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BACKGROUND Pharmacological stress is often used, and the drugs most frequently utilized are dipyridamole (Dip) and dobutamine (Dob). We aimed to evaluate the safety and the results obtained with a new protocol associating Dip, Dob, and atropine, compared with the Dip protocol. METHODS Thirty-two patients underwent rest Tl/Dip stress Tc-sestamibi myocardial perfusion tomography on the same day. Dip was administered intravenously (0.56 mg/kg) for 4 min, and Tc-sestamibi was injected 3 min after the end of the Dip injection. On another day, patients received the same Dip dose, immediately followed by the infusion of Dob [20 μg/kg/min for the first 2 min and 40 μg/kg/min in the next 2 min, with atropine (1 mg) given in the interval between the two Dob doses]. Images were acquired with a two-detector camera. In a 17-segment model of the left ventricle, each segment was automatically scored 0-4 (normal to absent radiotracer activity), and perfusion scores were obtained as the sum of stress score and sum of rest segmental score (SSS and SRS, respectively) and the difference between them [summed difference score (SDS)]. All scans were interpreted by two experienced physicians as either definitely normal, probably normal, probably abnormal, or definitely abnormal. RESULTS No serious complication was found independently of the protocol used. Heart rate and systolic and diastolic blood pressure were similar in both protocols at the basal level. Maximum heart rate (126 ± 21 vs. 82.7 ± 13.6, P

The conventional dobutamine (Dob) stress protocol for myocardial perfusion scintigraphy (MPS) is long, with frequent adverse effects, and generally requires atropine injection to reach target heart rate. Atropine is usually administered at the end of the protocol, when adverse effects are more frequent. Earlier atropine injection may be useful to shorten the stress protocol and reduce adverse effects. We sought to compare a Dob stress protocol with early atropine injection to a conventional Dob stress protocol in the same patients undergoing MPS. 30 patients underwent Dob-MPS with a conventional protocol (steps of 10, 20, 30 and 40 mcg/kg/min at 3 min intervals, adding atropine to the maximal Dob dose if necessary to achieve 85% of the age-corrected maximal predicted heart rate) and with an accelerated protocol with early atropine injection (at the end of the first stage). We compared stress duration, maximal heart rate (HR), percentage of maximal predicted HR, rate-pressure product, ST changes, MPS scores and the incidence of adverse effects between the 2 protocols. The accelerated protocol was shorter than the conventional protocol (7.1 ± 3.4 min vs. 11.8 ± 1.3 min; P < 0.0001), had the same efficacy to achieve hemodynamic parameters, without increasing adverse effects. The summed stress scores obtained by automatic analysis were similar in both protocols (6.3 ± 6.3 vs. 6.8 ± 6.3; P = NS) as well as the summed difference scores (2.5 ± 3.6 vs. 2.7 ± 3.4; P = NS). Early atropine injection during dobutamine stress protocol shortens stress duration. Our results suggest that patient safety and accuracy of MPS are unaltered, when compared to the conventional protocol, but further, larger studies are still necessary.

O objetivo deste trabalho foi determinar a existência de concordância entre os métodos radioisotópico e radiológico e, em caso positivo, avaliar a utilidade do SPECT ictal na determinação do foco epileptogênico. Foram realizados SPECT ictal, ressonância magnética (RM) e ressonância magnética com espectroscopia de prótons (RME) em seis pacientes com epilepsia de lobo temporal refratária. O SPECT ictal foi realizado após a retirada das drogas antiepilépticas durante monitoramento por vídeo-EEG, utilizando-se o 99mTc-ECD, administrado aos pacientes no início da crise. As imagens de RM foram obtidas em T1, T2 e FLAIR, com cortes de 3 e 5 mm de espessura, e a RME foi realizada com técnica PRESS, com voxel único posicionado no hipocampo, bilateralmente. A análise estatística incluiu os valores de Kappa (k), erro-padrão (ep) e o nível de significância (p) para a lateralização do foco. Os achados foram analisados com base na localização por EEG da descarga ictal, no tempo de duração da crise (109-280 s; média: 152 s) e no tempo de administração do traçador (30-262 s; média: 96 s). Obtivemos dados correlatos em quatro pacientes (67%), com valores de k = 0,67, ep = 0,38 e p = 0,041. Concluímos que existe concordância entre SPECT ictal, RM e RME, e a utilidade do procedimento radioisotópico está relacionada aos casos em que o EEG não é diagnóstico e quando há discordância ou indefinição diagnóstica na análise comparativa entre EEG, RM e RME.The purpose of this study was to determine the degree of concordance between radiological and radioisotopic methods and, if positive, to evaluate the usefulness of ictal SPECT in the localization of the epileptogenic focus. Ictal brain SPECT, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) were performed on six patients with refractory temporal lobe epilepsy. Ictal SPECT was performed after withdrawal of the anti-epileptogenic drugs during video-EEG monitoring, using 99mTc-ECD, administered to patients at the time of the ictus. MRI was performed in T1, T2 and FLAIR sequences and MRS was obtained using the PRESS technique, with a single voxel positioned in both hippocampi. The statistical analysis included the determination of the values of Kappa (k), standard error (se) and significance level (p) for the lateralization of the ictal focus. The analysis of all findings was based on EEG localization of the ictal discharge, seizure duration (109-280 s; 152 s average) and time of radiotracer injection (30-262 s; 96 s average). We obtained correlated data in four patients (67%), and values of k = 0.67, se = 0.38, and p = 0.041. We concluded that there is a concordance between ictal SPECT, MRI and MRS data and the usefulness of the radioisotopic procedure is related to a nondiagnostic EEG and when there is a discordant or misleading diagnosis after a comparative analysis of EEG and MRS.

