1,434 research outputs found
Hepatobiliary scintigraphy with SPET in the diagnosis of bronchobiliary fistula due to a hydatid cyst
In this report, we present the application of hepatobiliary scintigraphy using Tc-99m mebrofenin in the diagnosis of bronchobiliary fistula caused by a liver hydatid cyst, which penetrated the diaphragm. Hepatobiliary scintigraphy noticeably depicted the leakage of the tracer from the biliary system of the liver to the bronchial tree. Hepatobiliary scintigraphy stands as a robust modality in the accurate diagnosis and treatment planning of bronchobiliary fistulas. © 2015, P.Ziti and Co. All rights reserved
Sternal nonunion on bone scintigraphy: A case report
Sternal non-union is a severe complication of sternotomy closure following open heart surgeries. Healing problems typically occur in 0.3% to 5% of patients. Technetium-99m methylene diphosphonate (99mTc-MDP) bone scintigraphy has been used to assess bone nonunion to predict the healing response for proper management. In this report, we present the case of a marked sternal nonunion following coronary artery bypass graft (CABG), using radionuclide bone scintigraphy
The effect of an iodine restricted including no sea foods diet, on technetium-99m thyroid scintigraphy: A neglected issue in nuclear medicine practice
Although it is recommended to patients to avoid sea food and iodine-containing medications prior to iodine-131 ( 131I) scanning, the efficacy of this diet as for technetium-99m pertechnetate ( 99mTc-P) thyroid scintigraphy is not well addressed in the literature. We evaluated a self-managed, outpatients, iodine restricted diet (IRD) designed to reduce total body iodine in preparation for such a scan. We have studied 39 patients who referred to our Department for multinodular goiter, 30 females and 9 males, aged: 14-54 years and their 99mTc-P thyroid scintigraphy showed poor visualization of the thyroid gland. These patiens were living in regions with high consumption of sea foods went underwent a two-weeks iodine restriction including restriction of sea food diet for the reduction of iodine body content. These patients were called for a repeated scan after going on a IRD for at least two weeks. The two scans were compared visually, and by semiquantitative analysis. Semiquantitative analysis was applied in 8 regions of interest (ROI) by using Wilcoxon signed rank test. Thirty-six subjects had better quality scintigraphy images in the post IRD thyroid scan, as was visually assessed by two nuclear medicine physicians. Semiquantitatetively, there was a significant difference in the mean counts of ROI of the right and the left thyroid lobes in favor of the post IRD scans (P<0.05). In conclusion, this study suggests that in patients with multinodular goiter, living in regions with high consumption of sea foods a two-weeks diet for the reduction of iodine body content induces in most of the cases a slightly better diagnostic thyroid 99mTc-P scan
99mTc-MIBI Lung Scintigraphy in the Assessment of Pulmonary Involvement in Interstitial Lung Disease and Its Comparison With Pulmonary Function Tests and High-Resolution Computed Tomography: A Preliminary Study
The differentiation of active inflammatory processes from an inactive form of the disease is of great value in the management of interstitial lung disease (ILD). The aim of this investigation was to assess the efficacy of 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI) scans in distinguishing the severity of the disease compared to radiological and clinical parameters.In total, 19 known cases of ILD were included in this study and were followed up for 1 year. Five patients without lung disease were considered as the control group. The patients underwent pulmonary function tests (PFTs) and high-resolution computed tomography scans, followed by 99mTc-MIBI scanning. The 99mTc-MIBI scans were analyzed either qualitatively (subjectively) or semiquantitatively.All 19 ILD patients demonstrated a strong increase in 99mTc-MIBI uptake in the lungs compared to the control group. The 99mTc-MIBI scan scores were higher in the patient group in both the early phase (0.240.19-0.31 vs 0.110.10-0.15, P 0.14). The 99mTc-MIBI scan scores were not significantly correlated with the PFT findings (P > 0.05). In total, 5 patients died and 14 patients were still alive over the 1-year follow-up period. There was also a significant difference between the uptake intensity of 99mTc-MIBI and the outcome in the early phase (dead: 0.320.29-0.43 vs alive: 0.210.18-0.24, P < 0.05) and delayed phase (dead: 0.270.22-0.28 vs alive: 0.100.07-0.19, P < 0.05).The washout rate was ~40 min starting from 20 min up to 60 min and this rate was significantly different in our 2 study groups (ILD: 46.6115.61-50.39 vs NL: 70.9127.09-116.36, P = 0.04).The present study demonstrated that 99mTc-MIBI lung scans might distinguish the severity of pulmonary involvement in early views, which were well correlated with HRCT findings. These results also revealed that 99mTc-MIBI lung scans might be used as a complement to other diagnostic and clinical examinations in terms of functional information in ILD; however, further investigations are strongly required
