OPINION Don't start the revolution without us ! Russell Whitehorn MBBCh, FFRad(D)(SA) Bortz, Lake and Partners, Durban M any who are shopping for a new com- puter face a dilemma - they would like one that does less than those offered, The prospec- tive buyer may simply want to write letters. He finds computers and software that enable him to author books and multimedia publica- tions. Of course, you don't have to use all the features and power of your computer and soft- ware, but nobody likes to buy a loaf of bread and eat only a slice. The computer industry recognises this problem. Huge software "suites" that can do more than the average user can imagine let alone want have been dubbed "bloatware". There has been intense recent interest in so- called "Internet machines". These are low-price, stripped down computers that have one main purpose - to connect to the Internet. They will, by today's elevated standards, have slow proc- essors and little memory. The user who wants to use this computer for a particular task will pull the relevant program off the Internet, use it for that specific task and discard it. Instead of storing large volumes of data on your own computer it is proposed that servers, accessed over the Internet, be used. Some problems contain the seeds of their own solution. This is a solution that contains the seeds of its own problem. Anyone that has used the Internet knows that "Netsurfing" is a misnomer - "Webcrawling" is a far more ap- propriate metaphor. This modern version of the server/dumb terminal concept may work in a fast local network situation but the cur- rent speed of Internet traffic makes it a dubi- ous starter in this context. The modern standalone desktop computer is immensely powerful, and is becoming increasingly afford- able and easy to use. Communication between computers on opposite sides of a city, country or the world is also improving in many ways. Modern software facilitates the connecting of computers and the exchange of information. Finland has the most advanced telecommuni- cations infrastructure in the world, having had a high speed ATM (Asynchronous Transfer Mode) backbone in place for two years while most other countries are still talking about the technology. The Finns were also the first to have a GSM network - in 1991. It is of inter- est to note that Finland has always had an un- regulated telecommunications market. As Vin- cent Schmidt of ADC Telecommunications has said regarding the shortage of bandwidth for the Information Highway, u ... these prob- lems will be solved. If there is a path to money, people will find it.". However more immediate, urgent and rel- evant other demands on the South African public purse appear, neglecting our onramp to the Information Superhighway will so weaken our competitiveness as a nation that the mouths we so justifiably want to feed now will simply be replaced by a greater number in the future and a spiralling descent into third- worldness will become unstoppable. You may well ask, "What has all of this to do with Radiology?" I believe that medicine in general and radiology in particular are ex- cellent examples of the need for affordable fast data communication. As we stare, like startled rabbits, into the oncoming headlights of %7 SA JOURNAL OF RADIOLOGY· September 1996 managed health care those of us in private prac- tice realise that increased efficiency and the pursuit of new markets is essential. I'm sure we all hate the cold business-like ring of that, but it appears that we are no longer going to be able to avoid being businessmen. High qual- ity teleradiology is one of the tools we can use in this regard. I stress high quality. If images are to be reported on via teleradiology, with- out subsequent review of the films, meticu- lous attention to quality and adherence to the emerging standards is required. Unless the source venue is of low volume or there is ac- ceptance of long turnaround times mainte- nance of quality will generally require greater bandwidth than telephone lines and modems can provide. For moderate volumes BRI ISDN may be the answer, if you can get it. Over short distances the cost of a dedicated, leased diginet line may be justifiable. However there is no currently acceptable solution for reporting films taken in remote areas. Reducing band- width requirements by decreasing the resolu- tion or colour depth (bits per pixel) is fraught with danger. Compression up to some as yet undetermined point is probably OK but re- member there is no such thing as a free lunch or even an inexpensive byte. For those with Internet access and who would like to see what the World Wide Web has to offer radiologists a good starting point would be the RSNA's Web site at: http://www.rsna .org/rsnahome.html You'll find information about courses and congresses as well as the RSNA's teaching re- sources. There are also many links to other use- ful Web sites. Another excellent site to find good radiology links is at Emory's Weblink: http://www.gen .emory.edu/medweb/ medweb.radiology.html One of the best destinations I have come across is the University of Iowa's Virtual Hos- pital. The radiology page is at: http://indy. radiology. uiowa .edu/Providers/ ProviderDept/lnfoByDept.Rad.html topage28 http://www.gen Don't start the revolution vvithout us ! (rom