Magnetic Resonance Imaging Critique

Running head: MAGNETIC RESONANCE IMAGING
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Magnetic Resonance Imaging Critique
Name
Institutional Affiliation
Executive Summary

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Today, advancement in technology is engulfing every industry. Healthcare is not left
behind with corporation of sophisticated technological equipment like Magnetic Resonance
Imaging being useful in patient care. Notably, MRI is considered a non-invasive technology of
imaging that produces comprehensive anatomical images that are three dimensional. Besides,
MRI is useful in diagnosis, disease detection as well as treatment monitoring (Hashemi, Bradley,
& Lisanti, 2012). Categorically, MRI can be very useful not only in detecting blood vessel as
well as brain abnormalities but also in determination of the region of brain affected by stroke.
Notably, stroke can be defined as a neurological dysfunction which occurs when there is absence
in flow of blood to a given brain region. In clinical setting, according Zhao, Ma, Greiser,
Zhang, An, and Fan (2016), a Magnetic Resonance Imaging scan be useful in the diagnosis as
well as aid in the pathology management through the use of sequences which rely on
pathological changes which occurs post ictus with sensitivity as well as specificity. However, it
is worth noting that, for effective management as well as treatment of a patient suffering from
stroke; diagnosis is best and effectively done within therapeutic window through the use of
DWI/ADC sequence which allows the demonstration of stroke within some onset minutes
(Weishaupt, Froehlich, Nanz, Koechli, Pruessmann, & Marincek, 2013). Moreover, immediate
and effective treatment of stroke can be helpful in reducing disability as well as saving lives by
reducing pressure and controlling bleeding in hemorrhagic stroke case or restoring blood flow
especially in ischemic stroke.
Clinical Indication and Anatomical Protocol
The necessity of patients requiring brain imaging is rising since stroke is regarded as the
3rd leading cause of death across the world with a considerable disabilities among survivors.
According to Fiebach and Schellinger (2013), in the quest to help solve complexity of stroke,

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imaging attempts to optimise therapeutic window phase of patients. Therefore, it is worth noting
that, MRI medical imaging is not only considered as a sensitive modality in the detection of
stroke but also in stroke diagnosis in patients that shows an acute neurological deficit as well as
consciousness alternation. Furthermore, the techniques involved include DWI/ADC (diffusion-
weighted imaging/apparent diffusion co-efficient), GREWI (gradient-recalled echo weighted
imaging), T2WI (weight image), TOF MRA (time of flight magnetic resonance angiography), T2
FLAIR (Fluid-attenuated inversion recovery imaging), and T1FSWI (T1 fat suppression
weighted image).
Sequentially, MR imaging visualized can be ischemic cascade which happens after
vascular occlusion. According to Caplan (2016), ischemic cascade include apoptosis and
inflammation, depolarization, K+/Na+ pump failure, free radicals generation, intracellular Ca2+
increase, and blood brain barrier disruption. Besides, it worth noting that DWI/ADC especially
during therapeutic window stage is a stroke indicator mostly as a result of the sequence. The
result of intracellular cytotoxic oedema is the prolongation of T1 and T2 relaxation with
T2weighed images showing six to eight hours post stroke, subcortical hypointensityan and loss
of normal vessel signal.
Moreover, T2 Flair has higher detection rates for small infarctions due to its ability to
null the signal from cerebrospinal fluid despite having a hypersensitivity to oedema (González et
al., 2010). Furthermore, The Oxygination content in blood changes the magnetic susceptibility
hence breaking down red blood cells. In addition, this degradation process is sensitive to GRE
T2 sequence, thus, providing images of acute or chronic haemorrhages, with hypointense regions
of interest makes GRE T2 a sequence of choice for detection (Bushong & Clarke, 2014).
Consequently, MRI sequences show sensitivity to pathophysiological changes that follow a

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stroke thus providing prognostic and diagnostic approach in assessing brain infarction in a none
invasive setting (Haaga et al., 2008).
Alternative Techniques and Other Imaging Modalities
Detection as well as management of a cute stroke requires improved MRA as well as
perfusion weighted imaging sequences as alternative techniques. First, A CT perfusion scan is an
alternative to MR stroke imaging, offering a current view of cerebralvascular pathology. Also,
Gadolinium contrast media administered intravenously causing T2 weighted images a non-linear
signal loss. It is worth noting that, gadolinium administered to the patient intravenously, CE-
MRA is used (Baraee, Faeghi, Shokoohi, & Saeedi, 2016). Also, usage of T1 properties of the
contrast to reduce T1 relaxation time instead of flow dynamics creates a difference in appearance
between the intravascular lumen and adjacent tissue.
Furthermore, creating semi-quantitative perfusion maps as a CE technique estimates
cerebral blood volumes mean transit time of the bolus to transverse the network of capillaries as
well as cerebral blood flow. However, a T2 weighted images appear normal during an acute
stroke window thereby PWI can show cerebral ischemia (Bare, Faeghi, Shokoohi, & Saeedi,
2016). Notably, the integrity of the intra and extracranial vessels are evaluated using CE-MRA,
most usefully in the subacute as well as chronic stroke stages especially when pathophysiology is
not established.
Hardware Equipment
Production of images with high resolution requires high field strengths. Thus, the patient