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Differentiation of tumor recurrence from radiation-induced brain changes is the main challenge of neuroimaging in patients with treated cerebral tumor. The review presents the limitations of structural imaging and additional opportunities of perfusion imaging techniques, proton magnetic resonance spectroscopy and positron emission tomography in discriminating recurrent tumor from radiation injury.

Background. Neurodegenerative processes play an important role in the development of clinical features of multiple sclerosis (MS) as well as in the progression of the disease. At the same time, neurodegenerative mechanisms of MS are not completely clear, which makes researchers pay special attention to pathogenetic aspects of the disease that have not been studied before. Previously it was shown that MS patients can have alterations in the local cerebral blood flow, however, the meaning of the detected abnormalities is still not clear.The aim of our work is to evaluate the perfusion character in the demyelinating lesions and normalappearing brain structures, and to determine their relation to clinical features of MS.Material and methods. 49 patients with relapsing-remitting and secondary progressive MS with clinical and MRI remission were included in the study. The patients underwent contrast-enhanced MR perfusion of the brain on the 3 Tesla MR-tomograph, as well as the Functional System Score, Expanded Disability Status Score and Fatigue Status Score evaluation. The data analysis included automatic construction of perfusion maps of the cerebral blood volume (CBV), cerebral blood flow (CBF) and mean transit time (MTT) values in the normal-appearing brain structures and in the demyelinating lesions and statistical analysis.Results. The received results allow to presume that variation of CBV values in MS lesions can indicate heterogeneity of processes in these lesions – from reactivation of inflammation to remyelination.Significant reduction of perfusion in nucleus lenticularis was revealed. This reduction did not depend on the severity of the disease and correlated negatively with the fatigue score. This allows to suppose that the therapy focused on brain perfusion improvement can be used as symptomatic therapy of MS. Considering the fact that regional hypoperfusion precedes the development of brain structure atrophy, it is hypothesized that the improvement of perfusion may prevent neurodegeneration in MS. The obtained findings need further investigation.

Introduction. The Alberta stroke programme early CT score (ASPECTS) was developed for a unified approach to the diagnosis of Acute Ischemic Stroke. ASPECTS is currently used as a standard method for assessment of ischemic volumes in the anterior cerebral circulation. However, the scale is not fully standardized, which is a source of intersubject variability.The purpose of the review is to gain an understanding the advantages and limitations of the ASPECTS scale, as well as the level of inter-expert and intra-expert agreement.Results. A literary analysis demonstrates most researchers have identified many factors that affect both the interpretation and assessment of the distribution of ischemic changes by ASPECTS. These signs are diverse and include a wide range of parameters: from methodological standardization to personal factors of experts. Also, studies on the effectiveness of the ASPECTS scale showed quite heterogeneous results, which reflect a wide degree of variability in inter-expert agreement.Conclusion. The ASPECTS is a systematic, reliable and practical method that is widely used in modern clinical practice. However, the possibility of variability of expert assessments is the main limitation of its application. The pronounced variety of results and the heterogeneity of intrasubject variability does not currently allow us to consider this scale as a truly reliable version of a standardized assessment and may affect the further treatment process. To solve this problem, it looks promising to introduce into clinical practice the methods of semi-automatic and automatic processing of CT images using artificial intelligence systems. But for the full acceptance of such systems into clinical practice, their wide clinical approbation on independent sets of different data is necessary.

Retino-cochleo-cerebral angiopathy or Susac syndrome is a rare autoimmune disease that selectively affects the vessels of the retina, the inner ear and the central nervous system. Differentiation of Susac syndrome and multiple sclerosis presents difficulties due to the similarity of MRI semiotics of these two diseases. This article presents two clinical cases of patients with Susac syndrome who were diagnosed with multiple sclerosis at the onset of the disease. Based on the analysis of our own clinical observations and literature data, the issues of differential diagnosis of Susac syndrome and multiple sclerosis are highlighted. For the first time a variant of the MRI picture transformation in Susac syndrome is presented.