PURPOSE: Water removal is one of the computational bottlenecks in the processing of high-resolution MRSI data. The purpose of this work is to propose an approach to reduce the computing time required for water removal in large MRS data. METHODS: In this work, we describe a singular value decomposition-based approach that uses the partial position-time separability and the time-domain linear predictability of MRSI data to reduce the computational time required for water removal. Our approach arranges MRS signals in a Casorati matrix form, applies low-rank approximations utilizing singular value decomposition, removes residual water from the most prominent left-singular vectors, and finally reconstructs the water-free matrix using the processed left-singular vectors. RESULTS: We have demonstrated the effectiveness of our proposed algorithm for water removal using both simulated and in vivo data. The proposed algorithm encompasses a pip-installable tool ( https://pypi.org/project/CSVD/), available on GitHub ( https://github.com/amirshamaei/CSVD), empowering researchers to use it in future studies. Additionally, to further promote transparency and reproducibility, we provide comprehensive code for result replication. CONCLUSIONS: The findings of this study suggest that the proposed method is a promising alternative to existing water removal methods due to its low processing time and good performance in removing water signals.

• Klíčová slova
• MR spectroscopic imaging, functional MRS, low-rank approximations, water removal, water suppression,
• MeSH
• algoritmy MeSH
• magnetická rezonanční spektroskopie MeSH
• magnetická rezonanční tomografie * metody   MeSH
• reprodukovatelnost výsledků MeSH
• voda * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• voda * MeSH

Magnetic resonance spectroscopic imaging (MRSI) involves a huge number of spectra to be processed and analyzed. Several tools enabling MRSI data processing have been developed and widely used. However, the processing programs primarily focus on sophisticated spectra processing and offer limited support for the analysis of the calculated spectroscopic maps. In this paper the jSIPRO (java Spectroscopic Imaging PROcessing) program is presented, which is a java-based graphical interface enabling post-processing, viewing, analysis and result reporting of MRSI data. Interactive graphical processing as well as protocol controlled batch processing are available in jSIPRO. jSIPRO does not contain a built-in fitting program. Instead, it makes use of fitting programs from third parties and manages the data flows. Currently, automatic spectra processing using LCModel, TARQUIN and jMRUI programs are supported. Concentration and error values, fitted spectra, metabolite images and various parametric maps can be viewed for each calculated dataset. Metabolite images can be exported in the DICOM format either for archiving purposes or for the use in neurosurgery navigation systems.

• Klíčová slova
• DICOM export, LCModel, Metabolite images, Spectra processing, Spectroscopic imaging, TARQUIN, jMRUI,
• MeSH
• automatizované zpracování dat statistika a číselné údaje   MeSH
• Fourierova analýza MeSH
• funkční zobrazování neurálních procesů statistika a číselné údaje   MeSH
• lidé MeSH
• magnetická rezonanční tomografie statistika a číselné údaje   MeSH
• mozek metabolismus   patologie   MeSH
• programovací jazyk MeSH
• software * MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: A prospective quantitative MR study of brain tumours was performed to show the potential of combining different MR techniques to distinguish various disease processes in routine clinical practice. METHODS: Twenty-three patients with various intracranial tumours before treatment (diagnosis confirmed by a biopsy) and 59 healthy subjects were examined on a 3-T system by conventional MR imaging, 1H spectroscopic imaging, diffusion tensor imaging and T2 relaxometry. Metabolic concentrations and their ratios, T2 relaxation times and mean diffusivities were calculated and correlated on a pixel-by-pixel basis and compared to control data. RESULTS: Different tumour types and different localisations revealed specific patterns of correlations between metabolic concentrations and mean diffusivity or T2 relaxation times. The patterns distinguish given tissue states in the examined area: healthy tissue, tissue infiltrated by tumour, active tumour, oedema infiltrated by tumour, oedema, etc. This method is able to describe the complexity of a highly heterogeneous tissue in the tumour and its vicinity, and determines crucial parameters for tissue differentiation. CONCLUSIONS: A combination of different MR parameters on a pixel-by-pixel basis in individual patients enables better identification of the tumour type, direction of proliferation and assessment of the tumour extension. KEY POINTS: • Magnetic resonance offers many different methods of examining the brain. • A combination of quantitative MR parameters helps distinguish different brain lesions • Different tumour types revealed specific correlation patterns amongst different MR parameters • The correlation patterns reflect highly heterogeneous complex tissue within tumours.

