Nuclear-Medizin最新文献

The incorporation of 131-Iodo-deoxyuridine in rat tumours can be increased by partial synchronisation with hydroxyurea. The reported investigation was carried out to determine whether the incorporation could be further increased by using a basic 131-Iodo-deoxycytidine-monophosphate-protamine complex as a depot of Iodo-deoxyuridine. It was shown that the incorporation observed after synchronisation could be increased by using this complex (non-synchronized tumours 1,46% retention, synchronized tumours 2,28% retention; measured 4 hour after the final injection of hydroxyurea) whereas in a control group injected with 131-Iodo-deoxycytidine-monophosphate alone, only a small increase was observed. The large increase in activity in the liver and in the spleen (liver: non-synchronized 2,76%, synchronized 2,79% retention; spleen: non-synchronized 3,00, synchronized 3,80% retention; measured 4 hours after final injection of hydroxyurea) which is observed after injection of the 131-Iodo-deoxycytidine-monophosphate-protamine complex renders it unsuitable for use in the scintigraphic detection of tumours. 131-Iodo-deoxyuridine is shown to be more suitable for this purpose.

A preliminary study of iron absorption by whole body counting was carried on a group of 16 women. The cases included 8 patients suffering from iron deficiency anaemia and various infections as well as 8 healthy controls. High iron absorption is associated with iron deficiency, these changes being more marked in iron deficient controls than in those with infection or malignancy. In iron deficient controls results of whole body counting correlate very well with other haematological investigations.

The speed of flow between aortic arch and abdominal aorta was determined from the corresponding minimal transit time (MTT) measured with 113m-In-DTPA and the Fucks-Knipping gamma camera. A total of 144 individuals was examined: 62 normal persons, 34 patients with cardiac insufficiency; 31 patients with hyperkinetic syndrome (effort syndrome and hyperthyroidism) and 17 patients with isolated aortic sclerosis without impairment of cardiac function. In all individual groups there was a highly significant correlation between speed of flow and heart rate. For a given heart rate speed of flow was diminished in cases of cardiac insufficiency and aortic sclerosis; it was accelerated in patients with hyperkinetic syndrome. By plotting the speed of flow through the aorta, normalized to an arbitary heart rate, against the corresponding MTT, also normalized to the same heart rate, the presence of aortic sclerosis could be differentially recognized in 14 of the 17 patients with this disease.

Minimal transit times (MTTs) were determined with the Fucks-Knipping gamma camera from differences between arrival times in consecutive cardiac compartments of blood radioactively labelled with 113m-In-DTPA Measurements were made on 50 patients with effort syndrome, 59 patients with hyperthyroidism before and after thyroid suppression therapy partly suffering from associated heart disease, and 25 patients with hypothyroidism before and after therapy with thyroid hormone. In patients with effort syndrome and hyperthyroidism, MTTs were often, but not always shortened below the control values; consequently, in case of associated heart disease, MTT-prolongation may be masked in such instances where hyperthyroidism causes MTT shortening. Hypothyroidism caused MTTs to be prolonged. The prolonged MTTs reverted to normal values upon adequate therapy with thyroid hormone.

Technetium 99m-polyphosphate bone images are correlated with bone roentgenography, and serum calcium, phosphorus and alkaline phosphatase in 91 patients with suspected bone metastasis. Technetium polyphosphate bone images are the most sensitive and serum level of calcium and phosphorus are the least sensitive indicator of bone lesions. Bone roentgenography is not as sensitive as technetium polyphosphate images. Abnormal bone images with normal or abnormal bone roentenography associated with increased alkaline phosphatase in the absence of liver metastasis are highly suggestive of metastatic bone disease. Abnormal bone images adjoining the joints, associated with normal serum alkaline phosphatase and abnormal joint roentgenography suggest arthritis. It is recommended that technetium 99m-labelled phosphate bone images are considered to be the diagnostic procedure of choice to detect skeletal lesions. Polyphosphate bone images are highly sensitive, with the combination of elevated alkaline phosphatase they become relatively more specific for a metastatic bone disease.

