Search

João P Lima,1 João Carvalho,1 Vasco Quaresma,1 Edgar Tavares-da-Silva,1 Rodolfo Silva,2 Paulo Azinhais,2 Gracinda Costa,2 Arnaldo Figueiredo1 1Urology and Renal Transplantation Department, Coimbra University Hospital Center, Coimbra, Portugal; 2Nuclear Medicine Department, Coimbra University Hospital Centre, Coimbra, PortugalCorrespondence: João P LimaUrology and Renal Transplantation Department, Coimbra University Hospital Center, Praceta R. Prof. Mota Pinto, Coimbra, 3004-561, PortugalEmail joaopedrosolima@gmail.comBackground: Recommended imaging modalities for prostate cancer staging have disappointing sensitivities, whereas [68Ga]-PSMA PET/CT (PET-PSMA) shows promising sensitivities and specificities in the initial management of prostate cancer. Recent studies have revealed that a significant change of management when PET-PSMA was used, with favorable negative predictive values.Methods: In this retrospective study, we analyzed every PET-PSMA performed in our center for initial staging of intermediate and high-risk prostate cancer. Patients were divided into two groups based on whether imaging modalities other than PET-PSMA were performed. In patients submitted to radical prostatectomy, PET-PSMA findings were compared to histological analysis of the specimen.Results: PET-PSMA results of 57 patients were gathered, with 77.2% (n=44) having performed CT scan or bone scan (BS) prior to PET-PSMA. Prostate cancer management strategy was changed in 61.4% (n=27), when PET-PSMA was performed following CT and BS. BS and CT results were consistent with PET-PSMA in 43.2% and 44.8%, respectively. In 30 cases, a curative strategy was used based on PET-PSMA findings. PET-PSMA revealed a negative predictive value of 95.2% in 23 patients submitted to radical prostatectomy with bilateral pelvic lymphadenectomy. Prostate SUV values on preoperative PET-PSMA correlated with initial PSA, ISUP grade, PC risk staging and presence of extraprostatic lesions.Conclusions: PET-PSMA is a key element for prostate cancer staging and management, with high diagnostic accuracy. More prospective studies need to be implemented to determine its role as a first-line staging tool.Keywords: PET-CT, prostate cancer, specificity and sensitivity, metastasis, lymphatic metastases, bone metastases

Roberto Jarimba,1 João Pedroso Lima,1 Miguel Eliseu,1 João Carvalho,1 Hugo Antunes,1,2 Edgar Tavares da Silva,1,2 Pedro Moreira,1 Arnaldo Figueiredo1,2 1Urology and Renal Transplantation Department, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal; 2Faculty of Medicine, University of Coimbra, Coimbra, PortugalCorrespondence: Roberto JarimbaUrology and Renal Transplantation Department, Centro Hospitalar e Universitário de Coimbra, Rua Professor Mota Pinto, Coimbra 3004-561, PortugalTel +351968209250Email robertojarimba@chuc.min-saude.ptIntroduction: Prostate cancer is the most commonly diagnosed cancer in men. Radical prostatectomy is a potentially curative alternative for localized disease, although a significant percentage of these patients will suffer a biochemical recurrence with associated mortality. A wide spectrum of anticancer properties of statins has been demonstrated and the role of these drugs in prevention and treatment of other types of cancer is being increasingly studied.Objective: The aim of this study was to investigate whether the use of statins is associated with reduced risk of biochemical recurrence among patients submitted to radical prostatectomy.Patients and Methods: We retrospectively reviewed 875 patients submitted to radical prostatectomy between January 2009 and December 2018. Approximately 45.7% of the patients were on medication with statins at the time of surgery. We evaluated a possible association between statin use and biochemical recurrence and which patients would benefit the most with statin treatment.Results: Overall, statins were associated with an approximately 40% reduction in risk of biochemical recurrence at a median follow-up time of 51.2 months (HR 0.599, p< 0.05). Patients with pT2c staging (HR 0.486, p=0.017) and ISUP ≥ 3 (HR 0.61, p=0.011) seem to have benefited more from statin use.Conclusion: In this cohort, use of statins proved beneficial in reducing the risk of biochemical recurrence among patients submitted to radical prostatectomy. Prospective studies are required to confirm this result and to evaluate its safety profile in those patients.Keywords: prevention, prostate cancer, radical prostatectomy, recurrence, statins

