Whoever expects automatic assembly lines, robots or other wonders of modern engineering will be disappointed when entering the production halls of the Siemens concern north of Chicago: Manual labor dominates the manufacture of capital devices such as CT, PET or SPECT at Siemens the same as at any other manufacturer of such products.
Medical imaging: The trend goes towards second modality
What Siemens technicians screw together in Chicago are mainly SPECT devices and PET scanners. Those are mainly manufactured as half tubes today. At the customer's, they are assembled accurately to a computer tomography which was carted there coming from Germany. In the end stands the PET/CT or SPECT/CT, machines combining the advantages of functional nuclear medical diagnostics with the superior display of computer tomography. "The introduction of the PET/CT caused the market of independent PET devices to literally collapse" says Wilfried Löffler, Vice President of the Molecular Imaging Group of Siemens Medical Solutions.
Today, no PET scanners to speak of are delivered without CT. About a fifth of the devices are a combination with CT tubes. The reason for that difference: SPECT devices are a whole lot cheaper than PET scanners. And the price difference between SPECT and SPECT/CT is accordingly larger than between PET and PET/CT. Nonetheless: The combination devices are coming.
PET beards the magnet-lion in his den
Just one front was really quiet: The combination between magnetic resonance imaging (MRI) and PET did only exist on the wish list of passionate diagnosticians, but not in the real world. "Common PET systems just don't function within the magnetic fields of an MR device", explains Löffler. An obstacle tough to clear. But now everything is supposed to change: Siemens is talking about "a turning point in diagnostics and therapy for millions of patients" during the presentation of the worldwide first prototype of a PET/MRI. The dream machine was developed with the energetic aid of physicians at the universities of Tennessee and Tübingen.
To get around the problem with the magnetic fields, a new type of photo diodes is being used in the PET component which was mainly used in laser physics so far. The marriage between the PET and a 3-Tesla MRI made sure that there was no doubt about it that a high tech device is planned. Nonetheless – the project is not ready for commercialization: "It will take a few more years until serial production", Löffler carefully estimates.
One man's meat is another man's poison…
Until then the machine will be checked and tested in great detail. Mainly neurologists are highly delighted with the possibilities. Up to now they were able to separate easy cognitive deficits from Alzheimer-Dementia with the PET. And they were able to identify the brain volume very precisely with MRI thus gaining evidence of a developing brain atrophy. The PET/MRI can do those tests all in one go, which makes the early detection of Alzheimer a whole lot easier. The PET/MRI could be a show-stopper in stem cell research as well: Since it enables anatomic and functional measuring in a high resolution yet unknown, the migration of therapeutically used or also body's-own stem cells, could be observed practically in real time – a most fascinating perspective.
If all this is designed to make medicine more favourable long-term – as Siemens Medical Chief Erich Reinhardt never tires to tell – has to prove yet. For now the health systems of several countries are fighting with the PET/CT regarding diagnostics since it has set new standards for costs of device as well as shot. The health insurance companies therefore will not be ungrateful for a device foreseen to create new costs records to take just a little bit longer to conquer the market.