RESUMO
The objective of the present study was to elucidate the association between glomerular complement depositions belonging to the alternative (AP) and lectin (LP) pathways, and clinical findings of lupus nephritis (LN). Immunofluorescence (IF) was performed on 17 LN patients using antibodies against factor B, factor H, properdin, mannose-binding lectin (MBL) and L-ficolin. Compared with factor B/factor H negative patients (n = 9), positive patients (n = 8) showed longer duration of LN (p < 0.05) and more severe interstitial fibrosis (p < 0.05). Eleven patients had properdin deposition in glomeruli, and in three of them, with a duration of LN of less than 1 month, factor B was undetectable. Compared with properdin negative patients (n = 6), positive patients (n = 11) showed significantly higher urinary protein excretion (p < 0.01). MBL/L-ficolin positive patients (n = 11) also had significantly higher urinary protein excretion (p < 0.05) compared with negative patients (n = 6). An independent association was found between glomerular deposition of properdin and that of MBL/L-ficolin (p < 0.01) in addition to factor B/factor H. Traces of glomerular activation of AP and LP reflected the clinical status of LN. It appears that glomerular deposition of each complement component, especially properdin, may be an index of the histological activity of LN.
Assuntos
Via Alternativa do Complemento/imunologia , Lectina de Ligação a Manose da Via do Complemento/imunologia , Glomérulos Renais/imunologia , Nefrite Lúpica/imunologia , Adulto , Fator B do Complemento/imunologia , Fator H do Complemento/imunologia , Fibrose , Humanos , Glomérulos Renais/patologia , Lectinas/imunologia , Nefrite Lúpica/patologia , Nefrite Lúpica/fisiopatologia , Masculino , Lectina de Ligação a Manose/imunologia , Pessoa de Meia-Idade , Properdina/imunologia , Proteinúria/imunologia , Adulto Jovem , FicolinasRESUMO
Early and delayed 201Tl SPECT studies were performed on 13 patients with intracranial meningiomas, which were classified in three groups according to their histological types: meningothelial (n = 7); transitional and fibroblastic (n = 3); and malignant types (n = 3). The early uptake indices (UI, ratios of average counts/pixel in the lesion to those of the contralateral area on early images) were relatively high in all types: meningothelial meningiomas, 5.75 +/- 2.16 (mean +/- s.d.); transitional and fibroblastic meningiomas, 4.69 +/- 0.54; and malignant meningiomas, 7.10 +/- 3.72. There were no statistical differences in relation to histological type. The delayed uptake indices were 2.65 +/- 0.89, 3.37 +/- 1.02, and 5.16 +/- 1.62, respectively. Statistically, the delayed UI of meningothelial meningiomas were lower than those of malignant types (p < 0.05). The retention indices (RI, ratios of delayed to early UI) were 0.48 +/- 0.08, 0.79 +/- 0.16, and 0.84 +/- 0.16, respectively. The RI of the meningothelial type were also statistically lower than those of the other two groups (p < 0.05). There were no statistically significant differences between transitional plus fibroblastic types and malignant meningiomas. We conclude that 201Tl exhibits early high accumulations in all types of meningiomas, but its retention rates probably differ according to histological types, and a high retention index is predictive of the malignant potential in a meningioma.
Assuntos
Neoplasias Meníngeas/diagnóstico por imagem , Meningioma/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/patologia , Meningioma/diagnóstico , Meningioma/patologia , Pessoa de Meia-IdadeRESUMO
Two patients presenting with progressive dementia coupled with motor neuron disease underwent brain SPECT using N-isopropyl-p iodine-123-iodoamphetamine [( 123I]IMP). The characteristic clinical features of progressive dementia and motor neuron disease were noted. IMP SPECT also revealed reduced uptake in the bilateral frontal and temporal regions, with no reduction of uptake in the parietal, parietal-occipital regions. We conclude that IMP SPECT has potential for the evaluation of progressive dementia with motor neuron disease.