Introdução: A tomografia por emissão de positrões/tomografia computorizada - FNa-F18 vem sendo considerada como uma modalidade imagiológica com vantagens na pesquisa de metastização óssea. Comparámos a sua capacidade para deteção de metástases ósseas com a de outras técnicas imagiológicas.Material e Métodos: Avaliámos retrospetivamente 114 doentes que realizaram tomografia por emissão de positrões/tomografia computorizada - FNa-F18. Destes, 49 realizaram também cintigrafia óssea, 61 tomografia por emissão de positrões/tomografia computorizada - FDG-F18 e 10 tomografia por emissão de positrões/tomografia computorizada - FCH-F18. Identificámos a técnica que detetou um maior número de metástases ósseas. Comparámos ainda a tomografia por emissão de positrões com a componente tomografia computorizada da tomografia por emissão de positrões/tomografia computorizada - FNa-F18. Registámos as situações nas quais a tomografia por emissão de positrões/tomografia computorizada FNa-F18 e a cintigrafia óssea necessitaram de exames adicionais para esclarecimento complementar.Resultados: A tomografia por emissão de positrões/tomografia computorizada - FNa-F18 foi superior à cintigrafia óssea em 49% dos doentes (p < 0,001); foi superior à tomografia por emissão de positrões/tomografia computorizada - FDG-F18 em 59% dos doentes (p < 0,001) e foi superior à tomografia por emissão de positrões/tomografia computorizada - FCH-F18 em 40% dos doentes (p < 0,001). Nenhuma das técnicas imagiológicas avaliadas lhe foi superior. Na tomografia por emissão de positrões/tomografia computorizada -FNa-F18 a componente tomografia por emissão de positrões foi superior à tomografia computorizada em 35% dos casos (p < 0,001). Foi sugerida investigação complementar em apenas 3,5% dos doentes que realizaram tomografia por emissão de positrões/ tomografia computorizada - FNa-F18 (45% para a cintigrafia óssea) (p < 0,001).Discussão: Em conformidade com o referido por outros autores, a nossa experiência confirma que a tomografia por emissão de positrões/tomografia computorizada - FNa-F18 tem excelente desempenho na deteção de metástases ósseas, sendo capaz de identificar lesões em mais doentes, e em maior número, quando comparada com outras técnicas imagiológicas.Conclusão: A tomografia por emissão de positrões/tomografia computorizada - FNa-F18 revelou superioridade na deteção de metástases ósseas comparativamente à cintigrafia óssea, à tomografia por emissão de positrões/tomografia computorizada - FDG-F18 e à tomografia por emissão de positrões/tomografia computorizada - FCH- F18.

Introdução: No carcinoma da próstata, é frequente, após terapêutica com intuito curativo, ocorrer recidiva bioquímica. O objectivo deste trabalho foi avaliar o impacto da PET/CT com fluorocolina-F18 no restadiamento e orientação destes doentes e analisar a influência, da estratificação de risco, dos valores do PSA e da terapêutica de supressão hormonal, na sensibilidade da técnica. Material e Métodos: Análise retrospectiva de 107 doentes com carcinoma da próstata em recidiva bioquímica que realizaram PET/CT com fluorocolina-F18 no nosso hospital, entre dezembro de 2009 e maio de 2014. Resultados: A sensibilidade global foi de 63,2% sendo 80,0% quando PSA > 2 ng/mL. Foi possível identificar doença à distância em 28% dos doentes. A sensibilidade aumentou de 40,0% em doentes de risco baixo e intermédio para 55,2% em doentes de alto risco. Sem terapêutica de supressão hormonal, a sensibilidade foi de 61,8% enquanto no grupo sob essa terapêutica, foi de 67,7%. Discussão: A PET/CT com fluorocolina-F18 forneceu informações relevantes, mesmo em doentes com baixos valores do PSA, contudo, com incremento significativo da sensibilidade nos doentes com PSA >2 ng/mL. A sensibilidade foi superior nos doentes de alto risco comparativamente com os de risco baixo e intermédio, contudo, sem uma diferença estatisticamente significativa. A terapêutica de supressão hormonal parece não influenciar a captação de Fluorocolina-F18 nos doentes resistentes à castração. Conclusões: Neste estudo, a PET/CT com fluorocolina-F18 apresentou bons resultados no restadiamento de doentes com carcinoma da próstata em recidiva bioquímica, distinguindo entre doença loco-regional e sistémica, informação com importantes consequências na definição da estratégia terapêutica.