The preparation technique for 99m-Tc-DTPA(Sn)-complex has been studied in detail in order to find the optimal conditions for preparation. The concentration of DTPA should be at least 10 mM, and that of Sn(II) less than 1 mM, in order to obtain a reproducible high-labelling yield. A dry sterile kit was prepared of 39.3 mg H-5DTPA and 2.3 mg SnCl-2 with 2H-2O in a 10 ml vial. The 99m-Tc-DTPA(Sn) was prepared by adding the 99m-Tc-eluate to the vial. After 1 min the solution was sterile-filtered and was ready for use. The plasma clearance of 99m-Tc-DTPA(Sn) in man determined by blood-sampling up to 200 minutes after administration shows a good correlation to endogenous creatinine clearance (r plus 0.93). The plasma disappearance curve studied during 24 h is, however, a sum of three exponentials corresponding to biological half-times of 18 plus or minus 8 min, 105 plus or minus 9 min and 17 plus or minus 4 h. The slow third component representing about 2% is assumed to be due to binding of 99m-Tc to plasma proteins. The absorbed radiation dose calculated for whole body is 8 mrad/mCi, kidneys 50 mrad/mCi, bladder 300 mrad/mCi, ovaries 17 mrad/mCi and testes 11 mrad/mCi. This agent is a valuable radiopharmaceutical for renovascular clinical problems. Scintigraphic imaging of the aorta, kidneys, ureters and bladder (for residual urinary volume-determination) could be performed.

Joint imaging with 99m-Tc-Polyphosphate was carried out in 21 patients having inflammatory or degenerative diseases of the joints of the hands. A comparison was made between 99m-TcPP, xeroradiography and radiography. In a total of 630 different joints 237 positive scans, 132 positive roentgenograms and 183 positive xeroradiograms were obtained. In the early stage of inflammatory joint disease only the scintigraphic results are positive, in the later stage 99mTcPP-imaging was less sensitive than xeroradiography and radiography. The reason for the increased concentration at the site of acute joint inflammation is probably the increased uptake in the soft tissues of the joints. The best time for scanning after the application of 99m-TcPP seemed to be at 3 hours.

Using quantitative sequential camera scintigraphy and simultaneous separated clearance determinations with 131-I-Hippuran and 169-Yb-EDTA renal function was measured applying a new surgical method which permits in-situ kidney perfusion and cooling in animals and patients. While mongrel dogs of 15 kg average weight (control group of N = 5) showed after 1 hour of normothermic ischaemia a postoperative delay of intrarenal transport of 131-I-Hippuran with reduction of 131-I-Hippuran and 169Yb-EDTA clearances, renal function returned to normal on the first postoperative day after 1-hour (N = 5) and 2-hour (N = 5) hypothermic ischaemia. In patients (N = 9) with hypothermic in-situ perfusion of between 40 and 92 min duration a transient postoperative delay of intrarenal 131-I-Hippuran transport and a reduction of the 131I-Hippuran clearance was observed which returned to almost normal 1 1/2 to 3 months after surgery. The results and the significance of the method discussed and are compared with clinical findings and with radiological and laboratory renal function studies.

Radioimmunological assays of HPL have been carried out in early pregnancy in uncomplicated cases (n = 100) and in cases of abortus imminens (n = 49). The earliest detection of HPL was possible in the 6th week of pregnancy. When the tendency of the HPL-level was decreasing follow-up examination showed a beginning abortus. In every case of decreased HPL-level the progress of pregnancy was abnormal. Conclusions about the prognostic value and the limits of the HPL-RIA are discussed.

The motions of the respiratory movement of the diaphragms were filmed and the character of the motion was evaluated. The line-spread function of a motionless line source was compared with that of a moving source (for two kinds of motion: regular and harmonic). Similar calculations were made for increasing the motion amplitudes of the source and for different values of static resolution. The final dynamic resolution was calculated. The results show that when respiratory motion exceeds 13 mm (which happens in about 50% of clinical examinations) the resolution decreases by more than 25% so that it is necessary to use special methods of eliminating these artefacts.