[en] Full text: Annexin is a 36 kD protein with high binding affinity to phosphatidylserine (PS), a phospholipid exposed on the membrane surface of cells upon activation of the enzyme caspase, the first step of apoptosis. Radiolabeled annexin V could thus be used for imaging apoptosis in-vivo. When the 319 amino acid protein is made by recombinant techniques and expressed as the human material, it can be radiolabeled with 99mTc after derivatization with a bifunctional agent such as HYNIC. Alternatively, the amino acid structure of the protein can be modified by producing annexin V mutants with an endogenous chelation site for 99mTc, the NH2 residue Ala-Gly-Gly-Cys-Gly-His-Met. Mutant annexin has similar affinity for membrane-bound PS as unmodified annexin. This study was performed to compare the biodistribution of 99mTc-labeled HYNIC annexin (HyA) to mutant annexin (MuA). 99mTc-labeling efficiency of the two annexin preparations was >99% by gel chromatography on Sephadex G10 columns. Groups of adult male mice (n 10, body weight 18-25 grams) were injected iv with either HyA or MuA (1-3 MBq, 3-9 μg/animal). Animals were sacrificed one hour later and dissected for organ biodistribution. Similar biodistribution was performed after pretreatment with cyclophosphamide (150 mg/kg ip 6-15 hr prior to the study). The results of the biodistribution study showed significantly reduced (p<0.05 to p<0.01) uptake of MuA versus HyA in the kidneys (Δ- 81.4%), spleen (Δ- 58.2%), liver (Δ- 56.2%), and bone marrow (Δ- 33.7%), while it was increased in lymph nodes (Δ+ 131%, p<0.001). Pretreatment with the pro-apoptotic agent cyclophosphamide induced significantly increased uptake of MuA (p<0.05) versus baseline in the heart (Δ+ 34.7%), spleen (Δ+ 30.1%) and bowel (Δ+ 44.5%), while uptake of HyA was increased only in the spleen (Δ+ 44.1%). The marked reduction in the renal, splenic, liver, and bone marrow localization of MuA compared to HyA in control animals outlines a pattern of biodistribution more favourable for imaging purposes, as it should improve lesion detection particularly in the abdomen. Uptake of MuA also changed more significantly than HyA when reflecting the apoptotic events induced by pretreatment with cyclophosphamide. (author)

[en] Objectives: To assess response to therapy with I-131 adjusting the dose to weight of the gland. Study Design: Retrospective and prospective. Descriptive study. Patients: A total of 146 patients was collected in the period between January 2002 and January 2007. The data were analyzed in Access database including age, sex, duration, approximate weight of the gland, dose, side effects, radiation measurement, outcome and response time. Conclusions: The therapeutic response in treatment with radioactive iodine is adequate if given the dose adjusted to the weight of the gland, without requiring excessive doses. Cases of treatment failures were predictable by even severe symptoms to those administered with high doses. Some of the patients had received prior therapy with high dose in other institutions and probably the failure to respond was due to thyroiditis and washing accelerated I-131

[en] Describe a rare case of false positive in the study of lung nodules. Describes the case of a patient 73 years, smoker with non-calcified pulmonary nodule in the right upper lobe of 22 mm, as an incidental finding in chest x-rays and CT. Pulmonary sclerosing hemangioma is a benign neoplasm; radiologically described as a well-circumscribed pulmonary nodule that is preferentially located in the lower lobes and enhanced with contrast medium, which is not possible to differentiate a malignant tumor. The specificity of PET-CT for characterizing lung nodules, benign vs. malignant adequate but not 100% (E: 76% -83%). The most frequent causes of false positives are usually inflammatory, but less frequently, such as sclerosing hemangioma has already been reported in the literature. In lung lesions with positive PET study with biopsy necessary to rule out the possibility of a false positive

[en] The first radionuclide gastric emptying study was performed in 1966 and has been the gold standard for gastric emptying detection of gastroparesis for decades, in spite of many other non radionuclide methods proposed and investigated. However, there has been no standardization of the gold standard. The methodology varies considerably between imaging clinics and hospitals, e.g., in the meal, the method of acquisition, processing, quantification, and normal values. Many times the normal values were not validated for the method and meal used. This has frustrated gastroenterologists and other clinicians because it was difficult to compare the results of studies done at different institutions and to have confidence in the results. Consensus Recommendations for Gastric Emptying Scintigraphy have been published simultaneously in 2008 in the Journal of Nuclear Medicine Technology (1) and the American Journal of Gastroenterology (2). Fourteen physicians, half nuclear medicine physicians and half gastroenterologists, met on several occasions, and after much discussion came to these consensus recommendations. This publication recommends the Tougas G, et al. protocol published in 2000 (3). This is a simplified and standardized methodology. It is simplified in the sense that a single image is required only at 0, 1, 2, and 4 hours. It is standardized in that a specific protocol and meal is recommended and normal values based on it were determined with 123 normal subjects from multiple institutions on different continents in different countries. This is by far the largest gastric emptying normal data base that has been published. Simplification is based results of three publications that found no overall significant difference between frequent imaging complicated quantification and a simplified methodology. The rationale for a four hour exam was the results of two publications that had shown increased detection of gastroparesis at four compared to two hours. We have published our experience in 175 patients at Johns Hopkins University with this simplified and standardized protocol (4). At 2 hours 35 patients had delayed emptying; at 4 hours 45 patients had delayed emptying. This was a 32% increase at 4 hours and was significantly different than 2 hours (p <0.02). We also found in that publication that the lag phase, the time before emptying begins was not predictive of overall emptying. (author)