• MeSH
• biopsie metody   MeSH
• difuze MeSH
• dospělí MeSH
• edém patologie   MeSH
• gliom MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetická rezonanční tomografie metody   MeSH
• mapování mozku metody   MeSH
• mozek patologie   MeSH
• nádory mozku diagnóza   patologie   MeSH
• počítačové zpracování obrazu MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• zobrazování difuzních tenzorů metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Proton magnetic resonance spectroscopy ((1)H MRS) is beneficial in the lateralization of the epileptogenic zone in temporal lobe epilepsy; however, its role in extratemporal and, especially, MRI-negative epilepsy has not been established. This study seeks to verify how (1)H MRS could help in localizing the epileptogenic zone in patients with MRI-negative extratemporal epilepsy. Seven patients (8-23 years) with MRI-negative refractory focal epilepsy were studied using (1)H MRS on a 1.5T MR system. Chemical shift imaging sequence in the transversal plane was directed towards the suspected epileptogenic zone localized by seizure semiology, scalp video/EEG, ictal SPECT and (18)FDG-PET. Spectra were evaluated using the program CULICH, and the coefficient of asymmetry was used for quantitative lateralization. MRS detected lateralization in all patients and was able to localize pathology in five. The most frequent findings were decreased ratios of N-acetylaspartate to choline compounds characterized by increasing choline concentration. The localization of the (1)H MRS abnormality correlated well with ictal SPECT and subdural mapping. In all cases, histopathological analysis revealed MRI-undetected focal cortical dysplasias. (1)H MRS could be more sensitive for the detection of discrete malformations of cortical development than conventional MRI. It is valuable in the presurgical evaluation of patients without MRI-apparent lesions.

• MeSH
• cholin metabolismus   MeSH
• dítě MeSH
• dospělí MeSH
• elektroencefalografie MeSH
• epilepsie parciální diagnóza   diagnostické zobrazování   metabolismus   patologie   MeSH
• fluorodeoxyglukosa F18 MeSH
• jednofotonová emisní výpočetní tomografie MeSH
• kreatin metabolismus   MeSH
• kyselina aspartová analogy a deriváty   metabolismus   MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetická rezonanční tomografie MeSH
• mapování mozku MeSH
• mladiství MeSH
• radiofarmaka MeSH
• senzitivita a specificita MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cholin MeSH
• fluorodeoxyglukosa F18 MeSH
• kreatin MeSH
• kyselina aspartová MeSH
• N-acetylaspartate MeSH Prohlížeč
• radiofarmaka MeSH

The dissolution mechanism of a poorly aqueous soluble drug from amorphous solid dispersions was investigated using a combination of two imaging methods: attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic imaging and magnetic resonance imaging (MRI). The rates of elementary processes such as water penetration, polymer swelling, growth and erosion of gel layer, and the diffusion, release and in some cases precipitation of drug were evaluated by image analysis. The results from the imaging methods were compared with drug release profiles obtained by classical dissolution tests. The study was conducted using three polymeric excipients (soluplus, polyvinylpyrrolidone - PVP K30, hydroxypropylmethyl cellulose - HPMC 100M) alone and in combination with a poorly soluble drug, aprepitant. The imaging methods were complementary: ATR-FTIR imaging enabled a qualitative observation of all three components during the dissolution experiments, water, polymer and drug, including identifying structural changes from the amorphous form of drug to the crystalline form. The comparison of quantitative MRI data with drug release profiles enabled the different processes during dissolution to be established and the rate-limiting step to be identified, which - for the drug-polymer combinations investigated in this work - was the drug diffusion through the gel layer rather than water penetration into the tablet.

