PubMed Health⌕ Search

Biomedical subjects

G N Hounsfield

Publications and source records attributed to G N Hounsfield.

12 recordsLinked to original sources
PubMed1985

Dimensional accuracy of magnetic resonance in studies of the heart.

Magnetic resonance (MR) can provide high-resolution tomographic images of the heart at any part of the cardiac cycle. Tests on static and dynamic phantoms showed that the technique can give accurate measurements of ventricular wall thickness, cavity volume, and stroke volume. In 20 patients with angina pectoris, electrocardiographically gated MR images of the left ventricle were compared with X-ray contrast ventriculograms. There was good correlation with the anteroposterior ventriculogram, but poorer correlation in the lateral projection because of difficulty in locating the aortic valve precisely on the ventriculogram. In 20 normal subjects, left and right ventricular volumes at end-diastole and end-systole were measured by summing the areas of the cavities in multiple contiguous sections. Stroke volumes and ejection fractions were thus calculated, and the ratio of left to right ventricular stroke volume was very close to the theoretical value of 1, in all cases. In any individual volume measurement, the error was approximately 2%. MR therefore provides an accurate non-invasive method of studying cardiac dimensions and function.

Animals↗
PubMed1976

Picture quality of computed tomography.

Some limitations that impair the picture quality of computed tomography are presented. Picture grain is analyzed in detail and its relationship to different matrix sizes is demonstrated. The choices of matrix size for viewing various parts of the body are defined, and the need for higher resolution in the future is debated. Comparison is made between two scanning systems: the moving fan beam with rotation and the simple rotating fan beam. Possible artifacts in the picture caused by drift and delay in dector response are discussed.

Computers↗
PubMed1976

Historical notes on computerized axial tomography.

The original experiments on computerized tomography at the Central Research Laboratories of EMI are discussed. Examples trace the history of improvement in definition and process time, leading to results from the first EMI Scanner which was installed in the Atkinson Morley's Hospital in September 1971.

Brain Diseases↗
PubMedDate not supplied

Gated computed tomography of the human heart.

Production of in vivo images of the human heart, with delineation of the individual cardiac chambers and myocardial wall thickness, was accomplished by coupling a relatively simple electrocardiographic gating device to a translate-rotate type of computed body tomographic scanner. Differentiation between the myocardial wall and the intracardiac blood pool was attainable in the patient with a normal hematocrit only when intravenous iodinated contrast media was used.

Adult↗