A Conversation with . . . David Naidich, MD, and Mark Wofford

CAD systems offer readers a second chance

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The syngo Lung CAD from Siemens can help a radiologist pinpoint possible abnormalities on a lung scan (note the small circle and No. 1). (Photo courtesy Siemens Healthcare.)

Mark Wofford is senior vice president of Siemens Healthcare in Malvern, Pa. (Photo courtesy Siemens Healthcare.)

Computer-aided detection systems (CAD) can have a positive impact on a clinician’s confidence during exam interpretations. Clinicians use CAD as a second reader tool to alert them to regions of interest that might have been missed. rt image talked to David Naidich, MD, and Mark Wofford about the importance of CAD systems, new developments, and how the Siemens syngo Lung CAD can help radiologists pinpoint possible abnormalities on a lung scan. Naidich is a professor of radiology in the department of radiology at New York University Medical Center in New York City. Mark Wofford is senior vice president of Siemens Healthcare in Malvern, Pa.

Q rt image: Why are CAD systems such an important part of the imaging review process?

A David Naidich: The use of CAD as a second reader improves detection of subtle lung nodules that might otherwise be overlooked.

Q image: What CAD system do you currently use and what are the primary benefits?

A Naidich: I currently use Siemens syngo Lung CAD with their syngo CAD Manager. (The CAD Manager is a non-medical software platform that supports various medical CAD algorithms.) The syngo CAD Manager provides seamless incorporation of a lung CAD detection system into routine PACS readings. Again, used as a second read, the simultaneous availability of routine CT images, along with lung CAD markings, has the advantage of increasing sensitivity for detecting nodules as well as improving confidence in the initial reading. 

Q image: How did you effectively integrate your CAD system into your existing workflow?

A Naidich: In addition to the benefits outlined above, we routinely use lung CAD markings in a PACS environment as a second read. They are immediately available, along with our routine reconstructed CT images for interpretation. As such, it has become a standard component of our everyday clinical CT workflow.

Q image: How did you ensure that all CAD users felt confident using the technology to aid diagnosis?

A Naidich: The interface with PACS is extremely straightforward. A series of images with CAD markings are available for interpretation and are readily scrolled sequentially. Advanced image analysis, including 3-D segmentation, volume rendering, and tools typically available on advanced workstations, are not part of this interface. This is essentially a minimalist approach, hence its ease of use.

Q image: Can you provide examples of how CAD technology has helped you deliver better care?

A Naidich: The only intent of a CAD system – at least as we are now using it – is to improve detection of small lung nodules that have been otherwise overlooked.

Q image: What is the single biggest benefit of incorporating CAD into any clinical workflow routine?

A Mark Wofford: CAD is able to positively impact the confidence of the clinician during exam interpretations. Clinicians use CAD as a second reader tool to alert them to regions of interest that might have been missed.

Q image: Where are most healthcare providers likely to incorporate CAD within their workflow today?

A Wofford: Among the areas where CAD is utilized, mammography CAD has evolved the most significantly and many providers incorporate CAD into their workflow today. Screening mammography is consistently growing, and clinicians benefit from tools such as CAD that streamline the reading workflow.

Q image: Where could CAD be utilized more and what's preventing this type of progress from occurring?

A Wofford: In clinical practice, hundreds of images are acquired during a diagnostic CT examination of the lungs, which could benefit from additional use of CAD. Seamless integration into the clinical workflow is key and until recently, CT lung CAD has primarily been available only on specialty workstations that are not well integrated into the PACS reading workflow. Siemens introduced syngo CAD Manager with syngo Lung CAD to allow an easier and efficient integration of CAD into the PACS reading workflow.

Q image: Are there any compatibility issues among current CAD systems?

A Wofford: In an imaging environment, CAD products should help give clinicians the freedom to benefit from enhanced workflow. In order to accomplish this, a CAD system needs to be tested for compatibility in two key areas.

One, the input data processed by CAD needs to be tested with the relevant image acquisition parameters. And two, the CAD output must be tested for compatibility with the display workstations on which the radiologist will review results.

Q image: What types of platforms or multisystem platforms do Siemens CAD systems work on?

A Wofford: Siemens CAD solutions are available on multiple platforms for flexible and convenient workflow options, so clients may choose the most suitable solution for their practice. For example, syngo Lung CAD is available on the syngo MultiModality Workplace for use with the syngo-based CT oncology application. It is also available on syngo CAD Manager for use in the PACS reading workflow.

Q image: What standards should all CAD systems adhere to?

A Wofford: All CAD manufacturers strive to produce quality CAD products that enhance the reading workflow. The validation of clinical benefits for a CAD product is the most important factor. The syngo Lung CAD has been clinically validated in one of the largest multi-case, multi-reader clinical studies for the use of CAD in thoracic CT. (The clinical data has been submitted to the FDA.)

The study showed that the syngo Lung CAD leads to increased accuracy to detect clinically significant lung nodules. All 17 readers significantly improved their detection accuracy with syngo Lung CAD as a second reader. The average area under the receiver operating characteristic curve increased from 0.783 to 0.821 (p < 0.001).

Q image: What’s on the horizon for CAD technology?

A Wofford: There are still tremendous opportunities for innovation in the area of CAD regarding algorithms as well as efficient deployment of CAD in the clinical workflow.

For example, Siemens recently launched a new deployment strategy for CAD at the 2010 European Congress of Radiology conference in Vienna. The syngo CXR CAD Subscription (which is not currently available in the United States) utilizes a “software as a service” model. Using cloud computing to further streamline the workflow, syngo CXR CAD Subscription eliminates significant on-site hardware requirements and provides more frequently updated CAD algorithms to users. At some point we believe many CAD algorithms will be deployed in a similar fashion.

Edited by Scott Huelskamp. Direct comments and questions to editorial@rt-image.com.