Metodología de la gammagrafía con leucocitos marcados en el diagnóstico de infección osteoarticular protésica/no protésica: ¿análisis visual o semicuantitativo? ¿Protocolo de uno o 2 días? / Diagnostic methodology in labelled leukocyte scan for prosthetic / non-prosthetic osteoarticular infection: Visual or semi-quantitative analysis? One- or two-day protocol?

Objetivo: Como hay poca literatura sobre el tema, nos propusimos comparar la utilidad diagnóstica del análisis semicuantitativo versus el análisis visual en la escintigrafía de glóbulos blancos etiquetados (WBCS) para la infección osteoarticular. Se evaluaron protocolos de uno y dos días, en particular en los dispositivos ortopédicos.Material y métodos: Estudio prospectivo de 79 pacientes consecutivos con sospecha de infección osteoarticular. En todos los pacientes, la SCBM se realizó a los 30 min, 4 h, 8 h y 24 h. Las imágenes se analizaron agrupándolas en dos protocolos: protocolo de un día (los expertos evaluaron imágenes planas de 30 min, 4 h y 8 h) y protocolo de dos días (los expertos evaluaron imágenes planas de 30 min, 4 h y 24 h). Las imágenes planas se interpretaron cualitativa y semicuantitativamente y también se compararon agrupando a los pacientes con y sin dispositivos ortopédicos. Para determinar qué valor de corte de la variación porcentual podía predecir la infección osteoarticular, se calcularon múltiples valores de corte en ambos protocolos a partir del índice de Youden. Tres lectores ciegos analizaron las imágenes.Resultados: Comparando el diagnóstico final, el análisis visual del protocolo de un día proporcionó mejores resultados con una sensibilidad del 95,5%, una especificidad del 93% y una precisión diagnóstica del 93,7% (p < 0,01) que el protocolo de dos días con valores del 86,4%, 94,7% y 92,4%, respectivamente (p < 0,01). Para el análisis semicuantitativo, el protocolo de un día también obtuvo mejores resultados con una sensibilidad del 72,7%, una especificidad del 78,9% y una precisión del 77,2% (p < 0,01) que el protocolo de dos días (sin resultados significativos; p = 0,14), especialmente en el grupo de pacientes con aparatos ortopédicos (sensibilidad del 100%, especificidad del 79,5% y precisión del 82,7%; p < 0,01)

Objective: As scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices.Material and methods: Prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images.Results: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (P<.01) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (P<.01). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (P<.01) than two-day-protocol (no significant results; P=.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; P<.01).Conclusions: Most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful

Diagnostic methodology in labelled leukocyte scan for prosthetic / non-prosthetic osteoarticular infection: Visual or semi-quantitative analysis? One- or two-day protocol? / Metodología de la gammagrafía con leucocitos marcados en el diagnóstico de infección osteoarticular protésica/no protésica: ¿análisis visual o semicuantitativo? ¿Protocolo de uno o 2 días?

OBJECTIVE: As scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices. MATERIAL AND METHODS: Prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images. RESULTS: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (P<.01) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (P<.01). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (P<.01) than two-day-protocol (no significant results; P=.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; P<.01). CONCLUSIONS: Most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful. In patients with joint prostheses, an increase in percentage variation above 9% obtained maximum sensitivity and negative predictive value.

Utilidad de la gammagrafía con hematíes desnaturalizados por calor marcados con 99mTc en el diagnóstico de una esplenosis intramuscular / Usefulness of 99mTc labelled heat-denatured red blood cell scintigraphy in the diagnosis of intramuscular splenosi

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Tratamiento del craneofaringioma quístico con 90Y-coloide. Presentación de 4 casos clínicos / Treatment of cystic craniopharyngioma with 90Y-Colloid. Four clinical cases

El craneofaringioma es un tumor intracraneal histológicamente benigno y frecuentemente quístico que puede presentar un comportamiento agresivo por compresión de estructuras vecinas. Su manejo terapéutico es complicado ya que si bien el tratamiento de elección suele ser la cirugía, esta no está exenta de una gran morbimortalidad y recidiva tumoral frecuente. En aquellos craneofaringiomas con un componente quístico importante la irradiación interna del tumor con isótopos radiactivos supone una alternativa a los tratamientos convencionales. Se presentan 4 casos de pacientes con craneofaringiomas quísticos tratados mediante administración intraquística con 90Y-coloide y su evolución después del tratamiento(AU)

Craniopharyngioma is a histologically benign and frequently cystic intracranial tumor. It may present aggressive behavior due to compression of nearby structures. Its therapeutic management is complicated because, although surgery is the usual treatment of choice, it is not exempt of high morbidity and mortality, and frequent tumor recurrence. In craniopharyngiomas with a significant cystic component, internal irradiation with radioactive isotopes is a therapeutic alternative to conventional treatments. We present the cases of four patients with cystic craniopharyngiomas who were treated with intracystic administration of 90Y-colloid, and their evolution after the therapy(AU)

Treatment of cystic craniopharyngioma with 90Y-Colloid. Four clinical cases.

Craniopharyngioma is a histologically benign and frequently cystic intracranial tumor. It may present aggressive behavior due to compression from nearby structures. Its therapeutic management is complicated because although surgery is the usual treatment of choice, it is not exempt of high morbidity and mortality and frequent tumor recurrence. In craniopharyngiomas with a significant cystic component,internal irradiation with radioactive isotopes is a therapeutic alternative to conventional treatments. We present the cases of four patients with cystic craniopharyngiomas who were treated with intracystic administration of 90Y-colloid, and their evolution after the treatment.

Evaluación mediante mapas estadísticos paramétricos de los cambios de la perfusión cerebral en pacientes con estenosis de la arteria carótida sometidos a endarterectomía / Evaluation by “statistical parametric mapping” of the cerebral perfusion changes in patients with carotid artery stenosis after endarterectomy

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)

[Evaluation by "statistical parametric mapping" of the cerebral perfusion changes in patients with carotid artery stenosis after endarterectomy]. / Evaluación mediante mapas estadísticos paramétricos de los cambios de la perfusión cerebral en pacientes con estenosis de la arteria carótida sometidos a endarterectomía.

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.

[Validation of the preparation of individual doses of 51Cr-EDTA in syringes]. / Validación de la preparación de dosis individuales de 51Cr-EDTA en jeringas.

The 51Cr-EDTA is one of the radiopharmaceuticals more used in the glomerular filtration rate determination. The necessity to prepare a daily reference dose every time that are prepared the patient's doses can go to a poor exploitation of the multidose vial. One way of improving its use consists on the preparation of individual doses in ready syringes to inject, for several days, employing only one of them as a standard. The aim of this study was to evaluate the storing of 51Cr-EDTA individual doses at room temperature and at 4 degrees C during 4 weeks, analyzing the radiochemical purity, the sterility and the radiopharmaceutical retention into the syringe. The results obtained showed that the radiochemical purity remains stable, always been greater than the value recommended for its use (> 95%). Likewise, there were not microorganism contamination nor 51Cr-EDTA appreciable retention into the syringes. We concluded that the preparation of individual doses of 51Cr-EDTA in syringes and their conservation at room temperature, or at 4 degrees C, during a period of 4 weeks, neither influence in the radiopharmaceutical quality nor increase its retention into the syringe.