title: An automated method for the detection of pulmonary embolism in V/Q-scans.
abstract: In this paper, a fully automatic method for the diagnosis of pulmonary embolism (PE) from V/Q-scans is presented. Image analysis is applied to the ventilation and the perfusion images obtained in the V/Q-scan. The difference of the ventilation and the perfusion is calculated after transformation and hot-spot reduction of the images. From this difference image the integral of the underperfused areas are used as features. With the aid of these features a simple test for PE is devised. The method is evaluated on two sets of patients. One set comprises 102 patients who have undergone both V/Q-scanning and angiography. The performance given as the area under the Receiver Operating Characteristic (ROC) curve is 0.85. Another set is made up by the 507 consecutive patients examined with V/Q-scanning at Lund University Hospital in Sweden. In this case, the reference was the consensus opinion of two radiologists, the ROC-area is 0.67. A fully automatic and reasonably robust expert system is developed to aid the radiologist in the interpretation of V/Q-scans for PE.
authors.affiliation: Center for Mathematical Sciences, Mathematical Statistics, Lund University, Box 118, SE-221 00 Lund, Sweden. attila@maths.lth.se
authors.forename: Attila
authors.initials: A
authors.lastname: Frigyesi
mesh_terms: D000465:Algorithms; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D010363:Pattern Recognition, Automated; D011655:Pulmonary Embolism / Q000145:classification / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011786:Quality Control; D011859:Radiography; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013668:Technetium Tc 99m Aggregated Albumin; D016284:Technetium Tc 99m Pentetate; D014692:Ventilation-Perfusion Ratio
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D016284:Technetium Tc 99m Pentetate