AimIn the evaluation of prostate cancer, clinical nomograms are commonly used to predict the probability of lymphatic and extra‐nodal spread. Those nomograms may suggest the presence and the extension of this cancer but do not allow a clear distinction between loco‐regional and distant disease. In this study, it was intended to evaluate the usefulness of 18F‐Fluorocoline positron emission tomography/computed tomography (18F‐FCH‐PET/CT) in the workup of patients with the initial diagnosis of prostate cancer and staged by this imaging technique.Material and methodsThe medical records of 39 patients with prostate cancer who underwent 18F‐FCH PET/CT for initial staging, between November 2010 and April 2015, were reviewed. Of these, 20 patients were excluded because they had already started hormonotherapy. In the other 19 patients, the performance of 18F‐FCH PET/CT for the detection of lymph node metastasis was evaluated by calculating the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy. Six patients had performed pelvic lymphadenectomy (total of 69 lymph nodes), allowing histological confirmation. When there was no histological confirmation (total of 30 lymph nodes and 3 cases of bone metastasis), the findings of 18F‐FCH PET/CT were correlated with the values of PSA and the information from multiple imaging modalities such as CT, bone scan, magnetic resonance (MRI), 18F‐Sodium Fluoride (18F‐NaF) PET/CT of control.ResultsThe sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for lymph node metastasis detection were, respectively, 96.8%, 80.9%, 69.8%, 98.2% and 85.8%. In our sample, this technique also allowed the identification of nodal extra pelvic or bone metastasis in 5 patients (26.3%) with implications in the treatment. It showed uptake suggestive of bone metastasis, corroborated by other diagnostic technics or by the follow‐up, in 3 patients, those with prostate specific antigen (PSA) of 9.5±2.9 ng/mL.Conclusion18F‐FCH PET/CT is an entire body and multi organ imaging modality that allows the identification, globally, of the sites of disease in patients with prostate cancer. In this study, 18F‐FCH PET/CT showed good results when used in the initial staging of these patients. It is highlighted the ability to detect distant disease, in particular bone metastasis, even with PSA