Radiation exposure from diagnostic nuclear medicine examinations in golestan province
Introduction: The aim of present study was to estimate effective dose from most common procedures performed in nuclear medicine departments of Golestan province. Methods: 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. Results: 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. Conclusion: 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
Numerical analysis of fluid-rock interactions in hydraulic fracturing
This is the author accepted manuscript. The final version is available from Thomas Telford via the DOI in this recordHydraulic fracturing is a process of fluid injection into the well. This process creates tensile stresses in the rock in order to overcome the tensile strength of the formation. In this study, a three-phase hydro-mechanical model is developed for simulating hydraulic fracturing. The three phases include: porous solid, fracturing fluid and reservoir fluid. Two numerical simulators (ANSYS Fluent for fluid flow and ANSYS Mechanical for geomechanical analysis) are coupled together to model multiphase fluid flow in hydraulically fractured rock undergoing deformations, ranging from linear elastic to large, nonlinear inelastic deformations. The two solvers are coupled, using system coupling in ANSYS Workbench. The coupled problem of fluid flow and fracture propagation is solved numerically. The fluid flow model involves solving the Navier-Stokes equations using the finite volume method. The flow model is coupled with the geomechanics model to simulate the interaction between fluid flow inside the fracture with rock deformations. For any time step, the pore pressures from the flow model are used as input for the geomechanics model for the determination of stresses, strains, and displacements. The strains derived from the gomechanics model are in turn used to calculate changes to the reservoir parameters that are fed as input to the flow model. This iterative process continues until both (fluid and solid) models are converged. A parametric study is conducted by changing various model parameters to study their effects on the hydraulic fracturing process. The results show that changes in rock mechanical properties as well as fluid parameters could lead to significant changes in the hydraulic fracture propagation
Comparison of three with six regions of interest analyses in patients with idiopathic constipation undertaking colon transit scintigraphy using 67Ga-citrate
OBJECTIVE AND INTRODUCTION: Preparation of data from 6 geometric regions of interest in the colon is time consuming, and can become impractical in the environment of busy Nuclear Medicine Departments. Therefore, we have investigated and demonstrated an alternative method for obtaining the same diagnostic information from an analysis of patients with idiopathic constipation who underwent colon transit scintigraphy using 67Ga-citrate. Data analysis methods using three regions of interest are compared to the results obtained using the more time consuming 6 regions of interest method to analyze the data. MATERIALS AND METHODS: In this study, we report our results of the comparative reanalysis of data obtained by more traditional methods. We compare 3 regions of interest (ROI) which were taken from areas including the right colon, left colon and the rectosigmoid colon, with original work using our alternative 6 (ROI) diagnostic methodology. In addition, the proximal colonic emptying (PCE) was determined at 24 hr post ingestion among members of 3 identified subject groups. RESULTS: The distribution of activity as the ingested 67Ga-citrate passes through the colon constitutes an activity profile. The mean activity position in the colon can be determined from subsequent radiographic images and from this the mean clearance time can be calculated. In quantitative assessment, this represents the time at which half of activity was eliminated from colon (mean half clearance time - MCT) which did not appear different in the reanalysis. There is no significant difference in the current study in GMC 24h, GMC 48h and GMC 72h between two groups using the Man Whitney u test (p > 0.05), while in the previous work the results were statistically significant for the two later time periods GMC (GMC 48h and GMC 72h) (p = 0.016 and p = 0.027 respectively). The PCE in the group 1 was = 2.50 (0.37); group 2, 1.57 (0.47) and group 3, 2.97. The PCE was not different between the two groups (p = 0.21). CONCLUSIONS: This investigation demonstrated that the radionuclide colon transit study using 67Ga-citrate is a safe, physiologic, and quantitative method for evaluating the transit of fecal material from cecum to rectum. Although, the visual assessment of diagnosis of the subjects in the two analyses is the same, it was not completely supported by quantitative measurements. Therefore, further studies need to be done
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