O objetivo deste trabalho foi determinar a existência de concordância entre os métodos radioisotópico e radiológico e, em caso positivo, avaliar a utilidade do SPECT ictal na determinação do foco epileptogênico. Foram realizados SPECT ictal, ressonância magnética (RM) e ressonância magnética com espectroscopia de prótons (RME) em seis pacientes com epilepsia de lobo temporal refratária. O SPECT ictal foi realizado após a retirada das drogas antiepilépticas durante monitoramento por vídeo-EEG, utilizando-se o 99mTc-ECD, administrado aos pacientes no início da crise. As imagens de RM foram obtidas em T1, T2 e FLAIR, com cortes de 3 e 5 mm de espessura, e a RME foi realizada com técnica PRESS, com voxel único posicionado no hipocampo, bilateralmente. A análise estatística incluiu os valores de Kappa (k), erro-padrão (ep) e o nível de significância (p) para a lateralização do foco. Os achados foram analisados com base na localização por EEG da descarga ictal, no tempo de duração da crise (109-280 s; média: 152 s) e no tempo de administração do traçador (30-262 s; média: 96 s). Obtivemos dados correlatos em quatro pacientes (67%), com valores de k = 0,67, ep = 0,38 e p = 0,041. Concluímos que existe concordância entre SPECT ictal, RM e RME, e a utilidade do procedimento radioisotópico está relacionada aos casos em que o EEG não é diagnóstico e quando há discordância ou indefinição diagnóstica na análise comparativa entre EEG, RM e RME. The purpose of this study was to determine the degree of concordance between radiological and radioisotopic methods and, if positive, to evaluate the usefulness of ictal SPECT in the localization of the epileptogenic focus. Ictal brain SPECT, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) were performed on six patients with refractory temporal lobe epilepsy. Ictal SPECT was performed after withdrawal of the anti-epileptogenic drugs during video-EEG monitoring, using 99mTc-ECD, administered to patients at the time of the ictus. MRI was performed in T1, T2 and FLAIR sequences and MRS was obtained using the PRESS technique, with a single voxel positioned in both hippocampi. The statistical analysis included the determination of the values of Kappa (k), standard error (se) and significance level (p) for the lateralization of the ictal focus. The analysis of all findings was based on EEG localization of the ictal discharge, seizure duration (109-280 s; 152 s average) and time of radiotracer injection (30-262 s; 96 s average). We obtained correlated data in four patients (67%), and values of k = 0.67, se = 0.38, and p = 0.041. We concluded that there is a concordance between ictal SPECT, MRI and MRS data and the usefulness of the radioisotopic procedure is related to a nondiagnostic EEG and when there is a discordant or misleading diagnosis after a comparative analysis of EEG and MRS.

Several radionuclides and different methods have been employed as cellular labels to study inflammatory sites in man. Here we present the results obtained with white blood cells (WBC) labeled with 99mTc using a simple and low cost new technique (SnTec). WBC were incubated with 12 micrograms/ml of stannous chloride for 10 min at room temperature. Then 99mTc was added. After 10 min, the 99mTc-labeled WBC were washed and injected into the patient. Comparison studies with 99mTc-labeled WBC using the HMPAO technique were carried out in patients with suspected osteomyelitis. Since the results are similar with both methods, we suggest the use of SnTec to label WBC, in cases of inflammatory diseases.

