ABSTRACT
La eficacia de la endarterectomía carotídea (EC) en los accidentes cerebrovasculares producidos por estenosis carotídea puede ser evaluada mediante la tomografía computarizada de emisión de fotón único de perfusión cerebral, utilizando SPM (statistical parametric mapping mapas estadísticos paramétricos).Material y métodosSe incluyeron en el estudio 12 pacientes con estenosis significativa de la arteria carótida que fueron sometidos a endarterectomía. A todos se les realizó un estudio de perfusión cerebral con 99mTc-etilen cisteinato dietilester (ECD) basal tras la endarterectomía. Mediante los SPM se comparó de forma independiente el estudio basal/poscirugía con el grupo control formado por 20 pacientes y se obtuvieron los correspondientes SPM. Se valoraron los cambios tanto en extensión (o número de vóxeles) como en intensidad (cambio en el valor de T) de las zonas significativamente hipoperfundidas y el sentido de estos cambios.ResultadosEn el grupo de 12 pacientes se observó una mejoría de la perfusión cerebral posquirúrgica, en 5 pacientes con disminución en la extensión de las zonas hipoperfundidas del 50,56% y de intensidad del 30,9% de media. Cuatro pacientes mostraron un aumento en la extensión de la hipoperfusión cerebral del 85,53% y de la intensidad del 34,21% de media. En tres pacientes no se apreciaron cambios significativos entre ambos estudios.ConclusionesEl SPM ha demostrado ser una herramienta útil que permite objetivar los cambios de flujo sanguíneo cerebral que se producen tras la intervención quirúrgica, valorando los cambios en extensión e intensidad de las zonas significativamente hipoperfundidas(AU)
The efficacy of carotid endartectomy (CE) in cerebrovascular accidents produced by carotid stenosis can be evaluated with the cerebral perfusion with single photon emission tomography, using statistical parametric mapping (SPM).Material and methodsTwelve patients with significant carotid stenosis who underwent endartectomy were included in the study. All underwent a cerebral perfusion study with 99mTc-etilen cisteinato dietilester (ECD) at baseline and after the endartectomy. Using SPM, the baseline/post-surgery study was compared independently with the control group made up of 20 patients and the corresponding parametric statistical mappings were obtained. Changes in extension (kE or voxel number) and intensity (change in the T value) of the significantly hypoperfused zones and direction of these changes were evaluated.ResultsIn the group of 12 patients, improvement of the post-surgical cerebral perfusion was observed in 5 patients with an average 50.56% decrease in the extension of the hypoperfused zones and average 30.9% decrease of intensity. Four patients showed an average 85.53% increase in the extension of cerebral hypoperfusion and of 34.21% in intensity. No significant changes between both studies were found in three patients.ConclusionsSPM has been shown to be a useful tool that makes it possible to objectify the cerebral brain flow changes produced after the surgical intervention, evaluating the changes in extension and intensity of the significantly hypoperfused zones(AU)
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Statistics as Topic , Statistics as Topic/methods , Carotid Artery Diseases/complications , Carotid Stenosis/complications , Carotid Stenosis/diagnosis , Endarterectomy/instrumentation , Endarterectomy/methods , Endarterectomy/statistics & numerical data , Endarterectomy/trends , Endarterectomy, Carotid/statistics & numerical data , /methods , Absorptiometry, Photon/instrumentation , Tomography, Emission-Computed, Single-Photon/methodsABSTRACT
UNLABELLED: The efficacy of carotid endartectomy (CE) in cerebrovascular accidents produced by carotid stenosis can be evaluated with the cerebral perfusion with single photon emission tomography, using statistical parametric mapping (SPM). MATERIAL AND METHODS: Twelve patients with significant carotid stenosis who underwent endartectomy were included in the study. All underwent a cerebral perfusion study with 99mTc-etilen cisteinato dietilester (ECD) at baseline and after the endartectomy. Using SPM, the baseline/post-surgery study was compared independently with the control group made up of 20 patients and the corresponding parametric statistical mappings were obtained. Changes in extension (k(E) or voxel number) and intensity (change in the T value) of the significantly hypoperfused zones and direction of these changes were evaluated. RESULTS: In the group of 12 patients, improvement of the post-surgical cerebral perfusion was observed in 5 patients with an average 50.56% decrease in the extension of the hypoperfused zones and average 30.9% decrease of intensity. Four patients showed an average 85.53% increase in the extension of cerebral hypoperfusion and of 34.21% in intensity. No significant changes between both studies were found in three patients. CONCLUSIONS: SPM has been shown to be a useful tool that makes it possible to objectify the cerebral brain flow changes produced after the surgical intervention, evaluating the changes in extension and intensity of the significantly hypoperfused zones.
