Levels of choline‐containing compounds in normal liver and liver metastases of colorectal cancer as recorded by ¹H MRS

Abstract

Purpose A relatively high signal for choline‐containing compounds (total choline, tCho) is commonly found in 1H MR spectra of malignant tumors, but it is unclear if this also occurs in tumors in the liver. We evaluated the potential of the tCho signal in single voxel 1H MR spectra of the human liver to assess metastases of colorectal cancers. Experiment MR spectra of an 8 cm3 PRESS‐localized voxel were obtained at 3 T from the livers of 12 healthy volunteers and from metastatic lesions in 20 patients in two different sessions. To correct for motion artifacts, sequentially recorded spectra were individually phased and frequency aligned before averaging. Spectra were analyzed using LCModel and tissue levels estimated by water referencing. Repeatability was assessed with Bland–Altman analyses. To estimate tumor necrosis, diffusion‐weighted imaging of the liver was performed. High resolution magic angle spinning (HRMAS) spectra of tumor and normal liver samples were obtained at 11.7 T. Results With increasing tumor volumes, tCho levels decreased, indicating a partial volume effect. Mean tCho content in tumors larger than the PRESS voxel (>8 cm3) was significantly lower (p < 0.01) than for normal liver: 1.6 (range 0.0–3.4) versus 6.9 (range 4.9–11.1) mmol/kg wet weight, while it was comparable for tumors smaller than 8 cm3: 7.0 (range 3.8–9.3) mmol/kg. The higher 90th percentile apparent diffusion coefficient value in the larger lesions indicates more necrosis. Measurement repeatability was average in normal livers and poor in tumors. HRMAS did not show substantial differences in choline‐containing compounds between normal liver and metastasis. Conclusion An increased tCho content was not observed in 1H MR spectra of liver metastasis of colorectal cancer, compared with normal liver. This may be due to the background of a high tCho signal in spectra of normal liver or to an intrinsic lower tCho content in these tumors, but is most likely the result of necrosis in metastatic tumor tissue.

Treatment response of colorectal cancer liver metastases to neoadjuvant or conversion therapy: a prospective multicentre follow-up study using MRI, diffusion-weighted imaging and 1H-MR spectroscopy compared with histology (subgroup in the RAXO trial)

“…Histology, on the other hand, did not associate with OS or PFS either. 1 H-MRS can be used to analyse the amount of free choline and other CCCs and it is usually clearly higher in the liver metastasis than in the surrounding liver parenchyma, 23,45 but it has not widely been studied in this setting. In our study, no association was detected between the relative amounts of free choline in the largest metastasis at baseline versus response according to RECIST or morphologic MRI criteria, neither in histological findings.…”

Non-Invasive Analysis of Human Liver Metabolism by Magnetic Resonance Spectroscopy

“…Aside from triglycerides, other hepatic metabolites that have been quantified by 1 H MRS include choline-containing compounds and glycogen [25][26][27] which were measured with a 3 T instrument. While many tumors have high levels of choline, in vivo 1 H MRS measurements of hepatic choline in patients with liver tumors did not observe any significant increases in choline compared to healthy subjects [27].…”

“…Aside from triglycerides, other hepatic metabolites that have been quantified by 1 H MRS include choline-containing compounds and glycogen [25][26][27] which were measured with a 3 T instrument. While many tumors have high levels of choline, in vivo 1 H MRS measurements of hepatic choline in patients with liver tumors did not observe any significant increases in choline compared to healthy subjects [27]. Glycogen observation by conventional in vivo 1 H MRS is hampered by several factors including short T 2 of its hydrogens and a significant loss of signal during presaturation of the water signal due to saturation transfer [28].…”

Non-invasive Analysis of Human Liver Metabolism by Magnetic Resonance Spectroscopy

“…Aside from triglyceride, other hepatic metabolites that have been quantified by 1 H MRS include choline and glycogen [24][25][26] which were measured with a 3 T instrument. While many tumours have high levels of choline, in vivo 1 H MRS measurements of hepatic choline in patients with liver tumours did not observe any significant increases in choline compared to healthy subjects [26].…”

“…Aside from triglyceride, other hepatic metabolites that have been quantified by 1 H MRS include choline and glycogen [24][25][26] which were measured with a 3 T instrument. While many tumours have high levels of choline, in vivo 1 H MRS measurements of hepatic choline in patients with liver tumours did not observe any significant increases in choline compared to healthy subjects [26]. Glycogen observation by conventional in vivo 1 H MRS is hampered by several factors including short T2 of its hydrogens and a significant loss of signal during presaturation of the water signal due to saturation transfer [27].…”