Diagnostic opportunities of new techniques of magnetic resonance imaging in detecting and differentiating dementia syndromes

Aging of population becomes an emerging health problem nowadays. One of symptoms of societal aging is an observed significant increase in the rate of dementia, which gradually excludes large group of patients from every aspect of life. Magnetic resonance imaging (MRI) is one of the most rapidly developing methods of neuroimaging. Modern MR techniques not only present structure and function of the brain, but also allow to assess metabolism, microcirculation and integrity if nervous tissue at the cellular level. The paper presents opportunities and perspectives of MRI in the diagnostics and differentiation of dementia.Starzenie się populacji staje się coraz bardziej aktualnym problemem zdrowotnym naszych czasów. Jednym z prze-jawów starzenia się społeczeństwa jest obserwowany istotny wzrost częstości zespołów otępiennych i związane z tym stopniowe wyłączanie dużej grupy chorych z każdego aspektu życia. Badanie metodą rezonansu magnetycznego (MR) jest jedną z najszybciej rozwijających się metod obrazowania mózgu. Współczesne techniki MR stwarzają nie tylko możliwość oceny zmian strukturalnych i czynnościowych, ale również metabolizmu, mikrokrążenia i integralności tkanki nerwowej na poziomie komórkowym. Praca przedstawia możliwości i perspektywy badania MR w diagnostyce i różnicowaniu zespołów otępiennych

Możliwości diagnostyczne nowych technik rezonansu magnetycznego w rozpoznawaniu i różnicowaniu zespołów otępiennych

Aging of population becomes an emerging health problem nowadays. One of symptoms of societal aging is an observed significant increase in the rate of dementia, which gradually excludes large group of patients from every aspect of life. Magnetic resonance imaging (MRI) is one of the most rapidly developing methods of neuroimaging. Modern MR techniques not only present structure and function of the brain, but also allow to assess metabolism, microcirculation and integrity if nervous tissue at the cellular level. The paper presents opportunities and perspectives of MRI in the diagnostics and differentiation of dementia.Starzenie się populacji staje się coraz bardziej aktualnym problemem zdrowotnym naszych czasów. Jednym z prze-jawów starzenia się społeczeństwa jest obserwowany istotny wzrost częstości zespołów otępiennych i związane z tym stopniowe wyłączanie dużej grupy chorych z każdego aspektu życia. Badanie metodą rezonansu magnetycznego (MR) jest jedną z najszybciej rozwijających się metod obrazowania mózgu. Współczesne techniki MR stwarzają nie tylko możliwość oceny zmian strukturalnych i czynnościowych, ale również metabolizmu, mikrokrążenia i integralności tkanki nerwowej na poziomie komórkowym. Praca przedstawia możliwości i perspektywy badania MR w diagnostyce i różnicowaniu zespołów otępiennych

Noninvasive evaluation of renal tissue oxygenation with blood oxygen level-dependent magnetic resonance imaging early after transplantation has a limited predictive value for the delayed graft function

Purpose: The aim of this study was to evaluate the feasibility of renal oxygenation assessment using blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in the early period after kidney transplantation and to estimate its prognostic value for delayed graft function. Material and methods: Examinations were performed in 50 subjects: 40 patients within a week after the kidney transplantation and 10 healthy controls, using T2*-weighted sequence. Measurements in transplant patients were correlated to basic laboratory parameters in the early period after transplantation and at follow-up. Results: Examinations of seven patients (18%) were rejected due to their poor technical quality. Mean R2* values in transplant recipients were lower than in controls (11.6 vs. 15.9 Hz; p = 0.0001). An R2* value of 0.28 Hz was calculated as the minimal detectable change. There was no relation between R2* values and laboratory parameters. However, patients eGFR ≥ 40 ml/min/1.73 m2 presented higher R2* values than recipients eGFR 0.7). Conclusions: Evaluation of renal graft oxygenation using BOLD MRI is technically challenging in the early period after transplantation. An R2* value of 0.28 Hz may in practice be considered as the minimal detectable change. The delayed graft function seems not to be dependent on early oxygenation values. Further, large-scale studies are necessary to confirm the latter observation

Metody i schemat okresowy kontroli obrazowej po przeznaczyniowym leczeniu tętniaków wewnątrzczaszkowych: systematyczny przegląd piśmiennictwa

