Magnetic Resonance Imaging of Gliomas

Open Access.This work was supported in part by grants CTQ2010-20960-C02-02 to P.L.L. and grant SAF2008-01327 to S.C. A.M.M. held an Erasmus Fellowship from Coimbra University and E.C.C. a predoctoral CSIC contract.Peer Reviewe

Correlation between arterial blood volume obtained by arterial spin labelling and cerebral blood volume in intracranial tumours.

OBJECTIVE: To compare measurements of the arterial blood volume (aBV), a perfusion parameter calculated from arterial spin labelling (ASL), and cerebral blood volume (CBV), calculated from dynamic susceptibility contrast (DSC) MRI. In the clinic, CBV is used for grading of intracranial tumours. MATERIALS AND METHODS: Estimates of aBV from the model-free ASL technique quantitative STAR labelling of arterial regions (QUASAR) experiment and of DSC-CBV were obtained at 3T in ten patients with eleven tumours (three grade III gliomas, four glioblastomas and four meningiomas, two in one patient). Parametric values of aBV and CBV were determined in the tumour as well as in normal grey matter (GM), and tumour-to-GM aBV and CBV ratios were calculated. RESULTS: In a 4-pixel ROI representing maximal tumour values, the coefficient of determination R (2) was 0.61 for the comparison of ASL-based aBV tumour-to-GM ratios and DSC-MRI-based CBV tumour-to-GM ratios and 0.29 for the comparison of parametric values of ASL-aBV and DSC-CBV, under the assumption of proportionality. Both aBV and CBV showed a non-significant tendency to increase when going from grade III gliomas to glioblastomas to meningiomas. CONCLUSION: These results suggest that measurement of aBV is a potential tool for non-invasive assessment of blood volume in intracranial tumours

Liver imaging reporting and data system: An expert consensus statement

The increasing incidence and high morbidity and mortality of hepatocellular carcinoma (HCC) have inspired the creation of the Liver Imaging Reporting and Data System (LI-RADS). LI-RADS aims to reduce variability in exam interpretation, improve communication, facilitate clinical therapeutic decisions, reduce omission of pertinent information, and facilitate the monitoring of outcomes. LI-RADS is a dynamic process, which is updated frequently. In this article, we describe the LI-RADS 2014 version (v2014), which marks the second update since the initial version in 2011

Microvessels in tumor tissue in patients with central nervous system tumors

Angiogenesis plays an essential role in the development of a tumor. The most preferred histological evaluation method of this process is the determination of microvessel density (MVD) in the biopsy. Numerous studies report the possibility of using various MRI techniques for imaging the network of neoplastic vessels and determining the angiogenesis in them, as well as the subsequent analysis of the obtained images. In this study, a classic MRI imaging with intravenous contrast agent administration was used, and in order to ensure objectification and repeatability, and to eliminate human error that may occur in classic MRI image analysis, an automatic evaluation algorithm was used to determine the degree of angiogenesis, which was then presented in the form of a statistical pixels analysis. The study involved 48 adult patients of both sexes, treated surgically at the Department of Neurosurgery, Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, due to a solid brain tumor. The highest mean density of MVD microvessels in tumor tissue was observed in high-grade gliomas. The high level of MVD expression in tumors of the central nervous system showed a positive correlation with the high degree of tumor malignancy. Based on the conducted research, it was concluded that the determination of the level of MVD expression in the tumor tissue is an additional prognostic factor in neoplasms of the central nervous system. The comparison of the results obtained with the tests performed routinely translates into a more accurate selection of treatment and assessment of the prognosis for survival

Advances in magnetic resonance imaging of musculoskeletal tumours

SummaryFunctional magnetic resonance imaging (MRI) improves tissue characterisation and staging of bone and soft-tissue tumours compared to the information usually supplied by structural imaging. Perfusion MRI, diffusion MRI, and in-phase/opposed-phase MRI can be performed in everyday practice. Nuclear magnetic resonance (NMR) spectroscopic imaging is a challenging technique that is available only in specialised centres. Tumour characterisation can benefit from perfusion MRI with dynamic gadolinium injection and enhancement time-intensity curve analysis or from diffusion MRI. Highly cellular malignant tumours restrict diffusion and consequently decrease the apparent diffusion coefficient (ADC). With some tumours, tissue heterogeneity or the presence of a myxoid component can hinder this evaluation. Chronic hematoma can be distinguished from haemorrhagic sarcoma. Perfusion and diffusion MRI contribute to the evaluation of tumour spread, in particular by differentiating oedema from tumour tissue. Another advantage of perfusion MRI and ADC mapping is the early identification of good responders to chemotherapy. The use of NMR spectroscopy remains limited. Evaluation of the choline peak can help to differentiate benign and malignant tumours. All available functional MRI techniques have limitations and leave some overlap between benign and malignant tumours. Functional MRI can be used only as an adjunctive imaging modality to complement morphological imaging