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Badania ultrasonograficzne z zastosowaniem środków kontrastujących

Fedak Andrzej

Inżynier i Fizyk Medyczny

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2019

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Vol. 8, nr 2

95--98

PL

Badania z zastosowaniem środków kontrastujących znacznie poszerzają możliwości ultrasonografii jako metody diagnostycznej. Autor przedstawił podstawy fizyczne, mechanizmy obrazowania oraz opisał możliwości zastosowania ultrasonografii z wykorzystaniem środków kontrastujących.

EN

Studies using contrast agents significantly expand the possibilities of ultrasonography as a diagnostic method. The author presented physical fundamentals, imaging mechanisms and described possibilities of using Contrast Enhanced Ultrasound.

2

The Forces Driving Streaming in the Presence of Scatterers Mimicking the Blood Cells and the Contrast Agents

Wójcik Janusz, Secomski Wojciech, Żołek Norbert

Archives of Acoustics

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2019

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Vol. 44, No. 4

659--668

EN

Acoustical Driving Forces (ADF), induced by propagating waves in a homogeneous and inhomogeneous lossy fluid (suspension), are determined and compared depending on the concentration of suspended particles. Using integral equations of the scattering theory, the single particle (inclusion) ADF was calculated as the integral of the flux of the momentum density tensor components over the heterogeneity surface. The possibility of negative ADF was indicated. Originally derived, the total ADF acting on inclusions only, stochastically distributed in ambient fluid, was determined as a function of its concentration. The formula for the relative increase in ADF, resulting from increased concentration was derived. Numerical ADF calculations are presented. In experiments the streaming velocities in a blood-mimicking starch suspension (2 μm radius) in water and Bracco BR14 contrast agent (SF6 gas capsules, 1 μm radius) were measured as the function of different inclusions concentration. The source of the streaming and ADF was a plane 2 mm diameter 20 MHz ultrasonic transducer. Velocity was estimated from the averaged Doppler spectrum obtained from originally developed pulsed Doppler flowmeter. Numerical calculations of the theoretically derived formula showed very good agreement with the experimental results.

3

Środki kontrastowe do obrazowania magnetyczno-rezonansowego na przykładzie związków kompleksowych żelaza

Kuźnik N., Wyskocka M.

Wiadomości Chemiczne

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2013

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[Z] 67, 7-8

665--694

EN

Nuclear magnetic resonance is already a broadly exploited phenomenon both in chemistry and medicine. Magnetic resonance imaging is a routine technique in medical diagnosis readily applied for soft tissues like brain, cardiovascular system or gastrointestinal tract. Contrast agents stepped into the field and enabled better recognition of a lesion in the early stage of a disease. The authors present an introductory description of a fascinating history, classification of contrast agents followed by the mechanisms of their action. Classes of positive and negative contrast agents are described. Further discussion is focused on the T1 (positive) molecular species. The mechanism was divided into (1) inner sphere, where both direct coordination of water molecule and its presence in second sphere is considered (Fig. 1) [1] and (2) an outer sphere mechanism which is assumed for the water molecules diffusing into the surrounding of the paramagnet [21, 28]. Further, the most important requirements for medical applications are given. Those are: high relaxivity, charge-osmolality, stability, toxicity via potential transmetallation of redox activity [42]. Molecular examples are quoted based on previously investigated iron complexes. Majority of them are iron(III) species [68], however, some iron(II) compounds like activable, self-immolative or ParaCEST systems have recently appeared [86, 89]. Iron compounds as positive contrast agents may soon accompany classic gadolinium complexes.