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Biomedical subjects

W Froncisz

Publications and source records attributed to W Froncisz.

48 records · Page 3Linked to original sources
PubMed1979

Hyperfine structure resolved by 2 to 4 GHz EPR of cytochrome c oxidase.

Using low frequency 2 to 4 GHz EPR at 10 K, we have resolved previously unseen hyperfine structure associated with the EPR-detectable copper signal of cytochrome c oxidase. The observed hyperfine structure appears consistent with hyperfine coupling to copper; although to account for all of the observed structure, an additional magnetic interaction is required as well. This work points out the utility of the 2 to 4 GHz EPR technique for resolving electronic hyperfine structural information from copper and possibly other paramagnetic sites in biomolecules when random variation in electronic g values is a cause of EPR line-broadening.

Copper↗
PubMedDate not supplied

High resolution MR imaging of glomus tumor.

High resolution magnetic resonance images of a surgically confirmed glomus tumor of the finger obtained with a surface coil are shown. Magnetic resonance has the potential to preoperatively evaluate soft tissue tumors of these regions which are poorly imaged by other modalities.

Female↗
PubMedDate not supplied

Planar-pair local coils for high-resolution magnetic resonance imaging, particularly of the temporomandibular joint.

The two-loop--one-gap loop--gap resonator (planar pair) has been investigated as a local receiving coil for high-resolution proton imaging at 1.5 T (63.8 MHz). Sensitivity contours were determined on the bench by measuring the voltage induced in the coil when it is placed on the surface of a tank containing 0.1-M NaCl, as a function of the coordinates and orientation of a radiating dipole inside the tank. Contours were obtained as a function of the diameter D of the two loops, and their separation d. For comparison, considerable data also were obtained for single-turn circular loops as a function of loop diameter. Coil quality factors, Q's, are reported in free space and the saline tank as a function of geometric parameters. Contours also were obtained using phantoms in a whole-body imager. Planar-pair coils couple to slabs of approximately (2D + d) X D cross section, and are superior to circular coils for imaging anatomic structures that are somewhat elongated. A particularly important feature of planar-pair local coils is that they are intrinsically isolated from the whole-body coil of the imager, and no special passive or active circuits are required when the whole-body coil is used for excitation. Planar-pair local coils have been optimized for imaging of the temporomandibular joint, and an image is shown.

Humans↗
PubMedDate not supplied

The cervical nerves and foramina: local-coil MR imaging.

A detailed study of the magnetic resonance (MR) appearance of the cervical nerves and neural foramina is presented. Using a "butterfly" local coil and a 1.5-T GE Signa MR system, the authors obtained 3-mm-thick axial, parasagittal, and 45 degrees oblique MR images of the cervical neural foramina in four normal volunteers. For the oblique images, subjects were rotated 45 degrees toward the right posterior oblique. Neural and vascular structures in the foramina were identified by correlation of the MR images with corresponding cryomicrotomic sections from four cadavers. The 45 degrees oblique images were more useful than axial or parasagittal images for demonstrating anatomic relations in the neural foramina. MR imaging with local coils demonstrates the complex anatomy of cervical neural foramina in various planes.

Adult↗