Wyniki wyszukiwania - Biblioteka Nauki

1

Assessmentof carotid artery stenoses in 3D contrast-enhanced magnetic resonance angiography, based on improved generation of the centerline

100%

Hoyos M. H. , Orkisz M. , Douek P. C. , Magnin I. E.

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tom Vol. 14, No. 4

349-378

EN

A methods is proposed for generation of the centerline of 3D tubular shapes using an extensible-skeleton model. Starting from a user-selected point, the skeleton grown by iteratively adding subsequent centerline points within a prediction-estimation scheme controlled by a multi-scale analysis of the image moments. The location of the next point is predicted according the local orientation of the tubular structure. The coordinates of the predicted point are corrected under the influence of image forces and of prior model shape constraints. The extraction of artery centerlines from magnetic resonance angiography (MRA) images is described. The goal is a quantitative assessment of arterial stenoses based on cross-sectional diameters and areas of the vessel contours in the planes locally perpendicular to the centerline. For this purpose, iso-contours extraction based on an adaptive local iso-value have been implemented. The robustness and accuracy of the method have been demonstrated on MRA data on 5 reference phantoms and on 17 patients' carotid arteries. 97% of the centerlines were exploitable in the carotid arteries (100% in the phantoms). On average, the centerlines were extracted within 1 second, and the whole quantification process took less than 1 minute per artery, including interaction and display. The Mean difference (± standard deviation) between stenosis percentages, semi-automatically measured and visually estimated by radiologists, was 0,23% ± 7.89%. The reproducibility of the semi-automatic method was significantly better.

2

Woven coronary artery: a case report and literature review

88%

Yuan S.-M.

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nr 3

EN

Woven coronary artery is extremely rare. It is characterised by thin channels arising from the coronary artery and reanastamosis at the distal portion. A 62-year-old man was diagnosed of coronary artery disease. Coronary angiography showed 3-vessel coronary artery disease. The distal right coronary artery derived 3 twisting thin channels, and the inferior thin channel sprouted second-class thin channels, which then reanstomosed distally. He received off-pump coronary artery bypass. The present patient had woven coronary artery with a more complex configuration of thin channels different from the previously reported cases. (Folia Morphol 2013; 72, 3: 263–266)

3

Configurations of the circle of Willis: a computed tomography angiography based study on a Polish population

75%

Klimek-Piotrowska W. , Kopec M. , Kochana M. , Krzyzewski R. M. , Tomaszewski K. A. , Brzegowy P. , Walocha J.

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nr 4

EN

The aim of the study was to investigate the distribution of the circle of Willis variants in Polish population by means of computed tomography angiography (CTA). The results were then analysed and compared with another study that used similar methods but that was carried out on an ethnically distinct population. Patients presenting with intracranial pathology were excluded from the initial study population. In total, 250 CTA belonging to 129 female and 121 male patients were reviewed. A modified classification system of the circle was proposed, which took into consideration the anterior and the posterior aspects of the circle individually. The typical variant of Willis’s circle occurred in 16.80% of cases. The anterior and the posterior portions of the circle were normal in 47.20% and 26.80% of the patients respectively. As for the anterior part, lack of the anterior communicating artery was the most frequent abnormality (22.80%). Bilateral absence of posterior communicating arteries was the most common anomaly in the posterior part of the circle (29.20%). This type of anomaly was also the most common, when taking into consideration the entire circle (12.00%). There were statistically significant differences between the age groups and genders when considering the occurrence of an incomplete circle. Overall, a substantial proportion of patients manifested clinically important variants that were incapable of providing collateral circulation. Comparison with other imaging-based and cadaveric studies revealed noticeable differences, that may have resulted from the variable technical features of other studies or other factors such as the ethnical origins of the studied populations. (Folia Morphol 2013; 72, 4: 293–299)

4

Z historii radiologii – „Nożycówka”, czyli nowatorski pomysł polskich konstruktorów w angiografii

75%

Urbanik A. , Urbanik M.

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tom Vol. 8, nr 5

359--360

PL

Autorzy przedstawiają nowatorskie rozwiązanie pozycjonera systemu angiograficznego zaprojektowane przez polskich konstruktorów.

EN

The authors present an innovative solution of the angiographic system positioner designed by Polish designers.

5

Clinical study on the coronary flow measurements method based on coronarographic image sequences

63%

Goszczyńska H. , Kowalczyk L. , Rewicki M.

