| Title: | Role of ventilation scintigraphy in diagnosis of acute pulmonary embolism. An evaluation using artificial neural networks |
| Fulltext: |  |
| Authors: | Evander, Eva and Holst, Holger and Järund, Andreas and Ohlsson, Mattias and Wollmer, Per and Åström, Kalle and Edenbrandt, Lars |
| Year: | 2003 |
| Publication: | Eur J Nucl Med Mol Imaging |
| Volume: | 30 |
| Issue: | 7 |
| Pages: | 961--965 |
| Document Type: | Journal Paper |
| Status: | Published |
| Refereed: | Yes |
| Keywords: | mage processing, Artificial neural net-
works, Pulmonary embolism |
| Publisher: | Springer |
| BibTeX item: |  |
| Extra: | labib, lth-mc-mig |
| Abstract: | The purpose of this study was to assess the
value of the ventilation study in the diagnosis of acute
pulmonary embolism using a new automated method.
Either perfusion scintigrams alone or two different com-
binations of ventilation/perfusion scintigrams were used
as the only source of information regarding pulmonary
embolism. A completely automated method based on
computerised image processing and artificial neural net-
works was used for the interpretation. Three artificial
neural networks were trained for the diagnosis of pulmo-
nary embolism. Each network was trained with 18 auto-
matically obtained features. Three different sets of fea-
tures originating from three sets of scintigrams were
used. One network was trained using features obtained
from each set of perfusion scintigrams, including six
projections. The second network was trained using fea-
tures from each set of (joint) ventilation and perfusion
studies in six projections. A third network was trained
using features from the perfusion study in six projections
combined with a single ventilation image from the poste-
rior view. A total of 1,087 scintigrams from patients with
suspected pulmonary embolism were used for network
training. The test group consisted of 102 patients who
had undergone both scintigraphy and pulmonary angiog-
raphy. Performances in the test group were measured as
area under the receiver operation characteristic curve.
The performance of the neural network in interpreting
perfusion scintigrams alone was 0.79 (95% confidence
limits 0.71–0.86). When one ventilation image (posterior
view) was added to the perfusion study, the performance
was 0.84 (0.77–0.90). This increase was statistically sig-
nificant (P=0.022). The performance increased to 0.87(0.81–0.93) when all perfusion and ventilation images
were used, and the increase in performance from 0.79 to
0.87 was also statistically significant (P=0.016). The au-
tomated method presented here for the interpretation of
lung scintigrams shows a significant increase in perfor-
mance when one or all ventilation images are added to
the six perfusion images. Thus, the ventilation study has
a significant role in the diagnosis of acute lung embo-
lism.
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