An In Vivo Bone Densitometer for use with a Diagnostic X-Ray Set

Abstract

An invivo bone densitometer has been designed to be used
with a full wave rectified X ray set. The densitometer has been
constructed to give a fast and accurate scan of the ulna with a
spatial resolution very much better than hitherto achieved.

The ulna was chosen so that a wide range of patients, who
might have limited agility could be easily scammed for bone
mineral content with a view to the early diagnosis of bone
disease and to study progress and response to therapy.

To overcome the X ray output fluctuations due to variations
of the supply voltage, an electronic compensation technique
using two detectors was developed. One of the detectors samples
the total incident X ray intensity over a portion of the every
half cycle, and the other the X ray intensity transmitted
through the ulna.

Tests to determine the performance of the compensation
mechanism over a wide range of operating conditions were made,
The reproducibility of the densitometer has been demonstrated
by making scans using simulated dead and invivo bone.

Theoretical calculations using a simplified theory have Been
made to predict the accuracy of the compensation technique and
the expected voltage signals. These calculations are compared
with experimental observation.

Date of Award	1973
Original language	English