations, would not only complement a liver biopsy but could replace it and be of particular value in assessing disease progression. (HEPATOLOGY 2003;37:788-794.)

Magnetic Resonance Spectroscopy: Principles and Techniques: Lessons for Clinicians

“…The in vitro MRS technique on body fluid samples has a role both in large-scale population-based screening without specific a priori hypotheses and in demonstrating the response of the individual to therapy. 48 At clinical magnetic field strengths, whole body in vivo MRS has provided insight into pathogenic mechanisms of cell turnover in cirrhosis, [49][50][51] the process of allograft rejection following liver transplantation, 52 changes in cognitive function, osmolyte concentrations and low-grade cerebral oedema in hepatic encephalopathy and the mechanisms underlying fatigue in primary biliary cirrhosis. 53,54 …”

Magnetic resonance imaging of hepatic fibrosis: Emerging clinical applications

“…45 For patients with varying degrees of involvement with chronic hepatitis, an increasing PME/PDE ratio was found to correlate with necroinflammatory and fibrosis scores on liver histology compared with healthy volunteers. [52][53][54][55] Although differences between means for each group were 31 P, labeled phosphorus; ISIS, image selected in vivo spectroscopy; TR, repetition time; NA, number of acquisitions; PBC, primary biliary cirrhosis; CSI, chemical shift imaging; PME, phosphomonoester; Pi, inorganic phosphate; Glx, glutamate; Glu, glucose; GPE, glycerophosphorylethanolamine; GPC, glycerylphosphorylcholine; PE, phosphoethanolamine; PC, phosphocholine; PDE, phosphodiester; ATP, adenosine triphosphate; P, inorganic phosphorus; n/a, not available; CTP, Child-Turcotte-Pugh; HA, hyaluronic acid; MRE, magnetic resonance elastography. statistically significant, there was some overlap between the patient groups.…”

Current and future applications ofin vitromagnetic resonance spectroscopy in hepatobiliary disease

“…In vivo hepatic MRS studies have been primarily used in the research environment and have generally utilized 31 P MRS [5] , because 1 H MRS is technically more challenging [6,7] . In vivo 31 P MRS gives information on cell turnover and energy state and has been used to grade patients with chronic liver disease [8] and to aid in diagnosis and treatment response in patients with cancer [9] . On the other hand, in vivo 1 H MRS allows quantification of intrahepatocellular lipid (IHCL) levels, and therefore has been utilized recently to quantify the extent of steatosis in patients with fatty liver [10,11] .…”

“…More recently, in vivo hepatic 31 P MRS has been used to stratify inflammation and fibrosis caused by hepatitis C virus, compared to histological staging from standard liver biopsy [8] . The PME/PDE ratio was found to be elevated in mild, moderate/severe fibrosis and cirrhosis compared to normal, healthy volunteers.…”

“…Furthermore, most standard liver function tests also depend on measurements of plasma components, rather than assessing markers at the site of disease. Recent studies on hepatitis C suggest that the MRS technique may be useful in monitoring response to treatment with interferon and ribavirin [8] .…”