Subject(s)
Brain Ischemia/diagnostic imaging , Brain/diagnostic imaging , Carotid Stenosis/surgery , Cerebrovascular Circulation , Endarterectomy, Carotid , Postoperative Complications/diagnostic imaging , Tomography, Emission-Computed, Single-Photon , Aged , Aged, 80 and over , Brain/blood supply , Brain Ischemia/etiology , Carotid Stenosis/complications , Carotid Stenosis/physiopathology , Female , Humans , Male , Middle Aged , Models, Statistical , Organotechnetium Compounds , Postoperative Complications/etiology , RadiopharmaceuticalsABSTRACT
AIM: The aim of this study was to analyse the relationship between left ventricular ejection fractions (EF) obtained using four different instruments. MATERIAL AND METHODS: Eighty-five EF values were analysed. Gated acquisition was performed with the same gammacamera (SOPHA) using 99mTc-labelled red cells. Each EF was obtained using four processing systems: NXT (SOPHA), Entegra (Gems), Odyssey (Philips) and Esoft (Siemens), always working in automated mode. The paired student's t-test, Spearman correlation and Bland-Altman analysis were used to compare methods, and Deming regression was applied. RESULTS: Mean values and standard deviations for each program were: NXT: 61 +/- 9; Entegra: 60 +/- 10; Odyssey: 60 +/- 9; Esoft: 60 +/- 10. Although no significant differences were found as a whole and the values were linearly related, the methods are not interchangeable. CONCLUSIONS: The same program should be used in the follow-up of each patient, which is now easily achievable by means of the DICOM standard.
Subject(s)
Gated Blood-Pool Imaging/instrumentation , Stroke Volume , Electrocardiography , Erythrocytes , Gated Blood-Pool Imaging/methods , Humans , Radiopharmaceuticals , Reproducibility of Results , Software , TechnetiumABSTRACT
Objetivo. Analizar la relación existente entre los valores de la fracción de eyección (FE) del ventrículo izquierdo obtenidos mediante ventriculografía isotópica en equilibrio utilizando cuatro equipos de procesado distintos. Material y métodos. Se han estudiado 85 FE. Las adquisiciones se realizaron en una única gammacámara (Sopha®) mediante sincronización con el electrocardiograma (ECG) y utilizando hematíes marcados con Tc-99m. Se ha obtenido cada una de las FE por cuatro sistemas de procesado: NXT (Sopha®), Entegra (Gems®), Odissey (Philips®) y Esoft (Siemens®). El modo empleado por defecto era el de cálculo automático. Se aplicó la prueba de comparación de medias para datos apareados agrupando las 4 series de datos dos a dos. Asimismo, se buscó la correlación de Spearman y se aplicó la prueba de Bland-Altman para intercambiabilidad y se analizó su regresión por el método de Deming. Resultados. Los valores medios ± desviación estándar según cada programa fueron: NXT: 61 ± 9, Entegra: 60 ± 10, Odyssey: 60 ± 9, Esoft: 60 ± 10. No se han detectado globalmente diferencias, pero los 4 programas generan valores no intercambiables entre sí. Conclusiones. Aunque linealmente relacionados y sin diferencias significativas, se concluye que si se han de comparar estudios de un mismo paciente se emplee el mismo programa, cosa actualmente factible mediante el formato DICOM
Aim. The aim of this study was to analyse therelationship between left ventricular ejection fractions (EF) obtained using four different instruments.Material and methods. Eighty-five EF values were analysed. Gated acquisition was performed with the same gammacamera (SOPHA®) using 99mTc-labelled red cells. Each EF was obtained using four processing systems: NXT (SOPHA®), Entegra (Gems®), Odyssey (Philips®) and Esoft (Siemens®), always working in automated mode.The paired students t-test, Spearman correlation andBland-Altman analysis were used to compare methods,and Deming regression was applied. Results. Mean values and standard deviations for each program were: NXT: 61 ± 9; Entegra: 60 ± 10; Odyssey: 60 ± 9; Esoft: 60 ± 10.Although no significant differences were found as a wholeand the values were linearly related, the methods are not interchangeable. Conclusions. The same program should be used in the follow- up of each patient, which is now easily achievable by means of the DICOM standard (AU)