• Klíčová slova
• Dissolution rate, FT-IR spectroscopy, Magnetic resonance imaging, Solid dispersion, Spray drying, Water penetration,
• MeSH
• aprepitant MeSH
• časové faktory MeSH
• magnetická rezonanční tomografie * přístrojové vybavení   MeSH
• molekulární struktura MeSH
• morfoliny chemie   MeSH
• polymery chemie   MeSH
• spektroskopie infračervená s Fourierovou transformací přístrojové vybavení   MeSH
• uvolňování léčiv MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aprepitant MeSH
• morfoliny MeSH
• polymery MeSH

Spectroscopic imaging (SI) is a method that enables the measurement of the spatial distribution of metabolite concentrations in tissue. In this paper, an overview of measurement and processing techniques for SI is given. First, the basic structure of SI pulse sequences is introduced and the concepts of k-space, point spread function and spatial resolution are described. Then, special techniques are presented for the purpose of eliminating spurious signals and reducing measurement time. Finally, basic post-processing of SI data and the methods for viewing the results of SI measurement are summarized.

• MeSH
• artefakty MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• mapování mozku metody   MeSH
• mozek - chemie MeSH
• mozek metabolismus   MeSH
• počítačové zpracování signálu MeSH
• tělesná voda metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Magnetic resonance spectroscopic imaging (MRSI) enables the simultaneous noninvasive acquisition of MR spectra from multiple spatial locations inside the brain. Although 1H-MRSI is increasingly used in the human brain, it is not yet widely applied in the preclinical setting, mostly because of difficulties specifically related to very small nominal voxel size in the rat brain and low concentration of brain metabolites, resulting in low signal-to-noise ratio (SNR). In this context, we implemented a free induction decay 1H-MRSI sequence (1H-FID-MRSI) in the rat brain at 14.1 T. We combined the advantages of 1H-FID-MRSI with the ultra-high magnetic field to achieve higher SNR, coverage, and spatial resolution in the rat brain and developed a custom dedicated processing pipeline with a graphical user interface for Bruker 1H-FID-MRSI: MRS4Brain toolbox. LCModel fit, using the simulated metabolite basis set and in vivo measured MM, provided reliable fits for the data at acquisition delays of 1.30 ms. The resulting Cramér-Rao lower bounds were sufficiently low (< 30%) for eight metabolites of interest (total creatine, N-acetylaspartate, N-acetylaspartate + N-acetylaspartylglutamate, total choline, glutamine, glutamate, myo-inositol, and taurine), leading to highly reproducible metabolic maps. Similar spectral quality and metabolic maps were obtained with one and two averages, with slightly better contrast and brain coverage due to increased SNR in the latter case. Furthermore, the obtained metabolic maps were accurate enough to confirm the previously known brain regional distribution of some metabolites. The acquisitions proved high reproducibility over time. We demonstrated that the increased SNR and spectral resolution at 14.1 T can be translated into high spatial resolution in 1H-FID-MRSI of the rat brain in 13 min using the sequence and processing pipeline described herein. High-resolution 1H-FID-MRSI at 14.1 T provided robust, reproducible, and high-quality metabolic mapping of brain metabolites with minimal technical limitations.

• Klíčová slova
• 1H‐FID‐MRSI, brain metabolites, magnetic resonance spectroscopic imaging, metabolite mapping, rat brain, ultra‐high field,
• MeSH
• krysa rodu Rattus MeSH
• magnetická rezonanční tomografie metody   MeSH
• metabolom MeSH
• mozek * metabolismus   diagnostické zobrazování   MeSH
• poměr signál - šum MeSH
• potkani Sprague-Dawley MeSH
• potkani Wistar MeSH
• protonová magnetická rezonanční spektroskopie metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: Imaging methods were used as tools to provide an understanding of phenomena that occur during dissolution experiments, and ultimately to select the best ratio of two polymers in a matrix in terms of enhancement of the dissolution rate and prevention of crystallization during dissolution. METHODS: Magnetic resonance imaging, ATR-FTIR spectroscopic imaging and Raman mapping have been used to study the release mechanism of a poorly water soluble drug, aprepitant, from multicomponent amorphous solid dispersions. Solid dispersions were prepared based on the combination of two selected polymers - Soluplus, as a solubilizer, and PVP, as a dissolution enhancer. Formulations were prepared in a ratio of Soluplus:PVP 1:10, 1:5, 1:3, and 1:1, in order to obtain favorable properties of the polymer carrier. RESULTS: The crystallization of aprepitant during dissolution has occurred to a varying degree in the polymer ratios 1:10, 1:5, and 1:3, but the increasing presence of Soluplus in the formulation delayed the onset of crystallization. The Soluplus:PVP 1:1 solid dispersion proved to be the best matrix studied, combining the abilities of both polymers in a synergistic manner. CONCLUSIONS: Aprepitant dissolution rate has been significantly enhanced. This study highlights the benefits of combining imaging methods in order to understand the release process.

