Iranian Journal of Nuclear Medicine
Volume:21 Issue: 2, Summer-Autumn 2013

To retrospectively analyze the outcome of patients who underwent Meckel’s scan in a local centre in Hong Kong over the past fifteen years. Diagnostic values in different referring indications were also reviewed. All patients who referred for Meckel’s scan in a local hospital in Hong Kong from 1/1/1996 to 31/12/2010 were identified. Patients’ demographic data, presenting symptoms, imaging and clinical findings were reviewed and analyzed. A total of 105 patients were recruited, including 62 children and 43 adults. There were eight patients with positive Meckel’s scans and 97 patients with negative scans. Eight Meckel’s diverticula were confirmed surgically. The sensitivity and specificity were 75% and 97.9% respectively. The positive and negative predictive values were 75% and 97.9% respectively. Accuracy was 96.2%. Performance was further improved if only patients with gastrointestinal bleeding were selected. Sensitivity (85.7%) and negative predictive value (98.6%) were higher when compared to all indications, while specificity, accuracy and positive predictive value remained similar (97.3%, 96.3% and 75% respectively). Meckel’s scan is an accurate and useful test if the patient was referred for gastrointestinal bleeding. However its role is in doubt for non-gastrointestinal bleeding cases.

Due to the anti-proliferative properties of platinum group-thiosemicarbazone complexes, the production of 191Os-labeled 2-acetyl pyridine 4-N-methylthiosemicarbazone (191Os-APMTS) was investigated. [191Osmium (T½= 15.4d) was produced via the 190Os(n,γ)191Os nuclear reaction using enriched target irradiated with thermal neutrons. Reaction of in-house synthesized 2-acetylpyridine thiosemicarbazone (APMTS) with 191Os yielded [191Os]APMTS checked by ITLC followed by stability, partition co-efficient and biodistribution determination. Following synthesis and spectroscopic determination of the ligand (>99% chemical purity), the complex was prepared with a radiochemical purity of more than 95% (RTLC) and specific activity of 21.5 GB/mM and was stable in the formulation and presence of human serum at 37°C for up to 48h. The partition coefficient was determined (log P. 1.23). The biodistribution study up to 4 days demonstrated significant tissue uptake differences in the bone, blood, heart and thyroid. This is the first Os-191 labeled thiosemicarbazone designed as an in-vivo therapeutic radionuclide generator. Further investigation is ongoing on the evaluation of the complex in tumor bearing animals.

We aimed to investigate the effect of right bundle branch block (RBBB) on perfusion and functional parameters in dipyridamole stress/rest Tc99m-MIBI gated myocardial perfusion SPECT (GSPECT) which may be helpful in interpretation of myocardial perfusion imaging. We studied 73 patients with low pre-test likelihood of coronary artery disease in two groups: 38 patients with RBBB and 35 subjects with normal ECG. Both groups underwent two-day dipyridamole stress–rest Tc99m-MIBI GSPECT. Two groups were matched. There was no significant difference in sex and age variable between two groups. Visual calculated SSS and SRS in all patients were between 0 and 3. Regarding the prone images, diaphragmatic attenuation and breast attenuation, all patients GSPECT findings were within normal limits. There was no significant difference in TID ratio between two groups: RBBB group: TID ratio= 1.02±0.16 and control group: TID ratio= 0.96±0.14 (P=0.09). There was no significant difference in left ventricular end-systolic volume, end-diastolic volume, ejection fraction, summed stress and rest motion & thickening scores between RBB patients group and control group. No regional LV wall motion abnormality was noticed in any patient in either group. High normality rate of the LV myocardial perfusion and functional indices in the presence of RBBB was noticed in gated Dipyridamole stress/rest Tc-99m sestamibi myocardial perfusion SPECT. No remarkable false positive perfusion findings or abnormal LV functional indices acquired by GSPECT in this group of patients.

