Patient with renal insufficiency
are at risk of developing a rare but serious complication (Nephrogenic systemic
fibrosis) if injected with a Gadolinium Contrast Medium. Precautionary measures
such as blood test must be done to ensure normal functioning of the kidney
prior to MRI (Waikhom, et al., 2011).
MRI produces an excellent image, thus, it became an essential diagnostic
test. However, not everyone is fit for MRI such as people with implants
(containing Iron). In the past, people with pacemakers (device that regulates
irregular heartbeat) are contraindicated for MRI scan due to possibility of
life-threatening complication (MRI scan, 2015; Magnetic resonance, anon).
Nevertheless, studies suggest that well-planned multidisciplinary management will qualify a person to safely undergo
MRI. Appropriate safety measures, extensive observation and monitoring and the
presence of the necessary medical team must be observed during and after MRI (Bovenschulte, et al., 2013)
MRI uses a strong magnet, strong enough to toss a
wheelchair inside the room, damage defibrillator, drug pumps, hearing aids and
other ferromagnetic materials, hence, vital safety procedures must be observed.
It doesn’t involve radiation, thus, vulnerable pregnant women and babies can
undergo with the test if it is necessary (MRI scan, 2015). Currently, there is a lack of consensus and
evidence that MRI causes unwanted damage to the fetus (Bulas, et al., 2013). On
the other hand, it is advisable to perform MRI during the third trimester and
using contrast agent must be avoided as it can cross the placental barrier. (Magnetic
resonance, anon). No data has been
established to prove risk from radio frequency and magnetic field during MRI, making MRI as one of the safest diagnostic test currently
available (MRI scan, 2015).
Magnetic resonance imaging
(MRI) is a non-invasive scanning technique without the use of ionizing
radiation that generates three dimensional images. Powerful magnetic energy and
radiofrequency pulses are utilized to generate anatomical images of the body. It
is the preferred test for non-bony parts of the body. As compared with other CT
scan, MRI produces clearer image for the spinal cord, ligaments, tendon, and
brain. It is one of the preferred test for
cardiac, lung, cancer, stroke and neuro function assessment (Magnetic resonance, anon).
MAGNETIC RESONANCE IMAGING
areas of the body are better assessed in MRI than in CT scan, such as brain,
internal organs specifically in the pelvis, and joints (knees and shoulders) (CT
scan, anon). It may be surprising that MRI produces a valuable image in
skeletal disease as solidified tissues do not produce signal during the scan.
This can be rationalized by the evidence that MRI provides images of the inside
and surrounding joint of the bone marrow (Rockall, et al. 2013).
A contrast media is being administered during the scan to enhance the
image quality (Pedicelli, G. et al., anon). However, intravenous contrast may harm patients with renal impairment, hence kidney
function must be verified prior to a scan. Patient with asthma and multiple
drug allergy may have a life-threatening reaction (bronchospasm, laryngeal
edema) to contrast media. (Rockall, et al. 2013). Special protocol is being followed for this
cases such as the administration of antihistamine (hydrocortisone).
According to Radiologyinfo.org,
there is no definitive evidence that small dose of radiation from CT scan can
cause cancer. However, a group of researcher, Brenner, et al 2007, suggested
that radiation from CT scan is one of the contributing factor for cancer in the
United States (0.4 % in 1991-1996). To address this issue, the State and Federal laws required CT scan
machines to technicians to deliver the
lowest possible radiation but creating a high-quality image (Mclntyre, R., et
Utilization of CT scan as a diagnostic tool has greatly increased due to
its promising advantages. Improvement in CT scan has resulted to lesser
exposure to radiation as compared to radiation acquired during long flights by
the airline customers (Pedicelli, G., anon).
It is a
high-quality diagnostic test that allows precise acquisition of the measurement
(shape, size and location) of internal organs specifically of soft tissues and blood vessels (McCollough, et al.,2009). It is a specialized tool that provides accurate
anatomical information and helps medical team for the detection, diagnosis and
treatment of a certain disease. It provides a comprehensive, cross-sectional
views of most tissue. It is usually the best technique to detect
various types of cancer since CT scan can provide detail on the existence of a tumor,
its size, exact location and degree of involvement with neighboring tissue (CT
scan, Anon). CT scan is also used to guide doctors to perform procedures
such as CT guided biopsy and radiofrequency ablation (CT scan, anon).
v Godfrey Hounsfield, a British engineer who
invented CT scan in 1972 (A history, anon).
Other names for this
test: Computed tomography scan, CAT scan, and spiral or helical CT.
Diagnostic imaging is one of the important investigative instrument for
numerous human infirmities. It has a vital role in diagnosing conditions,
monitoring therapy response and predicting treatment outcome. Radiology imaging
has numerous specialties with divergent principles, techniques, strengths and
limitations (The future, 2010). This review highlights some of the commonly
utilized contemporary diagnostic technique such as MPI-NM (Myocardial Perfusion
Imaging- Nuclear Medicine) and its role in evaluating cardiac disease, and MAG3
scan and its function in assessing a renal
problem. It also includes a brief review of CT scan (computed tomography) and
MRI (magnetic resonance imaging), and PET-CT (Positron Emission Testing) their
strength, limitations and applications. Estimated design and cost of a patient
with myocardial infarction is also included.