System for Eecient and Secure Distribution of Medical Images on the Internet

Because of the high compressibility of the medical images, data compression is desirable for digital storage despite the availability of inexpensive hardware for mass storage. A progressive transmission algorithm with automatic security ltering features for on-line medical image distribution using Daubechies' wavelets has been developed and is discussed in this paper. The system is practical for real-world applications, processing and coding each 12-bit image of size 512 512 within 2 seconds on a Pentium Pro. Besides its exceptional speed, the security lter has demonstrated a remarkable accuracy in detecting sensitive textual information within current or digitized previous medical images. The algorithm is of linear run time. INTRODUCTION As more and more advanced medical equipment is used in diagnosis and management of disease, it is becoming increasingly diicult to maintain and retrieve health care information manually. Besides the traditional textual data such as patient reports, health care records are being lled with X-ray images, MRI scans, CT scans, 3-D volume reconstructions, and video streams. EEcient data compression and progressive transmission with security ltering for digital medical images is desirable because of the high compress-ibility of the medical images and limited bandwidth of the network. In this paper, we present a wavelet-based lossless medical image compression and progressive transmission algorithm that also detects textual information (including identifying information) from some current or digitized previous medical images. Textual terms not known to be innocuous are eliminated 17]. The resulting processed images can then be made available to medical researchers, second-opinion physicians, students , and other legitimate users after being processed by our algorithm. Such a system may be used by health care institutions and other repositories of medical images as part of a real-time medical image distribution system.