A Critical Review: Comparing MRI and CT Scans for Stroke Imaging

This literature review critically analyzes the comparison between MRI and CT scans for stroke imaging and diagnosis. It highlights the advantages and disadvantages of each method, based on a review of scholarly articles. CT scans are faster and less expensive, providing detailed but non-contrast images, but they involve radiation exposure. MRI, on the other hand, offers clearer, contrasted images using magnetic fields but is more expensive and time-consuming. The review evaluates the importance of this comparison for education and healthcare management, aiming to inform both professionals and the public about the best practices in stroke diagnosis. This analysis will be beneficial for the person as well as for the health care professional, as they can manage the diagnosis of lethal disease faster and in easy way.

Running head: MRI VS CT SCAN TEST FOR STROKE IMAGING
MRI VS CT SCAN TEST FOR STROKE IMAGING
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MRI VS CT SCAN TEST FOR STROKE IMAGING
Executive summary
The primary aim of the study is to critically analyze the comparison between MRI and CT-scan
for imaging and diagnosis of stroke in patients. Critically reviewed article has been taken in
order to know the basic characteristic of the test. Through the analysis, theme has been
highlighted in the project that shows the advantageous and disadvantages of MRI and CT scan.
The thematic analysis has been done by critically reviewing the work of various author basic
search strategy. On the examination of CT scan, its various uses have been discussed. CT scan
gives faster result, less expensive and give detail picture but non-contrast in nature. However, CT
scan has various limitations also. They are invasive and cause various skin disease and cancer.
They use X-ray for the detection of stoke. MRI test uses non-invasive method of imaging the
stroke which employs the use magnetic field. They give clearer image of the stroke and the
picture is contrasted in nature. However, MRI is very expensive test and not affordable by many
people. MRI test is also not feasible as it takes long time to get the outcome of the disease. The
project has explained the various effect of use of CT scan and MRI in various disease detection.
Comparative analysis is done in order to know which test is better for imaging stroke. This
analysis will be beneficial for the person as well as for the health care professional, as they can
manage the diagnosis of lethal disease faster and in easy way.
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Table of Contents
Introduction......................................................................................................................................4
Background..................................................................................................................................4
Rationale......................................................................................................................................5
Research objective.......................................................................................................................6
Research aim................................................................................................................................6
Search strategy.................................................................................................................................7
Literature review..............................................................................................................................9
Advantageous of CT-scan............................................................................................................9
Disadvantageous of CT-scan.....................................................................................................13
Advantageous of MRI................................................................................................................14
Disadvantageous of MRI...........................................................................................................19
References......................................................................................................................................22
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List of abbreviation
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Introduction
The aim of the project is to critically analyses the literature review of MRI and CT scan
test as the mean of diagnosis of stroke. The project highlights the major disadvantages and
advantages of both imaging test by critically examining the literature. Basic search strategy has
been employed in order to find the result. The paper examines the comparative analysis of MRI
and CT scan test, in order to know the benefits of these in health sector.
Background
Stroke or cerebrovascular disease signifies the major cause of global high mortality rate,
an estimated 6 million deaths happening annually. It is the second leading cause of the high
mortality rate in all income group globally (McAloon et al. 2016). Stroke is known to be two
types; ischemic and hemorrhagic (Barrington, Lemarchand and Allan 2017). Looking into the
definition of cause of Ischemic stroke, it is triggered by the inefficient flow of blood in the brain,
which generally happens due to blockage or any blood clot. Hemorrhage is describing as loss of
internal blood. Ischemic stroke is most common accounting 85% of all stroke death (Pascotini et
al. 2018). Morbidity of such strokes is severe and extremely dependent upon diagnosis and
timely treatment. For appropriate diagnosis, a number of clinical tests are developed to aid in the
determination of the presence of any stroke in the human body. Although, these clinical test help
to diagnose the initial acute neurological disorder, they fail to provide a specific and sensitive
imaging test. Earlier no diagnosis had been developed that can differentiate between a
Hemorrhage and Ischemic stroke. With advancement in technology, an initial step has been
taken to manage the suspected stroke inpatient, through imaging examination. The examinations
included Computed tomography CT scan. It is a specialized test the used X-ray for imaging brain
and detecting early blockage as well other pathologies that tend to resemble strokes like migraine
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and spinal stroke (Vanier and Caplan2017). However, ischemia also has an arteriovenous
malfunction, and this calls for a distinction between the arterial occlusion, venous occlusion and
cause of ischemia. The treatment of these type of occlusion requires early diagnosis. For this
MRI known as magnetic resonance imaging was developed which was more sensitive than CT-
scan and can particular in distinguishing both stoke imitators and chronic ischemia. MRI is the
technology that employs the use of radio waves instead of X-ray to produce clear and contrast
picture of organs, neurons, bones or any other internal body structure (Westbrook and Talbot
2018). MRI can identify the cortical pattern of stroke, by lining up hydrogen atom in a person's
body and creating a magnetic field (Bivard et al. 2018). This help in the detection of other
pathologies that resemble stroke. In study, it has been shown that stroke was
spottedcorrectly83% of the time by MRI use as compared to 26% of the time by the CT scan test.