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2006

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tom Vol. 26, no. 2

63-73

EN

Many studies concerning evaluation of the artery blood flow based on coronarographic images have been made. Application of the indicator-dilution technique allows calculation of absolute values of the blood flow in the coronary arteries based on the densitometric analysis of coronarographic image sequences under some specific conditions imposed on injections of the contrast medium and digital image sequences registration. This method is based on densitometric measurements carried out in two sequences of images of the same artery. The first sequence is recorded during the routine injection of the contrast, and the other is recorded during the slow test injection of the contrast with a reduced amount of the indicator. The method was tested on coronarographic images obtained in routine examinations in two groups of control patients. The comparative analysis of 18 patients indicates that there exists a moderate consistency between the results of this method and the clinical assessment. The results of our studies are strongly dependent on the accuracy of the measurements and the method of recording. Proposed method, tested on the model of artery and measurements obtained from coronarographic examinations of control groups of patients, provides grounds for future studies.

6

Acute ischemic stroke within the area of MCA from ICA thrombosis complicating moderate COVID-19 infection

63%

Kurys-Denis E. , Prystupa A. , Sak J.

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nr 1

7

Metodyka obliczania dawki pochłoniętej przez pacjenta podczas zabiegów z zakresu neuroradiologii zabiegowej na podstawie kermy

63%

Modlińska S.

Inżynier i Fizyk Medyczny

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2016

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tom Vol. 5, nr 4

199--201

PL

Wymogi prawa narzucają na personel obliczanie dawki pochłoniętej (w grejach) i odniesienie jej wartości do limitów określonych w Rozporządzeniu Ministra Zdrowia z dnia 18 lutego 2011 r. w sprawie warunków bezpiecznego stosowania promieniowania jonizującego dla wszystkich rodzajów ekspozycji medycznej. Celem pracy jest przybliżenie metodyki obliczania dawki pochłoniętej w grejach [Gy] na podstawie parametrów otrzymanych z rejestratorów dawki, na przykład kermy. Zastosowanie współczynnika korekcji, współczynnika BSF oraz wykorzystanie arkuszy kalkulacyjnych umożliwia szybką i prostą realizację zadań postawionych przez Rozporządzenie.

EN

Legal requirements impose on staff necessity of calculation of the absorbed dose (expressed in grays) and the reference of the value to the limits set out in the Regulation of the Minister of Health on 18 February 2011 on the conditions for the safe use of ionizing radiation for all types of medical exposure. The aim of this work is to present the methodology of calculation of the absorbed dose in grays [Gy] on the basis of parameters obtained from the dosage recorders, for example kerma. The usage of correction factor, BSF factor and spread sheets enables quick and easy implementation of tasks set by the Regulation.

8

Wybrane zagadnienia z ultrasonografii

63%

Adamczewska D.

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tom z. 112

77-86

PL

Od kilkudziesięciu lat następuje szczególnie szybki rozwój badań diagnostycznych metodą ultradźwiękową. Badania te pozwalają uzyskać w sposób nieinwazyjny i dla pacjenta nieszkodliwy wiele cennych informacji o strukturach biologicznych, ich topografii, a także fizjo- i patofizjologicznych zjawiskach w organizmie człowieka. W dzisiejszych czasach można za pomocą ultradźwięków wykonywać badania angiograficzne (nieinwazyjne!) przy nieporównanie niższej cenie aparatu.

EN

In the paper some problems of ultrasonography application in medical diagnostic have been described. Examination types and their development are discussed.

9

Imaging the retinal and choroidal vasculature using Spatio-Temporal Optical Coherence Tomography (STOC-T)

63%

Liżewski K. , Tomczewski S. , Borycki D. , Węgrzyn P. , Wojtkowski M.

Biocybernetics and Biomedical Engineering

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2024

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tom Vol. 44, no. 1

95--104

EN

Spatio-Temporal Optical Coherence Tomography (STOC-T) is a novel imaging technique using light with controlled spatial and temporal coherence. Retinal images obtained using the STOC-T system maintain high resolution in all three dimensions, on a sample of about 700 μm, without the need for mechanical scanning. In the present work, we use known data processing algorithms for optical coherence tomography angiography (OCTA) and modify them to improve the rendering of the vasculature in the human retina at different depths by introducing the angio STOC-T method. The algorithms are primarily sensitive to the strong signal phase variance corresponding to the appearance of a wide Doppler band in STOC-T signals obtained for millisecond exposure times. After using STOC-T angiography, we can render high contrast images of the choroid.

10

Diagnostics in pulmonary hypertension

51%

Schannewll C. M. , Steiner S. , Strauer B.-E.

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tom 58

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nr 5