ABSTRACT
Cardiopulmonary complications are infrequent in patients with ventriculoatrial shunts (VAS). We report the case of an 18-year-old man with congenital hydrocephalus who developed pulmonary arterial hypertension (PAH) in the long-term follow-up after a VAS procedure. He presented with progressive exertional dyspnea, stabbing chest pain and acral cyanosis. Echocardiography showed severe PAH and a digitiform mass adhered to the distal catheter. A ventilation/perfusion scan suggested chronic pulmonary embolisms. Anticoagulation with intravenous heparin was started and thrombus resolution was achieved, but PAH remained. It is necessary to bear in mind complications linked to VAS when treating a patient with this device.
Subject(s)
Hydrocephalus , Hypertension, Pulmonary , Pulmonary Arterial Hypertension , Pulmonary Embolism , Male , Humans , Adolescent , Cerebrospinal Fluid Shunts/adverse effects , Hydrocephalus/etiology , Hypertension, Pulmonary/etiologyABSTRACT
OBJETIVO: El objetivo fue doble, valorar el acuerdo interobservador en la segmentación tumoral y la búsqueda de una metodología fiable y aplicable en la segmentación de gliomas usando PET/TC con 18F-fluorocolina. MATERIAL Y MÉTODOS: Se incluyeron 25 pacientes con glioma, procedentes de un estudio prospectivo no randomizado (Functional and Metabolic Glioma Analysis). Se analizó la variabilidad interobservador usando umbrales fijos. Diferentes estrategias se emplearon en la segmentación. Primero, se realizó una segmentación semiautomática, seleccionando el mejor umbral del SUVmáx-% para cada lesión. Posteriormente, se determinó una variable del SUVmáx-% dependiente del SUVmáx. Finalmente se realizó una segmentación usando un valor de umbral fijo de SUVmáx. Para ello, se realizó un muestreo de 10 regiones de interés (ROI de 2,8cm2) localizadas en cerebro normal. El valor superior obtenido de la media del muestreo+/-3 desviaciones estándar se usó como valor de corte. Todos los procedimientos fueron testados y clasificados como válidos o no en la segmentación tumoral en consenso por dos observadores. RESULTADOS: En la segmentación piloto, la media+/-DE del SUVmáx, SUVmedio y el umbral del SUVmáx-% fue de 3,64+/-1,77; 1,32+/-0,57 y 2,132+/-8,39, respectivamente. El valor óptimo del umbral SUVmáx-% mostró una asociación significativa con el SUVmáx (Pearson=-0,653; p = 0,002). Sin embargo, el modelo de regresión lineal del total de la muestra no fue bueno lo que justificó la división de la misma en dos grupos homogéneos, definiendo dos fórmulas para predecir el umbral del SUVmáx-%. Para el tercer procedimiento, el valor obtenido de la media SUVmáx+3 DE fue de 0,33. Este valor permitió segmentar correctamente una elevada proporción de casos, aunque no todos. CONCLUSIÓN: Se encontró una gran variabilidad interobservador en la segmentación tumoral. Ninguno de los métodos fue capaz de segmentar correctamente todos los gliomas probablemente debido a la amplia heterogeneidad en la PET/TC con 18F-fluorocolina
AIM: Our aim was two-fold, to study the interobserver agreement in tumour segmentation and to search for a reliable methodology to segment gliomas using 18F-fluorocholine PET/CT. METHODS: 25 patients with glioma, from a prospective and non-randomized study (Functional and Metabolic Glioma Analysis), were included. Interobserver variability in tumour segmentation was assessed using fixed thresholds. Different strategies were used to segment the tumours. First, a semi-automatic tumour segmentation was performed, selecting the best SUVmax-% threshold for each lesion. Next we determined a variable SUVmax-% depending on the SUVmax. Finally a segmentation using a fixed SUVmax threshold was performed. To do so, a sampling of 10 regions of interest (ROI of 2.8cm2) located in the normal brain was performed. The upper value of the sample mean SUVmax+/-3 SD was used as cut-off. All procedures were tested and classified as effective or not for tumour segmentation by two observer's consensus. RESULTS: In the pilot segmentation, the mean+/-SD of SUVmax, SUVmean and optimal SUVmax-% threshold were: 3.64+/-1.77, 1.32+/-0.57 and 21.32+/-8.39, respectively. Optimal SUVmax-% threshold showed a significant association with the SUVmax (Pearson=−0.653, p=.002). However, the linear regression model for the total sample was not good, that supported the division in two homogeneous groups, defining two formulas for predicting the optimal SUVmax-% threshold. As to the third procedure, the obtained value for the mean SUVmax background+3 SD was 0.33. This value allowed segmenting correctly a significant fraction of tumours, although not all. CONCLUSION: A great interobserver variability in the tumour segmentation was found. None of the methods was able to segment correctly all the gliomas, probably explained by the wide tumour heterogeneity on 18F-fluorocholine PET/CT