The aim of present study was to estimate effective dose from most common procedures performed in nuclear medicine departments of Golestan province. Data of nuclear medicine procedures performed in 2 nuclear medicine departments in Golestan province were collected during 4 years. Effective dose, collective effective dose and effective dose per examination were calculated using standard dosimetry tables. Based on the data of this study, results of 10437 nuclear medicine procedures performed during 4 years have lead to 3.97 mSv as average effective dose per examination and 10.37 human-Sv as mean collective effective dose. It was also revealed that Tc-99m was the main source of effective dose (98.3%), bone scan was the most common procedure (25.9%) and cardiac scan (MIBI-rest) has the highest collective effective dose (33.5%) during 4 years. Beside the cardiac scan which was the most common nuclear medicine procedure and the main contributor of effective dose in patients, due to geographical condition of the northeast of Iran, bone scan was the highest performed nuclear medicine examination in the Golestan province.

The purpose of this study is to assess the integrated role of scintigraphy by Tc99m MIBI in diagnosis of parathyroid adenoma and its impacts on the myocardium, and to evaluate whether myocardium perfusion gated SPECT study could be a complementary routine workup for patient with positive parathyroid adenoma on Tc99m MIBI parathyroid scan. Rest myocardium perfusion gated SPECT study was performed on the same day of parathyroid scintigraphy, the stress study were completed on the next day for complete assessment of the myocardium perfusion and LV functions. Population included 30 patients; 56% were positive for parathyroid adenoma and compared to 44% negative for parathyroid adenoma, the latter was considered as control group, the gated SPECT EF was normal in 62.5% and abnormal 37.5%. Myocardial perfusion was abnormal in 43.75%, the overall hemodynamic disorder including EF abnormalities as well as the perfusion defects in the study group were 62.5% compared to 27.5% in the controlled group with statically significant relationship (P value=0.03). The risk of premature cardiovascular death in p HPT is a serious problem and the present study indicates that scintigraphically detected parathyroid adenoma has an impact on the overall hemodynamic of the myocardium and the complementary role of rest/ stress two days protocol Tc99m MIBI myocardium perfusion gated SPECT study may be promising, but its usage as routine workup specially in patient with positive parathyroid adenoma and have high risk warranted further evaluation and reassessment.

In Islamic countries in the month of Holy Ramadan many Muslims based on their religious Legislation refuse fluid intake during the fasting time though instructed to drink after injection of Tc-99m Methylene-diphosphonates [Tc-99m MDP] used for skeletal scintigraphy. We aimed to establish whether fluid restriction in Tc-99m MDP skeletal scintigraphy has an impact on its quality. One hundred forty-four patients referred for skeletal scintigraphy were studied. Group 1 was well hydrated while group 2 was instructed not to drink till imaging. Image quality was assessed using quantitive measures where by the end of imaging, equal regions of interest (ROI) were drawn over the femoral diaphysis, and the contralateral adductor area. The total number of counts from the bone [B] ROI and soft tissue [ST] ROI was expressed as a ratio [B: ST ratio], and a mean value for each group was established. The image quality was also assessed without knowledge of individual’s water intake by a semiquantitative score. No statistically significant difference was found between the B:ST ratio means [P=0.46] and the semiquantitative scores [P=0.42] in both groups. Fluid restriction had no impact on the image quality in Tc-99m MDP skeletal scintigraphy though a higher radiation dose to the urinary bladder wall is anticipated.

Nowadays, science mapping is considered an excellent technique for decision-makers to find solutions for problems in research planning and development. In this work, we aimed to depict a science map of “radiology, nuclear medicine, and medical imaging” in Iran. All publications indexed in Thomson Reuters Web of Science database in the fields mentioned above with at least one affiliation corresponding to “Iran” were included in the study. “Visualization of similarities” (VOS) viewer software was then utilized to analyze the data for generating density maps and density cluster maps of organizations, authors, and journals based on bibliographic coupling and co-citation similarity measures. Various maps were then formed and discussed. Tehran University of Medical Sciences in all fields of radiology, nuclear medicine, and medical imaging was proved to be the dominant organization in the country. Applying VOSviewer software, data was analyzed for extracting bibliographic coupling and co-citation relations and theirs corresponding science maps in terms of affiliated organizations, authors, and publishing journals. More comprehensive studies can be performed to obtain more mature science maps. Performing such analyses for other countries and then comparing with the internal science maps can be useful for decision-makers.