Design and development of a fiber optic TDI CCD-based slot-scan digital mammography system

In the 1993 IS and T/SPIE Symposium on Electronic Imaging Science and Technology, the authors reported on the development, design and clinical evaluation of a CCD-based, high performance, filmless imaging system for stereotactic needle biopsy procedures in mammography. This system, the MammoVision, is currently in clinical use in over 50 hospitals across the world. The MammoVision system has a limited imaging area of 50 mm x 50 mm, since it is designed specifically for breast biopsy applications. The authors are currently developing a new filmless imaging system designed to cover the 18 cm x 24 cm imaging area required for screening and diagnostic mammography. The diagnostic mammography system is based on four 1,100 x 330 pixel format, full-frame, scientific grade, front illuminated, MPP mode CCDs, with 24 microm x 24 microm square pixels. Each CCD is coupled to an x-ray intensifying screen via a 1.7:1 fiber optic reducer. The CCDs are cooled to -10 C and operated in slow-scan, correlated double sample mode at a readout rate of 1.5 Mpixel per second per channel and at 12-bits per pixel. The CCD/fiber optic reducer assemblies are stacked in a row perpendicular to the patient's body. The detector assembly (180 mm long and 13.5 mm wide) is scanned across the patient's breast synchronously with the x-ray source, with the CCDs operated in time-delay integration (TDI) mode. The total scan time is 4.0 seconds