Background and purpose To review the diagnostic value of angiographic methods and the optimal timetable for follow-up imaging of patients after endovascular treatment of intracranial aneurysms. Material and methods A comprehensive computer-aided search for relevant primary papers was performed using the MEDLINE, PubMed, Embase, and Cochrane Collaboration database from January 1991 to March 2011. Original papers were included that reported either diagnostic value of angiographic modalities for follow-up vs. digital subtracted angiography (DSA) or comparison of aneurysm occlusion rate in delayed vs. early follow-up. Results The systematic review identified 35 relevant studies: 3 on the diagnostic value of three-dimensional (3D) DSA, 30 on the performance of magnetic resonance angiography (MRA), and 3 on time schedules for follow-up. 3D DSA had sensitivity of 100%, and specificity of 58.3-94.7%. Magnetic resonance angiography had sensitivity of 28.4-100%, and specificity of 50.0-100%. The proportion of aneurysms that recanalized between the early follow-up examination at 6 months and the delayed imaging at 1.5-6.0 years was 0-2.5%. Conclusions Magnetic resonance angiography seems to be the best imaging method for the follow-up. In selected cases, when invasive angiography is necessary, 3D DSA should be considered to improve the diagnostic accuracy. Most patients who present with stable and adequate aneurysm occlusion at 6 months after coiling may not require further follow-up.Wstęp i cel pracy Celem pracy był przegląd opublikowanych prac oryginalnych na temat wartości diagnostycznej metod angiograficznych oraz schematów czasowych kontrolnych angiografii u chorych po przeznaczyniowym leczeniu tętniaków wewnątrzczaszkowych. Materiał i metody Przeprowadzono przegląd systematyczny piśmiennictwa indeksowanego w bazach MEDLINE, PubMed, Embase i Cochrane Collaboration w okresie od stycznia 1991 do marca 2011 r. Do analizy włączono badania oryginalne, w których określano wartość diagnostyczną metod angiograficznych w ocenie tętniaków po embolizacji w porównaniu z konwencjonalną arteriografią subtrakcyjną (DSA). Włączono również badania, w których porównywano wyniki embolizacji we wczesnej i późnej kontroli angiograficznej. Wyniki Kryteria włączenia do analizy spełniło 35 prac, w tym 3 oceniające wartość trójwymiarowej DSA (3D DSA), 30 oceniających angiografię rezonansu magnetycznego (MRA) i 3 dotyczące schematu czasowego kontroli angiograficznej. W analizowanych pracach 3D DSA miała czułość 100% i swoistość 58,3–94,7%, natomiast czułość i swoistość MRA wynosiły odpowiednio 28,4–100% i 50–100%. Odsetek tętniaków, które uległy rekanalizacji pomiędzy wczesnymi (po 6 miesiącach) i późnymi badaniami kontrolnymi (po 1,5–6 latach), wyniósł 0–2,5%. Wnioski Angiografia rezonansu magnetycznego wydaje się najlepszą metodą angiograficznej kontroli chorych po embolizacji tętniaków. W przypadkach, kiedy konieczne jest wykonanie angiografii inwazyjnej, 3D DSA może istotnie poprawić wartość diagnostyczną badania. Znaczna część chorych, u których stwierdza się prawidłowe wypełnienie tętniaka po 6 miesiącach od embolizacji, nie wymaga dalszej kontroli

Ocena alternatywnych metod pomiaru ilości zwapnień w tętnicach wieńcowych w wielorzędowej tomografii komputerowej

