El papel de FDG PET-TAC en el diagnóstico diferencial de patologías pleurales / The role of FDG PET-CT in differential diagnosis of pleural pathologies

Introducción. El propósito de este estudio fue el de estudiar el impacto de F-18 Fluoro Desoxi Tomografía-Tomografía por Emisión de tomografía computerizada (FDG y PET-TAC) sobre la diagnosis diferencial de lesiones benignas y malignas en pacientes con sospecha de mesotelioma pleural maligno. Pacientes y métodos. Cincuenta pacientes (32 mujeres, 18 hombres, rango de edad 24-79 años, edad media 57,6) con engrosamiento pleural, derrame pleural, placas o calcificaciones vistas en imágenes en estudios previos con TAC fueron sometidos a la PET-TAC con FDG. Tras la inyección intravenosa de la FDG, se realizaron imágenes PET-TAC al cabo de una hora. Se obtuvieron imágenes tardías de la región torácica a las 2 horas de la inyección. Se llevaron a cabo análisis visual y semi cuantitativos con el valor de captación estándar (SUV). Los resultados del FDG PET-TAC fueron comparados con el diagnóstico histopatológico. Resultados. 39 pacientes demostraron captación aumentada en lesiones pleurales. Los resultados en la PET-TAC fueron negativos en 11 pacientes. Al comparar los resultados histopatológicos en el grupo de FDG-positivo, 34 pacientes tenían mesotelioma pleural maligno (MPM), 5 pacientes tenían patologías benignas. En el grupo FDG-negativo, las patologías fueron benignas en 8 pacientes, 3 pacientes tuvieron MPM. En los pacientes con imágenes tardías, 9 demostraron SUV aumentado, pero 3 tuvieron SUV disminuido en las imágenes tardías. En el grupo con SUV aumentado, 4 tuvieron MPM, 5 patología benigna (3, inflamación granulomatosa, y 2 placas asbestosis benignos). En el grupo de SUV disminuido, todos tuvieron patología benigna (la fibrosis, inflamación crónica, miofibrosis). Discusión. La FDG PET-TAC es una modalidad de imágenes útil en el diagnóstico diferencial de lesiones pleurales benignas y malignas. Imágenes tardías parecen ser útiles si existe una disminución en SUV sugerente de una patología benigna. Sin embargo, no parece contribuir a un diagnóstico diferencial si el SUV se aumenta(AU)

Objective. This study has aimed to evaluate the impact of F18 Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET-CT) in the differential diagnosis of malignant and benign pleural lesions in patients with suspected malignant pleural mesothelioma (MPM). Material and methods. Fifty patients (32 females, 18 males; age range 24-79 years) with pleural thickening, fluid, plaques or calcification on previous CT scan were examined with FDG PET-CT. PET-CT imaging was obtained 1h after FDG injection. In 12 patients, delayed imaging from the thoracic region was performed 2h after injection. FDG uptake was evaluated visually and semiquantitively using standardized uptake value (SUV). FDG PET-CT findings were compared with histopathologic diagnosis. Results. Thirty-nine patients had increased FDG uptake in pleural lesions but PET-CT results were negative in 11 patients. When compared with histopathological results in FDG positive group, 34 patients had MPM, 5 had benign pathology; in FDG negative group 8 patients had benign pathology, 3 had MPM. Of patients with delayed imaging, 9 showed increased SUV but 3 had a decreased SUV on delayed images. Increased SUV group had 4 MPM, 5 benign pathology (3 chronic granulomatous inflammation, 2 benign asbestotic plaque). Decreased SUV group all had benign pathology (fibrosis, chronic inflammation, myofibrosis). Discussion. FDG PET-CT is a useful imaging modality in differential diagnosis of malignant and benign pleural lesions. Delayed imaging seems to be useful if there is a decrease in SUV suggesting a benign pathology but does not seem to contribute to the differential diagnosis if the SUV is increased(AU)

Evaluation of P wave duration and P wave dispersion in adult patients with secundum atrial septal defect during normal sinus rhythm.

BACKGROUND: Paroxysmal atrial arrhythmias especially atrial fibrillation (AF) are frequently encountered in adult patients with atrial septal defect (ASD). Previously it was shown that maximum P wave duration and P wave dispersion in 12-lead surface electrocardiograms are significantly increased in individuals with a history of paroxysmal AF. The aim of this study was to determine whether P maximum and P dispersion in adult patients with ASD and without AF are increased as compared to healthy controls. In addition, the relationship of pulmonary to systemic flow ratio (Qp/Qs) and these P wave indices were investigated. METHODS AND RESULTS: Sixty-two consecutive patients [39 women, 23 men; mean age 33+/-13 years (range 16 to 61 years)] with ostium secundum type ASD and 47 healthy subjects [25 women, 22 men; mean age 36.6+/-9.5 years (range 18 to 50 years)] were investigated. P maximum, P minimum and P dispersion (maximum minus minimum P wave duration) were measured from the 12-lead surface ECG. There were no significant differences with respect to age (P=0.08), gender (P=0.3), heart rate (P=0.3), left atrial diameter (P=0.5) and left ventricular ejection fraction (P=0.3) between patients and controls. Pulmonary artery peak systolic pressure was significantly higher in patients with ASD as compared to controls (P<0.0001). P maximum was significantly longer in patients with ASD as compared to controls (P<0.0001). In addition, P dispersion of the patients was significantly higher than controls (P=0.001). P minimum was not different between groups (P=0.12). Mean Qp/Qs of the patients with ASD was 2.5+/-0.7 (minimum 1.5; maximum 4.1) and found to be significantly correlated with P maximum (r=0.34; P=0.006) and P dispersion (r=0.61; P<0.0001). CONCLUSIONS: Prolongation of P maximum and increased P dispersion could represent mechanical and electrical changes of atrial myocardium in patients with ASD. These changes of atrial myocardium may be more prominent with higher left to right shunt volumes.