Determination the Ischemic Stroke of Brain MRI Based on Apparent Diffusion Coefficient (ADC) with b Value Variation

The Research to Determination the Ischemic Stroke of Brain MRI Based on Apparent Diffusion Coefficient (ADC) with b Value variations. The purposes of this study were to find b valuevariations of Diffusion Weighted Image (DWI), determining the optimum b value to find out the Contrast to Noise Ratio (CNR) ischemic stroke lesion in DWI image, and To determine the Diffusion Coefficient range obtained from the ADC (Apparent Diffusion Coefficient) value between old ischemic stroke and new ischemic stroke. In this research, used are 0, 500 and 1000. The result obtained b value influenceon the quality of DWI were analyzed in 30 patients suspected with old ischemic stroke and new ischemic stroke. Data analysis was done quantitatively with the Region Of Interest (ROI) directly on computer MRI image planes and were conducted statistical tests Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR). The highest Signal to Noise Ratio (SNR) found in b 0, while the highest Contrast to Noise Ratio (CNR) on the b 1000 s/mm ². The statistics test show that significant SNR value of the Lesion, around the lesion, Liquor, WM, GM tissue is about 0,000 (p<0,05), while for the Contrast to Noise Ratio (CNR) of the lesion and around the lesion tissue is about 0,000 (p<0,05). This results showed that b value variation have a difference at lesion, around the lesion, Liquor, WM, GM tissue for MRI imaging quality. SNR and CNR are important aspect on imaging optimalization process to give the diagnose information. In this research, the diffusion coefficient value in new ischemic stroke is < 1 × 10^-3, whereas the old ischemic stroke is > 1 × 10^-3, the results showed that15 patients have new ischemic stroke and 15 patients have old ischemic stroke.