RESUMO
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.
Assuntos
Hidrocefalia , Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Embolia Pulmonar , Masculino , Humanos , Adolescente , Derivações do Líquido Cefalorraquidiano/efeitos adversos , Hidrocefalia/etiologia , Hipertensão Pulmonar/etiologiaRESUMO
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.