Digital X-Ray is as Effective as Lung Ventilation Perfusion in Detecting CTEPH

Konica Minolta Healthcare Americas Inc. is sharing study results that found Dynamic Digital Radiography (DDR) of the chest (a.k.a., DCR) is as effective as lung ventilation perfusion (V/Q) in detecting chronic thromboembolic pulmonary hypertension (CTEPH). In addition, DDR was performed without the need for contrast media and at a significantly lower radiation dose to the patient, approximately one-tenth of lung V/Q scintigraphy. The study by lead author Yuzo Yamasaki, M.D., Ph.D., from Kyushu University (Fukuoka, Japan), was published in Radiology, the scientific journal of the Radiological Society of North America.
 
Dynamic Digital Radiography is a radiographic technique that provides a series of individual digital X-ray images acquired at high speed and low radiation dose. These images provide a diagnostic-quality view of anatomical structures in motion and the ability to visualize the dynamic interaction with physiological changes over time. DDR provides enriched radiographic information and enhanced diagnostic capabilities such as the ability to visualize pulmonary hemodynamics without contrast media, which is the subject of this research. CTEPH is a complication of pulmonary embolism and a significant cause of pulmonary hypertension with associated morbidity and mortality if left untreated. As a potentially treatable cause of pulmonary hypertension, identification of CTEPH with imaging may significantly impact clinical outcomes of patients with this condition.
 
In this retrospective study, 50 patients with pulmonary hypertension diagnosed via right heart catheterization and invasive pulmonary angiography underwent dynamic X-ray imaging, with seven to 10 seconds of inspiratory breath holding, using a Konica Minolta AeroDR HD flat panel detector and pulsed X-ray system (RADspeed Pro, Shimadzu). Each patient also had conventional chest radiography and underwent a lung V/Q study on a SPECT/CT system with intravenous injection of technetium-99m macroaggregated albumin, 185 MBq. Of the 50 patients, 29 met the World Health Organization (WHO) criteria for CTEPH and 21 were classified as non-CTEPH.
 
Yamasaki and co-authors reported similar sensitivity and diagnostic accuracy of DDR (97% and 92%, respectively) compared to V/Q (100% and 94%, respectively) with the same specificity (86%). The agreement between DDR and V/Q interpretations was substantial (κ = 0.79 [95% CI: 0.61, 0.96] percent agreement=0.9 [95% CI: 0.79, 0.95]) and the interobserver agreements for both DDR and V/Q scans (κ = 0.71 and κ = 0.73, respectively) were also significant. Two chest radiologists evaluated the DDR images and two nuclear medicine physicians evaluated the V/Q data.
 
Although an early CTEPH diganosis is important for better patient outcomes, V/Q scanning is underused and there is a clinical need for an easy, noninvasive screening method, the study authors noted. Compared to other modalities, including dual-energy CT and MRI, the authors discovered that DDR has several advantages, including low radiation dose and no contrast media or radionuclides. Additionally, both dual-energy CT and MRI are more technically challenging, more expensive, have limited availability, and lack multicenter validation. The authors concluded that DDR “may be a low-cost alternative to V/Q scanning for the diagnosis of this disease,” and they said the DDR system can also be used as a conventional X-ray system and installed in a smaller space than what is needed for a SPECT/CT system.
 
In an accompanying editorial, John C. Wandtke, M.D., professor, and Katherine Kaproth-Joslin, M.D., Ph.D., Department of Imaging Sciences, University of Rochester Medical Center, identified a major advantage—the radiation dose is approximately one-tenth that of lung V/Q scintigraphy, one-twentieth that of standard CT pulmonary angiography, and one-fifth that of low-dose CT pulmonary angiography. The authors further highlight the clinical value of DDR for CTEPH. They said DDR may be a reliable alternative to contrast- and radionuclide-enhanced imaging methods and it “appears to represent an innovative method for fast and cost-effective screening of patients for CTEPH.”
 
“The ability to visualize pulmonary hemodynamics without contrast using images acquired with standard X-ray systems is groundbreaking. This is another step in realizing our vision of contributing to life changing advances by transforming primary imaging,” said Kirsten Doerfert, senior vice president of Marketing, Konica Minolta Healthcare.
 
Konica Minolta Healthcare provides and markets medical diagnostic imaging and healthcare information technology. Primary imaging, the most commonly used medical imaging technologies, include X-ray, ultrasound and imaging management systems. With nearly 150 years of endless innovation, imaging is in Konica Minolta’s DNA. From roots as a camera and film manufacturer, the company has cultivated its own technologies and continues to evolve techniques for visualizing what is not visible. Konica Minolta Healthcare Americas Inc., headquartered in Wayne, N.J., is a division of Konica Minolta Inc.