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PURPOSE: Bottom-of-sulcus dysplasia (BOSD) is a type of focal cortical dysplasia and an important cause of intractable epilepsy. While the MRI features of BOSD have been well documented, the contribution of PET to the identification of these small lesions has not been widely explored. The aim of this study was to investigate the role of F-18 fluorodeoxyglucose (18F-FDG) PET in the identification of BOSD. METHODS: Twenty patients with BOSD underwent both 18F-FDG PET and structural MRI scans as part of preoperative planning for surgery. Visual PET analysis was performed, and patients were classified as positive if they exhibited a focal or regional hypometabolic abnormality, or negative in the absence of a hypometabolic abnormality. MRI data were reviewed to determine if any structural abnormality characteristic of BOSD were observed before and after co-registration with PET findings. RESULTS: PET detected hypometabolic abnormalities consistent with the seizure focus location in 95% (19/20) of cases. Focal abnormalities were detected on 18F-FDG PET in 12/20 (60%) patients, while regional hypometabolism was evident in 7/20 (35%). BOSD lesions were missed in 20% (4/20) of cases upon initial review of MRI scans. Co-registration of 18F-FDG PET with MRI enabled detection of the BOSD in all four cases where the lesion was initially missed. CONCLUSION: Our findings show that 18F-FDG PET provides additional clinical value in the localisation and detection of BOSD lesions, when used in conjunction with MRI.
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PURPOSE: To assess the contribution of concurrent low-dose, noncontrast CT in the assessment of the malignant potential of incidental focal 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-avid colonic lesions on positron emission tomography/computed tomography (PET/CT). PROCEDURES: Routine FDG-PET/CT scans were reviewed for identification of focal FDG-avid colon lesions, and the CT component was independently reviewed for an anatomical lesion and malignant potential based on CT criteria. Clinical, endoscopic, and histopathology follow-up was obtained. RESULTS: A total of 85/2,916 (3%) oncology FDG-PET/CT scans had incidental focal colon lesions. Clinical and/or endoscopic follow-up was available in 83/85 (98%) patients. Focal, corresponding CT lesions were found in 44/83 (53%) patients, but features of malignancy were not assessable. Of the 44 patients with a final diagnosis, 32/44 (73%) were FDG-PET/CT true positives; 5/44 (11%) were false positives; and 7/44 (16%) had inconclusive FDG-PET/CT findings. CONCLUSIONS: Concurrent low-dose, noncontrast CT improves localization, but does not provide independent information on the malignant potential of incidental focal colonic activity on FDG-PET/CT.
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Doenças do Colo/diagnóstico , Meios de Contraste/metabolismo , Fluordesoxiglucose F18 , Achados Incidentais , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Endoscopia , Reações Falso-Positivas , Seguimentos , HumanosRESUMO
BACKGROUND: Accurate staging of lung cancer is essential in determining the most appropriate management plan, as detection of occult metastasis can significantly alter management. AIMS: The aims of this study are to determine the prevalence of occult metastasis in patients undergoing 2-(18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET) for evaluation of suspected/proven lung carcinoma and correlate pre-PET TNM stage with prevalence of metastasis. METHODS: FDG-PET, which identified patients with metastasis on institutional database, was re-evaluated by a nuclear medicine physician blinded to clinical information. The confidence level of metastasis was scored on a 5-point scale, with a score of >/=4 considered positive. RESULTS: There were 67 of 645 (10%) patients identified with suspected occult metastasis on FDG-PET. Twelve patients scoring =3 were excluded. Prevalence of occult metastasis was 10/156 (6%) in solitary pulmonary nodules (SPN); 22/319 (7%) and 23/170 (14%) in proven and suspected lung cancer, respectively. Positive predictive value of FDG-PET for metastasis was 8/10 (80%) in solitary pulmonary nodules, 14/20 (70%) and 17/21 (81%) in proven and suspected lung cancer, respectively. (18)F-FDG-avid lesions classified as false positives were patients with cholelithiasis, rib fractures and those with equivocal/negative bone scans or computed tomography on follow up. There was a higher incidence of true positive occult metastasis in patients in all stages of disease, particularly stage III disease. CONCLUSION: (18)F-FDG PET is predictive for occult metastatic disease in patients with solitary pulmonary nodules and proven or suspected lung cancer and is more likely to be present in all stages, particularly in stage III. PET findings should be actively pursued with correlative investigation to identify benign pathology in patients who remain candidates for curative treatment.
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Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/epidemiologia , Metástase Neoplásica/diagnóstico por imagem , Nódulo Pulmonar Solitário/diagnóstico por imagem , Nódulo Pulmonar Solitário/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluordesoxiglucose F18 , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons , Valor Preditivo dos Testes , Prevalência , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Nódulo Pulmonar Solitário/patologiaRESUMO
OBJECTIVES: The aim of this study was to correlate dobutamine-induced contractile reserve as detected by echocardiography with findings on positron emission tomography in patients with chronic ischemic left ventricular dysfunction. BACKGROUND: Contractile reserve induced by low dose dobutamine infusion has been proposed as a marker of myocardial viability. METHODS: Sixty patients with stable coronary artery disease and left ventricular dysfunction (mean ejection fraction [+/- SD] 29 +/- 10%) underwent transthoracic echocardiography with dobutamine infusion (up to 10 micrograms/kg body weight per min) and positron emission tomography with nitrogen-13 ammonia and fluorine-18 (F-18) fluorodeoxyglucose as a perfusion and a metabolic tracer, respectively. Regional wall motion, perfusion and metabolism were analyzed semiquantitatively by using a 16-segment model. Segments with F-18 fluorodeoxyglucose uptake > 50% were considered viable on positron emission tomography. RESULTS: After dobutamine infusion, hemodynamic variables changed significantly, and myocardial ischemia was evident in 17 patients. All 60 patients had dysfunctional myocardium considered viable on positron emission tomography (8 +/- 4 segments/patient), whereas 52 patients had dysfunctional myocardium with contractile enhancement by dobutamine echocardiography (4 +/- 2 segments/patient, p = 0.01). The extent of dysfunctional myocardium with contractile reserve appeared to correlate less closely with the total extent of viable dysfunctional myocardium identified by positron emission tomography than with the number of such segments associated with a pattern of perfusion-metabolism mismatch. CONCLUSIONS: In patients with chronic ischemic left ventricular dysfunction, echocardiography can be used to identify enhancement in the contractile function of viable dysfunctional myocardium after infusion of low dose dobutamine. In this study, the presence and extent of such enhancement were relatively less than the values obtained from positron emission tomography.
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Doença das Coronárias/diagnóstico , Dobutamina , Ecocardiografia Doppler , Contração Miocárdica , Tomografia Computadorizada de Emissão , Disfunção Ventricular Esquerda/diagnóstico , Doença das Coronárias/complicações , Doença das Coronárias/fisiopatologia , Dobutamina/farmacologia , Hemodinâmica , Humanos , Contração Miocárdica/efeitos dos fármacos , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a newly recognized autosomal dominant partial epilepsy. We studied seizure localization and intrafamilial variation using video-EEG monitoring (VEM) and functional neuroimaging in two pairs of subjects from unrelated families. The clinical features of seizures were similar from seizure to seizure in each individual, but varied between individuals. As is often found in frontal lobe epilepsies, ictal EEG localization was imprecise in three of four cases. One patient showed a consistent left fronto-polar onset that was corroborated by congruent focal hypometabolism on interictal PET and focal hyperperfusion on ictal single photon emission computed tomography (SPECT). A second case studied with ictal SPECT showed a right parasagittal, midfrontal focus. We conclude that this autosomal dominant epilepsy syndrome, which in one of the two families was due to a known neuronal nicotinic acetylcholine receptor mutation, causes frontal lobe foci that are unilateral and in variable locations in different individuals.
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Ritmo Circadiano , Epilepsia do Lobo Frontal/genética , Epilepsia do Lobo Frontal/fisiopatologia , Genes Dominantes , Variação Genética , Adolescente , Adulto , Criança , Epilepsia do Lobo Frontal/diagnóstico , Feminino , Humanos , Masculino , Linhagem , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
There are no accurate noninvasive methods to distinguish renal allograft dysfunction due to rejection or cyclosporine nephrotoxicity. We have studied the value of Tc-99M-DTPA renal scanning in 90 episodes of renal allograft dysfunction occurring in 44 patients subjected to 57 renal biopsies in whom a clear diagnosis could be established. Renal scintigrams were assessed qualitatively and quantitatively by a blinded observer. Rejection was diagnosed when deterioration in perfusion occurred in the presence of maintained or declining radionuclide excretion. The diagnosis of cyclosporine nephrotoxicity was made by exclusion. The final diagnosis was based on the clinical response to therapy and/or the findings on renal biopsy. The scintigraphic diagnosis of rejection had a specificity of 87.9% and significantly contributed to the exclusion of cyclosporine nephrotoxicity (negative predictive value of 90.6%). Furthermore, a scintigraphic diagnosis compatible with cyclosporine nephrotoxicity, in the presence of a drug level above the therapeutic range, indicated a 90.4% probability of true nephrotoxicity. We conclude that, even in cyclosporine-treated renal transplant patients, Tc-99M-DTPA scintigraphy is of clinical value and can be incorporated into an effective diagnostic algorithm for allograft dysfunction.
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Ciclosporina/efeitos adversos , Transplante de Rim , Rim/diagnóstico por imagem , Pentetato de Tecnécio Tc 99m , Ciclosporina/sangue , Rejeição de Enxerto , Humanos , Rim/efeitos dos fármacos , Cintilografia , Transplante HomólogoRESUMO
A 51-yr-old man with a history of pancreatic carcinoma was studied with [18F]fluorodeoxyglucose ([18F]FDG) and PET as part of staging for residual disease after chemotherapy. The PET study was performed during a clostridium difficile-associated diarrheal illness. Striking [18F]FDG uptake was demonstrated in the wall of the colon over its entire length. Clostridium difficile associated diarrhea and mechanisms of [18F]FDG uptake in normal and abnormal tissues are briefly reviewed and a mechanism for FDG uptake in this patient is postulated.
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Colo/diagnóstico por imagem , Desoxiglucose/análogos & derivados , Enterocolite Pseudomembranosa/diagnóstico por imagem , Radioisótopos de Flúor , Enterocolite Pseudomembranosa/complicações , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/tratamento farmacológico , CintilografiaRESUMO
A retrospective analysis was performed to determine whether coronal thoracic [18F]fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) scans, if viewed at the time of radiotherapy (RT) planning, would have influenced the anterior-posterior (AP) RT volumes that were administered to a group of unoperated lung cancer patients. Viewing of PET and diagnostic images enabled a qualitative assessment of whether abnormal thoracic PET activity was present in areas regarded as normal by diagnostic imaging; this would, therefore, have influenced the RT volume if done prospectively. Additionally a method of graphical co-registration was devised to quantitate the adequacy of coverage of each patient's abnormal PET activity by his/her actual RT field. Of 15 patients analyzed, 26.7% (four patients) would have had their RT volume influenced by PET findings, highlighting the potential value of PET in treatment planning.
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Fluordesoxiglucose F18 , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Planejamento da Radioterapia Assistida por Computador , Radioisótopos de Flúor , Humanos , Estudos Retrospectivos , Tomografia Computadorizada de EmissãoRESUMO
OBJECTIVE: Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG), a glucose analogue, as a metabolic tumour marker, has been proposed for the non-invasive staging of oncological disease. Tumours demonstrate increased glycolytic activity and thereby, FDG PET can differentiate benign from malignant lesions. To determine its role in the mediastinal staging of patients with suspected non-small cell lung cancer, a prospective study of FDG PET and computed tomography (CT) compared to surgery and pathology was performed. The analysis group consists of 50 patients, 37 men and 13 women, mean age 64 years (range, 41-78 years). METHODS: A nuclear physician, blind to the clinical and CT data, graded the FDG PET studies qualitatively on a five-point scale, based on the intensity of glucose uptake, for the presence of mediastinal nodal tumour involvement. Scores of four or greater were considered positive for tumour. An experienced radiologist interpreted the patients' CT scans blind to the other data. The CT criterion for tumour involvement was a nodal long axis diameter of 10 mm or greater. All patients underwent either thoracotomy or mediastinoscopy to obtain surgical specimens. The PET, CT, surgery and pathology were mapped according to the American Thoracic Society nodal classification resulting in 201 nodal stations evaluated. The imaging studies were analysed for N2 or N3 tumour involvement compared to histology or dissection of nodal stations. RESULTS: All patients had proven non-small cell lung carcinoma. PET excluded tumour in 175 of 181 nodal stations (specificity 97%) compared to 162 of 181 (specificity 90%) by CT. PET correctly identified 16 of 20 (sensitivity 80%) nodal stations with tumour compared to 13 of 20 by CT (sensitivity 65%). Overall, PET correctly staged 191 of 201 nodal stations (accuracy 95%) compared to 175 of 201 by CT (accuracy 87%). By the McNemar test, PET was significantly more specific than CT in excluding nodal tumour involvement (X2 = 5.5, P < 0.05). CONCLUSIONS: FDG PET is more specific than computed tomography in the non-invasive mediastinal staging of non-small cell lung cancer and has an important clinical role in the pre-operative staging of lung cancer patients.
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Carcinoma in Situ/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Fluordesoxiglucose F18 , Neoplasias Pulmonares/patologia , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão/métodos , Adulto , Idoso , Carcinoma in Situ/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/métodos , Estudos Prospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios XAssuntos
Adenocarcinoma/sangue , Antígeno Carcinoembrionário/análise , Carcinoma Medular/sangue , Neoplasias do Ceco/sangue , Segunda Neoplasia Primária/sangue , Tomografia por Emissão de Pósitrons , Neoplasias da Glândula Tireoide/sangue , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/cirurgia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais , Carcinoma Medular/diagnóstico por imagem , Carcinoma Medular/cirurgia , Neoplasias do Ceco/tratamento farmacológico , Neoplasias do Ceco/cirurgia , Quimioterapia Adjuvante , Terapia Combinada , Feminino , Humanos , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , TireoidectomiaRESUMO
The distribution of 99Tcm-sulphur colloid (99Tcm-SC) in 15 patients receiving human recombinant granulocyte colony-stimulating factor (G-CSF) following high-dose combination chemotherapy and autologous bone marrow transplantation (ABMT) for treatment of solid tumours was prospectively determined. 99Tcm-SC imaging was performed before treatment and at the time of leukocyte recovery during G-CSF administration. On the baseline 99Tcm-SC study, lung and bone marrow radiocolloid activity were not detected. The study performed during G-CSF infusion demonstrated lung colloid activity in 12 of 15 patients and bone marrow colloid activity in 11 of 15 patients. The average background corrected region of interest counts significantly increased for lung (P < 0.008), bone marrow (P < 0.0001) and cardiac blood pool (P < 0.05), and significantly decreased for liver (P < 0.0005) during G-CSF compared to the baseline study. No relationship between the distribution of 99Tcm-SC and response to therapy or patient outcome could be established. In conclusion, these data demonstrate a shift of 99Tcm-SC to lung, bone marrow and cardiac blood pool, and away from liver following high-dose combination chemotherapy and ABMT and during G-CSF administration in patients undergoing treatment for solid tumours.
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Transplante de Medula Óssea , Neoplasias da Mama/terapia , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Melanoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Masculino , Melanoma/diagnóstico por imagem , Melanoma/tratamento farmacológico , Estudos Prospectivos , Cintilografia , Coloide de Enxofre Marcado com Tecnécio Tc 99mRESUMO
Image registration techniques will become increasingly important in correlative multimodality imaging. In the case of PET, a structural imaging study can be invaluable in correlating structure metabolism relationships. A registered brain atlas of PET and MRI has been developed by the authors that allows clinicians, residents, fellows, and others to refer to a structural abnormality on MRI or metabolic abnormality on PET and correlate it neuro-anatomically.
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Encéfalo/anatomia & histologia , Desoxiglucose/análogos & derivados , Imageamento por Ressonância Magnética , Tomografia Computadorizada de Emissão , Encéfalo/diagnóstico por imagem , Fluordesoxiglucose F18 , Humanos , Valores de ReferênciaRESUMO
A Centre for Positron Emission Tomography (PET) has been operational within the Department of Nuclear Medicine at the Austin & Repatriation Medical Centre (A&RMC) in Melbourne for seven years. PET is a non-invasive imaging technique based on the use of biologically relevant compounds labelled with short-lived positron-emitting radionuclides such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18. The basic facility consists of a medical cyclotron (10 MeV proton & 5 MeV deuteron), six lead-shielded hotcells with associated radiochemistry facilities, radiopharmacy and a whole body PET scanner. A strong radiolabelling development program, including the production of 15O-oxygen, 15O-carbon monoxide, 15O-carbon dioxide, 15O-water, 13N-ammonia, 18F-FDG, 18F-FMISO, 11C-SCH23390 and 11C-flumazenil has been pursued to support an ambitious clinical and research program in neurology, oncology, cardiology and psychiatry.
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Radioisótopos/química , Compostos Radiofarmacêuticos/síntese química , Tomografia Computadorizada de Emissão/instrumentação , Desenho de Fármacos , Desenho de Equipamento , Glucose/metabolismo , Hipóxia/diagnóstico por imagem , Hipóxia/fisiopatologia , Doenças do Sistema Nervoso/diagnóstico por imagem , Oxigênio/metabolismo , Controle de Qualidade , Compostos Radiofarmacêuticos/normas , Fluxo Sanguíneo Regional , Tomografia Computadorizada de Emissão/métodosAssuntos
Fluordesoxiglucose F18 , Neoplasias Mandibulares/diagnóstico por imagem , Melanoma/diagnóstico por imagem , Neoplasias Bucais/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Compostos Radiofarmacêuticos , Neoplasias Cutâneas/patologia , Tomografia Computadorizada de Emissão , Adulto , Humanos , Masculino , Neoplasias Mandibulares/radioterapia , Neoplasias Mandibulares/secundário , Melanoma/radioterapia , Melanoma/secundário , Neoplasias Bucais/radioterapia , Neoplasias Bucais/secundário , Recidiva Local de Neoplasia/radioterapiaRESUMO
PURPOSE: To evaluate prognostic value of integrated 2-deoxy-2-[F-18]fluoro-D: -glucose-positron emission tomography/computed tomography (FDG-PET/CT) and correlate histopathological subtype with maximum standardized uptake value (SUV(max)) and survival in patients with malignant mesothelioma (MM). PROCEDURES: Retrospective review of FDG-PET/CT scans, with derivation of SUV(max) of FDG-avid lesions, was performed in patients with biopsy-proven MM. Clinical follow-up and Kaplan-Meier survival analysis was performed. RESULTS: Forty-six patients (37 M:9 F; mean age 61 years) with MM had a FDG-PET/CT scan in a 30-month period. Follow-up was available on 44/46 (96%) patients. Metastatic disease was detected in 9/46 (20%) patients on FDG-PET/CT, where 8/9 were previously undetected. Better survival was found in patients without metastases (p value < 0.05). Mean SUV(max) of primary pleural lesions in patients with metastatic disease was significantly higher than in patients without metastatic disease (p value < 0.05). Progression-free survival was significantly better in the epithelioid histology group compared to the biphasic group (p value 0.015). CONCLUSIONS: Detection of extrathoracic metastases on FDG-PET/CT and nonepithelioid histopathology are poor prognostic indicators in patients with MM.
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Fluordesoxiglucose F18 , Mesotelioma/patologia , Neoplasias Pleurais/patologia , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália , Intervalo Livre de Doença , Feminino , Fluordesoxiglucose F18/metabolismo , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Mesotelioma/diagnóstico por imagem , Pessoa de Meia-Idade , Neoplasias Pleurais/diagnóstico por imagem , Prognóstico , Radiografia , Compostos Radiofarmacêuticos/metabolismo , Fatores de TempoRESUMO
PURPOSE: To compare the localizing value of ictal single photon emission computed tomography (SPECT) and interictal fluorodeoxyglucose-positron emission tomography (FDG-PET) in refractory occipital lobe epilepsy. METHODS: Six patients who underwent surgery for refractory epilepsy associated with pathology in the occipital lobe were retrospectively selected from records of the Austin & Repatriation Centre Comprehensive Epilepsy Programme. Interictal SPECT and PET and ictal SPECT were obtained by standard methods. All studies were read by a nuclear medicine expert blinded to clinical data except the diagnosis of epilepsy. RESULTS: Ictal SPECT showed unilateral occipital hyperperfusion in five of six cases often accompanied by temporal lobe hyperperfusion. These patterns were seen in cases with or without magnetic resonance imaging (MRI) abnormality. Interictal SPECT was not localizing in any case, in contrast to PET, which showed occipital hypometabolism in three of five studies. CONCLUSIONS: Ictal SPECT can provide novel localizing data in MRI-negative occipital lobe epilepsy. Interictal PET can provide useful localizing information, but its role in providing novel information was not demonstrated. Interictal SPECT is useful only as a baseline to aid in interpretation of ictal studies.
