Search PubMed⌕ Search

Biomedical subjects

D M Kramer

Publications and source records attributed to D M Kramer.

39 records · Page 3Linked to original sources

Preliminary experimental results in humans and animals with a superconducting, whole-body, nuclear magnetic resonance scanner.

In order to determine the clinical usefulness of nuclear magnetic resonance (NMR) imaging, the investigators examined a variety of normal volunteers, patients with neoplastic lesions, and experimental animals. Preliminary results were obtained with the use of potential contrast agents. It was found that imaging applications of NMR in the vascular system, spine, brain, lung, and mediastinum offer certain advantages over other modalities. The absence of biological hazard as well as the ability to obtain unenhanced, noninvasive, gated images of the vascular system, as demonstrated in this study, make NMR particularly attractive. In addition to single-section capability, NMR makes it possible to obtain volume images of the spine and other organs which can be displayed in any desired plane or section thickness.

Animals↗

True three-dimensional nuclear magnetic resonance zeugmatographic images of a human brain.

A three-dimensional image of a preserved human brain, resolved into cubical 0.03 cm3 volume resonance (NMR) zeugmatography, using a two-stage represent concentrations of water and other liquids or liquid-like substances. The image has been displayed as computer-generated multiple transverse, coronal and sagittal sections, so as to display most clearly a number of anatomical features. The potential of this technique in physiological research and clinical practice is discussed.

Brain↗

Separation of water and fat MR images in a single scan at .35 T using "sandwich" echoes.

A method was developed for separation of water and fat MR images in a single scan with correction of static field inhomogeneity. The imaging sequence uses a single radiofrequency (RF) echo that is "sandwiched" between two gradient echoes. The gradient echoes are used to determine the B(0) distribution and to produce out-of-phase images after phase correction using the field map. An algorithm was developed to unwrap the phase images for quantitating the B(0) inhomogeneity. To account for differences in geometric distortion between the RF echo image and the gradient echo images due to the reversal of the read gradients, methods were developed to correct the images before the calculation of the final water and fat images. The proposed technique was implemented at .35 T. Both phantom and human images were acquired using the method. It is shown that water- and fat-separated images can be obtained in a single scan using the "sandwich" echoes in the presence of a relatively large B(0) inhomogeneity.

Adipose Tissue↗