[en] Inflammation is a non specific reaction to injury which could be physical, chemical, radiation, immunologic or due to microorganisms. When due to microorganisms it represents infection. Despite the advancements in diagnosis and treatment of infection it is still a common problem worldwide particularly in the third world. Clinical diagnosis can be difficult. Several imaging modalities are useful in infection diagnosis and localization. When there are localizing signs, morphologic modalities including ultra-sonography, computed tomography and MRI are adequate for the diagnosis of most soft tissue infections while if the infection is suspected at a Skeletal site, nuclear medicine modalities are more useful with some exceptions. When there are no localizing signs as in the case of fever of unknown origin, nuclear medicine studies are the modalities of choice since they can survey the whole body. The choice of study depends on several factors including availability, cost and duration of symptoms and signs. The following algorithm is provided to guide the strategy of imaging of infection. (author)

[en] Obesity with its alarming increase in number among adults and children represents a significant health problem with serious medical, social, psychological and economical reverberations. The burden that is put upon the medical care system due to this problem has a significant effect on the medical services provided including radiological imaging. The effect of obesity on nuclear medicine services includes many aspects starting with problems with patient preparation prior to imaging, while radiotracer administration and during patient imaging. In addition, altered imaging techniques, including timing, imaging duration, and protocol alteration. Furthermore, obtaining suboptimal images brought by artifacts due to soft tissue attenuation and incomplete whole body coverage during image acquisition and performing sub optimal quantification, especially in positron emission tomography. Finally, dealing with mechanical problems such as weight limits of the imaging table and bore size in PET or SPECT/CT. These issues are discussed in this review clarifying the impact of this epidemic health problem on the nuclear medicine services and possible solutions to overcome the difficulties encountered in the nuclear medicine department. (author)

[en] Full text: Objective: To evaluate the utility of 99mTc-HMPAO labeled leucocyte, 99mTc-labeled anti-granulocyte antibody and 67Ga scintigraphy in patients suspected to have infected hip and knee replacements, from March/1998 to March/ 2002. Methods: Retrospective study of 33 patients (12 male, 21 female) with an average age of 61,1 ± 7,3 years. Nineteen had hip replacements and 14 were submitted to knee replacements. 99mTc-HMPAO labeled leucocyte scintigraphy was performed in 17 patients, 99mTc-labeled anti-granulocyte antibody scintigraphy in 13 patients and 67Ga scintigraphy in 3 patients. Twenty-six patients were also submitted to 3-phase 99mTc-MDP bone scintigraphy. Results were compared to those from studies with infection/inflammation agents. Concordant positive studies were considered to be a positive result for infection. A second study using 67Ga was also performed in 3 patients. Results: Diagnosis was based on surgical findings in 14 patients, pathologic study of biopsy specimen in 1 case and clinical/ imaging follow-up in 18 patients. Infection was detected in 22 cases and absent in 11. The conjoined evaluation of scintigraphic studies considered infection to be present in 20 cases and absent in 13. With infection/inflammation agents, 20 cases were positive (+) and 13 cases were negative (-). Using 99mTc-HMPAO labeled leucocytes, 12 cases were (+) and 5 cases were (-). With 99mTc-labeled anti-granulocyte antibodies, 8 cases were (+) and 5 were (-). With 67Ga, all 3 cases were (-). In patients with (+) studies using infection/ inflammation agents, a false positive case with 99mTc-HMPAO labeled leucocytes was reported. Two false negative cases were detected, both with 99mTc-labeled antigranulocyte antibodies, in patients with (-) studies. Regarding the studies with 99mTc-MDP, 24 were (+) and 2 were (-). Eighteen of these (+) cases were also (+) in studies with infection/inflammation agents, but 6 were (-) with these agents. Negative cases were also (-) in studies with infection/inflammation agents. Conclusions: Scintigraphy with infection/ inflammation agents yielded a sensitivity of 91%, a specificity of 92%, a PPV of 95%, a NPV of 85% and a diagnostic accuracy of 85%. Bone scintigraphy yielded sensitivity, specificity, PPV and NPV values of 100%, 56%, 50% and 100%, respectively. (author)

