Behavior of40Kand137Cs on the radial direction of the annual ring of sugi (Cryptomeria japonica D. DON) was investigated by means of γ-ray spectrometry. It was confirmed that40Kand137Csmove from one annual ring to another. The concentration of the activity of these nuclides are almost constant in the heartwood, but changes markedly near the sap and heartwood boundary. Distribution profiles of these radioactive nuclides along the radial direction of the annual ring are similar to those of their stable isotopes and of another alkali metal elements such asNaandRb.The results suggest that alkali metal elements have intimate relation with the heartwood formation of sugi.
A new method was developed to display left ventricular wall motion using two dimensional polar representation of cardiac SPECT image. After intravenous administration of 740 MBq (20 mCi) 99mTe (in vivo labeling of red blood cell), ECG-gated SPECT image of cardiac pool was recorded (32 directions, 180 degrees) . The short axis images of left ventricle were constructed at end-diastole (ED) and end-systole (ES) . Then the functional images of (ED-ES) /ED were calculated at each compatible slices and displayed in color according the degree of wall motion. In 8 cases with cardiac diseases this method was applied and clinically useful functional images could be obtained. The area of akinesia or hypokinesia are successfully demonstrated clearly separated from the area of normokinesia. We conclude that this method is useful to show left ventricular wall motion and to evaluate the segment and grade of abnormal wall motion of left ventricle.
In a field of bio-medical science, low energy β-emitting nuclides, such as3Hand14C, are used frequently. However, contamination with those nuclides on laboratory workers is not detectable by the ordinary hand-foot-cloth monitor, if it occurs. Therefore, a new contamination check method, hand washing combined with lyophilization, was studied and feasibility of the method has been confirmed. The lyophilizaion step of the method takes about ten hours so it is not practical to use the method as a daily contamination check. However, it can be done at regular intervals and it will give valuable information for the maintenance of the radioisotope laboratory.