OBJECTIVES: to assess the feasibility of CT with an integrated photon-counting-detector system (PC-CT) in the body imaging of clinical patients. METHODS: 120 examinations using photon counting detector CT were evaluated in six groups: 1/ a standard-dose lung, 2/ low-dose lung, 3/ ultra-high resolution (UHR) lung, 4/ standard-dose abdominal, 5/ lower-dose abdominal, 6/ UHR abdominal CTA. All CT examinations were performed on a single-source prototype device equipped with a photon counting detector covering a 50 cm scan field of view. Standard dose examinations were performed with the use of detector element size of 0.4 mm, ultra-high-resolution examinations with the detector element size of 0.2 mm, respectively. The stability of the system during imaging was tested. The diagnostic quality of the acquired images was assessed based on the imaging of key structures and the noise level in five-point scale, the effective dose equivalent, dose length product and noise level, and also relation to body mass index and body surface area were compared with three similar groups of CT images made with energy integrating high end scanner. The parameters were evaluated using Wilcoxon test for independent samples, the independence was tested using Kruskal-Wallis test. RESULTS: When PC-CT images radiation dose is compared with the similar imaging using energy integrating CT, the PC-CT shows lower dose in ultra-high resolution mode, the dose is significantly lower (p < 0.0001), the standard dose examinations were performed with the comparable radiation doses. PC-CT exhibited the significantly higher ratio between parenchyma signal and background noise both in lung and in abdominal imaging (p < 0.0001). CONCLUSIONS: PC-CT showed imaging stability and excellent diagnostic quality at dose values that are comparable or better to the quality of energy integrating CT, the better signal and improved resolution is most important advantage of photon counting detector CT over energy integrating detector CT.

• MeSH
• fantomy radiodiagnostické MeSH
• fotony * MeSH
• lidé MeSH
• plíce MeSH
• počítačová rentgenová tomografie * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

CT s photon-counting detektory je nová technologie, která umožňuje překonat některé nevýhody spojené s konvenčně využívanými energy-integrating detektory. Photon-counting detektory umožnují odlišit jednotlivé rtg fotony, proto je možné minimalizovat elektronický šum. Mimo to umožňují získat ultra vysoké rozlišení bez nutnosti vyšší dávky. A v neposlední řadě tyto detektory poskytují spektrální data, proto je možné odlišit různé materiály v CT obrazech, a rekonstruovat tak virtuální obrazy různých energií a také nativní obrazy.

CT with photon-counting detectors is an emerging technology that overcomes some drawbacks of the conventional CT with energyintegrating detectors. It can differentiate individual X-ray photons, so acquired data does not suffer from electronic noise. Moreover, photon-counting detectors provide ultra high resolution without increased dose. And finally, detectors provide spectral data which enables differentiation of different materials in CT data, therefore virtual monoenergetic and non-contrast images can be reconstructed.

• MeSH
• fotony * MeSH
• lidé MeSH
• počítačová rentgenová tomografie * metody   MeSH
• počítačové zpracování obrazu MeSH
• scintilace - počítání MeSH
• spektrální analýza MeSH
• statistika jako téma MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

PURPOSE OF REVIEW: This review summarizes novel MRI approaches for the investigation of lesion burden and understanding of the pathophysiology of multiple sclerosis (MS). RECENT FINDINGS: Recent technical advances are improving our ability to detect and define the nature of focal lesions and 'diffuse' tissue damage in MS as well as the functional consequences of such structural abnormalities. New contrast agents allow to monitor the pluriformity of MS inflammation. Double inversion recovery sequences enable us to detect and monitor the evolution of MS lesions in the cortex. High and ultra-high field scanners are improving imaging of MS-related abnormalities at an unprecedented resolution. Furthermore, this new generation of scanners has the potential to ameliorate structural and functional MR studies of the disease. All of this has contributed, and is likely to continue to contribute, to the definition of the factors associated with the development of irreversible disability in MS. Finally, new analysis methods have allowed to track regional disease-related changes and are resulting in an increased correlation between MRI and clinical deficits. SUMMARY: Novel MR approaches highlighted previously unrecognized or neglected aspects of MS pathophysiology, which are likely to improve our understanding of the heterogeneous clinical manifestations of this condition.

