When worlds collide for the better

January 30, 2007

We are at this moment witnessing the ground being laid for an evolutionary leap in medical disciplines: the union of radiology and pathology. A transformation of radiology far beyond the boundaries that now define this discipline is leading inexorably to the end of medical imaging as we know it.

We are at this moment witnessing the ground being laid for an evolutionary leap in medical disciplines: the union of radiology and pathology. A transformation of radiology far beyond the boundaries that now define this discipline is leading inexorably to the end of medical imaging as we know it.

These two disciplines, now distinct and medical worlds apart, will be drawn together by developments in molecular diagnostics. Their common ground will be the foundation being poured by the discovery of molecular biomarkers of disease. These are showing up in dribs and drabs in medical journals and scientific presentations as indicators of Alzheimer's disease, cancers, heart disease, and HIV.

Their significance is seen alternately as too little or too great, viewed as an individual achievement or as the harbinger of a new age of personalized medicine that is too grand to believe. But it's not idealism that will drive the transformation of radiology and pathology, not altruism that will make personalized medicine a reality. It is hard, cold economic sense.

Tools that make medicine cheaper, faster, and better are on the rise. Insurance companies want these tools, they want preventive medicine, but they will have it only if the early signs of disease can be found cost-effectively. That is why molecular diagnostics will take hold and radiology and pathology will join together.

Radiology will not morph into this new discipline on the wings of molecular imaging. It will become a part of molecular diagnostics, a subdiscipline of equal and complementary nature to pathology. The two will be different sides of the same coin. They will share the same cornerstone, the biomarker.

In vitro, the biomarker will drive the lab on a chip (LOC). This handheld microminiaturized bioassay detects the biomolecular indicators of disease. In vivo, the biomarker will guide the targeted contrast agent, visualizing and quantifying the extent of disease.

Radiology and pathology will share the same objectives: to illuminate diseases before they become symptomatic and to track the effectiveness of therapies. They will come from the same research, studies aimed at identifying molecules specific for disease indicators. They will be performed in the same place - molecular diagnostic centers that perform the right test for the right job - in vitro, in vivo, or both.

Clinical IT will unite radiology and pathology with information sharing, first between imaging centers and pathology labs, forging alliances that lead to consolidations and, ultimately, one-stop diagnostic shops that will cement the merger.

Some might see separate and distinct roles for in vitro and in vivo products: LOCs that screen for disease and contrast agents that determine the stage of the disease or response to therapy, respectively. That might be how it starts, but it won't stay that way.

Some LOCs will screen for some types of disease, and some in vivo agents will screen for others. Either or both will follow the progression of the disease in patients and their response to therapy. The distinction will be in the biomarker and in the character of the disease.

An example comes from New York City's Mount Sinai Hospital and its collaborators, who are developing an in vivo MR agent that indicates the presence of macrophages in arterial walls. This presence indicates the kind of inflammation that causes atherosclerotic plaque, which can trigger a heart attack or stroke if it becomes unstable, the researchers said. Animal studies suggest that such a targeted contrast agent might identify patients prone to develop acute coronary syndromes or at risk of sudden death or myocardial infarction. Such a screening test cannot be done in vitro.

Siemens and GE already have recognized the potential synergies of in vitro and in vivo diagnostics. They are spending billions to bring them together through corporate deals. GE's deal to acquire much of Abbott's diagnostics business is pending, and Siemens has completed mergers with Bayer Diagnostics and Diagnostics Product Corporation. In vitro and in vivo businesses will be separate, yet each will benefit from economies of scale, one building on the accomplishments of the other.

The common ground for R&D is set. The corporate mergers are taking place. Macroeconomics is pushing medicine toward prevention. The need for efficiency and cost-effectiveness will draw together the use of imaging agents with in vitro diagnostics, just as IT will serve as the catalyst for their use in medical practice.

But unlike the clashes and turf battles that have characterized meetings between radiology and other disciplines, this will be a friendly and gradual coming together. Radiologists and pathologists will find themselves working together as a natural consequence of mutual interests and needs. The evolutionary change will be complete when specialists in medical imaging and in pathology are trained in molecular diagnostics, engage in synergistic practices at molecular diagnostic centers, and consult on patient cases.

Then the union of radiology and pathology will be done, the practice of medicine will be forever changed, and personalized medicine will be a reality.