Want a second opinion? Ask the computer
New mammography CAD software supports diagnosis
Radiologists frequently have limited time when examining mammography images, especially under screening conditions. In addition to their training and experience, the computer can offer beneficial support in the detection of breast cancer, due to special Computer Aided Detection (CAD) software solutions
At RSNA 2007, Daniela Zimmermann of European Hospital spoke with Ram Balasubramanian (RB) (left), Carestream Health’s CAD Business Manager for Europe, the Middle East and Africa, who presented the company’s latest equipment designed for digital mammography.
The target customers for the Kodak Digital Mammography CAD System are mainly screening centres with a high daily patient flow, explained Ram Balasubramanian. Using the system they capture the images from their digital mammography systems. Soon, he added, they will be able to do this not only from the Kodak CR but also from other companies’ FFDM systems. ‘We’ve installed units in five countries since October, and have received only positive feedback. All units are implemented in combination with a separate computer to process the images with algorithms and generate a CAD report, which is then sent to the workstation. This report consists of a small file that provides information about where suspicious areas are located, the type of cancers detected and the position of those cancers. All this information can be matched with the images acquired, so the CAD mats overlay the images and show where the cancer could be. The mammography CAD can detect densities, architectural distortion and clusters of micro calcification and give doctors a second chance to review those suspicious areas.’
DZ: Could the CAD for mammography seduce a physician into relying on those results without examining the images themselves — is that a danger?
RB: No, our system should be seen as a second opinion. The doctor still goes through the read as normal the first time, but CAD offers the opportunity for a second read and therefore a chance for the doctor to return to suspicious areas. For example, if there is calcification, the CAD indicates where it is and the doctor can say: “I have already seen it”. Or it might happen that the physician missed it, but has the opportunity to go back and double check.
Actually, studies showed that radiologists have a sensitivity between 60-80%, which means that between 40-20% of cancers will remain undetected. It’s not because radiologists are insufficiently trained, but because they have to read the images very quickly and some lesions are very subtly presented. CAD is a tool that supports the doctor; it does not deliver a diagnosis. Studies confirm that CAD could significantly increase sensitivity, even if there are two doctors reading the mammograms, by up to 20%.
Carestream Health is not the only firm to offer such a CAD solution. What makes your system different?
The radiologist often only looks at the CAD mats, but what makes the difference is the performance and database. We have over 1,000 CR mammography systems installed around the world, so have had the opportunity to collect a lot of data for our CAD and we receive considerable feedback from our customers on how to improve our CAD algorithms. We also reinforce our team of image capture scientists with our CAD algorithm developers to create a fully integrated mammography CAD algorithm. The other advantage that Carestream Health can provide is our service and support, particularly in Europe, where we have a large and dedicated support organisation that smaller CAD vendors have difficulty matching.
Due to its apparently greater accuracy than digital mammography, MR Mammography is increasingly discussed. Is this a strong competitor against your solutions?
MR sensitivity seems to be higher, but X-ray is still the standard of care, primarily because of cost. So, in my opinion, MR will remain a follow-up examination and not replace X-ray, especially for screening.