The 18F-NaF positron emission tomography/computed tomography is being considered as an excellent imaging modality for bone metastases detection. This ability was compared with other imaging techniques.We retrospectively evaluated 114 patients who underwent 18F-NaF positron emission tomography/ computed tomography. Of these, 49 patients also had bone scintigraphy, 61 18F-FDG positron emission tomography/computed tomography and 10 18F-FCH positron emission tomography/computed tomography. We identified the technique that detected the largest number of bone metastases. For the detection of skeletal metastases with the 18F-NaF positron emission tomography/computed tomography study, the contribution of the positron emission tomography component was compared with the contribution of the computed tomography component. Cases in which 18F-NaF positron emission tomography/computed tomography and bone scintigraphy required further additional tests for diagnosis clarification were registered.The 18F-NaF positron emission tomography/computed tomography was superior to bone scintigraphy in 49% of the patients (p0.001); it was superior to 18F-FDG positron emission tomography/computed tomography in 59% of the patients (p0.001) and it was superior to 18F-FCH positron emission tomography/computed tomography in 40% of the patients (p0.001). None of the compared imaging techniques were superior to 18F-NaF positron emission tomography/computed tomography. The positron emission tomography component was superior to computed tomography in 35% of the cases (p0.001). Further investigation was suggested in only 3.5% of patients who underwent 18F-NaF positron emission tomography/computed tomography (45% for bone scintigraphy) (p0.001).As with other authors, our experience also confirms that 18F-NaF positron emission tomography/computed tomography is an excellent imaging modality for the detection of bone metastases, detecting lesions in more patients and more lesions per patient.The 18F-NaF positron emission tomography/computed tomography showed a superior ability for the detection of bone metastases when compared with bone scintigraphy, 18F-FDG positron emission tomography/computed tomography and 18F-FCH positron emission tomography/computed tomography.Introdução: A tomografia por emissão de positrões/tomografia computorizada - FNa-F18 vem sendo considerada como uma modalidade imagiológica com vantagens na pesquisa de metastização óssea. Comparámos a sua capacidade para deteção de metástases ósseas com a de outras técnicas imagiológicas.Material e Métodos: Avaliámos retrospetivamente 114 doentes que realizaram tomografia por emissão de positrões/tomografia computorizada - FNa-F18. Destes, 49 realizaram também cintigrafia óssea, 61 tomografia por emissão de positrões/tomografia computorizada - FDG-F18 e 10 tomografia por emissão de positrões/tomografia computorizada - FCH-F18. Identificámos a técnica que detetou um maior número de metástases ósseas. Comparámos ainda a tomografia por emissão de positrões com a componente tomografia computorizada da tomografia por emissão de positrões/tomografia computorizada - FNa-F18. Registámos as situações nas quais a tomografia por emissão de positrões/tomografia computorizada FNa-F18 e a cintigrafia óssea necessitaram de exames adicionais para esclarecimento complementar.Resultados: A tomografia por emissão de positrões/tomografia computorizada - FNa-F18 foi superior à cintigrafia óssea em 49% dos doentes (p0,001); foi superior à tomografia por emissão de positrões/tomografia computorizada - FDG-F18 em 59% dos doentes (p0,001) e foi superior à tomografia por emissão de positrões/tomografia computorizada - FCH-F18 em 40% dos doentes (p0,001). Nenhuma das técnicas imagiológicas avaliadas lhe foi superior. Na tomografia por emissão de positrões/tomografia computorizada -FNa-F18 a componente tomografia por emissão de positrões foi superior à tomografia computorizada em 35% dos casos (p0,001). Foi sugerida investigação complementar em apenas 3,5% dos doentes que realizaram tomografia por emissão de positrões/ tomografia computorizada - FNa-F18 (45% para a cintigrafia óssea) (p0,001).Discussão: Em conformidade com o referido por outros autores, a nossa experiência confirma que a tomografia por emissão de positrões/tomografia computorizada - FNa-F18 tem excelente desempenho na deteção de metástases ósseas, sendo capaz de identificar lesões em mais doentes, e em maior número, quando comparada com outras técnicas imagiológicas.Conclusão: A tomografia por emissão de positrões/tomografia computorizada - FNa-F18 revelou superioridade na deteção de metástases ósseas comparativamente à cintigrafia óssea, à tomografia por emissão de positrões/tomografia computorizada - FDG-F18 e à tomografia por emissão de positrões/tomografia computorizada - FCH- F18.

