Biomedical Engineering Reference
In-Depth Information
be subtle and insidious, and often the diagnosis is difficult. A noninvasive
tool with which to diagnose early Alzheimer's disease is therefore highly
desirable. In two studies of Alzheimer's disease employing proton MR spec-
troscopy,
N
-acetyl aspartate (NAA) was decreased and myoinositol was
increased [13,14]. These findings were present even in cases of mild to mod-
erate dementia. It should be possible to detect these chemical changes with
vibrational spectroscopy with even greater precision.
Colon Cancer
British researchers looked at changes affecting 18 genes that play a key role in
the very early stages of colon cancer and found a pattern of chemical changes
in people who had precancerous polyps likely to develop into a tumour. This
could help us to predict people more likely to get colon cancer in the future
according to research at Britain's Institute of Food Research. The researchers
focused on a chemical process called
methylation
, which turns genes on and
off [15]. We believe that spectroscopic analysis of colonic adenomas versus
carcinomas would allow detection of these changes.
gynaecological Cancers
Spectroscopic techniques have the potential to differentiate between normal
and malignant ovarian, endometrial, and cervical tissues, with good sensi-
tivity and specificity demonstrated in some studies, as detailed in Chapter 5
of this text. Changes associated with preinvasive cervical cancer have also
been studied and described.
lung Cancer
Lung cancers are largely divided into non-small cell lung cancer (NSCLC)
accounting for 80-85% of lung cancers, and small cell lung cancer (SCLC)
accounting for 15-20% of lung cancers. NSCLC is a heterogeneous aggregate
of histologies, including epidermoid or squamous cell carcinoma, adenocar-
cinoma, and large cell carcinoma. These histologies are classified together as
NSCLC because approaches to diagnosis, staging, prognosis, and treatment
are similar.
Lung cancer diagnosis and staging's based on Chest X-ray, CT scan, PET-CT
(Positron Emission Tomography-CT) scan and biopsy (commonly via bron-
choscopy or CT-guided biopsy). Chest x-ray has its limitations and can miss
some small lung cancers, and does not always reliably distinguish between
lung cancer and other lung diseases [16]. CT of the chest is an important infor-
mative tool that helps in detailed imaging of the primary tumour and its ana-
tomic relationship to other structures, and it provides information with respect
to the size of mediastinal lymph nodes and the status of the pleural space, and
hence staging. However, CT criteria for adenopathy are based on size alone and
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