Simulation Of Contrast Enhancement Of Various Brain Lesions (Without Iv Gadolinium) By Using The Neural Network

Abstract

PURPOSE:To produce an enhancement-like effect of the brain lesions of MRI images mathematically, without intravenous injection of contrast.INTRODUCTION:To improve the visibility of internal body structures, MRI contrast agents are used. Gadolinium (Gd 3+), a paramagnetic substance, is the most commonly used compound for contrast enhancement. Gd is introduced into the blood stream for enhancement of brain tumors and various lesions depending upon the degradation of the blood-brain barrier. Due to their hydrophilic character, gadolinium chelates do not pass the blood-brain barrier. Contrast (Gd) mediated nephropathy (CMN) and systemic fibrosis are two notorious, irreversible complications.MATERIALS AND METHODS: A multi-slice EPI IR sequence was used to assess T1 relaxation times of various brain lesions and brain tumors before and after administration of gadolinium. T1 relaxation time and signal intensity with corresponding gray scale values (out of 256 shades) of various brain lesions before and after IV contrast were tabulated. A statistical relationship was determined for the magnitude of changes in the T1 values of brain tumors before and after the contrast material was added. Enhancement-like effects of the lesions could be reproduced mathematically with the help of neural networks without the IV contrast injection. With the help of Kmean clustering, the data were classified. A mapping function was generated that corresponded between these independent components and the cross-sectional data by using the neural network after training the network with a sample dataset. The training sample for the network was selected using K-mean clustering. A mapping of the lesion was done overlaid on the T1 weighted image.CONCLUSION: An attempt was successfully made to enhance various brain lesions statistically utilizing neural networks and without using IV contrast.