Quantitative imaging Dotaz Zobrazit nápovědu
1 online zdroj
- MeSH
- diagnostické zobrazování * metody MeSH
- Publikační typ
- periodika MeSH
- Konspekt
- Lékařské vědy. Lékařství
- NLK Obory
- radiologie, nukleární medicína a zobrazovací metody
The 255th ENMC workshop on Muscle Imaging in Idiopathic Inflammatory myopathies (IIM) aimed at defining recommendations concerning the applicability of muscle imaging in IIM. The workshop comprised of clinicians, researchers and people living with myositis. We aimed to achieve consensus on the following topics: a standardized protocol for the evaluation of muscle images in various types of IIMs; the exact parameters, anatomical localizations and magnetic resonance imaging (MRI) techniques; ultrasound as assessment tool in IIM; assessment methods; the pattern of muscle involvement in IIM subtypes; the application of MRI as biomarker in follow-up studies and clinical trials, and the place of MRI in the evaluation of swallowing difficulty and cardiac manifestations. The following recommendations were formulated: In patients with suspected IIM, muscle imaging is highly recommended to be part of the initial diagnostic workup and baseline assessment. MRI is the preferred imaging modality due to its sensitivity to both oedema and fat accumulation. Ultrasound may be used for suspected IBM. Repeat imaging should be considered if patients do not respond to treatment, if there is ongoing diagnostic uncertainty or there is clinical or laboratory evidence of disease relapse. Quantitative MRI is established as a sensitive biomarker in IBM and could be included as a primary or secondary outcome measure in early phase clinical trials, or as a secondary outcome measure in late phase clinical trials. Finally, a research agenda was drawn up.
- MeSH
- biologické markery MeSH
- kosterní svaly patologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- myozitida * diagnóza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- konzilia MeSH
- Geografické názvy
- Nizozemsko 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
- práce podpořená grantem MeSH
OBJECTIVE: An extension of single- and multi-channel blind deconvolution is presented to improve the estimation of the arterial input function (AIF) in quantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). METHODS: The Lucy-Richardson expectation-maximization algorithm is used to obtain estimates of the AIF and the tissue residue function (TRF). In the first part of the algorithm, nonparametric estimates of the AIF and TRF are obtained. In the second part, the decaying part of the AIF is approximated by three decaying exponential functions with the same delay, giving an almost noise free semi-parametric AIF. Simultaneously, the TRF is approximated using the adiabatic approximation of the Johnson-Wilson (aaJW) pharmacokinetic model. RESULTS: In simulations and tests on real data, use of this AIF gave perfusion values close to those obtained with the corresponding previously published nonparametric AIF, and are more noise robust. CONCLUSION: When used subsequently in voxelwise perfusion analysis, these semi-parametric AIFs should give more correct perfusion analysis maps less affected by recording noise than the corresponding nonparametric AIFs, and AIFs obtained from arteries. SIGNIFICANCE: This paper presents a method to increase the noise robustness in the estimation of the perfusion parameter values in DCE-MRI.
- MeSH
- algoritmy MeSH
- arterie patologie MeSH
- kontrastní látky chemie farmakokinetika MeSH
- magnetická rezonanční tomografie * MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- perfuze MeSH
- počítačová simulace MeSH
- počítačové zpracování obrazu * MeSH
- reprodukovatelnost výsledků MeSH
- vylepšení obrazu * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Spatial light modulators have become an essential tool for advanced microscopy, enabling breakthroughs in 3D, phase, and super-resolution imaging. However, continuous spatial-light modulation that is capable of capturing sub-millisecond microscopic motion without diffraction artifacts and polarization dependence is challenging. Here we present a photothermal spatial light modulator (PT-SLM) enabling fast phase imaging for nanoscopic 3D reconstruction. The PT-SLM can generate a step-like wavefront change, free of diffraction artifacts, with a high transmittance and a modulation efficiency independent of light polarization. We achieve a phase-shift > π and a response time as short as 70 µs with a theoretical limit in the sub microsecond range. We used the PT-SLM to perform quantitative phase imaging of sub-diffractional species to decipher the 3D nanoscopic displacement of microtubules and study the trajectory of a diffusive microtubule-associated protein, providing insights into the mechanism of protein navigation through a complex microtubule network.
