Medical imaging II

229 (i.e.,of the so-calledactiveapproach, using cast lightand a singlecamera) which were described at the meeting, were noteworthy because of theiruse exclusivelyof digitalrecording. If surface measuring techniques are to gain acceptance for the applicationsto which they are suited, it may be crucialto derive those resultswhich are of particular interestto the medical practitioner and to then present them in a most usable form. The significanceof attempts by Hierholzer and Drerup and by Turner-Smith and Thomas to deduce the required spinaldescriptors from back surface measurement should not be lost on the interestedphotogr-mmetrists. Significantalsowas the emphasis on means of displayingresults,discussedin a number of papers. This interestwas presumably generated by the complex 3D spatialnature of the resultsprovided by the newer measuring methods. A m o n g the users of photogrammetry, Adams and Kovdts in particularraisedthe question of the best method of presentingsurfacecoordinatesfor the medical practitioner. Attendees at the Biostereometricsmeeting had widely differingbackgrounds and interests,and a forum session would seem to be a valuable addition to the programme. For many photograrnmetrists,there may be some need to learn exactlywhat is wanted by the medical practitionerin order to decide how the photogrAmmetric experiencecan be most useful.Some discussiondid refer to the appropriate form of communication between the clinicianand the measurer, and it also became clearduring the meeting that the problem of presenting quantified 3D, and sometimes 4D, resultsto permit theirfulland accurateuse by the clinician,appeared as a perplexingquestion. A meeting such as thiscould provide a idealopportunity for a fulldiscussionof such matters. Copies of presented papers were not availableat the meeting and in factproceedings willnot be availableuntilsome fivemonths afterthe meeting. Fortunately,the majority of presentations (all in English) were of an excellentstandard, assistedas they were by the superb facilitiesand generous serviceofferedat the Hoffmann-LaRoche Congress Centre in Basel.The meeting proceeded with a minimum of fuss,and without ceremony. Sessions (which proceeded as closeto timetable as could be expected) were attended by only about 40 people on average. It was also unfortunate that, oftbe 52 papers listedin the program, some nine were not presented, (not always with prior advice), much to the annoyance of organisersand possiblyto attendees. The registrationfee of 280 Swiss francs included a reception and dinner party, but it did not include a copy of the proceedings. They willbe availablefrom SPIE, P.O. Box 10, Bellingham, Washington 98227-0010, USA, at a price of $US 68. Overall,the Meeting confirmed Baumann's introductory remarks that the Biostereometricsmeetings were typifiedby diversity,by informality and by variety among the attendees,their subjectsand their mathematical approaches. The next Biostereometricsmeeting is scheduled for 1991. H.L. Mitchell,Newcastle-Australia

Medical I m a g i n g II 31 January-5 February 1988, Newport Beach CA-USA The International Society for Optical Engineering (SPIE) sponsored this meeting. It was attended by about 500 scientists, engineers and medical professionals from a dozen or so countries. There were two poster exhibits, a technical exhibit and three receptions. The meeting began with discussions of magnetic, both nuclear resonant and bio, and acoustic imaging (sessions 1, 2 and 3). There is obviously a great deal more potential in these modalities and they continue to evolve rapidly. In many respects NMR and ultrasound are not yet up against fundamental SNR limits and large measures of progress are being achieved by exploiting increased understanding of the physics of the formation of these images and improvements in image acquisition technique and image processing. It was suggested to import the chirp technique from radar to ultrasonic imaging. Session 4 moved into a classic field for this conference, the physics and statistics of X-ray phosphors. The experience gained over the years in studying intensifying screens is now being

230 applied to the photostimulated, optically read phosphors. The competition between these two technologies is beginning to heat up. At the end of the first day, R.F. Wagner gave an excellent tutorial on the current understanding of the physics of ultrasound images and the interpretation of their statistics as indicators of tissue characteristics. Sessions 5, 6, 7 and 8 covered new work on the physics of radiographic systems for mammography and image intensifier based digital systems for fluoroscopy, radiography and tomography. Session 8 concluded with discussions of image reconstruction, and an introduction to the image processing discussions to follow. The formal presentations of the second day ended with a very successful tutorial on "Morphological Modeling Using Fractal Geometrics" by T.R. Nelson which set the stage for two papers in session 9 the following morning. The devotion of the attendees to their subject was attested by their enthusiasm for the first of our poster sessions which had 8 papers on image formation, 29 on image processing and 2 on medical photography and ended the second day. Fractals made their first appearance at the meeting this year with Nelson's tutorial and two papers in session. From the reception they received it is evident that we have not seen the last of them. The robustness of their encoding of physiological information in the work of Cargill et al was quite impressive. Sessions 10, 11 and 12 continued the image processing theme. The third day ended with a special early evening session on the Dutch PACS experience very nicely organized and presented by our good friends from the Netherlands. Session 13 on the morning of the fourth day ended the coverage of image processing for this year with applications in microscopy. Session 14 on digital medical photography ended the first section of the meeting, "Image Formation, Detection, Processing and Interpretation". The second section, "Image Data Management and Display", began with session 15 on image data compression. The last formal session of the day was number 16 on the display of digital images. The day concluded with a panel discussion on recent activities of the ACR-NEMA committee dealing with interfaces between PACS and HIS and RIS. The long relationship between this committee and the meeting has been of considerable benefit to the community. The first half of the fifth day, sessions 17 and 18 concluded the topic of display with discussions of performance evaluation and workstation design. The second half of the fifth day got into the full subject of PACS. The day concluded with the second poster session with 35 papers on digital image capture and formatting, digital image display PACS system design and evaluation and archives for PACS. The sixth day began with session 21 on PACS clinical experience. Session 22 reported experience with the ACR-NEMA interface standard and session 23, the last of the meeting dealt with archives for PACS. It is clear that the rate of development remains high in all aspects of medical imaging. It is heartening to see the serious and extensive application of science and sound engineering in a field so important to the public's well-being and the value and importance of the results as reported here. Proceedings are available from SPIE, P.O. Box 10, Bellingham, Washington 98227-0010 USA, at $165. The next meeting in this series will be Medical Imaging III, 29 January to 3 February 1989 in the same location. The society's telephone number is + 1-206-676 3290. The telex number is + 23-467 053. R.H. Schneider, Rockville, MD-USA