O objetivo deste estudo foi avaliar o fluxo sanguíneo cerebral no córtex cerebelar (4 sub-regiões) e no córtex pré-frontal, em repouso e durante uma tarefa motora. A amostra foi composta por 8 sujeitos saudáveis, ambos os sexos, entre 23 e 36 anos. O grupo foi submetido a tarefa visuo-motora (memória implícita) que consistia na ação de desviar um submarino de supostas minas que percorriam a tela do monitor. Para avaliar a perfusão, foi utilizado o método de análise semi-quantitativa para imagens de SPECT cerebral - 99mTc-ECD. Os resultados evidenciaram aumento de atividade nas áreas de interesse durante a realização da tarefa. Em conclusão, quatro sub-regiões do córtex cerebelar e ambos os hemisférios do córtex pré-frontal apontaram uma ativação simultânea durante a tarefa. Ainda, e conforme estudos prévios, nossos resultados sugerem um modo de operação em paralelo do sistema nervoso central, no intuito de integrar uma informação sensorial e motora. The objective of the present study was to evaluate the cerebral blood flow in the cerebellar (4 sub-regions) and pre-frontal cortex, when subjects were in rest and during a motor task performance. The sample consisted of 8 healthy subjects, male or female, between 23 and 36 of age. The visuo-motor task _ implicit memory _ requires the subjects to navigate and swerve a graphic submarine from missiles that run on the screen. Semi-quantitative analysis with brain SPECT (99mTc-ECD) was used to evaluate regional perfusion. The results revealed an increased activity in all areas of interest during motor task. In conclusion, four sub-regions of cerebellar cortex and both pre-frontal hemispheres showed a simultaneous activation during task. Moreover, our findings suggest as seen in previous experiments that the central nervous system operates in a parallel fashion, in order to integrate sensory and motor information.

The objective of the present study was to evaluate the cerebral blood flow in the cerebellar (4 sub-regions) and pre-frontal cortex, when subjects were in rest and during a motor task performance. The sample consisted of 8 healthy subjects, male or female, between 23 and 36 of age. The visuo-motor task - implicit memory - requires the subjects to navigate and swerve a graphic submarine from missiles that run on the screen. Semi-quantitative analysis with brain SPECT (99mTc-ECD) was used to evaluate regional perfusion. The results revealed an increased activity in all areas of interest during motor task. In conclusion, four sub-regions of cerebellar cortex and both pre-frontal hemispheres showed a simultaneous activation during task. Moreover, our findings suggest as seen in previous experiments that the central nervous system operates in a parallel fashion, in order to integrate sensory and motor information.

OBJETIVO: Determinar a frequencia e localizacao das alteracoes parenquimatosas da trombose venosa cerebral nos exames de ressonância magnetica e de angiorressonância, bem como a correlacao com o territorio e a drenagem venosa comprometida. MATERIAIS E METODOS: Foram analisados exames de 21 pacientes realizados entre 1996 e 2004, com diagnostico clinico e radiologico de trombose venosa cerebral em exames de ressonância magnetica e de angiorressonância nas sequencias 2D PC, 3D PC e 3D TOF com contraste paramagnetico. Analise estatistica foi realizada com o teste do qui quadrado. Quatro pacientes tinham exames de controle e tres realizaram angiografia por subtracao digital. RESULTADOS: Dos 21 pacientes, 18 eram mulheres, todos com idade entre tres e 82 anos (media de 40 anos e mediana de 36 anos). Os principais fatores etiologicos foram infeccao, uso de contraceptivos orais, reposicao hormonal e colagenoses. Predominaram os sintomas de deficit focal, cefaleia, alteracao do nivel de consciencia e convulsoes. Por frequencia, as manifestacoes parenquimatosas foram: edema/infarto de distribuicao cortical e/ou subcortical, congestao venosa e circulacao colateral, realce meningeo e infarto ou edema dos talamos e nucleos da base. Os principais seios comprometidos foram o sagital superior, o transverso esquerdo, o sigmoide esquerdo e o seio reto, sendo incomum o acometimento dos seios cavernosos e de veias corticais. CONCLUSAO: A trombose venosa cerebral e causa incomum de acidente vascular encefalico, com prognostico favoravel pelo carater reversivel das lesoes. Seu diagnostico depende fundamentalmente da capacidade do radiologista reconhecer suas formas de apresentacao, principalmente nos casos em que ele e sugerido pelas alteracoes parenquimatosas e nao necessariamente pela visualizacao do trombo. A precisao e a rapidez no diagnostico permitem o pronto tratamento, reduzindo a morbi-mortalidade da doenca. Unitermos: Ressonância magnetica; Trombose venosa cerebral; Infarto cerebral; Hemorragia intracraniana. Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography. OBJECTIVE: To determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. MATERIALS AND METHODS: Retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. RESULTS: Main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. CONCLUSION: Cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid