High-resolution 1H NMR spectroscopy of cerebrospinal fluid in spinal diseases.

Twenty-nine patients with disk herniations, 7 patients with intraspinal tumors, 4 patients with multiple sclerosis and one patient with infection by borrelia have been studied by CT, myelography and/or MR. To gain information on the metabolism of central nervous system disease (CNS), and thus, to improve diagnosis the cerebrospinal fluid (CSF) was studied in all cases using high-resolution 1H NMR spectroscopy at 360 MHz. Seventeen metabolites could be identified in CSF in addition to the usual clinical chemical parameters. As compared to a control group discrimination of tumors from inflammation was possible by means of different metabolites and/or metabolite concentration. The CSF in disk herniations differed in the concentration of acetate from the control group. In CSF of tumors, multiple sclerosis and of infection by borrelia distinct differences in the concentrations of putrescine, citrate, valine, alpha-alanine, acetate, creatinine, glucose, beta-hydroxy-butyric acid, glutamine and creatine have been observed both as compared directly and in comparison to the control group. Thus, high-resolution 1H NMR spectroscopy of CSF gives speedy information on metabolism, since a variety of metabolites, usually examined only in different tests, can be studied in one single step. Thus, high-resolution 1H NMR spectroscopy supports imaging, especially MR, as morphological changes in diseases may be differentiated by means of different metabolite profiles. This assumption needs further confirmation on a prospective study with a larger patient population.

Pre-operative localized in vivo proton spectroscopy in cerebral tumors at 4.0 Tesla--first results.

Sixteen patients with prediagnosed cerebral lesions were studied with stimulated echo localized 1H-spectroscopy at 4 Tesla. Initially, CT cerebral angiography and MR investigation at 1.5 Tesla were performed. After selecting a patient and receiving his agreement the high field examination started with the acquisition of an MR image of the known tumor at 4 Tesla using head or surface coil. 1H-spectroscopy was performed by selectively exciting a cubic volume between 8 to 20 cubic centimeters in the center of the tumor, in one case below 4 ccm (pinealoma). If possible, in a second examination the corresponding opposite side of the brain was studied. The extirpation of the tumor followed during the next days. Macroscopic aspects, histology and grading of the investigated lesions were determined. In some cases, specimens of the tumors were cooled in cooking salt solution and in liquid nitrogen, respectively, in order to perform in vitro proton MRS at 8.4 Tesla. The evaluable in vivo spectra showed good resolution and significant differences between corresponding cerebral areas with and without tumor as well as between different types of tumor histologies like medulloblastoma, astrocytoma and meningeomas. Often a good correspondence between in vivo and in vitro spectroscopy was seen. No clinically relevant side effects or complications were observed during the in vivo high field examination.

Characterization of CNS lesions by using high-resolution 1H MR spectroscopy of CSF: preliminary results.

Sixty-six samples of CSF from 66 patients with a variety of diseases, including tumors, arteriovenous malformations, aneurysms, brain infarctions, and lumbar back pain, were studied with 1H MR spectroscopy at 360 MHz. 1H MR spectroscopy offers a simple means to obtain fast information about different metabolites simultaneously. As compared with the control group, which consisted of 19 CSF samples from the same group of 66 patients, but from individuals who had no abnormal findings on neurologic examination, common clinicochemical tests, or neuroradiologic studies, our preliminary results suggest that tumors and hemorrhages may be differentiated by 1H MR spectroscopy. MR peak intensities relative to lactate peak intensity were used as variables in a statistical analysis to determine the significance of individual resonance intensities in predicting CNS abnormalities. The most important factors for diagnosis were analyzed by means of a multivariate general linear hypothesis and a principal component method. The most important factors for predicting CNS abnormalities in the studied diseases were creatinine, glucose, creatine, citrate, protein content, glutamine, amount of cells, and valine. By using this model for discriminant analysis, we could predict hemorrhages correctly in 88% of cases and tumors in 75% of cases. All samples of controls were determined correctly. In cases of brain infarctions, different signals were observed, which may lead to further characterization of such lesions. 1H MR spectroscopy may offer a simple means for further characterizing CNS lesions. However, this needs confirmation by a prospective study, which would include a larger patient population with different diseases.

Cerebrospinal fluid: detection of tumors and disk herniations with MR spectroscopy.

Cerebrospinal fluid (CSF) samples from 84 patients with confirmed or suspected diseases of the central nervous system were studied with hydrogen-1 magnetic resonance (MR) spectroscopy. In 19 of the patients, clinical chemical tests of the CSF indicated normal protein contents and normal quantities of cells; these samples were used as controls. Preliminary results indicate that tumors may be reflected in the MR spectra of CSF; disk herniations could not be distinguished on the basis of the MR spectral characteristics.

Sodium binding to and protonation of ATP: a multinuclear magnetic double resonance study at 8.46 tesla.

We show that the interaction of ATP with Na+ and H+, whether binding or dissociation, gives rise to exchange broadened 31P-NMR spectra at 8.4 T, pH 6.7 and 310 K. We interpret the effect as being due to a two-step conversion between two NMR-differentiated ATP pools. A quantitative analysis yields all involved equilibrium constants and some of the dynamic parameters. Our results help to understand previous studies of magnesium binding to ATP and the appearance of high-field in vivo 31P-NMR spectra.

The in vivo contour plot. An improved representation of stimulus experiments.

The in vivo contour plot is a superior representation of the data from stimulus experiments. Its performance is illustrated by four examples, viz., necrosis of a superfused rat heart, anoxia on perfused mouse liver, ischemiae on Langendorff heart in the presence and absence of a Ca antagonist, and the internal stimulus of the cardiac cycle. The in vivo contour plot visualizes line intensities (metabolite concentrations), line positions (pH), and linewidths, as well as the time derivatives of these parameters in any available number of spectra.