• MeSH
• centrální nervový systém patofyziologie   patologie   MeSH
• diferenciální diagnóza MeSH
• kontrastní látky diagnostické užití   MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   trendy   MeSH
• mozková kůra patofyziologie   patologie   MeSH
• myelinová pochva patologie   MeSH
• počítačové zpracování obrazu metody   trendy   MeSH
• posuzování pracovní neschopnosti MeSH
• progrese nemoci MeSH
• roztroušená skleróza diagnóza   patofyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

BACKGROUND AND PURPOSE: Characterization of iron deposition associated with demyelinating lesions of multiple sclerosis and neuromyelitis optica has not been well studied. Our aim was to investigate the potential of ultra-high-field MR imaging to distinguish MS from neuromyelitis optica and to characterize tissue injury associated with iron pathology within lesions. MATERIALS AND METHODS: Twenty-one patients with MS and 21 patients with neuromyelitis optica underwent 7T high-resolution 2D-gradient-echo-T2* and 3D-susceptibility-weighted imaging. An in-house-developed algorithm was used to reconstruct quantitative susceptibility mapping from SWI. Lesions were classified as "iron-laden" if they demonstrated hypointensity on gradient-echo-T2*-weighted images and/or SWI and hyperintensity on quantitative susceptibility mapping. Lesions were considered "non-iron-laden" if they were hyperintense on gradient-echo-T2* and isointense or hyperintense on quantitative susceptibility mapping. RESULTS: Of 21 patients with MS, 19 (90.5%) demonstrated at least 1 quantitative susceptibility mapping-hyperintense lesion, and 11/21 (52.4%) had iron-laden lesions. No quantitative susceptibility mapping-hyperintense or iron-laden lesions were observed in any patients with neuromyelitis optica. Iron-laden and non-iron-laden lesions could each be further characterized into 2 distinct patterns based on lesion signal and morphology on gradient-echo-T2*/SWI and quantitative susceptibility mapping. In MS, most lesions (n = 262, 75.9% of all lesions) were hyperintense on gradient-echo T2* and isointense on quantitative susceptibility mapping (pattern A), while a small minority (n = 26, 7.5% of all lesions) were hyperintense on both gradient-echo-T2* and quantitative susceptibility mapping (pattern B). Iron-laden lesions (n = 57, 16.5% of all lesions) were further classified as nodular (n = 22, 6.4%, pattern C) or ringlike (n = 35, 10.1%, pattern D). CONCLUSIONS: Ultra-high-field MR imaging may be useful in distinguishing MS from neuromyelitis optica. Different patterns related to iron and noniron pathology may provide in vivo insight into the pathophysiology of lesions in MS.

• MeSH
• algoritmy MeSH
• dítě MeSH
• dospělí MeSH
• elektromagnetická pole MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• mapování mozku MeSH
• mladiství MeSH
• mladý dospělý MeSH
• neuromyelitis optica diagnostické zobrazování   metabolismus   MeSH
• novorozenec MeSH
• počítačové zpracování obrazu MeSH
• předškolní dítě MeSH
• roztroušená skleróza diagnostické zobrazování   metabolismus   MeSH
• železo metabolismus   MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• Evropská unie MeSH
• výzkum MeSH
• Publikační typ
• abstrakty MeSH
• Geografické názvy
• Evropa MeSH

• Konspekt
• Veřejné zdraví a hygiena
• NLK Obory
• veřejné zdravotnictví
• politologie, politika, zdravotní politika

• O autorovi
• Commission of the European Communities. Biomedical and Health Research Programme Autorita