- MeSH
- časové faktory MeSH
- interferenční mikroskopie metody statistika a číselné údaje MeSH
- kovové nanočástice ultrastruktura MeSH
- lidé MeSH
- mikroskopie atomárních sil MeSH
- mikroskopie fázově kontrastní metody statistika a číselné údaje MeSH
- mikrotubuly metabolismus ultrastruktura MeSH
- nanotechnologie MeSH
- nanotrubičky ultrastruktura MeSH
- optické jevy MeSH
- počítačová simulace MeSH
- proteiny asociované s mikrotubuly metabolismus MeSH
- proteiny buněčného cyklu metabolismus MeSH
- Schizosaccharomyces pombe - proteiny metabolismus MeSH
- světlo MeSH
- tubulin metabolismus MeSH
- zlato MeSH
- zobrazování trojrozměrné metody statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECT: To evaluate the potential of quantitative MR techniques [voxel-based morphometry (VBM), T2-relaxometry, mean diffusivity (MD), fractional anisotropy (FA)] in the diagnostics of amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS: Thirty-three ALS patients and thirty age- and sex-matched healthy volunteers were included in the cross-sectional study. T1WI, T2WI and T2 relaxometry sequences were performed at 1.5T. DWI was performed in a subgroup of 12 patients. Disease severity was estimated with the ALS Functional Rating Scale (ALS-FRS). RESULTS: We detected decreased T2 relaxation rate (R2) in the frontal white matter (FWM) (left and right P < 0.005) and caudate nucleus (left P < 0.005) in ALS patients. R2 in the FWM correlated with age in patients and controls. A correlation (P < 0.01, cluster-level corrected) between atrophy in the corona radiata and the limb ALS-FRS subset was found, as well as a difference between patients and controls in this area. No correlation between FA/MD and ALS-FRS was observed in the T2 hyperintense region of the posterior limb of the internal capsule (PLIC), or in the site of atrophy detected by VBM. No R2 or PD changes in the PLIC were detected. TBSS revealed decreased FA in the corona radiata and callosal body. CONCLUSIONS: Decreased R2 in the left caudate and bilateral FWM may help in the diagnostic process and disqualifies these regions as internal controls in ALS studies. The PLIC is not a reliable diagnostic marker of ALS.
- MeSH
- amyotrofická laterální skleróza diagnóza MeSH
- difuzní magnetická rezonance metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- mozek patologie MeSH
- průřezové studie MeSH
- senioři MeSH
- stupeň závažnosti nemoci MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
European respiratory review, ISSN 0905-9180 vol. 15, rev. 101, December 2006
105-232 s. : il., tab. ; 28 cm
Cancer therapy for both central nervous system (CNS) and non-CNS tumors has been previously associated with transient and long-term cognitive deterioration, commonly referred to as 'chemo fog'. This therapy-related damage to otherwise normal-appearing brain tissue is reported using post-mortem neuropathological analysis. Although the literature on monitoring therapy effects on structural magnetic resonance imaging (MRI) is well established, such macroscopic structural changes appear relatively late and irreversible. Early quantitative MRI biomarkers of therapy-induced damage would potentially permit taking these treatment side effects into account, paving the way towards a more personalized treatment planning.This systematic review (PROSPERO number 224196) provides an overview of quantitative tomographic imaging methods, potentially identifying the adverse side effects of cancer therapy in normal-appearing brain tissue. Seventy studies were obtained from the MEDLINE and Web of Science databases. Studies reporting changes in normal-appearing brain tissue using MRI, PET, or SPECT quantitative biomarkers, related to radio-, chemo-, immuno-, or hormone therapy for any kind of solid, cystic, or liquid tumor were included. The main findings of the reviewed studies were summarized, providing also the risk of bias of each study assessed using a modified QUADAS-2 tool. For each imaging method, this review provides the methodological background, and the benefits and shortcomings of each method from the imaging perspective. Finally, a set of recommendations is proposed to support future research.
