Richard Znamirowski

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PURPOSE To image cartilage-bone interfaces in naturally occurring and experimentally prepared human cartilage-bone specimens at 3 T by using ultrashort echo time (TE) (UTE) and conventional pulse sequences to (a) determine the appearance of the signal intensity patterns and (b) identify the structures contributing to signal intensity on the UTE MR images.(More)
Tendons and entheses are magnetic resonance (MR) "invisible" when imaged with conventional clinical pulse sequences. When the highly ordered, collagen-rich fibers in tendons and entheses are placed at the magic angle, dipolar interactions are decreased and their T2s are often considerably increased. The bulk magnetic susceptibility of tendons and entheses(More)
Carotid plaque calcification normally appears as a signal void with clinical MR sequences. Here, we describe the use of an adiabatic inversion recovery prepared two-dimensional ultrashort echo time sequence to image and characterize carotid plaque calcification using a clinical 3-T scanner. T(1), T 2*, and free water content were measured for seven carotid(More)
Collagen fibers in tendons and entheses are highly ordered. The protons within the bound water are subject to dipolar interactions whose strength depends on the orientation of the fibers to the static magnetic field B(0). Clinical pulse sequences have been employed to investigate this magic angle effect of the Achilles tendon, but only limited to imaging(More)
OBJECTIVE The aim of the study was to determine whether quantitative ultrashort echo time (UTE) -T1ρ magnetic resonance (MR) measurements are sensitive to proteoglycan degradation in human menisci by trypsin digestion. METHODS Conventional and quantitative UTE-T1ρ MR sequences were performed on 4 meniscal samples using a 3T scanner. Magnetic resonance(More)
We describe the use of ultrashort echo time (UTE) sequences and fast spin echo sequences to assess cortical bone using a clinical 3T scanner. Regular two- and three-dimensional UTE sequences were used to image both bound and free water in cortical bone. Adiabatic inversion recovery prepared UTE sequences were used to image water bound to the organic matrix.(More)
Biological tissues usually contain distinct water compartments with different transverse relaxation times. In this study, two-dimensional, multi-slice, ultrashort echo time spectroscopic imaging (UTESI) was used with bi-component analysis to detect bound and free water components in musculoskeletal tissues. Feasibility studies were performed using numerical(More)
As part of a program to establish international standards of selected allergens, 6 coded extracts of Alternaria were assessed in 6 laboratories by immunochemical, biochemical and physicochemical procedures. Direct RAST, RAST inhibition, quantitative skin tests and leukocyte histamine release were used to assign relative orders of potency to the 6 extracts.(More)