Value of joint scintigraphy in the prediction of erosiveness in early rheumatoid arthritis.

The value of scintigraphy in predicting development of new erosions in small peripheral joints was studied by visual evaluation of scintigrams and by three computerised methods. In 13 patients with newly diagnosed rheumatoid arthritis a total of 387 joints were examined clinically, scintigraphically, and radiographically. The follow up period was 24 months. Four eroded joints in three patients were found at the onset. Of the joints which were to become eroded, 46/47 were scintigraphically active at all the check ups. Erosions were detected earlier in foot joints than in finger joints. New erosions were especially prone to appear in joints with persisting and high scintigraphic activity. On the contrary, inactive joints by repeated scanning never eroded. Scintigraphic and clinical activity and radiographic erosiveness correlated significantly with each other. The sensitivity and specificity of visual scintigraphic assessment and the relative pixel activity method proved to be superior to the region of interest methods and clinical evaluation for prediction of erosiveness.

Scintigraphy of rheumatoid peripheral joints. Reliability of visual assessment vs. computerized methods.

99mTc-methylene diphosphonate (99mTc-MDP) scintigraphy of peripheral joints was studied by visual evaluation (Visual Assessment) of the scintigrams and by a computerized region-of-interest (ROI) method without, or with a reference region (ROI method or Corrected ROI method). Sixteen rheumatoid patients and a total of 477 peripheral joints were studied and the results compared with clinical joint activity evaluated by joint palpation. The ROI method without a reference proved to be insensitive and hence unsuitable for clinical use. The results of Visual Assessment and the Corrected ROI method correlated well with each other and with clinical joint activity. The sensitivity of the methods in detecting a clinically inflamed finger joint was: ROI 6%, Corrected ROI 71% and Visual Assessment 75%. The corresponding figures for peripheral joints of the feet were as follows: 28%, 41% and 58%. We conclude that, for clinical use, Visual Assessment of the scintigram is adequate and the method of choice.

Technetium-99m in the study of rheumatic joints.

The accumulation of Tc-99m in knee and finger joints was studied in 41 rheumatic patients and 25 controls. The accumulation of the radioisotope was correlated with the intensity of active inflammation. Rheumatoid joints showed a stronger Tc-99m uptake than joints with osteoarthritis. There was some overlap, however, which limits the value of the method. The effect of local and systemic anti-rheumatic treatments could be followed with joint scanning. Radioactivity was also measured in the synovial fluid but this fraction of the Tc-99m was not large. The synovial fluid radioactivity tended to increase as the Tc-99m accumulation in the knee area decreased. Accumulation of Tc-99m in joints is regarded as principally due to the enhanced circulation in inflamed joint tissues.

A comparison of 99mTc-MDP and 99mTc-pertechnetate by computerized quantitative joint scintigraphy.

Computerized, quantitative joint scintigraphies were performed using both 99mTc-MDP and 99mTc-pertechnetate. 17 joint pairs with asymmetric active arthritis were selected for the study. The joint activity ratio was calculated by dividing the curve peak value of the inflamed joint by the curve maximum of the contralateral symptomless joint. A very high joint activity ratio with 99mTc-MDP was observed in the case of septic arthritis with osteolytic lesions. In all the rheumatoid joints the activity ratios were higher with 99mTc-MDP than with 99mTc-pertechnetate. In reactive arthritis the mean joint activity ratio was equal with both tracers. It appears that 99mTc-MDP is more sensitive in detecting active rheumatoid arthritis than 99mTc-pertechnetate and that high 99mTc-MDP values might be prognostic of destructive changes.

Radiation-induced changes in regional blood flow in human tumors.

In 43 patients the blood flow in 48 superficial metastatic tumors was measured with the 133xenon wash-out method. In all cases the blood flow was measured before the start of radiotherapy and then one week later during radiotherapy. In 36 cases the blood flow was measured after 2 weeks during radiotherapy, and in six patients the follow-up lasted 5-6 weeks. The blood flow increased during the first week of radiotherapy in the whole series from 20.1 +/- 18.0 ml/min/100g to 31.3 +/- 24.9 ml/min/100g. The increase during the first week was significant (p less than 0.001). During the second week of radiotherapy the blood flow decreased to 27.0 +/- 19.3 ml/min/100g; the decrease was also significant (p less than 0.05). The changes in the different tumor groups during radiotherapy seemed to be in the same direction. In a longer follow-up the gradual decrease in the blood flow seemed to continue.

Intervillous blood flow in normal and complicated late pregnancy measured by means of an intravenous 133Xe method.

Intervillous blood flow (IVBF) was measured intravenously with a new quantitative 133Xe method in 50 normal and 74 complicated late pregnancies between the 35th and 42nd weeks. The distribution of individual flow rates seemed to be fairly wide in both the normal and the pathological groups. The mean rate of IVBF in normal pregnancies was 140 ml/100 ml of intervillous space/min. The lowest mean flow values were observed in pregnancies complicated by diabetes mellitus (class B-E), cholestasis of pregnancy and severe pre-eclampsia, a highly significant difference (p less than 0.001) from the mean IVBF observed in normal pregnancies. The significance of the results in the different groups has been discussed in detail. This method may open up a new diagnostic area in the management of high-risk pregnancies.

Erbium--169 versus triamcinolone hexacetonide in the treatment of rheumatoid finger joints.

