An Automated Method for the Detection of Pulmonary Embolism in V/Q-scans
Centre for Mathematical Sciences
Lund Institute of Technology,
In this paper a fully automatic method for the diagnosis of pulmonary embolism
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 warping 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 we define a simple
test for pulmonary embolism.
Our 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 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, were the reference was the consensus opinion of two
radiologists, the ROC-area is 0.67.
Thus we have developed a fully automatic and robust expert system to aid
the radiologist in the interpretation of V/Q-scans for pulmonary embolism.
Pulmonary Embolism, V/Q-scan, Image Analysis, Hot-spots, erosion, opening,