Assuntos
Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular , Demência/complicações , Neurônios Motores , Doenças Neuromusculares/complicações , Anfetaminas , Demência/diagnóstico por imagem , Feminino , Humanos , Radioisótopos do Iodo , Iofetamina , Masculino , Pessoa de Meia-Idade , Doenças Neuromusculares/diagnóstico por imagem , CintilografiaRESUMO
UNLABELLED: The aim of this study was to review the etiology of CCD and study factors that affect the development and manifestation of CCD. METHODS: Three hundred and eleven patients with supratentorial lesions were evaluated for the presence of CCD with SPECT and 123I-IMP. In representative cases, continuous arterial blood sampling was done and rCBF was calculated using Kuhl's method. RESULTS: IMP-SPECT detected an abnormality in 206 patients, of whom 30 had CCD. Of CCD patients, 27 had more than single lobe involvement, 17 had motor impairment, 8 of 11 had rCBF of less than 29.1 +/- 10.9 ml/100 g/min. There was also a significant difference in rCBF between non-CCD and CCD cases. CONCLUSION: Although CCD can also occur with dementia (mixed or vascular type), it is more common with multilobar lesions. It is also associated with the presence of motor impairment but not related to its severity. It is more likely to develop, however, if rCBF is less than 29.1 +/- 10.9 ml/100 g/min regardless of etiology.
Assuntos
Anfetaminas , Doenças Cerebelares/diagnóstico por imagem , Radioisótopos do Iodo , Encéfalo/diagnóstico por imagem , Doenças Cerebelares/fisiopatologia , Circulação Cerebrovascular , Humanos , Iofetamina , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
UNLABELLED: The purpose of this study is to clarify the changes of hippocampal perfusion in neuropsychiatric diseases, including dementia, compared with control subjects, and to correlate hippocampal perfusion with the dementia rating scale and the severity of memory disturbance in patients with these diseases. METHODS: A total of 45 right-handed patients were investigated (13 with dementia of Alzheimer type, 6 with multi-infarct dementia, 4 with progressive dementia with motor neuron disease (MND), 3 with transient global amnesia, 5 with other diseases and 14 control subjects). Regional cerebral blood flow (rCBF) in the parietal cortex and hippocampus was evaluated by high-resolution SPECT technique with HMPAO in all subjects. RESULTS: The rCBF measurements in the bilateral parietal cortices and hippocampus were lower in dementia of Alzheimer type and multi-infarct dementia patients than in controls. Hypoperfusion in the hippocampus was a more sensitive marker than hypoperfusion in the parietal cortex in diagnosing dementia of Alzheimer type. Hippocampal hypoperfusion was observed in demented patients regardless of etiology and in patients having memory disturbance without dementia, such as transient global amnesia. Finally, hippocampal hypoperfusion reflected the severity of dementia and memory disturbance regardless of etiology. CONCLUSION: The rCBF image with high-resolution SPECT system may be useful in assessing the extent of dementia and memory disturbance in patients with neuropsychiatric diseases.
Assuntos
Circulação Cerebrovascular , Hipocampo/diagnóstico por imagem , Transtornos Neurocognitivos/diagnóstico por imagem , Transtornos Neurocognitivos/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Demência/diagnóstico por imagem , Demência/etiologia , Demência por Múltiplos Infartos/diagnóstico por imagem , Demência por Múltiplos Infartos/fisiopatologia , Hipocampo/irrigação sanguínea , Humanos , Memória , Pessoa de Meia-Idade , Transtornos Neurocognitivos/psicologia , Lobo Parietal/irrigação sanguínea , Lobo Parietal/diagnóstico por imagemRESUMO
UNLABELLED: PET with 13N-ammonia permits the noninvasive quantification of myocardial blood flow (MBF) in humans. The present study was done to assess the reproducibility of quantitative blood flow measurements at rest and during pharmacologically induced hyperemia in healthy individuals. METHODS: Thirty healthy volunteers (26 men, 4 women) were studied. Paired measurements of MBF at rest (n = 21), during adenosine (n = 15) and during dipyridamole (n = 7) were performed using a two-compartment model for 13N-ammonia PET. The mean difference between baseline and follow-up blood flow (% difference) was calculated to assess reproducibility. RESULTS: No significant difference was observed between resting blood flow at baseline or follow-up (15.8% +/- 15.8%; p = ns). Baseline and follow-up resting blood flow were linearly correlated (r = 0.63, p < 0.005). Normalization of resting blood flow to the rate pressure product improved the reproducibility significantly (15.8% +/- 15.8% versus 10.1% +/- 10.5%, p < 0.05). Baseline and follow-up hyperemic myocardial blood flow did not differ (11.8% +/- 9.4%; p = ns) and were linearly correlated (r = 0.69, p < 0.0005). CONCLUSION: MBF at rest can be measured reproducibly with 13N-ammonia PET. The individual response to pharmacologic stress appears to be relatively consistent. Thus, serial blood flow measurements with 13N-ammonia PET can be used to quantify the effect of various interventions on MBF and vasodilatory reserve.