In prostate cancer, after therapy with curative intent, biochemical recurrence frequently occurs. The purpose of this study was to evaluate the impact of PET/CT with 18F-fluorocholine in restaging these patients and in their orientation, and to analyze the effect of the risk stratification, the values of PSA and the hormone suppression therapy, in the technique sensitivity.Retrospective analysis of 107 patients with prostate carcinoma in biochemical recurrence who underwent PET/CT with 18F-fluorocholine in our hospital, between December 2009 and May 2014.The overall sensitivity was 63.2% and 80.0% when PSA2 ng/mL. It was possible to identify distant disease in 28% of the patients. The sensitivity increased from 40.0%, in patients with low and intermediate risk, to 55.2% in high-risk patients. Without hormonal suppression therapy, the sensitivity was 61.8%, while in the group under this therapy, was 67.7%.PET/CT with 18F-fluorocholine provided important information even in patients with low levels of PSA, however, with significantly increased sensitivity in patients with PSA2 ng/mL. Sensitivity was higher in high-risk patients compared with low and intermediate risk patients, however, without a statistically significant difference. The hormone suppression therapy does not appear to influence uptake of 18F-fluorocholine in patients resistant to castration.In this study, PET/CT with 18F-Fluorocholine showed good results in restaging patients with prostate cancer biochemical recurrence, distinguishing between loco regional and systemic disease, information with important consequences in defining the therapeutic strategy.Introdução: No carcinoma da próstata, é frequente, após terapêutica com intuito curativo, ocorrer recidiva bioquímica. O objectivo deste trabalho foi avaliar o impacto da PET/CT com fluorocolina-F18 no restadiamento e orientação destes doentes e analisar a influência, da estratificação de risco, dos valores do PSA e da terapêutica de supressão hormonal, na sensibilidade da técnica. Material e Métodos: Análise retrospectiva de 107 doentes com carcinoma da próstata em recidiva bioquímica que realizaram PET/CT com fluorocolina-F18 no nosso hospital, entre dezembro de 2009 e maio de 2014. Resultados: A sensibilidade global foi de 63,2% sendo 80,0% quando PSA2 ng/mL. Foi possível identificar doença à distância em 28% dos doentes. A sensibilidade aumentou de 40,0% em doentes de risco baixo e intermédio para 55,2% em doentes de alto risco. Sem terapêutica de supressão hormonal, a sensibilidade foi de 61,8% enquanto no grupo sob essa terapêutica, foi de 67,7%. Discussão: A PET/CT com fluorocolina-F18 forneceu informações relevantes, mesmo em doentes com baixos valores do PSA, contudo, com incremento significativo da sensibilidade nos doentes com PSA2 ng/mL. A sensibilidade foi superior nos doentes de alto risco comparativamente com os de risco baixo e intermédio, contudo, sem uma diferença estatisticamente significativa. A terapêutica de supressão hormonal parece não influenciar a captação de Fluorocolina-F18 nos doentes resistentes à castração. Conclusões: Neste estudo, a PET/CT com fluorocolina-F18 apresentou bons resultados no restadiamento de doentes com carcinoma da próstata em recidiva bioquímica, distinguindo entre doença loco-regional e sistémica, informação com importantes consequências na definição da estratégia terapêutica.

Radioisotopes are extensively used in medicine for diagnosis, either in vivo or in vitro, for therapeutics and also for investigation purposes. Nuclear medicine (NM) studies in vivo are used to detect minimal amounts of radiopharmaceuticals in organs (the morphology) and their course over time (the function), resulting from physico-chemical interactions of the tracers within the body, in the sequence of specific physiological processes. In vitro applications of radioisotopes have become a most important tool in biochemical analysis. Therapeutic uses of radioisotopes cover from external gamma-ray sources in teleradiotherapy to direct cell irradiation in metabolic therapy. The information, which is conveyed by NM, is essentially metabolic and differs from that supplied by the other imaging techniques, which is basically structural. This quality is important in early detection and diagnosis. Efforts have steadily been made to bring NM imaging as close as possible to an ideal medical diagnostic tool: non-invasive and allowing studies yielding functional, morphological, three-dimensional and quantitative information simultaneously. Of the two tomographic techniques available in NM, positron emission tomography (PET) is probably closer to this goal than single-photon emission tomography (SPECT). High-contrast functional images of the dynamics of labelled molecules (native or functionally similar) that are metabolized by the organs under investigation, are obtained with these techniques. Nuclear medicine has progressed as a result of advances in four strategic areas: the development of new radiopharmaceuticals, the technology and reliability of detectors, the capacity for modelling the metabolic fate of the inputs in the biological systems, and finally the ability to extract and process data.

