The magnetic resonance imaging assessment of optic nerve sheath diameter in pediatric acute liver failure patients.

OBJECTIVE: To evaluate the diagnostic value of optic nerve sheath diameter (ONSD) using brain MRI in the pretransplantation period in the pediatric acute liver failure patients, and correlate the ONSD with clinical grade of hepatic encephalopathy (HE) and MRI findings. PATIENTS AND METHODS: Forty acute liver failure patients and 40 control group patients were retrospectively analyzed. The high signal intensities in T2W (T2-weighted image), FLAIR (Fluid Attenuated Inversion Recovery) and DWI (diffusion-weighted imaging) sequences were evaluated and ONSD was measured. The patients were grouped first into 5 according to their West Haven score, and HE grade 0 and grade 1 were accepted as low grade HE, HE grade 2, 3 and 4 were accepted as high grade HE. The patients were grouped to 2 according to the MRI findings as low grade and high grade MRI group. RESULTS: The mean value of ONSD was 6.0 ± 1.80 and 4.94 ± 1.27 in the all patients and in the control group, respectively. There was statistically significant difference between both the ONSD and the low grade-high grade HE groups (p=0.01), and between the ONSD and the low grade-high grade MRI groups (p<0.001). CONCLUSIONS: Although high ONSD values do not make the diagnosis of cerebral edema, it may cause suspicion in the early period. MRI can be helpful in the diagnoses of increased intracranial pressure like ultrasound. Our study is the first study to compare ONSD and MRI findings in addition to HE grades. The widespread use of MRI in children in recent years may help determine the normal range of ONSD values.