Assuntos
Circulação Coronária , Tomografia Computadorizada de Emissão , Adenosina/farmacologia , Adulto , Amônia , Circulação Coronária/efeitos dos fármacos , Dipiridamol , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Hiperemia , Masculino , Radioisótopos de Nitrogênio , Reprodutibilidade dos Testes , Descanso , VasodilatadoresRESUMO
UNLABELLED: We compared the acetazolamide challenge test using 99mTc-ECD SPECT and 123I-IMP SPECT images in patients with chronic occlusive cerebrovascular disease. We also evaluated the usefulness of linearization correction for acetazolamide challenge test of 99mTc-ECD SPECT. METHODS: Twenty patients with unilateral chronic occlusive cerebrovascular disease (10 patients had middle cerebral arterial lesion and 10 had internal carotid lesion) were included in the study. Split-dose (a dose fractioning was 1:2), and sequential SPECT technique was used for 99mTc-ECD SPECT studies while only acetazolamide challenge test studies for 123I-IMP SPECT were performed. Permeability surface area product model (PS model) and back-diffusion model (Lassen's correction) were used for linearization correction of acetazolamide challenge with 99mTc-ECD SPECT. RESULTS: Six of 16 patients with reduced vasodilatory capacity in 123I-IMP SPECT were underestimated by 99mTc-ECD SPECT acetazolamide challenge test. Relative ECD uptake normalized by cerebellar uptake compared with IMP uptake showed a nonlinear relationship, indicating relatively less uptake in high flow range. The underestimations of limited vasodilatory capacity observed in 99mTc-ECD SPECT without linearization correction was modified by linearization algorithm. However, the effect of correction based on PS model was superior than that of Lassen's correction. The corrected 99mTc-ECD uptake ratio, based on PS model, and IMP uptake ratio demonstrated a better linear relationship than that of Lassen's correction. CONCLUSION: Technetium-99m ECD SPECT corrected based on the PS model is a better method of linearization for evaluating cerebrovascular reserve using acetazolamide challenge.
Assuntos
Acetazolamida/farmacologia , Anfetaminas , Transtornos Cerebrovasculares/diagnóstico por imagem , Cisteína/análogos & derivados , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Idoso de 80 Anos ou mais , Circulação Cerebrovascular/efeitos dos fármacos , Transtornos Cerebrovasculares/fisiopatologia , Doença Crônica , Feminino , Humanos , Iofetamina , Masculino , Pessoa de Meia-Idade , Vasodilatação/efeitos dos fármacosRESUMO
UNLABELLED: We studied the usefulness of IMP SPECT with acetazolamide in 16 patients with moyamoya disease. Cerebral angiography was performed for all patients who were classified in three grades according to their angiographic stages. METHODS: Techniques used included ring-type emission computed tomography with a minicomputer system. Patients received 111 MBq of 123I-IMP and SPECT images were obtained 20 min postinjection. Nine patients were studied using iodoamphetamine (IMP) SPECT with and without acetazolamide. IMP SPECT with acetazolamide was performed 20 min after each injection of 1 g of acetazolamide. RESULTS: Low perfusion areas in the upper and lower frontal, parietal and temporal regions in grades 2 and 3 using IMP SPECT were observed. The mean cerebral-to-cerebellar activity ratios (C/C ratio) of six regions (upper and lower frontal, temporal, parietal occipital and basal ganglia) in grades 1, 2 and 3 were 0.96 to 1.06, 0.91 to 0.96 and 0.76 to 0.88, respectively. CONCLUSION: Our results indicate that measurement of regional cerebral blood flow (rCBF) elucidates cerebral hemodynamic factors, including the reactivity of cerebral vessels which cannot be detected angiographically in patients with moyamoya disease, and that the acetazolamide test is useful for detecting cerebral blood flow reserve. The test can be used to detect disease progress prospectively.
