New Non-Invasive Method In Lung Diagnostics

magnetic resonance imaging (MRI) as a non-invasive diagnostic method has been evolving into an attractive alternative to methods which are associated with radiation exposure. This development now also starts to manifest itself in lung perfusion imaging. This was reported by Dr. Christian Fink and colleagues of the Radiology Division of the Deutsches Krebsforschungszentrum (German Cancer Research Center) in a recent issue of the journal Radiology*.

Diagnosis of numerous diseases of the lungs requires precise imaging of lung perfusion. The standard method used is called perfusion scintigraphy. It involves injecting a radioactive substance into a patient’s bloodstream and then making a scan of its distribution in the lungs. An equally precise and absolutely radiation-free method for evaluating lung perfusion now turns out to be magnetic resonance imaging (MRI, also called nuclear magnetic resonance (NMR) scan).

In a comparative study of 7 healthy probands and 20 patients with suspected lung cancer, the researchers compared magnetic resonance imaging to the standard method of perfusion scintigraphy. MRI showed a higher temporal and spatial resolution in lung perfusion imaging and provides the additional advantage of three-dimensional image data, which makes it easier to recognize blood circulation changes. Perfusion defects caused by tumors were recognized with high accuracy. In direct comparison with the standard method, MRI was found to be at least equally good.

It is too early yet for MRI to become a routine clinical method of lung perfusion imaging. The value of the new method first needs to be assessed in larger studies. But the investigators are optimistic that the radiation-free option may turn into the method of choice: “Image resolution in MRI is about twice as high as in perfusion scintigraphy so that we expect a higher detail precision compared to the standard method”, says Fink. Alongside evaluation of perfusion, MRI also provides additional information, e.g. about the anatomy of blood vessels in the lungs and the temporal process of lung perfusion. Thus, it provides insight about both vessel organization and function of blood circulation down to the tiniest branches of the lungs.

The method can be used not only in diagnostics and surgery planning for lung tumor patients. It may in future also be beneficial in non-invasive diagnostics of other lung diseases such as pulmonary embolism, emphysema, and chronic bronchitis. Presently, however, MRI is substantially more expensive than the standard method (approx. 300 euros versus 75 euros per examination), since the remuneration system does not yet take adequate account of innovative methods of this kind.

The task of the Deutsches Krebsforschungszentrum in Heidelberg (German Cancer Research Center, DKFZ) is to systematically investigate the mechanisms of cancer development and to identify cancer risk factors. The results of this basic research are expected to lead to new approaches in the prevention, diagnosis, and treatment of cancer. The Center is financed to 90 percent by the Federal Ministry of Education and Research (BMBF) and to 10 percent by the State of Baden-Wuerttemberg. It is a member of the Helmholtz Association of National Research Centers (Helmholtz-Gemeinschaft Deutscher Forschungszentren e.V., HGF).