A preliminary review of physical concepts related with the solubility of inert gases in tissues and with the permeability of inert gases through the alveolar-capillary membrane in the context of this paper, is firstly presented. The solubility laws of gases in liquids and tissues, the concept of partial pressure of a gas in a tissue, the solubility and partition coefficients, the equilibrium of gases in the lungs, the gas diffusion through the capillary walls, etc., are brevely dealed with in this part of the work. The importance of a physiological method to study the alveolar-capillary barrier permeability with local information is emphasized. In the present paper the physiological and practical reasons which favour gas utilization, and particularly 133 Xe, instead of aerosols, to evaluate the alveolar-capillary barrier permeability are considered. A method to evaluate the disappearance times of 133 Xe activity and obtain parametric images is described. The advantages to display 133 Xe permeability images concomitantly with the ventilation and perfusion images and its interest is shown with some examples. General aspects of the use of 99m Tc-DTPA aerosols and CO classical spirometry with infra red analysis to study the alveolar-capiillary barrier permeability are considered. In a group of pacients, parametric images of the alveolar-capillary barrier permeability were obtained both with 133 Xe, using our technique and with the usual method of Nuclear Medicine using 99m Tc-DTPA aerosols. The disapearence times obtained by the two techniques are in general terms correlated, however, a considerably higher specificity is obseved in the case of 133 Xe. In a second group of patients the global mean disapearence times of 133 Xe, in the region of interest of the lungs, were compared with the CO diffusion times obtained with a convencional CO test. The agreement between the tests is very good in what concerns the ability to distinguish normal from abnormal, however, the local information offered by the 133 Xe technique was felt to be an information of great value in many situations. The results obtained, up to now, with 133 Xe indicate that the information provided may be a further step in the study of the alveolar-capillary barrier compromises, even in the early stages.

Resumo: A drenagem linfática pulmonar profunda (DLPP) desempenha um papel importante na remoção de materiais estranhos, constituindo os macrófagos alveolares a primeira linha de defesa fagocitária, dada a grande afinidade para microrganismos patogénicos. Os Bacillus subtilis são saprófitas do tracto respiratório humano com ampla utilização em investigação e em biotecnologia.As cadeias linfáticas pulmonares profundas (CLPP) constituem um dos primeiros locais de disseminação de tumores pulmonares.Neste trabalho pretendeu-se desenvolver e validar um método não invasivo para avaliar as CLPP através de nanorradiolipossomas aerosolisados e modulados pela parede do esporo do Bacillus subtilis. O objectivo final foi produzir uma formulação de nanorradiolipossomas capaz de imitar a dinâmica da remoção de esporos pelas CLPP e simultaneamente ter propriedades ideais como traçador para imagiologia molecular.Testámos sete diferentes formulações lipossómicas, tendo a formulação F demonstrado possuir propriedades fisicoquímicas e radiofarmacêuticas que a tornam o traçador ideal para imagiologia molecular in vivo das CLPP.Os nanorradiolipossomas da formulação F após marcação com 99mTc-HMPAO foram administrados sob a forma de aerossóis a 20 Sus scrofa. Visualizaram-se comunicações hilares e interpulmonares nos primeiros 5 minutos após a inalação, as cadeias infradiafragmáticas entre os 10 e os 20 minutos, os gânglios da cadeia aórtica aos 20 minutos e os da região hilar renal aos 30 minutos.Em conclusão, o método proposto visualiza os gânglios linfáticos e a rede linfática pulmonar profunda. A modulação dos nanorradiolipossomas permite que eles atinjam órgãos ou tecidos específicos, conferindo-lhes importantes potencialidades no âmbito do diagnóstico e/ou da terapêutica.Rev Port Pneumol 2009; XV (2): 261-293 Abstract: Lung deep lymphatic drainage (LDLD) plays an important role in the removal of foreign materials from lungs being alveolar macrophages the first line of phagocytic defence with high affinity for pathogenic microorganisms. Bacillus subtilis is a well-known genome-decoded saprophyte of the human respiratory tract used in research and in the biotechnology industry.Lung deep lymphatic chains (LDLC) constitute one of the first sites of lung tumoursâ dissemination. In this work we intended to develop and validate a non-invasive method for assessing LDLC by nanoradioliposomes aerosolised modulated on the Bacillus subtilis spore wall. The final goal was to produce a nanoradioliposome formulation that can mimics the dynamics of preferential removal of spores by LDLD and present the ideal properties as a tracer for molecular imaging studies.Seven different liposomal formulations were tested, and the formulation-F demonstrated physicochemical and radiopharmaceutical properties that make it an ideal candidate as an in vivo probe for molecular imaging studies of the LDLC.Nanoradioliposomes of the formulation-F after labelling with 99mTc-HMPAO were administered as aerosols to 20 Sus scrofa. Hilar and interpulmonary communications were visualized in first 5 minutes post-inhalation, infradiaphragmatic chains between 10 and 20 minutes, the ganglia of the aortic chain at 20 minutes and those of the renal hilar region at 30 minutes.Conclusion: the proposed method enables visualization of deep lymphatic lung network and lymph nodes. Besides, this technique involving the modulation of nanoradioliposomes targeting specific organs or tissues may be an important tool for diagnostic or even for therapeutic purposes.Rev Port Pneumol 2009; XV (2): 261-293 Palavras-chave: Nanorradiolipossomas, modulação molecular, drenagem linfática pulmonar, imagem nuclear funcional, Key-words: Nanoradioliposomes, molecular modulation, lung lymphatic drainage, functional nuclear imaging

