O btaining high-quality 35-mm slide reproductions of black-and-white diagnostic images quickly, easily, and inexpensively is a goal shared by most lecturing radiologists. Several approaches have been described. Traditionally, Kodak Rapid Process Copy Film (Eastman Kodak, Rochester, NY) has been used for this purpose. This film offers the advantages of adequate grayscale display, rapid processing in a readily accessible radiology processor, and low cost. The long exposure times and copy stand required, the uncertainty about exposure parameters often requiring “bracketing,” and the need to manually develop, trim, and mount the slides make this method time-consuming and cumbersome. Polaroid’ s 35-mm black-andwhite slide film (PolaPan 35-mm instant black-and white-slide film; Polaroid, Cambridge, MA) would appear to be an attractive option, but the slides also require manual developing, trimming, and mounting, and they are easily damaged during handling. Companies providing specialized black-and-white film and processing for radiograph reproduction offer the advantage of convenience but the drawbacks of greater expense and turnaround time. Use of color slide film is appealing for a number of reasons. Film may be processed in as little as 3 hr, is widely available and relatively inexpensive, renders a copy stand unnecessary, and allows reproduction of color images (Doppler sonography, single-photon emission computed tomography nuclear medicine, textbook or journal articles, and illustrations), which is increasingly prevalent. Furthermore, the same roll of film may be used for both personal and professional purposes. Several approaches described in the literature require a custom-made incandescent viewbox [1], use of specialized bulbs in a standard viewbox [2], or variable filtration requiring exposure of a test roll to use available light sources [3]. Because of these limitations, we sought to develop a standardized photographic technique suitable for use with viewboxes typically found in radiology departments. We explored several film and filtering combinations and found one that produces highquality results with various standard viewboxes in our department. Ektachrome 400 color slide film (Eastman Kodak) exposed with a macro lens/three-filter combination (FLD, 8lB, and 8 12; Tiffen Manufacturing, Hauppauge, NY), f-stop compensation of plus one, and exposure time of 1/60th of a second or longer has yielded slides whose sharpness, contrast, gray scale, and light balance are consistently excellent. Viewbox brightness should be confirmed by a light meter to fall within the 350to 900candela range. The total cost of the three filters is less than $40 and the light meter costs approximately $20. A residual blue-green cast is present with use of the FLD filter alone. The addition of the other two filters effectively eliminates this blue-green overtone. The plus-one f-stop compensation, although not essential, ensures adequate light balance in virtually all cases, particularly with darker imaging studies such as CT, sonography, and MR imaging. The minimum 1/60th of a second exposure time prevents fluorescent cycling artifact (gold horizontal bar): in practice, 1/60th of a second time is usable for nearly all except very dark originals, which require slightly longer times. Casual hand-held exposure directly from the viewbox is adequate to produce slides free of motion artifact. Our apertures range from 12.5 to fl 1 and average f3.5/f4. Color images on paper (Doppler sonography and single-photon emission computed tomography nuclear medicine) are conveniently photographed under daylight or incandescent light with an 8 lB (yellow) filter. Our success rate with this approach has been greater than 95%, and bracketing exposures has not been necessary. Although similar results can be obtained with Kodachrome 200 slide film (Eastman Kodak) and the same filtering combination, we have found no benefit, and several drawbacks to its use include loss of one f stop, decreased availability of film and processing, and longer processing turnaround time (generally at least 3 days). We have described a method of producing consistently high-quality slides of black-andwhite diagnostic images that is easy-to-use, rapid, convenient, and inexpensive. We believe this technique is superior in these respects to the available alternatives and provides the additional advantage of allowing slide reproduction of color images.
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Dec 23, 2003
M Vanrell + 4
Open Access