The field of computed tomography (CT), which is a basic diagnostic tool in clinical practice, has recently undergone rapid technological advances. These include the evolution of dual-energy CT (DECT) and development of photon-counting computed tomography (PCCT). DECT enables the acquisition of CT images at two different energy spectra, which allows for the differentiation of certain materials, mainly calcium and iodine. PCCT is a recent technology that enables a scanner to quantify the energy of each photon gathered by the detector. This method gives the possibility to decrease the radiation dose and increase the spatial and temporal resolutions of scans. Both of these techniques have found a wide range of applications in radiology, including vascular studies. In this narrative review, the authors present the principles of DECT and PCCT, outline their advantages and drawbacks, and briefly discuss the application of these methods in vascular radiology.

It is already known that patients with glioma develop functional plasticity, including recruiting regions of contralateral hemisphere. However, it is still unclear, if and what kind of structural changes in contralateral hemisphere are present, and there is lack of comprehensive comparison of studies on this issue. First aim of this review was to summarize methodology and findings of morphometric studies of contralateral hemisphere of patients with glioma before treatment. Second aim was to discuss the possible neurobiological background of changes, methodological difficulties and possibilities, and to identify challenges for future studies. Neuroimaging studies were searched in four electronic databases. Found studies were compared and discussed regarding their methodology and outcomes, and undergone thorough quality assessment. In this systematic review, we eventually included 16 studies from 2080 initially found articles. Analyzed groups of patients suffered from different types and grades of gliomas. For brain scan analyses, authors used voxel-based or surface-based morphometry. Results differed across studies, reporting both increase and atrophy of contralateral grey matter. We identified some methodological issues in papers, which were further discussed. Contralateral hemisphere in glioma patients undergoes complicated structural changes, including grey matter volume increase and atrophy, which both could be signs of compensation. These are dependent on tumor location, grade of glioma, individual attributes of a given patient, and should be interpreted carefully. There is still need for further research, and we present challenges and issues which should be overcome.

Peripheral arteriovenous malformations (PVMs) can be classified into high-flow malformations (HFVMs) and low-flow malformations (LFVMs). Adequate distinguishment is crucial for therapeutic decision and can be done using dynamic contrast-enhanced MRI (DCE-MRI). The main aim of this retrospective study was to determine the diagnostic value of quantitative DCE-MRI ratios for differentiation between HFVM and LFVM, their optimal cut-off points, and predictive values. DCE-MRI time-resolved angiography with stochastic trajectory (TWIST) examinations of 90 patients with PVMs were included [28 HFVM (31%), 62 LFVM (69%)]. The measurements of artery-lesion time, maximum lesion enhancement, slope of the enhancement curve, and maximum percentage increase of signal intensity (SI) were obtained. The optimal cut-offs for HFVMs calculated using the Youden index were: for slope of enhancement curve < 8.7 s (sensitivity of 86%, specificity of 89%), artery-lesion time ≤ 5.6 s (sensitivity of 89%, specificity of 77%), time to maximum enhancement ≤ 30 s (sensitivity of 94%, specificity of 100%), and maximum percentage enhancement of the lesion > 662% (sensitivity of 68%, specificity of 69%). To summarize, DCE-MRI is very valuable for differentiation between HFVM and LFVM, especially if quantitative measurements are done.

Chest computed tomography (CT) is proven to have high sensitivity in COVID-19 diagnosis. It is available in most emergency wards, and in contrast to polymerase chain reaction (PCR) it can be obtained in several minutes. However, its imaging features change during the course of the disease and...