While scintillation cameras have been extensively used for examinations of the kidney, the information obtained has not necessarily been applied effectively to clinical diagnosis. We have attempted to enhance the clinical value of these examinations by using a computer to record and process all the radioisotope images from the scintillation camera.
The apparatus used in our research is a new digital data processing system. It is assembled of the following components: a data acquisition unit, a data display unit with a light-pen, a central processing unit having an 8 kiloword core memory (1 word=24 bits), a direct memory access channel, a high-speed burst channel, a magnetic drum (100 kilowords), a high-speed digital magnetic tape recorder, and a teletypewriter. The apparatus is capable of continuously recording at certain time intervals up to 100 frames of radioisotope image changes with time. The collected data are reproduced on an oscilloscope for smoothing, three-dimensional display and drawing profile curves. With regard to any given region of interest, changes of radioactivity can be expressed in curves, which we call regional renogram.
Radioistopes used were 200μCi of 2(3Hg-chlormerodrin, 200μCi of 131I-hippuran, and 4-10mCi of Na 99mTcO4, and 1 or 2 kinds of them were selected depending on the case. About 10-40 frames of scintigrams were obtained at 5-90 second intervals immediately following intravenous injection.
Sixteen cases with space occupying lesions were examined and 5 cases of them were explained in detail.
Processing and studying of these data gave the following findings:
1) From the profile curves, split renal and regional functions can be appraised semiquantitively.
2) Changes of radioactivity with time in any given region of the kidney can be obtained as what may be called regional renogram.
3) The three-dimensional display enables cold areas to be readily located.
4) Renal lesions can be discriminated by selective use of various radioisotopes and adjusting programs.
