Biomedical subjects

M Maryanski

Publications and source records attributed to M Maryanski.

4 recordsLinked to original sources

PubMed2002

3D dosimetry study of 188Re liquid balloon for intravascular brachytherapy using bang polymer gel dosemeters.

It has been suggested that the combination of intravascular brachytherapy and coronary stent implantation may result in further reduction of restenosis after percutaneous balloon angioplasty. The use of an angioplasty balloon filled with a 188Re liquid beta source for intravascular brachytherapy provides the advantages of accurate source positioning and uniform dose distribution to the coronary vessel wall. The effect of source edge and stent on the dose distribution of the target tissue may be clinically important. In BANG gels, the absorbed radiation produces free-radical chain polymerisation of acrylic monomers that are initially dissolved in the gel. The number of polymer particles is proportional to the absorbed dose. In this study, 3D dose distributions are presented for 188Re balloons, with and without stents, using a prototype He-Ne laser CT scanner and the proprietary BANG polymer gel dosemeters.

Brachytherapy↗

PubMedDate not supplied

Polyacrylamide-based phantoms as tissue substitute in experimental radiation physics.

Polyacrylamide-based tissue-equivalent phantoms simulating cortical bone and muscle are described. The equivalency is based upon similar elemental composition and density, and partial similarity in the morphology of bone. Satisfactory results were obtained when the phantoms were tested at low (20 keV) and high (15 MeV) gamma radiation. Applicability of this phantom material to neutron transport is discussed. The material can be molded and shaped and its composition is easily modified by altering the proportions of the constituents. Trace elements or radionuclides are easily added. Details of the physical and radiation characteristics of the formulated systems are given together with the manufacturing procedures.

Acrylic Resins↗

PubMedDate not supplied

Continuous three-dimensional radiation dosimetry in tissue-equivalent phantoms using electron paramagnetic resonance in L-alpha-alanine.

A new tissue-equivalent phantom material has been developed which also acts as a dosimeter. The new phantom material has a similar elemental composition to that of soft tissue and has a density 1.1 g/cm3. The phantom has an agar-gel base, and contains crystallized L-alpha-alanine which traps radiation-induced free radicals. Samples from the phantom were analyzed by an electron paramagnetic resonance (EPR) spectrometer and the intensity of the EPR signal was related to the absorbed dose. When calibrated, the phantom material acts as a dosimeter, with applications in radiation therapy.

Alanine↗

PubMedDate not supplied

In vivo measurement of cortical bone lead using polarized x rays.

An x-ray fluorescence system which utilizes polarized radiation to measure lead in vivo in human subjects is described. The minimum detection limit is approximately 6.4 ppm wet weight lead in the cortex of the tibia with 4 mm of overlying soft tissue. This appears to be adequate for assessing lead stores in lead-toxic preschool children. The measurement requires 16.5 min and is associated with an effective equivalent whole body dose to the subject of 2.5 muSv. The system, its calibration and its validation are described herein.

Bone and Bones↗