Background: Determining coronary artery calcifications is one o f the methods of coronary heart disease screening. However, the traditional Agatston Calcium Score (CS) shows low interexamination reproducibility. The aim of this study was to evaluate the interscan variability coefficients of calcium measures based on three modifications of the original Agatston equation. Material/Methods: Fifty adults (37 men and 13 women; mean age 46.2 ± 9.2 years) were included in the study. Each patient was examined with two consecutive, prospectively electrocardiographically triggered, multi-detector-row CT acquisitions to detect and quantify coronary artery calcifications. CS was calculated according to the method by Agatston et al. Alternative scores were calculated using a continuous weighting factor (CS-CM), the average lesion attenuation value (CS-SA), or both (CS-CA). The mean and median interscan percent variabilities o f the methods were evaluated using nonparametric analysis of variance. Results: In the 50 patients, 1315 calcified lesions were found. The alternative scores correlated well with CS (for CS vs. CS-SA, CS-CM, and CS-CA, r = 0.990, 0.840, and 0.946, respectively, P < 0.0001). The mean and median percent variabilities did not differ significantly among the methods tested (P = 0.370). For CS, CS-SA, CS-CM, and CS-CA the mean variabilities were 13.24%, 13.36%, 16.00%, and 13.62%, respectively. Except for CS-CM, the methods showed similar distributions o f variability vs. score on Bland and Altman plots. Conclusion: None of the tested modifications o f the Agatston method brought improvement in the interscan reproducibility of coronary calcium scoring. In our opinion, a significant reduction in variability may be achieved by a standardization of image acquisition and reconstruction

Interaction of diatomic molecules with nickel ions inside the channels of high silica zeolites : an EPR and DFT study

Interaction of CO, NO, and O-2 diatomics with Ni-II and ions dispersed in ZSM-5 zeolite was investigated by electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT) modelling. The resulting adducts Ni-I-CO, Ni-II-NO, and Ni-I-O-2 were identified based on g-tensor parameters, obtained by computer fitting of the powder EPR spectra, and next ascertained by parallel relativistic DFT calculations of the corresponding g-tensor values. The structures of the Ni-I-CO, Ni-II-NO, and Ni-I-O-2 complexes were obtained by geometry optimization with the Kohn-Sham method. Binding of the diatomics was discussed in terms of the spin-pairing and electron density transfer events. Interaction of CO with Ni-I cations led to the pronounced change in the coordination and electronic structure of the Ni-I center, however, no redox processes were observed in agreement with the "innocent" nature of CO as a ligand. On the contrary, strong electron and spin density redistribution was observed upon NO and O-2 interaction ("non-innocent ligands") leading to the formation of the bound nitrosonium NO delta+ and superoxo O-2(-) species, respectively

Improved imaging of colorectal liver metastases using single-source fast kVp-switching dual-energy CT : preliminary results

Purpose: Computed tomography remains the first-choice modality for assessment of colorectal cancer liver metastases (CRLM). Dual-energy computed tomography (DECT) is a relatively new technique that is becoming increasingly available. One of the advantages of DECT is the ability to maximise iodine detection. Our aim was to test whether single-source, fast kVp-switching DECT can improve imaging quality of CRLM compared to conventional (polychromatic) CT. Material and methods: Twenty consecutive patients were enrolled into a preliminary prospective study. The scanning protocol consisted of four phases: non-contrast with standard 120 kV tube voltage and three post-contrast phases with rapid voltage switching. As a result, three sets of images were reconstructed: pre- and postcontrast polychromatic (PR), monochromatic (MR), and iodine concentration map (IM). To compare the sensitivity of the tested reconstructions, the number of CRLMs and the maximum diameter of the largest lesion were calculated. Objective image quality was measured as signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The radiation dose was expressed as CTDIvol. Results: Imaging was successfully performed in all patients. The number of detected lesions was significantly lower on PR images than on IM and MR 50-70 keV (mean number: 4.20 and 4.45, respectively). IM and MR at 70 keV presented the highest quality. SNR was significantly higher for IM and 70 keV images than for other reconstructions. The mean radiation dose was 14.61 mGy for non-contrast 120 kV scan and 17.89 mGy for single DECT scan (p < 0.05). Conclusions: DECT is a promising tool for CRLM imaging. IM and low-photon energy MR present the highest differences in contrast between metastases and the normal liver parenchyma

Coronary artery aneurysm after implantation of an endothelial progenitor cell capturing stent

The GenousTM stent coated with anti-CD34 antibodies has been designed to accelerate healing of the vessel by attracting circulating endothelial progenitor cells. Rapid restoration of a functional endothelial layer with a full coverage of the stent struts aims to minimise arterial injury after coronary stenting and to prevent thrombus formation and neointima proliferation. We report a case of a 56 year-old man who developed a coronary artery aneurysm after the implantation of a GenousTM stent due to an edge restenosis in sirolimus-eluting stent. We present diagnostics of our patient with the application of intravascular ultrasound and coronary computed tomography angiography, discuss his management, and hypothesise about the pathomechanism of aneurysm formation