Researchers at the Institute of Diagnostic, Interventional, and Pediatric Radiology at the University Hospital Bern in Switzerland have discovered that bone-suppression software from Riverain Technologies, Dayton, Ohio, is comparable to dual-energy subtraction (DES) in terms of its ability to detect lung nodules, while producing superior image quality.
In this retrospective study, three radiologists independently reviewed chest images of 143 patients: 101 patients with 155 lung nodules between 5 and 29 mm previously confirmed using CT, and 42 subjects with no lung nodules. Each radiologist marked suspected nodules on each patient’s original chest x-ray image and individually on DES and bone-suppressed images with and without computer-aided detection (CAD).
“We performed this study because we were interested in the diagnostic performance of the electronic bone suppression in side-by-side comparison with classic dual-energy subtraction for [chest x-rays],” said Zsolt Szucs-Farkas, MD, PhD, chief investigator on the study. Szucs-Farkas also was interested in finding out if CAD “provided any incremental value to the diagnosis of pulmonary nodules, and, if so, which images, non-subtracted classical [x-rays] or soft tissue images,” were preferable.
“Electronic bone suppression provides equivalent detection rates for lung nodules as DES, with better image quality, and might be a cost-effective alternative to DES chest radiography in the detection of lung nodules,” said Szucs-Farkas.
“We have no detailed data [on] why readers found image quality with electronic bone suppression significantly better than with dual-energy subtraction. I personally found margins of vascular structures [to be] sharper with electronic bone suppression compared with dual-energy subtraction,” he said.
New research shows that Riverain Technologies’ bone-suppression software with and without CAD is equivalent to DES imaging.
The research team at University Hospital Bern compared CAD markings before radiologist interpretation to the radiologist’s findings and determined that, while the CAD software and the radiologists detected many of the same lung nodules, each also detected nodules that the other didn’t find.
The results of Szucs-Farkas’ research are encouraging to Steve Worrell, chief technology officer at Riverain. “Working together, radiologists and our CAD with bone-suppression software bring different strengths to the table and significantly improve the detection of nodules that may be lung cancer by using conventional chest x-ray,” said Worrell.
This research is important, says Worrell, because the chest x-ray is the most common radiological exam and also serves as an integral part of surgery pre-op that is unrelated to lung cancer. “If you have the tools available to you for an incidental finding [of lung cancer], it’s a great opportunity to detect that cancer early—before a patient is symptomatic.
“Radiologists detected as many lung nodules using Riverain bone-suppression software on conventional x-ray images as they detected using a dedicated piece of imaging equipment that is more expensive, may expose patients to more radiation, and can be used only in the single location where it’s housed,” said Worrell.
According to Riverain, its ClearRead bone-suppression software uses machine-learning algorithms to transform any conventional chest x-ray image into an enhanced, soft-tissue image without the ribs and clavicles that sometimes obscure early lung cancer. The company’s CAD software, ClearRead+Detect, provides further support in decision making by circling suspicious areas on a bone-suppressed image that may be lung cancer, a final determination that will be made by a radiologist.
Worrell says that Riverain’s solutions require no software integration with PACS systems and can be deployed via a virtual machine or a virtual server. Further, he says that the applications themselves sit on the hospital network and the images are pushed to Riverain’s applications from a modality or from the hospital’s PACS system.
These bone-suppression software applications—both of which are FDA-approved and generally available since late 2010—immediately enhance any standard chest x-ray image, after capture, and can be used throughout entire health care systems without additional imaging equipment, staff, or space requirements, and without any additional tests or radiation dose for patients, according to the company.
