Densidad escanográfica de los senos venosos en pacientes sanos a 2.600 metros sobre el nivel del mar

Abstract

Introduction: There is a relationship between the intravascular density measured in Hounsfield units (HU) in computed tomography (CT) and the hematocrit levels, which increases in people who live above sea level. The expected density in venous sinuses is lower than 70 HU in healthy people living at 1000 meters above sea level. However, this measure has not been established in people living at higher geographic altitudes. In this study, this value was determined for normal people living at 2,600 meters above sea level. Objective: The purpose of this study is to characterize the normal density of the venous sinuses in patients who live at geographical altitudes of 2,600 m above sea level. Methodology: We measured the density on CT at the superior longitudinal venous sinus and at the junction between the transverse sinus and sigmoid sinus of 240 subjects living at 2600 meters above sea level from January 2008 to June 2016. These patients consulted for headache, seizures, altered state of consciousness or neurological focus. Initially, all participants had a non-enhanced CT brain, hemoglobin and hematocrit levels with a difference of no more than 3 days between the CT study and the hemogram, as well as confirmatory studies of positivity or absence of intracranial sinus thrombosis by non-enhanced MR or MRA. Results: The mean HU was 59.8 with a range between 43.2 and 74.9, for normal patients. A positive correlation of 0.49 was found between hematocrit and HU, as is widely known in the literature. Conclusion: We obtained a wide range in the HU of healthy patients compared to the values reported in other papers, and exceeds the highest value by 4 points. This may be attributable to the increased hematocrit in healthy patients living at 2,600 meters above sea level. In order to establish whether patients with venous sinus densities greater than 70 HU have venous thrombosis, our suggestion is to evaluate the symmetry of the density compared to the contralateral venous sinus, as well as to evaluate the morphology and the location of the ROI used to measure venous density.