Subject(s)
Humans , Ventricular Function, Left/physiology , Radionuclide Ventriculography/instrumentation , Reference ValuesABSTRACT
No disponible
Subject(s)
Humans , Tomography, Emission-Computed , Image Interpretation, Computer-Assisted , AlgorithmsABSTRACT
OBJECTIVE: To study the influence of the 18F-FDG radioactive concentration and the usual greatest storage time of the radiopharmaceutical at the Radiopharmacy Unit (RU) over its radiochemical purity. MATERIAL AND METHODS: Thirty 18F-FDG preparations coming from different batches were studied. The radiochemical purity was determined at the RU by means of TLC to saline-diluted (1:10) and undiluted samples of each preparation, in the early 30 minutes since its arrival and 5 hours later. The radiochemical purity of the original 18F-FDG was determined at the PET radiopharmaceutical producer Laboratory (PETL) by means of HPLC in the early hour since the 18F-FDG dispensing. RESULTS: The increase of 18F-Fluoride found in the (5 h-30 min) period was significantly greater in the samples without diluting than in the diluted ones (p < 0.0001). We found a significant correlation between the percent of this increase of 18F-Fluoride (y) and the radioactive concentration of the 18F-FDG (x): y = 0.00061x + 0.1759 (R2 = 0.198; p < 0.0005). The percent of 18F-Fluoride determined at the RU was significantly higher than the percent of 18F-Fluoride determined at the PETL (p < 0.0001). A significant correlation between the differences of the percent of 18F-Fluoride determined by TLC and HPLC (y) and the radioactive concentration (x) was found: y = 0.0139x + 0.3146 (R2 = 0.196; p = 0.016). A significant correlation among the differences of percent 18F-Fluoride determined by TLC and HPLC ([%F] RU - [%F] PETL), the radioactive concentration (RC) and the time since the radiopharmaceutical dispensing (t) was found: [%F] RU - [%F] PETL = 0.01159*RC (mCi/mL) + 0.250*t (h) - 0.01903 (R2 = 0.226; p < 0.014). CONCLUSIONS: The stability of the 18F-FDG preparations with time increases when diminishing its concentration. We recommended the dilution of these preparations with physiological saline solution.
Subject(s)
Fluorodeoxyglucose F18/chemistry , Acetylation , Chromatography, High Pressure Liquid , Drug Stability , Drug Storage , Fluorine Radioisotopes/analysis , Radioactivity , Time FactorsABSTRACT
Objetivo. Determinar la influencia de la concentración radiactiva de la 2-[ 18F]-fluoro-2-desoxi-D-glucosa ( 18F-FDG) y el tiempo de almacenamiento máximo habitual del radiofármaco en la Unidad de Radiofarmacia (UR) sobre su pureza radioquímica. Material y métodos. Se estudiaron 30 preparaciones de 18F-FDG procedentes de lotes diferentes. Se determinó la pureza radioquímica en la UR dentro de los 30 minutos siguientes a su recepción y a las 5 horas mediante cromatografía en capa fina (TLC) a las muestras diluidas con suero salino fisiológico (1:10) y sin diluir. La pureza radioquímica también se determinó en el Laboratorio de radiofármacos PET (LPET) dentro de la primera hora posterior a su dispensación por cromatografía líquida a alta presión (HPLC). Resultados. El aumento de porcentaje de 18F-Fluoruro a las 5 horas fue significativamente mayor en las muestras sin diluir que en las diluidas (p < 0,0001), encontrándose una correlación significativa entre el aumento de porcentaje de 18F-Fluoruro con el tiempo (y) respecto a la concentración radiactiva (x): y = 0,0061x + 0,1759 (R 2 = 0,1977; p < 0,0005). El porcentaje de 18F-Fluoruro determinado en la UR fue significativamente mayor que el determinado en el LPET (p < 0,0001), obteniéndose una correlación significativa entre el aumento de porcentaje de 18F-Fluoruro (y) y la concentración radiactiva (x): y = 0,0139x + 0,3146 (R 2 = 0,196; p = 0,016). Se obtuvo una correlación significativa entre este aumento ([ %F] UR [ %F] LPET), la concentración radiactiva (CR) y el tiempo desde la dispensación (t): [ %F] UR [ %F] LPET = 0,01159*CR (mCi/ml) + 0,250*t (h) 0,01903 (R 2 = 0,226; p = 0,014). Conclusiones. La estabilidad de las preparaciones de 18F-FDG aumenta al disminuir su concentración. Aconsejamos la dilución de estas preparaciones con solución salina fisiológica
