Fan beam CT scanner with compensating detector motion

US4417353A · kind A · utility

Assignee

• U.S. Philips Corporation · US

Inventors

• Gunther Groh · Hamburg, DE
• Hermann Weiss · Hamburg, DE
• Wolfgang Wagner · Preetz, DE
• Klaus Pasedach · Hamburg, DE
• Gunter Kowalski
• Dietrich Meyer-Ebrecht

Key dates

• Filing date: Jan 5, 1977
• Grant date: Nov 22, 1983
• Expiry date: Jan 5, 1997

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B6/032
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

In fan beam X-ray scanners operating with a large number of detectors, errors at and near the center of rotation are caused by the fact that the radiation absorption in said area is substantially always measured by the same detectors and that the sensitivity of all detectors is not exactly the same. The invention provides an improvement in that the measurement is carried out with a larger number of detectors than is necessary for the measurement of the scanning field and that the detectors pivot during the measurement. As a result, the absorption in the center of rotation is measured by different detectors so that, for a sufficient number of detectors the different sensitivities, errors are averaged and thus reduced or cancelled.