Improving Signal to Noise Ratio of Low-Dose CT Image Using Wavelet Transform

Now-a-days, diagnosis of human diseases has become comparatively easier with the help of modern technology. Use of new technology provides more information about the patient condition and also patient’s health can be monitored continuously. Early detection is a very important aspect in diagnosis. CT scanning is one such technique which is very effective and useful for early detection but the patient is exposed to harmful radiation when he/she undergoes CT scan. If the amount of radiation is reduced, the CT image qualitydecreases i.e. signal to noise ratio (SNR) decreases. Wavelet transform is a tool to analyzed signals and the entire set of wavelet share some common properties but each wavelet has certain unique properties of Image decomposition, de-noising and reconstruction whichprovides difference in PSNR. In this paper, it is proposed to determine an analysis technique which will provide the requiredinformation from low-dose CT image, hence less harmful to the patient. Again in this paper an analysis is carried out on different low dose CT image using different wavelets. Images are decomposed, de-noised and reconstructed and then analyzed in terms of PSNR.