Biomedical Engineering Reference
In-Depth Information
research and potentially for clinical diagnosis because of the
obvious role of oxidative metabolism in the pathology associ-
ated with many brain disorders and neurodegenerative diseases
such as schizophrenia, Alzheimer's disease, Huntington's disease,
Parkinson's disease, mitochondrial dysfunction and aging prob-
lems (e.g.,
(146-150)
). One line of evidence is the histopatholog-
ical findings indicating that the activity of cytochrome oxidase,
the key mitochondrial enzyme that catalyzes the reduction of
oxygen to form water, is significantly impaired in schizophrenic
(146)
and Alzheimer's patients
(147, 148)
. Another line of evi-
dence is from the studies of diseases caused by mitochondrial
DNA mutations suggesting that a variety of degenerative pro-
cesses in Parkinson's disease and Alzheimer's disease may be
associated with defects in mitochondrial oxidative phosphory-
lation
(151, 152)
. Thus, the in vivo
17
OMRSand
31
PMT
approaches may play vital roles for investigating the neurode-
generative diseases associated with the mitochondrial abnormal-
ity and metabolic syndrome with great potential in clinical diag-
nosis and monitoring the brain functional recovery after medical
treatment.
6. Conclusion
Although, in reality, in vivo heteronuclear MRS has not been
widely applied compared to
1
H MRI/MRS due to its lower
detection sensitivity, the currently available ultrahigh MRI/MRS
scanners, technology and their associated high field merits have
undoubtedly stimulated the in vivo heteronuclear MRS research
and methodological development
(153)
. Significant progresses
have been made for advancing in vivo MRS in brain research. One
of the unique in vivo MRS utilities is to noninvasively measure
the cerebral metabolic fluxes and their dynamic changes, which
may lead to many important applications in medical research.
Two interesting and exciting applications of the in vivo
17
O
MRS approach and/or
31
P MRS MT approach are: (i) to study
the dynamic changes in oxygen utilization and oxidative ATP
metabolism during activation in normal brains; (ii) to explore the
possibility for detecting abnormality in the oxidative metabolic
fluxes during the progression of brain diseases prior to showing
metabolite concentration abnormality. The outcomes from these
applications will be essential for better understanding of brain
function and dysfunction. Finally, the in vivo
17
Oand
31
PMRS
can be readily combined with many other MRI utilities for imag-
ing brain anatomy, perfusion, diffusion and BOLD etc within the
same scanning session. This combined MRS/MRI strategy can
make it particularly powerful in neuroscience research.
