dc.description.abstracten |
Accurate nodule detection in computed tomography (CT) scans is an essential
step in the early diagnosis of lung cancer. Radiologists often use Computer-aided
detection (CAD) systems to receive a second opinion during images examination.
Nodule classification is a crucial stage of the full process, which comes as the second
phase in a CAD system, right after candidates detection. Its task is to distinguish
between true nodules and false positives.
The main goal of this thesis was to compare different deep learning methods,
that can be used for nodule classification by evaluating their efficiency on a common
database - LIDC-IDRI. We implemented three neural networks with 2-D convolution
and three with 3-D, tested their performance and reported competitive FROC sensi-
tivity scores. Used methods are compared among themselves and across other stud-
ies. Experimental results demonstrate a strong dependence between higher scores
and 3-D CNNs application. For instance, VGGNet-11 gives 72.1% sensitivity at 8
FPs/scan, while same model with three dimensional convolution - VGGNet-11 3-D
produces 91.9% at 8 FPs/scan rate. Based on the obtained results we recommend to
use VGGNet-11 3-D for nodule detection, as it showed the best performance com-
pared to other implemented methods. Moreover, received sensitivity of 91.9% at 8
FPs/scan and 90.6% at 4 FPs/scan rate demonstrates the promise of chosen network
and its competitiveness with the state of the art method, which reported 92.2% at 8
FPs/scan and 90.7% at 4 FPs/scan. Our source code 1
is publicly available so it can
be used for future work in other studies. |
uk |