Assuntos
Anfetaminas , Circulação Cerebrovascular , Doença de Moyamoya/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Acetazolamida , Adulto , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/efeitos dos fármacos , Meios de Contraste , Feminino , Humanos , Radioisótopos do Iodo , Iofetamina , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/fisiopatologiaRESUMO
UNLABELLED: Technetium-99m methoxyisobutylisonitrile (MIBI) is a myocardial perfusion imaging agent that has been reported to effectively localize in various tumors (e.g., lung and thyroid carcinomas and osteogenic sarcoma). To determine its usefulness in thyroid tumors, we compared 99mTc-MIBI with 201TI imaging. METHOD: We evaluated 25 patients with thyroid tumors (papillary carcinoma in 11, follicular carcinoma in 2, follicular adenoma in 7, adenomatous goiter in 5). Fifteen metastatic lesions from differentiated thyroid carcinomas were also evaluated. Early (10 min after injection) and delayed images (120 min after injection) were obtained for both 99mTc-MIBI and 201TI scintigraphy. RESULTS: The early images showed very similar findings for both 99mTc-MIBI and 201TI. However, the delayed images showed that malignant tumors tended to retain more tracer agent than benign nodules. Marked retention was in 61.5% (8 of 13) of 201TI images and 53.8% (7 of 13) of 99mTc-MIBI images. For metastatic lesions from thyroid carcinomas, the findings for 99mTc-MIBI imaging were nearly identical to those for 201TI imaging. A slight difference in clarity was seen that may have been due to the effect of the 99mTc. CONCLUSION: Although 99mTc-MIBI scintigraphy does not have particularly good results in differentiating malignant from benign thyroid tumors, it may be useful in evaluating metastases or predicting recurrence because of its better imaging characteristics.
Assuntos
Tecnécio Tc 99m Sestamibi , Radioisótopos de Tálio , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Adenocarcinoma Folicular/diagnóstico por imagem , Adenoma/diagnóstico por imagem , Adulto , Idoso , Carcinoma Papilar/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , CintilografiaRESUMO
An 11-yr-old female presented with a 6-wk history of left upper lid tenderness and left eye lacrimation. Left lateral supraorbital mass and left preauricular lymph node were the only significant physical examination findings. On skull x-ray, a left frontal bone defect was noted. CT and MRI showed a soft-tissue mass in the area of the bone defect. Bone scintigraphy exhibited peripheral uptake within the central photon deficient area. With 201TI SPECT, high uptake was noted on early and delayed images. Diagnosis of eosinophilic granuloma was performed by biopsy. Since thallium uptake was seen in the area where photon deficiency was exhibited by 99mTc-MDP scintigraphy, we speculate that thallium SPECT could detect eosinophilic granuloma when radiographic skeletal survey or radionuclide bone scan are equivocal. It could also rule out multiple bone involvement and recurrence or regrowth after therapy.