• Klíčová slova
• FT-IR spectroscopic imaging, amorphous solid dispersion, confocal Raman spectroscopy, crystallisation, magnetic resonance imaging,
• MeSH
• aprepitant MeSH
• chemie farmaceutická metody   MeSH
• krystalizace MeSH
• magnetická rezonanční tomografie metody   MeSH
• morfoliny chemie   MeSH
• nosiče léků chemie   MeSH
• polyethylenglykoly chemie   MeSH
• polymery chemie   MeSH
• polyvinyly chemie   MeSH
• pyrrolidiny chemie   MeSH
• rozpustnost MeSH
• spektroskopie infračervená s Fourierovou transformací metody   MeSH
• uvolňování léčiv MeSH
• voda chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aprepitant MeSH
• morfoliny MeSH
• nosiče léků MeSH
• poly(N-vinylpyrrolidine) MeSH Prohlížeč
• polyethylenglykoly MeSH
• polymery MeSH
• polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer MeSH Prohlížeč
• polyvinyly MeSH
• pyrrolidiny MeSH
• voda MeSH

A combination of morphological imaging of the brain with microstructural and functional imaging provides a comprehensive overview of the properties of individual tissues. While diffusion weighted imaging provides information about tissue cellularity, spectroscopic imaging allows us to evaluate the integrity of neurons and possible anaerobic glycolysis during tumor hypoxia, in addition to the presence of accelerated synthesis or degradation of cellular membranes; on the other hand, PET metabolic imaging is used to evaluate major metabolic pathways, determining the overall extent of the tumor (18F-FET, 18F-FDOPA, 18F-FCH) or the degree of differentiation (18F-FDG, 18F-FLT, 18F-FDOPA and 18F-FET). Multi-parameter analysis of tissue characteristics and determination of the phenotype of the tumor tissue is a natural advantage of PET/MRI scanning. The disadvantages are higher cost and limited availability in all centers with neuro-oncology surgery. PET/MRI scanning of brain tumors is one of the most promising indications since the earliest experiments with integrated PET/MRI imaging systems, and along with hybrid imaging of neurodegenerative diseases, represent a new direction in the development of neuroradiology on the path towards comprehensive imaging at the molecular level.

• Klíčová slova
• Brain tumors, Hybrid imaging, Multiparametric imaging, PET/MRI, Positron emission tomography,
• MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• mozek diagnostické zobrazování   MeSH
• multimodální zobrazování metody   MeSH
• nádory mozku diagnostické zobrazování   MeSH
• pozitronová emisní tomografie metody   MeSH
• radiofarmaka * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• radiofarmaka * MeSH

Current possibilities and limitations of the simulation of in vivo magnetic resonance spectroscopic signals are demonstrated from the point of view of a simulation software user as well as its programmer. A brief review of the quantum-mechanical background addresses the specific needs of simulation implementation and in vivo MR spectroscopy in general. Practical application examples demonstrate how flexible simulation software, such as NMRScopeB, can be utilized not only for the preparation of metabolite basis signals for quantification of metabolite concentrations, but also in pulse sequence development, assessment of artifacts and analyzing mechanism leading to unexpected signal phenomena.

• Klíčová slova
• In vivo spectroscopy, Magnetic resonance spectroscopy, Metabolite concentration quantitation, Quantum mechanical simulation,
• MeSH
• biologické modely MeSH
• kvantová teorie * MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• magnetická rezonanční tomografie metody   MeSH
• počítačová simulace MeSH
• software * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH