RESUMEN
OBJECTIVE: The purpose of this study was to examine the (11)C-methionine (MET) and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) findings of central nervous system (CNS) germinoma and the diagnostic utility of these findings. METHODS: We retrospectively evaluated the cases of 10 patients who were diagnosed with CNS germinoma according to their histopathological or clinical findings. All the patients underwent pretreatment MET and/or FDG-PET scans, and the resultant images were assessed qualitatively and quantitatively. In the qualitative assessments, we used 3- and 5-grade visual scoring systems for the MET- and FDG-PET images, respectively. In the quantitative assessments, the maximal standardized uptake value (SUVmax) and the ratio of the SUVmax of the tumor (T) divided by the mean SUV for the normal white or gray matter [T/N (WM), T/N (GM)], was calculated. RESULTS: The mean and SD values of SUVmax, T/N (WM), and T/N (GM) were 1.9 ± 1.4, 2.5 ± 1.3, and 1.7 ± 0.9 on MET-PET and 5.8 ± 2.2, 1.6 ± 0.5, and 0.8 ± 0.2 on FDG-PET, respectively. On MET-PET, only one lesion was not detected. On the other hand, on FDG-PET all of the lesions exhibited uptake values that were intermediate between those of the normal white matter and gray matter. CONCLUSION: In terms of its tumor-contouring ability, MET is a good tracer for diagnosing CNS germinomas; therefore, MET-PET is considered to be useful for planning biopsies or surgery. Although FDG-PET is capable of detecting CNS germinomas, it produced insufficient image contrast in the present study. Further studies are needed before FDG-PET can be used in clinical examinations of CNS germinoma.
Asunto(s)
Radioisótopos de Carbono , Neoplasias del Sistema Nervioso Central/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Germinoma/diagnóstico por imagen , Metionina , Tomografía de Emisión de Positrones , Adolescente , Adulto , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Radioisótopos de Carbono/farmacocinética , Niño , Femenino , Fluorodesoxiglucosa F18/farmacocinética , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Metionina/farmacocinética , Fibras Nerviosas Mielínicas/diagnóstico por imagen , Fibras Nerviosas Amielínicas/diagnóstico por imagen , Radiofármacos/farmacocinética , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVE: The purpose of the study was to compare observer performance in the detection of cerebral infarction on a brain CT using medical-grade liquid crystal display (LCD) monitors calibrated with the gray-scale standard display function and with γ 2.2 and using an iPad with a simulated screen setting. MATERIALS AND METHODS: We amassed 97 sample sets, from 47 patients with proven cerebral infarction and 50 healthy control subjects. Nine radiologists independently assessed brain CT on a gray-scale standard display function LCD, a γ 2.2 LCD, and an iPad in random order over 4-week intervals. Receiver operating characteristic (ROC) analysis was performed by using the continuous scale, and the area under the ROC curve (A(z)) was calculated for each monitor. RESULTS: The A(z) values for gray-scale standard display function LCD, γ 2.2 LCD, and iPad were 0.875, 0.884, and 0.839, respectively. The difference among the three monitors was very small. There was no significant difference between gray-scale standard display function LCD and γ 2.2 LCD. However, the A(z) value was statistically significantly smaller for the iPad than the γ 2.2 LCD (p < 0.05). CONCLUSION: Observer performance for detecting cerebral infarction on the LCD with γ 2.2 calibration was found to be similar to the LCD with gray-scale standard display function calibration. Although observer performance using the iPad was poorer than that using the other LCDs, the difference was small. Therefore, the iPad could not substitute for other LCD monitors. However, owing to the promising potential advantages of tablet PCs, such as portability, further examination is needed into the clinical use of tablet PCs.
Asunto(s)
Infarto Cerebral/diagnóstico por imagen , Computadoras de Mano , Intensificación de Imagen Radiográfica/instrumentación , Tomografía Computarizada por Rayos X/métodos , Análisis de Varianza , Calibración , Estudios de Casos y Controles , Femenino , Humanos , Cristales Líquidos , Masculino , Persona de Mediana Edad , Neuroimagen , Curva ROCRESUMEN
PURPOSE: To compare left adrenal venous sampling (AVS) in two locations: the central adrenal vein and the common trunk. MATERIALS AND METHODS: A total of 22 patients (12 men and 10 women; mean age, 50 y; range, 26-65 y) who were suspected of having primary aldosteronism (PA) and underwent successful AVS with cortisol concentration measurement and/or venography between November 2010 and August 2011 were retrospectively analyzed. In regard to the left adrenal vein, collections were done at two locations: at the common trunk below the confluence of the inferior phrenic vein and at the central adrenal vein, which was above the confluence. The effects of the inflow from the inferior phrenic vein on plasma aldosterone and cortisol levels were analyzed. RESULTS: Eight patients had bilateral hypersecreting lesions and 13 had a unilateral lesion. One was diagnosed as having secondary hypertension other than PA. The median cortisol levels below and above the confluence were 129 µg/dL (range, 21-400 µg/dL) and 215 µg/dL (range, 21-690 µg/dL), respectively. The median aldosterone levels were 2,120 pg/mL (range, 164-42,700 pg/mL) and 4,275 pg/mL (range, 119-59,000 pg/mL), respectively. The median aldosterone/cortisol (A/C) ratios were 244 (range, 34-2,401) and 278 (range, 25-2,251), respectively. Cortisol and aldosterone levels were significantly higher above the confluence (P = .0050 and P = .0003, respectively), whereas the A/C ratio showed no significant difference (P = .12). CONCLUSIONS: Although higher levels of cortisol and aldosterone were obtained upstream, A/C ratio was not significantly different between the central adrenal vein and the common trunk.
Asunto(s)
Glándulas Suprarrenales/irrigación sanguínea , Aldosterona/sangre , Recolección de Muestras de Sangre/métodos , Hidrocortisona/sangre , Adulto , Biomarcadores/sangre , Femenino , Humanos , Hiperaldosteronismo/sangre , Hiperaldosteronismo/diagnóstico , Hiperaldosteronismo/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Flebografía , Estudios Retrospectivos , VenasRESUMEN
PURPOSE: The aim of our study was to examine the usefulness of PET with C-methionine (MET) and F-fluorodeoxyglucose (FDG) in the differentiation of glioblastoma multiforme (GBM) and intracranial diffuse large B-cell lymphoma (DLBCL). MATERIALS AND METHODS: We evaluated 22 patients retrospectively with an enhancing brain tumor on MRI, including 15 GBM and 7 DLBCL, which was confirmed by histopathology. Dynamic PET scans with MET and FDG were performed for preoperative differential diagnosis. We assessed the images qualitatively and quantitatively. In quantitative assessment, the SUVmax was used on FDG PET and both late and early phases on MET PET. In addition, the ratio of SUVmax in the late and early phases on MET-PET was evaluated (ΔSUVmax). RESULTS: SUVmax on FDG PET of DLBCL was significantly higher than that of GBM. Setting an SUVmax of 12.0 as the cutoff for differentiating DLBCL from GBM, 1 GBM and 1 DLBCL were found to be false-positive and false-negative, respectively.SUVmax in the late and early phases of MET-PET was not significantly different between DLBCL and GBM; however, we also found significant differences in ΔSUVmax on MET-PET. Using ΔSUVmax 1.17 as the cutoff, we could differentiate DLBCL from GBM completely. In the present study, ΔSUVmax on MET-PET was slightly superior to SUVmax on FDG PET. CONCLUSIONS: Both SUVmax on FDG PET and ΔSUVmax on MET-PET were considered to be good diagnostic tests when encountering difficulties in this differential diagnosis.