Objective. To study the influence of the 18F-FDG radioactive concentration and the usual greatest storage time of the radiopharmaceutical at the Radiopharmacy Unit (RU) over its radiochemical purity. Material and methods. Thirty 18F-FDG preparations coming from different batches were studied. The radiochemical purity was determined at the RU by means of TLC to saline-diluted (1:10) and undiluted samples of each preparation, in the early 30 minutes since its arrival and 5 hours later. The radiochemical purity of the original 18F-FDG was determined at the PET radiopharmaceutical producer Laboratory (PETL) by means of HPLC in the early hour since the 18F-FDG dispensing. Results. The increase of 18F-Fluoride found in the (5 h-30 min) period was significantly greater in the samples without diluting than in the diluted ones (p < 0,0001). We found a significant correlation between the percent of this increase of 18F-Fluoride (y) and the radioactive concentration of the 18F-FDG (x): y = 0,00061x + 0,1759 (R 2 = 0,198; p < 0,0005). The percent of 18F-Fluoride determined at the RU was significantly higher than the percent of 18F-Fluoride determined at the PETL (p < 0,0001). A significant correlation between the differences of the percent of 18F-Fluoride determined by TLC and HPLC (y) and the radioactive concentration (x) was found: y = 0,0139x + 0,3146 (R 2 = 0,196; p = 0,016). A significant correlation among the differences of percent 18F-Fluoride determined by TLC and HPLC ([ %F] RU [ %F] PETL), the radioactive concentration (RC) and the time since the radiopharmaceutical dispensing (t) was found: [ %F] RU [ %F] PETL = 0,01159*RC (mCi/mL) + 0,250*t (h) 0,01903 (R 2 = 0,226; p < 0,014). Conclusions. The stability of the 18F-FDG preparations with time increases when diminishing its concentration. We recommended the dilution of these preparations with physiological saline solution
Subject(s)
Humans , Radiopharmaceuticals/chemistry , Drug Storage/methods , 35476 , Drug Storage/standards , Fluorodeoxyglucose F18/chemistry , Time Factors , Radionuclide Density Factor , Quality ControlABSTRACT
Presently, only a few clinical laboratories produce their own reference values, while the great majority use reference intervals reported in the literature. An alternative to this unsatisfactory situation is to estimate indirect reference limits by means of mathematical/statistical procedures from patients' results obtained routinely in the laboratory. The procedures of Bhattacharya (A simple method of resolution of a distribution into Gaussian components. Biometrics 1967;23:115-135) Martin et al. (Reference values based on populations accessible to hospitals. In: Gräsbeck R, Alström T, editors. Reference Values in Laboratory Medicine. Chischester: Wiley, 1981:233-262) and Kairisto et al. (Generation of reference values for cardiac enzymes from hospital admission laboratory data. Eur J Clin Chem Clin Biochem 1994;32:789-796) were applied to 14 biochemical quantities. In order to verify these procedures, the indirect reference limits obtained from patients' results were validated by statistical comparison with reference limits estimated from a reference sample according to recommendations of the International Federation of Clinical Chemistry (IFCC). Calculated indirect reference limits for most quantities studied were reliable, but indirect reference limits for bilirubins and potassium ion substance concentrations, alanine aminotransferase, and aspartate aminotransferase catalytic concentrations in serum were not suitable. We conclude that indirect reference limits can be obtained from patients' results by all procedures studied when skewness and kurtosis of mixed distribution are not too large, but other factors also seem to have an influence on the reliability of these procedures.