page 27 Don't let these daunting addresses fool you into thinking you can cancel your journal subscriptions and sell your Radiology text- books yet. Only the foundations of the Infor- mation Highway are currently under construc- tion, Information is still very patchy and var- ies from excellent to non-existent. The 'Net gives you a peep into the future rather than a currently dependable source of information, Relevant Usenet newsgroups are: alt.image.medical sci.med.radiology sci.med.telernedicine comp, protocols, dicom The computer revolution that has swept the world over the last two decades has been manic in its pace, Even in this high speed context the current construction of the "Infobahn" is frenetic, The World Wide Web is said to grow at 50 per cent per month, Microsoft reportedly has more people work- ing on Internet products than on any other single project. The huge profits realised by Internet entrepreneurs has lead to the claim that it is the last gold rush of the millennium, In the words of Bill Gates, CEO of Microsoft, "We are watching something historic happen, and it will affect the world seismically, rock- ing us the same way the discovery of the sci- entific method, the invention of printing, and the arrival of the industrial age did.. The high- way is going to happen," It's up to us to make sure we're not stranded on a sideroad. Intraoperative digital subtraction angiography in neurovascular disorders (rompage 25 angiography), Martin et al reported close correlation between intraoperative and postoperative angiograms in their series.' There were three false negative intraoperative angiograms in 66 patients (2 residual aneurysm necks and a small re- sidual thalamicAVM) ,We did not perform postoperative angiography to correlate with the intraoperative angiographic findings, It is well recognised amongst neurosurgeons that the successful treat- ment of intracranial aneurysms andAVMs is dependent on complete obliteration, Postoperative angiograms are performed routinely in some units following aneurysm clipping, In a series of7lS cases Fuerberg et al found a residual aneurysm neck in 3,8% of cases,4 Lin et al documented regrowth of aneurysms from residual necks in 19 cases' Fourteen of these cases presented with a rebleed at an average interval of nine years from clipping, Intraoperative angiography enables the surgeon to identify and correct any incompletely treated lesions under the same anaesthetic. It has also been suggested that the immediate availability of intraoperative angiography allows the sur- geon to access the extent of resection of an AVM at any stage and therefore avoid ex- cessive resection that may include normal brain and nutrient arteries." It is well docu- mented that normal arteries can also be in- advertently occluded by aneurysm clips,3,6,7 Immediate recognition of this may prevent infarction, We have found intraoperative angiograms useful in patients presenting with nontraumatic subdural haemorrhage and nonhypertensive intracerebral haemor- rhage who are acutely deteriorating second- ary to mass effect, An angiogram in theatre allows the surgeon to identify and treat any underlying aneurysm or AVM, Intraoperative angiography is particularly useful in the management of mycotic aneu- rysms for several reasons, Surgicallocalisa- tion may be extremely difficult as they are commonly situated on a peripheral vessel and are hidden away in a sulcus, These an- eurysms can spontaneously thrombose or appear at new sites on the cerebral vasculature. 8,9Theintraoperative angiogram allows the confirmation of aneurysms about to be clipped, identifies new ones that may have formed since the last angiogram and helps localise them by using radio-opaque markers. We have also found intraoperative angiography valuable in localising and man- aging traumatic false aneurysms and fistulae 28 SAJOURNAL OF RADIOLOGY· September 1996 If attempted endovascular occlusion of a carotid cavernous fistula is unsuccessful, an intraoperative angiogram is invaluable in ensur- ing that surgical packing of the cavemous sinus has successfullyoccluded the fistula, Conclusion In our series 29% of the angiograms per- formed revealed findings which altered the surgical procedure in some way,We recom- mend the use of intraoperative digital subtrac- tion angiography in any neurovascular proce- dure where the technical result is going to be difficult to assessintraoperatively, References 1. Hieshima CB, Reicher MA, Higashida RT, et al.lntraoperative digital subtraction neuroangiography: a diagnostic and therapeu- tic tool. AlNR 1987;8:759-767. 2. Foley KT, Cahan LD and Hieshima CB. Intraoperative angiography using a portable digital subtraction unit.] Neurosurg 1986;64:81&818. 3. Martin NA, Bentson J,Vinuela F,er al.lntraoperative digital sub- traction angiography and the surgical treatment of intracranial aneurysms and vascular malfonnations.] Neurosurg. 1990; 73:526- 533. 4. Fuerberg I, Lindqvist C, Lindqvist M and Steiner L. Natural his- tory of postoperative aneurysm rests.] Neurosurg 1987;66:30-34. 5. Lin 1; FoxAJ and Drake CG. Regrowth of aneurysm sacs from residual neck following aneurysm clipping. ] Neurosurg 1989;70:556-560. 6. Barrow DL, Boyer KL and Joseph CJ. Intraoperative angiography in the management of neurovascular disorders. Neu- 7tl