Journal of nuclear biology and medicine (Turin, Italy : 1991)最新文献

Dynamic liver radionuclide scanning was performed in cirrhotic patients to correlate three parameters derived by this technique to the severity of liver function impairment and clinical-endoscopic signs of portal hypertension. We found a close association between the severity of liver failure (Child-Pugh criteria) and both the relative blood flow (p < 0.05) and the shape (shifting to the left) of the early flow curve (p < 0.01). A significant association between the presence of portal hypertension and shifting to the left of the flow curve was demonstrated in all cases in which tense ascites was associated with varices (p < 0.05). Finally, a statistically significant association (p < 0.05) was found between the degree of esophageal varices (Beppu's criteria) and the liver-to-spleen uptake ratio. These data suggest that dynamic isotope liver scanning could be an important tool in the diagnostic evaluation of liver function impairment and portal hypertension.

Nuclear medicine imaging techniques, whether applied in the initial diagnosis or in assessing the response to therapy, are indispensable in the evaluation of malignant diseases that afflict infants and children. The major role of these techniques (bone, 67Ga and 201Tl scintigraphy, imaging with labeled leucocytes, immunoscintigraphy) is that of complementing, in an essential manner, other first choice diagnostic investigations (radiological, bioptic, etc.) such as in evaluating malignant skeletal tumors, soft tissue sarcomas, lymphomas, leukemia and histiocytosis X. Nevertheless, due to their high tissue specificity and/or diagnostic reliability, 99mTc-MDP (or analogues) imaging in the screening of bone metastases, 123/131I-MIBG scintigraphy in the diagnosis and management of neuroblastoma and 131I whole body scan in staging postoperatively differentiated thyroid cancers are proposed as first choice modalities. Well established (131I therapy) or recently developed (131I-MIBG therapy and radioimmunotherapy) therapeutic modalities are available today to be either integrated with or to substitute the conventional treatment of differentiated thyroid carcinoma and neuroblastoma.

In the post-surgical follow-up of a patient with follicular thyroid carcinoma, a palpable mass in the left supraclavicular region was highly indicative of metastatic disease. Technetium-99m methoxy isobutyl isonitrile (99mTc-MIBI) showed an increased but heterogeneous uptake within the lesion. Surprisingly, a different neoplastic disease was histologically demonstrated. Lymph node abnormalities due to non-Hodgkin's lymphoma rather than metastatic thyroid disease were demonstrated. In conclusion, non-Hodgkin's lymphoma may occur in patients with follicular thyroid carcinoma. This new lesion significantly concentrated 99mTc-MIBI. Thus, the results of 99mTc-MIBI imaging have to be carefully evaluated during the follow-up of patients with thyroid cancer.

The determination of brain death relies on unequivocal clinical data and on supportive studies. The replacement of the electroencephalogram (EEG) as the gold standard is unanimously felt as appropriate. Scintigraphic imaging with technetium-99m hexamethylpropylenamineoxime (99mTc-HMPAO) seems to offer an adequate substitute given its metabolic features, ideally to be used with a mobile gamma-camera which simplifies the approach to this type of patient. We correlated EEG with the scintigraphic data, which were found to be concordant and therefore substitutive in the establishment of brain death.

We present the results obtained in the follow-up of 66 children with vesico-ureteric reflux (VUR) of different grades (111 refluxing renal units, RU; the VUR being bilateral in 47 children), employing the renal cortical agent 99mTc-aprotinin (TcA). Together with the visual inspection of the scan, we adopted a quantitative approach, expressing the results as the split percent uptake of the injected dose. The detection of morphological anomalies was more frequent in the cases of more severe reflux. Scars were noted in 38 RU, with a higher prevalence in more severe grades, except for grade V where severe impairment was more frequent. With regard to the amount of functioning parenchyma, the probability of a significant loss of nephrons (expressed by a low uptake of TcA), rose with the grades, although the higher grades were not invariably associated with parenchymal failure. The abnormality detection rate is higher by about 2:1 with the TcA scan than with other diagnostic modalities such as i.v. pyelography or echography. No differences were found between RU with or without scars as regards evolution over time; only when the TcA uptake at presentation was lower than 10% was the normal development of the RU likely to be hindered. From these data it can be concluded that early diagnosis is the key factor in the management of these children with VUR; the morpho-functional assessment with TcA uptake is probably the most effective technique for the detection of parenchymal abnormalities. In addition, the test has a high prognostic value, an uptake lower than 10% indicating an unfavourable prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Blocking the thyroid gland when administering radioiodinated materials is a common practice. Since pharmacologic quantities of potassium iodide (KI) in the range of 100-300 mg daily are usually administered for this purpose, the potential exists for iodide toxicity. Concomitant with the tracer administration is the risk produced from ionizing radiation. Reports in the literature demonstrated thyroid function abnormalities in patients administered iodides. Based on the latter observations the object of the present investigation is to determine the effectiveness of thyroid blocking with a lesser daily quantity of KI. Fifteen adult hip replacement patients (7 men, 8 women; 58.2 +/- 11.5 years) received 2.5 mg Ki orally every 12th hour twice daily 2 days prior to surgery and 125I-fibrinogen [(3,700 kBq)(100 microCi)], and each day up to 10 days thereafter. Thyroid and precordial counts were obtained daily and the latter two were used for calculating the 125I thyroid uptake. These data were used for estimating the thyroid blood disappearance and cancer risk. An attempt was made to compare the radiation risk to that from KI ingestion. The 125I% thyroid uptake for the study population (n = 15) was 1.83 +/- 1.25%. This compares to a thyroid uptake of 0.064 +/- 0.037% in a published report using 300 mg KI daily in the course of an 125I-fibrinogen test. The mean thyroid radiation dose for the study population was 6.09 cGy after receiving 5 mg KI daily. The specific risk estimate (SRE) for contracting thyroid cancer was calculated to be 4.5B-04. The NCRP calculated thyroid function risk after ingesting KI is 1-10E-07.(ABSTRACT TRUNCATED AT 250 WORDS)

Diethylenetriaminepentaacetic acid (DTPA)-conjugated purified rabbit anti-human serum albumin antibody was subjected to free-flow, semipreparative isoelectrophoresis using an apparatus that fractionates protein molecules based on isoelectric point (pI). The results indicate that (1) the apparatus was capable of developing linear pH gradients and separating proteins, (2) > or = 86% of the protein was recovered following fractionation, and (3) the protein concentration of the individual fractions varied. Focusing the fractions on an isoelectric slab gel revealed that the pIs of the isoforms were modified. The isoforms were radiolabeled with indium-111, their DTPA to antibody molar ratios determined, and their immunoreactivities evaluated by a solid-phase radioimmunoassay. The results demonstrate that (1) the molar ratio of DTPA to antibody varied among the fractions, and (2) the immunoreactivity of the majority of fractions was higher than that of unfractionated DTPA-antibody conjugate. Semipreparative isoelectric focusing may therefore improve the potential of radioimmunoconjugates in the radio-diagnosis and therapy of disease.