Subject(s)
Humans , Central Nervous System Neoplasms/diagnostic imaging , Central Nervous System Neoplasms/pathology , Fluorodeoxyglucose F18 , Glioma/diagnostic imaging , Glioma/pathology , Tomography, X-Ray Computed , Radiopharmaceuticals , Observer Variation , Positron-Emission Tomography , Tomography, X-Ray Computed/methods , Prospective StudiesABSTRACT
AIM: Our aim was two-fold, to study the interobserver agreement in tumour segmentation and to search for a reliable methodology to segment gliomas using 18F-fluorocholine PET/CT. METHODS: 25 patients with glioma, from a prospective and non-randomized study (Functional and Metabolic Glioma Analysis), were included.Interobserver variability in tumour segmentation was assessed using fixed thresholds. Different strategies were used to segment the tumours. First, a semi-automatic tumour segmentation was performed, selecting the best SUVmax-% threshold for each lesion. Next we determined a variable SUVmax-% depending on the SUVmax. Finally a segmentation using a fixed SUVmax threshold was performed. To do so, a sampling of 10 regions of interest (ROI of 2.8cm2) located in the normal brain was performed. The upper value of the sample mean SUVmax±3 SD was used as cut-off. All procedures were tested and classified as effective or not for tumour segmentation by two observer's consensus. RESULTS: In the pilot segmentation, the mean±SD of SUVmax, SUVmean and optimal SUVmax-% threshold were: 3.64±1.77, 1.32±0.57 and 21.32±8.39, respectively. Optimal SUVmax-% threshold showed a significant association with the SUVmax (Pearson=-0.653, p=.002). However, the linear regression model for the total sample was not good, that supported the division in two homogeneous groups, defining two formulas for predicting the optimal SUVmax-% threshold. As to the third procedure, the obtained value for the mean SUVmax background+3 SD was 0.33. This value allowed segmenting correctly a significant fraction of tumours, although not all. CONCLUSION: A great interobserver variability in the tumour segmentation was found. None of the methods was able to segment correctly all the gliomas, probably explained by the wide tumour heterogeneity on 18F-fluorocholine PET/CT.
Subject(s)
Central Nervous System Neoplasms/diagnostic imaging , Central Nervous System Neoplasms/pathology , Fluorodeoxyglucose F18 , Glioma/diagnostic imaging , Glioma/pathology , Positron Emission Tomography Computed Tomography , Radiopharmaceuticals , Humans , Observer Variation , Positron Emission Tomography Computed Tomography/methods , Prospective StudiesABSTRACT
La fractura de apófisis odontoides de la segunda vértebra cervical representa entre el 10 y el 15% de todas las fracturas cervicales. En el medio militar, esta lesión puede ser originada por la práctica de deportes, actividades de especial riesgo como el paracaidismo y armas de fuego o artefacto explosivo. Un diagnóstico precoz y un adecuado tratamiento multidisciplinar pueden colaborar para el correcto manejo integral de una baja. Se ha realizado una revisión de la literatura en la base de datos del PUBMED, utilizado la palabra clave «fractura odontoides», «sedación», «Halo-Jacket»
Odontoid fracture of the second cervical vertebra represents between 10 and 15% of all cervical fractures. In a military environment, this injury may be caused by the practice of sports, special risk such as skydiving and firearms or explosive device. Early diagnosis and appropriate multidisciplinary treatment can work for the proper management of a casualty. A literature review has been carried out in PUBMED database, using the keywords «fractura odontoides», «sedación», «Halo-Jacket»