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Epilepsias Parciais/diagnóstico por imagem , Lobo Occipital/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada de Emissão , Adulto , Idade de Início , Epilepsias Parciais/diagnóstico , Epilepsias Parciais/fisiopatologia , Feminino , Fluordesoxiglucose F18 , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Occipital/anatomia & histologia , Lobo Occipital/fisiopatologia , Lobo Temporal/anatomia & histologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologiaRESUMO
The role of cholecystokinin (CCK) as a central and peripheral satiety factor was studied using the CCK-B (L-365,260) and CCK-A (MK-329) receptor antagonists in esophageal-fistula dogs. Suppression of feeding was induced by either balloon gastric distension or small bowel nutrient infusion and was measured as the volume sham fed. Intracerebroventricular L-365,260 abolished satiety behavior from gastric distension (volume sham fed 2,667 +/- 211 ml vs. vehicle alone 1,217 +/- 446 ml, P < 0.05) but not small bowel infusion. Intravenous MK-329 abolished satiety behavior from small bowel infusion (volume sham fed 1,900 +/- 521 ml vs. vehicle alone 210 +/- 198 ml, P < 0.05) but not from gastric distension. The volume sham fed after intracerebroventricular MK-329 with balloon gastric distension or small bowel infusion did not differ from control. These results suggest that, in the brain, CCK is a physiological mediator of satiety behavior from gastric distension but not small bowel nutrients and, in the periphery, CCK is a physiological mediator of satiety behavior from small bowel nutrients but not gastric distension.
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Benzodiazepinonas/farmacologia , Encéfalo/fisiologia , Compostos de Fenilureia , Receptores da Colecistocinina/antagonistas & inibidores , Resposta de Saciedade/efeitos dos fármacos , Animais , Cateterismo , Devazepida , Cães , Nutrição Enteral , Injeções Intravenosas , Injeções Intraventriculares , Estômago/fisiologiaRESUMO
BACKGROUND: The detection of lymphoma by computed tomography (CT) scanning is known to be improved by positron emission tomography (PET) and/or gallium scanning, although the direct comparative accuracy of these imaging modalities remains a subject of ongoing review. AIMS: The aim of the present study was to compare PET scanning with conventional imaging (CT and/or gallium scanning) in patients with lymphoma. METHODS: A retrospective study of 38 patients (25 men; 13 women; median age 39.5 years; range 18.0-81.0 years) who had had PET scans (24 scans at initial staging and 46 scans at restaging, including suspected disease relapse) was carried out. Thirty-one concurrent gallium scans had been performed. Disease was validated with clinical follow up or biopsy. RESULTS: The sensitivities of PET and CT at initial staging were 96 and 71%, respectively. PET identified additional sites of disease compared with CT in 29% of patients. Of the 15 patients who had had all three imaging modalities, the sensitivities of PET, CT and gallium were 93, 67 and 87%, respectively. At treatment completion, the positive predictive values of PET, CT and gallium scans for relapse given a residual mass were 100, 33 and 0%, respectively (P = 0.006 for PET and CT comparison). The negative predictive values of PET, CT and gallium were 76, 0 and 70%, respectively (P-value not significant). In suspected disease relapse, PET results changed management in 50% of patients. CONCLUSION: Compared with CT and gallium scans, PET has superior accuracy in staging and restaging, and its greatest value lies in its positive predictive value for relapse in patients with residual masses.
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Doença de Hodgkin/diagnóstico por imagem , Linfoma não Hodgkin/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Radioisótopos de Gálio , Doença de Hodgkin/patologia , Humanos , Linfoma não Hodgkin/patologia , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Estudos Retrospectivos , Medição de Risco , Sensibilidade e Especificidade , Índice de Gravidade de DoençaRESUMO
Recent developments in personal computer hardware and software allow the manipulation of radiologic images. We developed an interactive, computer-based atlas of clinical neurologic positron emission tomographic studies for use as an educational resource. A personal computer and multimedia software were used to assemble the clinical case studies. For each clinical case, the user had available the clinical history, positron emission tomographic and correlative anatomic images, study interpretation, discussion, and references. The clinical cases were selected for their educational value, either as a representative example of an abnormality or for their ability to illustrate a common pitfall in positron emission tomographic imaging of the brain.