Collateral flow, even when developed after acute myocardial infarction (AMI), prevents the progressive left ventricular dilation and remodeling after AMI. independent of infarct size reduction. The mechanisms underlying this situation are unknown. The purpose of this study was to examine the hypothesis that collateral flow influences the collagen volume fraction in the necrotic area. We studied ten mongrel dogs with AMI. The dogs were sacrificed five days later. The hearts were arrested in diastole, perfusion fixed, and sliced. Sections from each slice were taken from the center of the infarct zone, and stained with hematoxylin and eosin or picrosirius red. Collagen analysis was performed using polarized light microscopy. Using a random sampling morphometric technique, the relative density of collagen, was calculated. To confirm the results from morphometry fresh transmural myocardial tissue samples were also taken from the center of the infarct zone, and processed for measurement of hydroxiproline content (μg/mg dry tissue weight). Myocardial blood flow was measured with 99mTc labeled microspheres(10 μLm). Collagen deposition was analyzed in relation to baseline variables including the anatomic area at risk, necrosis, collateral blood flow and hemodynamic determinants of myocardial metabolic demand (heart rate, blood pressure, rate pressure product). Stepwise multivariate regression analysis showed that only collateral blood flow contributed to the model predicting an increase in myocardial collagen content (r2 = 0.89) P = 0.01. In conclusion, we found that after a myocardial infarction a rich collateral flow to the necrotic area is associated with an increase in the collagen content. This is probably one of the reasons why after AMI, collateral flow has a positive influence on ventricular remodeling, independent of infarct size reduction. Download : Download high-res image (42KB) Download : Download full-size image

This paper describes and discusses the performance of spark chambers which are designed to visualise the distribution of β-emitting radioactivity on chromatograms. The chambers comprise an assembly of individual detectors with spiral wire cathodes and concentric wire anodes. This design leads to ease of construction with good uniformity of sensitivity and stability of operation; sufficient for routine use in radiochromatography.

The main difficulty in using spark chambers in routine laboratory applications such as autoradiography is the appearance of spurious sparks which are not associated with the passage of ionisation radiation through the gas of the detectors. This paper describes an investigation of the production of initiatory electrons from the cathode surfaces of detectors by field emission effects. Electron emission rates from cathode surfaces have been measured as a function of applied electric field, cathode material and spark frequency. The results show that emission rates are high enough to account for a significant proportion of spurious sparks. Other effects leading to ionisation in the gas will also contribute to the spurious sparking rate. Conclusions are drawn as to suitable materials for spark counter cathodes.

The synthesis and characterization of a new class of DOTA (1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecane) monoamide-linked glycoconjugates (glucose, lactose and galactose) of different valencies (mono, di and tetra) and their Sm(III), Eu(III) and Gd(III) complexes are reported. The proton NMR spectrum of Eu(III)-DOTALac(III) shows the predominance of a single structural isomer of square antiprismatic geometry of the DOTA chelating moiety and fast rotation about the amide bond connecting to the targeting glycodendrimer. The in vitro relaxivity of the Gd(III)-glycoconjugates was studied by proton nuclear magnetic relaxation dispersion (NMRD), yielding parameters close to those reported for other DOTA monoamides. The known recognition of sugars by lectins makes these glycoconjugates good candidates for medical imaging agents (MRI and gamma scintigraphy).

Problems common to the visualization in multimodal clinical environments are presented. Three different solutions for the visualization of 3D multimodal clinical data are proposed, having in mind the constrains related to the interactivity goal. Some resulting images containing this type of data in an integrated form are presented.