Lateral Ventrikül Görünür Difüzyon Katsayısı Leptomeningeal Karsinomatozis Tanısında Yararlı Olabilir mi?

Abstract

Leptomeningeal carcinomatosis (LMC) is caused by the spread of malignant cells within cerebrospinal fluid (CSF). Diffusion-weighted imaging (DWI) is quantified by the apparent diffusion coefficient (ADC) value. The decreased ADC of CSF in pyogenic ventriculitis due to pleocytosis and the protein content has been reported. With similar argument, we hypothesized ADC in LMC can be decreased due to higher CSF viscosity caused by levated factors such as cell count, total protein. The purpose of our study was to evaluate whether increased CSF viscosity in LMC causes low ADC values in CSF. Thirty-one patients with LMC and 31 age and sex-matched subjects having normal brain MRI were included in this study. ADC measurements were made on both sides in posterior lateral ventricle (LV) and lateral pterigoid muscle (LPM). The ADC ratio (=ADCCSF/ADCLPM) was calculated by dividing the ADC values to prevent individual and device-dependent differences. ADCCSF and ADC ratios were compared between the groups. Both the ADCCSF and ADCCSF/ADCLPM ratio in the LMC group was lower than those in the control group with statistical significance. ROC analysis showed a cutoff value of 2844 for the ADCCSF (sensitivity 51.61%, specificity 96.77%, under curve 0.800) and a cutoff value of 1.97 for the ADC ratio (sensitivity 74.19%, specificity 93.55%, under curve 0.833) for differentiating LMC and control groups. ADC value may be used as a complementary tool to increase diagnostic accuracy of LMC.