It's been a very stimulating afternoon and there are many comments that I would like to make but I'm sure I won't have time for all of them. Our interest in small focal spots started from our interest in getting better images for angiography and for radiology it. general. We started out with the first magnification tube capable of serial filming made in this country by Machlett back in 1966 and from that point recognized in the clinical setting the great value that magnification played in many different areas of clinical application. We constantly pushed for improvements in development in this area and this led to the development by Bill Holland of Machlett of the technique of biasing focal spots so that one could manipulate the distribution from standard line type focus double peaking distributions that we were used to looking at and that Dr. Milne and Dr. Doi brought to the attention of the radiology world was not an ideal way to image. With the use of the very versatile application of biasing we then looked toward what was the practical question and that was what type of outputs could we get from these small focal spots--because in the real world the factor that we have to deal with is motion, a fact that has only been alluded to in this conference very briefly, and I must say that the Japanese patients must be smaller than the American patients because with the focal spots of that size we could not begin to get stationary images at exposure times greater than 80 milliseconds.