Assuntos
Granuloma Eosinófilo/diagnóstico por imagem , Osso Frontal/diagnóstico por imagem , Medronato de Tecnécio Tc 99m , Radioisótopos de Tálio , Criança , Granuloma Eosinófilo/patologia , Feminino , Seguimentos , Osso Frontal/patologia , Humanos , Imageamento por Ressonância Magnética , Cintilografia , Tomografia Computadorizada por Raios XRESUMO
Unilateral Moyamoya disease presents as unilateral stenosis or obstruction of the supraclinoid internal carotid artery, which causes cerebral hypoperfusion resulting in seizures or TIA-like attacks. In severe cases, surgical treatment is performed with superficial temporal artery-middle cerebral artery anastomosis. In mild cases, conservative management is the treatment of choice. Flunarizine is a calcium ion anti-blocking agent, whose primary effect is that the cerebral vessels have been used for the treatment of postcerebrovascular disorders. Recently, it has been suggested that flunarizine could be used to treat Moyamoya disease. This report documents the efficacy of flunarizine to improve regional cerebral perfusion in Moyamoya disease.
Assuntos
Encéfalo/diagnóstico por imagem , Bloqueadores dos Canais de Cálcio/uso terapêutico , Flunarizina/uso terapêutico , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/tratamento farmacológico , Compostos de Organotecnécio , Oximas , Tomografia Computadorizada de Emissão de Fóton Único , Criança , Quimioterapia Combinada , Humanos , Masculino , Doença de Moyamoya/diagnóstico , Tecnécio Tc 99m Exametazima , Ticlopidina/uso terapêuticoRESUMO
Regional cerebral blood flow was evaluated by single-photon emission CT (SPECT) with 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) in 11 patients with dementia of the Alzheimer type, three patients with progressive dementia and motor neuron disease, and eight healthy control subjects. Regional blood flow measurements in the bilateral frontal, parietal association, and temporal cortices were lower in the Alzheimer dementia patients than in controls. Flow deficits in the parietal association cortex were demonstrated in all patients with Alzheimer-type dementia; these deficits were correlated with the severity of disease. Lateral hemispheric asymmetry was seen in nine of 11 patients with Alzheimer-type dementia. In all three patients with progressive dementia and motor neuron disease, flow deficits were demonstrated in the bilateral frontal and temporal cortices, but no flow deficits were seen in the parietal association cortex. Brain SPECT with 123I-IMP may be useful in the differential diagnosis and evaluation of the severity of degenerative dementia.
Assuntos
Anfetaminas , Circulação Cerebrovascular/fisiologia , Demência/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Demência/fisiopatologia , Feminino , Humanos , Radioisótopos do Iodo , Iofetamina , Masculino , Pessoa de Meia-Idade , Neurônios Motores/diagnóstico por imagem , Neurônios Motores/fisiologia , Doenças Neuromusculares/diagnóstico por imagem , Doenças Neuromusculares/fisiopatologiaRESUMO
PURPOSE: To investigate cerebral vasodilatory capacity by acetazolamide challenge in healthy subjects and in patients with chronic occlusive cerebrovascular disease by using susceptibility-weighted gradient-echo MR imaging. METHODS: Eight patients with chronic occlusive cerebrovascular disease and four healthy volunteers were studied with susceptibility-weighted MR imaging before and after intravenous administration of 1000 mg of acetazolamide. Signal intensities were measured as a function of time in several regions of interest defined on anatomic images. In all patients with chronic occlusive cerebrovascular disease, acetazolamide challenge and resting regional cerebral blood flow were also evaluated with single-photon emission CT (SPECT). RESULTS: In healthy volunteers, signal intensities began to increase 3 to 4 minutes after acetazolamide administration, with a continuous increase during the subsequent 10 minutes. The effect lasted for approximately 45 minutes after administration. In patients with chronic occlusive cerebrovascular disease, signal changes on susceptibility-weighted MR images of occluded areas with normal vasodilatory capacity on SPECT images did not differ from signal changes of nonocclusive areas. In those patients with changes that reflected diminished vasodilatory capacity, the MR images showed a lower percentage of signal changes after acetazolamide administration than those in normally perfused areas. CONCLUSION: Susceptibility-weighted MR imaging offers an alternative method for estimating vasodilatory capacity.
