|Topic:||Functional MRI of hypercapnia data|
|Supervisor:||Prof. Dr. Ing. Jan Kybic|
|Description:||Hypercapnia is a condition of increased presence of carbon dioxide in the
blood. Normal reaction of brain to this condition is vessel dilation that will
increase the blood ﬂow in the brain in order to compensate for the decreased
presence of oxygen in blood. This processes can be monitored over time using a
special MRI sequence called BOLD. The BOLD sequence is sensitive to the level
of oxygen in blood and increased oxygen concentration shows as increased signal
in the images. Hypercapnia BOLD imaging can used to study the vasoreactivy
of vessels to the ﬂuctuating level of carbon dioxide in blood. It can be used
to identify brain regions with non-standard reaction and as such to identify
problematic vessels that may contain stenos or some other vascular pathology.
The hypercapnia is usually induced by letting the subjects breath air with
increased carbon dioxide concentrations during MRI examination. In our data,
we have used several periods of controlled breatholds which is more convenient
for use in clinical practice. This, however, brings additional issues in data
evaluation as the patients are not always capable to dutifully follow the protocol.
The aim of this thesis is to evaluate clinical data from 50+ patients obtained
during one or more sessions. The brain of each patient is supposed to contain
normal regions and it may contain also pathological regions. The time course
of BOLD signal in each patient needs to be examined ﬁrst to identify what is
the normal reaction for each patient (as being close to the expected response).
Subsequently, the whole brain of each patient needs to be studied to identify if
there are regions with no reaction and with pathological reaction. The result
of the automatic analysis of the hypercapnia fMRI data will be compared with
clinical ﬁndings and the sensitivity and speciﬁcity of the automatic method and
the BOLD examination will be assessed.
Data and clinical ﬁndings will be supplied by University hospital in Dresden.
The results will be evaluated in close collaboration with medical doctors from
the hospital. The aplicant is expected to visit Dresden regularly.
The applicant is expected to be ﬂuent in English and have good
programming skills in Matlab. Willingness to learn basic
principles of fMRI and BOLD imaging as well as to learn the basic
medical background of the problem is expected.
[In collaboration with Mgr. Jan Petr, Ph.D.]
|Instruction:||1. Learn the principles of functional MR imaging and data processing.
2. Design and implement a method for evaluation of hypercapnia sequences, to distinguish between normal and pathological regions.
3. Experimentally evaluate the developed method on provided clinical data.
|Bibliography:||-Bernstein, King, Zhou: Handbook of MRI pulse sequences.
-McRobbie, Moore, Graves, Prince: MRI From picture to proton.
-U. S. Yezhuvath, K. Lewis-Amezcua, R. Varghese, G. Xiao, and H. Lu, “On
the assessment of cerebrovascular reactivity using hypercapnia BOLD
MRI.,” NMR in biomedicine, vol. 22, no. 7, pp. 779–86, Aug. 2009.
|Realization form:||kod v Matlabu, vysledky experimentu|