Magnetic resonance spectroscopy in intracranial tumours of glial origin.

BACKGROUND AND PURPOSE: To determine in vivo magnetic resonance spectroscopy (MRS) characteristics of intracranial glial tumours and to assess MRS reliability in glioma grading and discrimination between different histopathological types of tumours. MATERIAL AND METHODS: Analysis of spectra of 26 patients with glioblastomas, 6 with fibrillary astrocytomas, 4 with anaplastic astrocytomas, 2 with pilocytic astrocytoma, 3 with oligodendrogliomas, 3 with anaplastic oligodendrogliomas and 17 control spectra taken from healthy hemispheres. RESULTS: All tumours' metabolite ratios, except for Cho/Cr in fibrillary astrocytomas (p = 0.06), were statistically significantly different from the control. The tumours showed decreased Naa and Cr contents and a high Cho signal. The Lac-Lip signal was high in grade III astrocytomas and glioblastomas. Reports that Cho/Cr ratio increases with glioma's grade whereas Naa/Cr decreases were not confirmed. Anaplastic astrocytomas compared to grade II astrocytomas had a statistically significantly greater mI/Cr ratio (p = 0.02). In pilocytic astrocytomas the Naa/Cr value (2.58 ± 0.39) was greater, whilst the Cho/Naa ratio was lower (2.14 ± 0.64) than in the other astrocytomas. The specific feature of oligodendrogliomas was the presence of glutamate/glutamine peak Glx. However, this peak was absent in two out of three anaplastic oligodendrogliomas. Characteristically, the latter tumours had a high Lac-Lip signal. CONCLUSIONS: MRS in vivo cannot be used as a reliable method for glioma grading. The method is useful in discrimination between WHO grade I and WHO grade II astrocytomas as well as oligodendrogliomas from other gliomas.

Differential diagnosis of intracranial meningiomas based on magnetic resonance spectroscopy.

BACKGROUND AND PURPOSE: To determine in vivo magnetic resonance spectroscopy (MRS) characteristics of intracranial meningiomas and to assess MRS reliability in meningioma grading and discrimination from tumours of similar radiological appearance, such as lymphomas, schwannomas and haemangiopericytomas. MATERIAL AND METHODS: Analysis of spectra of 14 patients with meningiomas, 6 with schwannomas, 2 with lymphomas, 2 with haemangiopericytomas and 17 control spectra taken from healthy hemispheres. RESULTS: All the patients with meningiomas had a high Cho signal (long TE). There were very low signals of Naa and Cr in the spectra of 10 patients. A reversed Ala doublet was seen only in 2 cases. Four patients had a negative Lac signal, whereas 3 had high Lac-Lip spectra. Twelve spectra showed high Cho signals (short TE). In one case the Cho signal was extremely low. All spectra displayed a very low Cr signal, but high Glx and Lac-Lip signals. Ala presence was found only in 3 patients. The mean Cho/Cr ratio (PRESS) was 5.97 (1.12 in normal brain, p < 0.05). Lac-Lip was present in all the meningiomas (STEAM). The Ala signal was seen only in 2 spectra with long TE and in 3 sequences of the short TE sequences. There were both ß/γ-Glx and α-Glx/glutathione signals in all 14 meningiomas. CONCLUSIONS: MRS is unable to discriminate low and high grade meningiomas. The method seems to be helpful in discriminating lymphomas (absent Glx signal), schwannomas (mI signal in the short TE sequences) and haemangiopericytomas (presence of mI band) from meningiomas.

Magnetic resonance imaging of rare intracranial neoplasms--role of the in vivo 1 h spectroscopy in the radiological differential diagnostics.

BACKGROUND: The object of this study was to evaluate the usefulness of magnetic resonance (MR) spectroscopy in differentiating rare intracranial tumours in adult patients. Review of the literature on results of MR spectroscopy in these lesions is also included. MATERIAL AND METHOD: 89 patients with brain tumours were evaluated preoperatively with in vivo 1.5 T MR spectroscopy (according to eTumour study requirements). 8 of them were diagnosed as having very rare neoplasms: haemangiopericytoma (2), lymphoma (2), plexus papilloma (2), chondroma (1) and purkinjoma (1). Spectra of these tumours were compared to spectra of common brain tumours that could resemble these lesions. RESULTS: MR spectroscopy enabled discrimination between meningiomas and haemangiopericytomas, meningiomas and lymphomas, and purkinjomas or chondromas and other brain tumours. The method was unreliable in distinguishing between glioblastomas and lymphomas. CONCLUSION: The small number of patients made statistical analysis impossible. However, at present, it seems that neuroradiological diagnosis should not rely on MR spectroscopy alone.

Clinical evaluation of the polypropylene-polyester knit used as a cranioplasty material.

UNLABELLED: The paper presents clinical evaluation of the polypropylene-polyester knit used as a cranioplasty material. MATERIAL: Between year 1980 and 2002 275 cranioplastic procedures using the polypropylene-polyester plates Codubix were carried out in the Department of Neurosurgery of the Medical University of Lódz. There were 146 patients who primarily sustained head injuries and 129 non-traumatic patients with craniectomies carried out for various other reasons. In the majority of cases, i.e. in 158 patients, cranioplasty was performed later than 6 months after the primary surgery. The largest implant measured 430 cm2. RESULTS: Excellent and good outcome was achieved in 92% of the patients whereas the rate of local infection was 8%. CONCLUSIONS: Codubix knitted polypropylene-polyester implant proved to be useful and a safe cranioplastic material.