Multi-modal Interaction in Biomedicine - Ambient Intelligence for Scientific Discovery - page 193

The next step is consultancy, which is usually conducted by a vascular sur-
geon. The consultation includes diagnosis and identification of contraindications
with the corresponding explanations for minimization of risk factors in future
(e.g., stop smoking or low cholesterol level) [8]. Physical examination can also be
conducted: it includes measurements of blood pressure and pulse rhythm, as well
as special tests, e.g., the 'walk test' [9]. If a vascular surgeon is an experienced
practitioner, this examination will be sucient to make a diagnosis and to plan
the further treatment for a typical case, even including a surgical intervention if
necessary.
As for non-typical cases, further testing is required, which implies collabo-
rative work of radiologists and surgeons to make correct diagnosis and plan a
proper treatment. Several imaging techniques can be used to determine the lo-
cation of the obstruction or narrowing of the artery. One of them is echo-doppler
(duplex) examination. It permits to picture the vein to determine the location of
a vascular disorder. The echo-doppler examination utilizes an ultrasound probe
to visualize the vein structure either through the chest wall or by placing a probe
through the mouth into the esophagus [17].
If the echo-doppler examination does not help in better understanding of the
patient's conditions, computed tomography (CT), magnetic resonance imaging
(MRI) or magnetic resonance angiography (MRA) can be used for the further
examination [17]. 3D data acquired by CT or MRI is always converted into a
set of 2D slices that can be displayed and evaluated from various perspectives
and levels. MRA is a technique for imaging blood vessels that contain flowing
blood. It is very popular among cardiovascular specialists because of its ability to
non-invasively visualize a vascular disease. The choice of the imaging technique
is determined by the structure or anomaly that needs to be observed, given that
some techniques are better suited for certain cases than others [21].
Although, the data acquired by imaging techniques is always presented in
2D, radiologists and surgeons can easily process it. However, for complicated
non-typical cases 3D reconstruction of scans is also performed to get an extra
insight in the geometry. In this respect the VRE system might be very helpful,
for the prediction of the behavior of a bypass or even a stent in the future. In
any case, the VRE will always remain only an assistant in making a decision.
Nevertheless to the available functionality of the VRE in future, the final decision
will be made always by clinicians. Thus, currently the final decision about the
diagnosis and further intervention is usually made during a 'vascular meeting'
where both radiologists and surgeons are present.
A simplified use-case diagram for the VRE system is shown in Fig. 6. This
diagram corresponds only to assisting in decision-making. As for another pos-
sibility of using the VRE as a training environment for medical students and
novice clinicians, currently it is only possible if the training process is guided
and controlled by a teacher, who is a confident user of the VRE.