IRANIAN JOURNAL OF NUCLEAR MEDICINE
Year:2002 | Volume:- | Issue:18|Papers Count:15

Radioisotope scanning is very important in evaluation, diagnosis and proper treatment of urinary tract infection (UTI) and Vesico ureteral reflux (VUR) because of high sensitivity of this technique and less radiation dose delivered to the patients. This is a descriptive cross-sectional study to determine the frequency VUR in a group of children aged 28 days to 14 years referred to our department with diagnosis of UTI. The radioisotope scanning was conducted for all of patient (30 patients) and the results were analyzed. The results showed that UTI is seen in wide age group and is usually associated with VUR. The above findings revealed the important role of radioisotope scanning in early diagnosis and subsequent treatment of UTI to detect VUR and prevent subsequent side effects in these patients.

Scientimammography (SMM) is a new non-invasive method of imaging breast tumors which in various studies the overall sensitivity of 83%-95.8% and specificity of 52%-95% is reported. The purpose of our study was to evaluate the usefulness of 99mTc-MIBI SMM in our environment in detecting breast cancer and in reducing the rate of biopsy. 65 patients aged 23-70 years were included in this study. The overall sensitivity and specificity of SMM were 84.6% and 71.8% respectively. The PPV of 66.6% and NPV of 87.5% were similar to that obtained by others. These results showed that, SMM did not increase the specificity and PPV of mammography. However SMM is a useful method for evaluating patients with low suspicion or indeterminate mammographic or palpable findings or lesions larger than 1.5 cm.

Urinary tract infection (UTI) is a common disease in childhood specially in female. In this study 50 patients with established diagnosis of UTI were evaluated by both renal scan with Tc-99m DMSA and renal sonography. The study revealed that most urinary tract infections are in children, Female sex between 5-9 years of age. Therefore the most important complications (Renal scarring) are also common in this age-sex distribution. Occurrence of renal scars increase with increasing the number of recurrent infections. Vesicoureteral reflux is one of the most important, common risk factors for renal scarring. Renal Tc-99m DMSA scan is more sensitive than renal sonography in detecting the renal scars

This study evaluated the relationship between the location of the most severe coronary artery stenosis and the subsequent acute myocardial infarction (AMI). Methods: Of 1590 patients who were admitted with a diagnosis of AMI, we identified 44 patients who had undergone previous myocardial perfusion SPECT. Thirty-one of these patients also had previous coronary angiography. The relationship between the location of the myocardial perfusion defects, the coronary artery stenosis and site of subsequent AMI were studied in these patients. Results: The concordance between the location of the most severe reversible defects detected by SPECT and the site of subsequent AMI was 71% (k=0.499). The concordance between the most severe stenosis detected by coronary angiography and the site of subsequent AMI was 64% (k=0.451). Conclusion: The culprit lesion is not always the one that is manifested by the most severe reversible perfusion defect or the most critical coronary stenosis. Myocardial SPECT and coronary angiography can peredict the location of a future AMI in 71% and 64% of patients respectively. The percentage is higher when the interval between investigations and subsequent AMI is <3 month, for moderate to severe perfusion defects and for 90-99% coronary stenosis

Radionuclide shuntography is a safe and simple method to determine shunt patency and analyze changes in CSF (Cerebro-Spinal-Fluid) flow. We present a case of complicated CSF shunt, in which radioisotopic scan correctly identified disconnection of the shunt tubing system localizing the site of extravasation accurately. The findings were confirmed by surgery performed for correction of the shunt system

Human nonspecific polyclonal IgG was labeled with125I through direct and indirect labeling methods using chloramines-T and a non-Phenolic radio iodinated intermediate N-Succinimidyl-4-[125I] iodobenzoate (125I-SIB), respectively. Tissue distribution of radio iodinated IgG was assessed in normal and induced inflammation mice. Although, radio iodinated IgG accumulated in the inflammatory area, results showed decreased thyroid and stomach activity and improved inflammatory thigh-to-normal tissue ratios with the indirect labeling method (125I-IB-IgG) compared with direct labeling method (125I-IgG), indicating reduced in vivo deiodination. These results indicate that the 125I-SIB is probably a preferable approach for labeling antibodies with iodine radioisotopes.

Introduction: In spite of large number of studies regarding relation between thyroid cancer and childhood irradiation, controversy still exists management of these patients. This study tries to find optimal method of thyroid evaluation in this group. Methods and patients: In a recall program using mass media in Khorasan, all patients with childhood irradiation were invited for thyroid evaluation. One hundred and eighty patients with previous history of radiation for Tinea Capitis were studied using thyroid examination, thyroid sonography and thyroid scintigraphy. FNAB was performed in all patients with palpable nodules and surgery was recommended. Results: Eighty two cases out of 179 patients (45.8%) had nodules in thyroid examination. The number were 85 from 166 (51.2%) in sonography and 75 from 165 (45.5%) in thyroid scintigraphy. Using Chi-square tests, no significant difference was noted in detection of thyroid nodules in different methods (P=0.78) as well as between the methods (P>0.5). Sonographically detected nodules which were not palpated or were not seen in scintigraphy, were <10 mm in size in most of cases. FNAB were performed in 60 patients which revealed benign pathology in 89.9% inadequate in 5% and suspicious for malignancy in other 5% of cases. Also 27 patients underwent surgery and pathological studies showed 3 cases (11.1 %) of papillary carcinoma. Conclution: This study revealed that sonography detects small nonpalpable nodules which are not clinically significant. Very high correlation between the results of thyroid examination and thyroid scintigraphy indicates adequacy of thyroid examination in these patients. We suggest to follow these patients with physical examination and FNAB and use thyroid scanning or sonography in doubtful cases only.

Although, most of the abnormal structures of human brain do not alter the shape of outer envelope of brain (surface), some abnormalities can deform the surface extensively. However, this may be a major problem in a surface-based registration technique, since two nearly identical surfaces are required for surface fitting process. A type of verification known as the circularity check for the shape of the detected head contours was defined based on the curvature measurement. Any unacceptable deformity (or hole) existing in the brain surface can be detected by the circularity check and reformed by a type of interpolation process. Two techniques were suggested to reform the abnormal regions and holes on the surfaces: one based on median filtering and another based on contour reflection

Radiolabeled monoclonal antibodies, have created new innovations in diagnosis, research and therapy of disease in last 2 decades. One of the serious limitation of applications of radiolabeled antibodies in vivo is relatively low target to background activity. Various strategies have been proposed to solve this problem including pre-targeting methods that was suggested in 1989. Regarding importance of monoclonal antibodies and radioisotopes, based on pre-targeting strategy, we have introduced new derivative of Biotin and DTPA to decrease background activity. DTPA-bio and new derivative (DTPA-bio-10X) were labeled with ¹¹¹In, labeled compounds and injected through tail veins into Balb/c mice, and percent of injected dose per gram of blood (%ID/g of blood) was determined at 15, 30, 60, 120, 180, and 240 min after injection. Based on results,¹¹¹In-DTPA-bio rapidly cleared from serum, indicating molecular weight of label is increased causing delayed clearance from serum. Therefore, there is enough time for label to accumulate in the target tissues. With advent of second generation of monoclonal antibodies and antibody engineering, pretargeting methods have changed greatly. It seems that derivatives we introduced will have an important role in new pre-targeting methods