[en] Full text: Objectives: Evaluate in vivo response to specific immunotherapy in maintenance status, with leukocytes labelled with 99mTc-HMPAO. Methods: The leukocytes were labelled with 99mTc-HMPAO using the standard technique. After resuspension the labelled white cells with cell-free plasma they were injected intravenously in a peripheral vein faraway from the place where the therapeutic allergen suspension was applied. The both two administration were made at the same time. Simultaneously with the two injections, a 90 min dynamic acquisition, at thorax level, 64x64 matrix, at two frame/minute in anterior view, was carried out through a gamma camera. Static images, 256x256, 5 minutes, at 2, 3, 4, 5, 6, 8 and 21 hours after injections, of thorax and pelvis in anterior view, were acquired. During the examination, the local erythema was monitored. Results: The results obtained show that 40 min after injection local inflammatory activity at the IT administration place, with a progressive increase of local activity. 60 minutes after injection, ascendant lymphatic drainage directed to the homolateral axillary region ant to the lymphoid tissue of the upper mediastinum and anterior region of the neck were visualized. The static images show a progressive improvement of the inflammatory area corresponding to the place where IT was applied, with individualization of focal supraclavicular areas, bilaterally. In the latter images, thoracic, mediastinal, bowel and upper cervical localizations, were observed. Discussion and conclusions: In the patients studied, the specific IT shows great efficiency linked with the tolerability to different allergens (provocation test) achieved and with a significant fall of the Prick reactivity. However, at the aqueous extract application place, the local erythema with papula is always less than 60 mm. In these patients, the inflammatory response was significantly bigger in depth, time dependent, even after complete disappearance of the erythema. These results were conformed by the images. The progressive involvement of lymphatic nodes, bone marrow, BALT, GALT and MALT, with good visualization at the latter images, corresponding to an immune response induced by the subcutaneous IT. (author)

[en] Full text: Infections are responsible for more than half of all deaths among the poorest 20% of the world and more than two-thirds of the deaths in Africa. HIV/AIDS, TB and malaria are the world's great killers. Three million people died of AIDS in 2001. Tuberculosis accounted for 1.7 million deaths in 2000. In the same year, malaria killed more than 1 million people, mostly children in Africa. Worldwide, they account for 41% of global DALYS (disability adjusted life years), a rough measure of aggregate economic loss. The strategic goal for technical cooperation with Member States is that it ^shall increasingly promote tangible socio-economic impact by contributing directly in a cost-effective manner to the achievement of the major sustainable development priorities of each country^. With rapid developments in genetics and biotechnology, molecular biological and immunological techniques, including those based on radionuclides, are playing an unprecedented role in medicine. In the field of infections, the IAEA has successful ongoing projects in developing countries on malaria and tuberculosis, related to the use of molecular biological techniques like polymerase chain reaction and hybridisation with 32P- labelled probes, dot blot hybridisation, single-strand conformation polymorphism (SSCP), etc. for monitoring drug resistance and strain variation. Other ongoing IAEA projects on communicable diseases address hepatitis C, dengue, filariasis, diarrhoeal diseases and human papilloma virus infection. These projects provide valuable support for national programmes and clinicians. In terms of Nuclear Medicine imaging techniques the Agency has three areas of developments: 1. Assist programmes of transfer of technology related to traditional white cell labelling techniques. 2. Use of bacterial specific agents such as 'Tc99m- Ciprofloxacin ('Infecton'), and 3. Use of simple 'shake and mix' formulations such human immune globulin HIG and liposomes. One of the largest coordinated research programmes was the multi-centre trial of Infecton involving eight countries, Argentina, Chile, Egypt, Greece, India, Indonesia, Singapore and the UK. A total of 879 patients were studied. There were in total 574 positive studies and 295 negative studies with an overall sensitivity of 85.4% and specificity of 81.7% for detecting infective foci. The investigators confirmed the robustness of the preparation, ease of imaging and the absence of side effect. It also concluded that serial imaging with Infecton was useful in monitoring clinical responses and optimising the duration of antimicrobial treatment. The present strategy is to use white cell imaging and non-specific imaging with HIG and liposomes for first line approach and reserve the more specific agents for targeted clinical decisions. The use liposomes could be particularly important for assessment and delivery of pharmacologically active material at selective sites such as during fungal infection involving HIV patients. This approach may aide decisions related to toxicity and usefulness of expensive medicines such as the anti-fungal. Therefore, the Agency has a broad and strategic role in the use of radioisotope techniques for assisting many Member States with infection control programmes. (author)

[en] Review of nuclear medicine techniques in suspected sarcoidosis with myocardial. Usefulness of the fusion of images. Study design: Case presentation. Patient: 65 year old woman with history of mediastinal lymphadenopathy and multiple respiratory symptoms, diagnosed by pathology of sarcoidosis, who presented severe cardiac arrhythmia requiring antiarrhythmic treatment