Assuntos
Acetazolamida , Encéfalo/irrigação sanguínea , Inibidores da Anidrase Carbônica , Transtornos Cerebrovasculares/diagnóstico , Imageamento por Ressonância Magnética/métodos , Oxigênio/sangue , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Vasodilatação/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo/fisiologia , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/fisiopatologia , Transtornos Cerebrovasculares/fisiopatologia , Humanos , Pessoa de Meia-Idade , Valores de Referência , Fluxo Sanguíneo Regional/fisiologiaRESUMO
The aim of this study was to evaluate the efficacy of 99mTc-MIBI and 123I subtraction scintigraphy for the detection of abnormal parathyroid glands to be referred for surgical treatment. Thirty-nine consecutive patients, including 35 primary and four secondary cases of hyperparathyroidism, were evaluated. 99mTc-MIBI/123I subtraction scintigraphy (MIBI/I) was performed on all patients, and the results were compared with delayed images of 99mTc-MIBI (D-MIBI), magnetic resonance imaging (MRI) and ultrasonography (US). The overall sensitivity of MIBI/I, MRI, US and D-MIBI was 55.9%, 43.4%, 50.8% and 39.0%, respectively. In cases of single-gland disease, the sensitivity of MIBI/I, MRI, US and D-MIBI was 62.1%, 48.3%, 55.2% and 44.8%, respectively. In cases of multi-gland disease, the sensitivity of MIBI/I, MRI, US and D-MIBI was 50.0%, 37.5%, 46.7% and 36.7%, respectively. In cases of parathyroid adenoma, the sensitivity of MIBI/I, MRI, US and D-MIBI was 71.4%, 50.0%, 71.4% and 50.0%, respectively. In cases of parathyroid hyperplasia, the sensitivity of MIBI/I, MRI, US and D-MIBI was 55.2%, 42.3%, 50.0% and 39.7%, respectively. It is concluded that 99mTc-MIBI/123I subtraction is more useful than the delayed imaging of 99mTc-MIBI, MRI and US.
Assuntos
Hiperparatireoidismo/diagnóstico por imagem , Radioisótopos do Iodo , Glândulas Paratireoides/diagnóstico por imagem , Técnica de Subtração , Tecnécio Tc 99m Sestamibi , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hiperparatireoidismo/diagnóstico , Hiperparatireoidismo Secundário/diagnóstico , Hiperparatireoidismo Secundário/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/patologia , Seleção de Pacientes , Cuidados Pré-Operatórios/métodos , Cintilografia , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , UltrassonografiaRESUMO
The aim of the study was to evaluate the use of 201Tl single photon emission tomography (SPET) in differentiating histological types and lymph node sized of lung tumours based on the early uptake ratio (EUR), delayed uptake ratio (DUR) and retention index (RI). We also wished to compare the effectiveness of 201Tl SPET and computed tomography (CT) in detecting lymphadenopathy. We examined 41 subjects using both 201Tl SPET and CT. Fifty-seven lymph nodes were detected and were grouped according to size. The EUR, DUR and RI were determined and analysed using Student's t-test and a P-value < 0.05 was considered significant. Lymphadenopathy detected by both 201Tl SPET and CT correlated with the operative findings. There were no statistically differences in the EUR, DUR and RI between the various histological types. Statistically significant differences in EUR were noted between lymph nodes > 5 cm in size and those 3-5 cm in size, as well as between those < 3 cm and > 5 cm in size No significant differences were seen for the RI. The specificity, sensitivity and accuracy of 201Tl SPET were 81.3, 90.2 and 87.7% respectively, whereas for CT they were 81.3, 100 and 94.74% respectively. In conclusion, quantitative analysis with 201Tl SPET was unable to differentiate with accuracy between histological types but it could differentiate between nodes of varying sizes. However, CT had a better specificity and accuracy.
Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X , Adenocarcinoma/diagnóstico por imagem , Carcinoma/diagnóstico por imagem , Carcinoma de Células Escamosas/diagnóstico por imagem , Humanos , Pneumopatias/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Linfonodos/diagnóstico por imagem , Metástase Linfática , Sensibilidade e Especificidade , Radioisótopos de Tálio/farmacocinéticaRESUMO
We assessed the relationship between 99Tcm-HMDP extraosseous accumulation (EOA), the histopathology of primary lesions and various laboratory findings. In 155 of 4824 patients, 163 EOA were noted. Of these, 33.7% were in the abdomen, 27.6% in the chest, 22.7% in the extremities, 9.8% in the pelvic area and 6.1% in the head and neck area. We found that 72.4% of EOA were due to malignant processes and 27.6% to benign processes. In the abdomen, 36.6% of the EOA were due to hepatocellular carcinoma and intestinal carcinoma. In the chest, 46.7% of EOA were a result of breast carcinoma. In the extremities, 28.7% of the EOA were due to sarcoma. The mean white blood cell count was elevated (8.0 +/- 6.3 x 10(3)) in patients with malignant processes. The mean serum haemoglobin and haematocrit in benign and malignant processes, for both males and females, were below normal values. All other laboratory findings were within normal limits. Significant differences in serum haemoglobin and haematocrit were noted between male and female patients with benign processes (P = 0.04 and P = 0.04, respectively). No other significant differences between benign and malignant processes were noted. Therefore, EOA is more frequently associated with malignant processes of primary lesions and is often accompanied by leukocytosis and anaemia.
Assuntos
Osso e Ossos/diagnóstico por imagem , Compostos Radiofarmacêuticos/farmacocinética , Medronato de Tecnécio Tc 99m/análogos & derivados , Idoso , Envelhecimento/metabolismo , Neoplasias Ósseas/diagnóstico por imagem , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Estudos Retrospectivos , Medronato de Tecnécio Tc 99m/farmacocinética , Ultrassonografia , Contagem Corporal TotalRESUMO
Regional cerebral blood flow (rCBF) was measured using N-isopropyl-123I-iodoamphetamine (123I-IMP) with single photon emission computed tomography (SPECT) in 27 patients with diabetes mellitus with an average age of 64.1 years and with an average fasting plasma glucose of 145 mg dl-1. Their data were compared with those of 12 non-diabetic subjects with an average age of 64.6 years. None had cerebral infarction on computed tomographic (CT) studies. There were no significant differences in the physiological or laboratory data between the diabetic and non-diabetic groups except for their fasting plasma glucose and HbA1c levels. A reference sampling method using continuous arterial blood sampling was employed to quantify the rCBF. The average rCBF in each region of the cerebrum and cerebellum was significantly lower in the diabetic group than in the non-diabetic group (P < 0.01). Although a definite cause was obscure, the rCBF of the diabetic patients was reduced even in the absence of findings indicative of cerebral infarction on a CT study.
Assuntos
Anfetaminas , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Diabetes Mellitus/fisiopatologia , Radioisótopos do Iodo , Tomografia Computadorizada de Emissão de Fóton Único , Glicemia/análise , Infarto Cerebral/diagnóstico por imagem , Diabetes Mellitus/diagnóstico por imagem , Feminino , Hemoglobinas Glicadas/análise , Humanos , Iofetamina , Masculino , Pessoa de Meia-IdadeRESUMO
The aim of this study was to investigate the relationship between autonomic nerve dysfunction and myocardial uptake of 123I-meta-iodobenzyl guanidine (MIBG) in patients with diabetes mellitus. Twenty-two non-insulin-dependent diabetic patients, 9 with autonomic neuropathy [ANP(+)] and 13 without autonomic neuropathy [ANP(-)], and 8 controls were included in the study. Both planar and single photon emission tomographic (SPET) images were obtained 30 min (early) and 3 h (delayed) after the 123I-MIBG injection. The heart-to-mediastinal uptake ratio (H/M) and the washout ratio of 123I-MIBG (%WR) were calculated from planar images. The uptake ratio of the inferior wall to the anterior wall (I/ A) and the %WR of both the inferior and anterior walls were calculated from the SPET images. On the early plantar images, the mean H/M ratio in the ANP(+) group was significantly lower than that of the control group. The mean %WR on the planar images in the ANP(-) group was significantly higher than that of the controls. The SPET images demonstrated a reduction in MIBG uptake and significantly increased clearance in the inferior wall of the ANP(-) patients. These findings extended to other areas of the heart in the ANP(+) patients. In the quantitative analysis of the SPET images, the ANP(+) group had significantly lower I/A values and significantly higher %WR values in the anterior wall. The ANP(+) group showed significantly increased clearance of 123I-MIBG in the inferior wall. We conclude that 123I-MIBG myocardial scintigraphy is a useful diagnostic tool both in the early detection and evaluation of the progression of myocardial sympathetic nerve dysfunction in patients with diabetes mellitus. Both the I/A and %WR calculated from SPET images are useful parameters.