Erbium--169 was compared with triamcinolone hexacetonide in the topical treatment of 32 patients suffering from rheumatoid arthritis. Erbium--169 was injected into 83 and triamcinolone hexacetonide into 54 proximal interphalangeal or metacarpophalangeal joints. Both treatments produced alleviation of joint pain and swelling and improvement of grip strength. At every check-up (1--18 months) the percentage of remissions was higher after triamcinolone hexacetonide injection than after erbium--169. The difference was significant at 1, 3, and 6 months.

An intravenous 133Xe method for measuring regional distribution of placental blood flow.

A new method for measuring regional distribution of placental blood flow is presented. After 2-5 mCi of 133Xe saline has been injected intravenously, the counts over the placenta are registered with a scintillation camera interfaced with a digital data storage and television readout system. Using "area of interest" technique, time activity curves are obtained for different regions. Analysis of the curves is based on two-exponential curve fitting. In normal pregnancy the mean intervillous flow in 16 healthy women was 125 ml/min/100 ml and myometrial flow 17 ml/min/100 g. The intervillous flow in the central part of the placenta was 55% higher than in the marginal parts. The myometrial flow in the placental area was nearly the same as outside the placenta.

Measurement of intervillous and myometrial blood flow by an intravenous 133Xe method.

A new 'non-invasive' method for measuring intervillous and myometrial blood flow is presented. After 2 mCi of 133Xe in physiological saline was injected intravenously the patient held her breath for 20 seconds. The tracer entered the placenta as a short bolus and its removal was followed with a scintillation detector. Intervillous and myometrial blood flow per unit volume was calculated from the two-exponential curve. The mean +/-SD intervillous flow in normal pregnancy was 135+/-49 ml/minute/100 ml, the corresponding half time being 0-56+/-0-16 minutes. The myometrial flow was 7-7+/-2-5 ml/minute/100 g. The method gave reproducible results and took only 20 minutes to perform. The dose of radiation to the mother was less than 1 mrad.

Regional blood flow in human tumours with special reference to the effect of radiotherapy.

Blood flow in 41 superficial tumour nodules, of which nine were lymphomas, nine anaplastic carcinomas and 23 differentiated malignomas was measured using the 133Xe-clearance method. The lymphomas showed statistically higher blood flow (38-4 ml./min/100 g) than anaplastic (11-4 ml./min/100 g) and differentiated tumours (13-7 ml./min/100 g). After one week of radiation treatment the mean blood flow in anaplastic carcinomas was higher than the initial value. After an interval following the end of the radiation treatment the circulation diminished significantly compared with that observed immediately at the end of radiotherapy. The size of the tumours did not correlate with the blood flow.

Changes in tumour cell selenite (75Se) affinity due to irradiation.

The uptake of 75Se sodium selenite in the liver and tumour tissue of irradiated Wistar rats was studied by radiation measuring methods and radiochromatography. In in vitro experiments liver slices were incubated in selenite solution following irradiation of the liver. The uptake in proteins diminished by 11% as compared with the unirradiated rats. The in vivo 75Se uptake in Ehrlich ascites tumour cells was 71% of that of the controls, when the selenite was administered intravenously after irradiation. The in vivo accumulation of selenite in proteins of Guérin tumours after irradiation was 62% of that in the controls. The radiochromatogram pattern showed a distinct difference between the irradiated and unirradiated tumours. These results are in accord with the clinical 75Se-scintigraphy findings, which show a clear decrease in Se-accumulation after irradiation.

Retention and extra-articular spread of intra-articularly injected 90Y silicate.

A study was performed on the retention and distribution of intra-articularly injected colloidal 90Y silicate in 7 patients with rheumatoid arthritis (8 knees). In 5 knees retention was complete within the limits of measuring accuracy, and in the remaining 3, 82-84% was retained. No radioactivity was detected in the liver and heart areas or in the blood samples. The cumulative urine activity was less than 1.8%. In the inguinal lymph nodes, activity was detectable %0.5-2%) in only 3 cases. We conclude that 90Y silicate is a safe radioactive agent for the treatment of knee effusions, provided the limb is strictly immobilized after the injection.

Cardiopulmonary blood volumes at rest and during muscular exercise measured by 113mIn radiocardiography.

Cardiac output, stroke volume, right heart and left heart blood volume, pulmonary blood volume and pulmonary mean time were measured at rest and during muscular exercise in 14 healthy subjects in the supine position. The method used was 113mIn radiocardiography measured precordially with a single detector. The results were analyzed with a minicomputer by a modified gamma function fitting method. The increase in cardiac output during exercise was 140 per cent (p is less than 0.001). The stroke volume increased 15 per cent (p is less than 0.05) in subjects with heart rates less than 160 beats/min, and decreased in subjects with heart rates greater than or equal to 160 beats/min. The right heart blood volume decreased from 115 ml/m2 to 105 ml/m2 to 215 ml/m2 (5 per cent; p is less than 0.1) and the left heart blood volume decreased from 120 ml/m2 to 110 ml/m2 (5 per cent; p is less than 0.01). The total heart blood volume thus decreased from 235 ml/m2 (5 per cent; p is less than 0.05). The pulmonary blood volume showed a corresponding increase from 250 ml/m2 to 280 ml/m2 (12 per cent; p is less than 0.005), and the cardiopulmonary blood volume did not markedly change (485 ml/m2 and 495 ml/m2). Pulmonary mean time decreased from 5.0 s to 2.4 s (52 per cent; p is less than 0.001).