Medición volumétrica de grasa visceral abdominal con RM y su relación con elastografía hepática en una población diabética

Abstract

Background. Increase in visceral fat is associated to the development of fatty liver and liver fibrosis. Hepatic elastography is a novel noninvasive method for assessing liver fibrosis. Objective. To evaluate the relationship between visceral adipose tissue volume (VAT), subcutaneous adipose tissue volume (SAT) as measured by Magnetic Resonance Imaging (MRI) and transient elastography (TrE) values using ARFI (Acoustic Radiation Force Impulse) in type 2 Diabetic Mellitus patients (DM2). Methods. We included 20 DM2 patients (mean age: 62 years, range: 55-75, mean weight: 77.8 kg, range: 61.5-97). Patients underwent an MRI study in a Philips Intera 1.5T scanner. MR imaging protocol included a spectral excitation sequence centered on the fat peak. The sequence included 32 cross sections, 7mm thick, from the diaphragmatic cupula to the inferior border of the kidney. VAT was measured by using the semiautomatic Image J software. Each patient underwent a hepatic elastograpy (HE); 10 ARFI measurements were performed in the right hepatic lobe. Finally, a statistical analysis was performed by applying Pearson correlation between abdominal fat volumes and ARFI scores Results. Mean VAT was 2472 ± 861 cc, (1173-4020 cc), whilst the mean ARFI was 1.62 ± 0.8 m/s, (0.8-3.4 m/s). Correlations obtained were r= 0.08 between VAT and ARFI (p= 0.72); 0.13 between SAT and ARFI (p= 0.57), and-0.06 between (VAT+SAT) and ARFI (p= 0.77). By subdividing the sample universe, we observed that the group with ARFI scores greater than 1.6 m/s (7 patients) had a correlation of 0.63 between VAT and ARFI (p= 0.12); of 0.66 between SAT and ARFI (p= 0.10), and of 0.94 between VAT+SAT and ARFI (p= 0.001). In the subgroup with ARFI values inferior to 1.6 m/s (13 patients), the correlation was of 0.11 between VAT and ARFI (p= 0.71); of 0.26 between SAT and ARFI (p= 0.38), and of 0.32 between (VAT+SAT) and ARFI (p= 0.28). When adjusted for gender, ARFI scores greater than 1.6m/s (6 patients) in the subgroup of female patients revealed a correlation of 0.79 (p= 0.05) between ARFI and VAT, and of 0.92 (p= 0.009) for VAT+SAT. Conclusions. In DM2 patients, ARFI values greater than 1.6 m/s seem to be indicative of a good correlation between VAT and VAT+SAT, thus indicating that those with greater liver damage may present increased abdominal fat accumulation.