Assuntos
Doenças do Sistema Nervoso Autônomo/diagnóstico por imagem , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Neuropatias Diabéticas/diagnóstico por imagem , Coração/diagnóstico por imagem , Radioisótopos do Iodo , Iodobenzenos , 3-Iodobenzilguanidina , Idoso , Doenças do Sistema Nervoso Autônomo/complicações , Diabetes Mellitus Tipo 2/complicações , Neuropatias Diabéticas/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Thallium-201 (201Tl) is widely used in the diagnosis of malignant tumours. However, its use in predicting the response to radiation therapy for head and neck cancer has not been established. Nineteen patients with histologically proven head and neck cancer were studied. 201Tl single photon emission tomographic (SPET) images were obtained 15 min (early) and 4 h (delayed) post-injection of the radionuclide. For a semi-quantitative assessment, regions of interest were drawn over the lesions and normal soft tissue. Lesion-to-normal tissue uptake ratios of 201Tl activity were measured from mean counts-per-voxel obtained on both the early and delayed scans, representing the early index (EI) and delayed index (DI) respectively. Subsequently, a retention index (RI) was calculated using the formula: RI = (DI - EI) x 100/(EI). The patients were classified into two groups according to the effect of radiotherapy: a partial response or complete response group (PR-CR group) and a no change group (NC group). In the analysis of primary lesions, both the delayed and retention indexes of the PR-CR group were significantly higher than those of the NC group. However, the early index was not significantly different between the two groups. In the metastatic lymph nodes, only the retention index was significantly different between the two groups. Our results demonstrate that 201Tl SPET and a 201Tl index can be used to predict the response to radiotherapy for primary head and neck cancer and lymph node metastases. The retention index is a useful parameter for estimating the effects of radiotherapy.
Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/radioterapia , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Feminino , Neoplasias Gengivais/diagnóstico por imagem , Neoplasias Gengivais/radioterapia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/diagnóstico por imagem , Neoplasias Orofaríngeas/radioterapia , Valor Preditivo dos Testes , Radioisótopos de TálioRESUMO
The aim of this study was to develop a new artificial amino acid radiopharmaceutical labelled with radioiodine for detection of malignant melanoma, based on melanin formation. By considering the affinity for tyrosinase, a starting enzyme on the branching point to melanin biosynthesis, 3-[125I]iodo-4-hydroxyphenyl-L-cysteine (125I-L-PC) was synthesized and evaluated biologically. Labelling of 125I-L-PC using the chloramine-T method was carried out conveniently and efficiently in a short period of time, with high specific activity. In a biodistribution study, 125I-L-PC showed a low accumulation in normal tissue and relative retention in B16 melanoma. A high contrast image of peripheral tumour was obtained during autoradiography. During an in vitro accumulation study, inhibition of 125I-L-PC with a tyrosinase inhibitor suggested interaction of this tracer with tyrosinase. It indicates that the uptake mechanism of 125I-L-PC to melanoma tissue was dependent on high tyrosinase activity in melanoma cells. Thus, 125I-L-PC appears to be a promising radioiodinated amino acid radiopharmaceutical for imaging malignant melanoma in relation to melanin formation, namely specific metabolism with high tyrosinase activity.