Rationale
The importance of proper imaging for the diagnosis of stroke is the primary step for the
initiation of necessary treatment. With the rise in technology, two most vital test has been
popularized are CT scan and MRI. CT scan is broadly used than MRI as it is less expensive, non-
invasive and provide faster imaging of tissue and internal organ. However, MRI gives detailed
and depth information at the tissue level and does not use X-ray. Both of these tests is
contradicting in nature and involves both risk and benefit (Irshad et al. 2018). The primary issue
of today's health care sector is to determine which method is best for the patient diagnosis for
stroke.This is an issue as because health care professional often goesfor CT scan as it is less
expensive, but sometimes it fails to give an accurate result, the doctor then conducts MRI test for
detail information. This involves more cost and late diagnosis, thus late treatment (Frye et al.
2015). This has been the major issue of today health care sector, today’s doctors are directly
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going for MRI test in cases where it does not require, hence, making expensive and non-
affordable for many patients. The principal rationale for the research project that distinguishes
the imaging tests CT scan and MRI is to identify its potential uses in early diagnosis and
treatment. It will be necessary for the people as they will getcorrectly diagnosedand can proceed
with the procedure. For the medical students and health care staff, it is essential to know which
test will be more beneficial. There is the need for them to see the theory of each analysis and
bring this in practice for managing of lethal disease.
Research objective
The primary aim of the study is to critically analyses the comparison between MRI and
CT-scan for imaging and diagnosis of stroke in patients.
Research aim
The major objectives of the study are:
1. To determine the advantageous and disadvantageous of CT-scan
2. To identify the advantageous and disadvantageous of MRI.
3. To critically analyses the comparison between CT scan and MRI.
4. To evaluate the importance of comparison for the purpose of education and health care
management.
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Search strategy
The primary purpose of conducting a literature review is to provide an exhaustive and
detailed information on the research phenomenon being investigated, by undertaking a
theoretical and structural review of already published scholarly pieces of evidences. Literature
reviews based on an assortment of qualitative scientific articles facilitate the collection of
findings that represent opinions, perceptions and thoughts. In addition, inclosing quantitative
articles helps in providing a theoretical framework to the study and also facilitates summarisation
of pertinent numerical information on the phenomenon under investigation.
The literature review was based on a thorough computerised investigation for relevant
scientific literature that was outlined by the proposed research question, aims, and objectives.
The procedure of collecting scholarly articles focused on gathering information from appropriate
texts that had been published in peer-reviewed journals and/or professional-body periodicals.
Additional search was also piloted for including ‘grey’ literature sources. These sources were
generally produced in electronic and/or printed format by academic, industry, government, and
business organisations.
The literature search strategy comprised of using snowball technique that primarily involved
conducting a manual search of the reference list and/or bibliography of the identified articles and
associated journals, with the aim of recognising additional significant literature. This was
followed by conducting a literature explorations that was continually updated at numerous stages
of the investigation, in order to evaluate the quality of the included articles. Scholarly evidences
were selected from four electronic clinical databases that had been recommended by the library
services at the university and Aveyard for undertaking a comprehensive investigation associated
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to medicine and health (Aveyard 2014). The databases and search engines that were searched
included the following:
 Cumulative Index of Nursing and Allied Health Literature (CINAHL)
 PubMed Central (PMC)
 Medical Literature Analysis and Retrieval System Online (MEDLINE)
The electronic databases and search engine mentioned above were typically selected for
article extraction taking into consideration their prominence in the domain of healthcare and
bioscience. These databases only contained literature that had already been published and
excluded any unpublished material such as, manuscripts. In order to eliminate chances of
publication bias, efforts were also taken to include grey literature sources (if any) from the
source given below:
 Google Scholar
The key words and search phrases that were used for the extraction of pertinent articles from
the aforementioned sources were namely, “computed tomography”, “CT”, “MRI”, “magnetic
resonance imaging”, “effectiveness”, “comparison”, “scanning”, “modality”, “efficacy”, and
“stroke”. With the aim of ensuring the inclusion and acknowledgment of important articles,
several strategies were followed that augmented the search procedure.
 exploring applicable keywords by grouping them and searching for their synonyms with
the use of free-text terms and ‘medical subject heading’ (MeSH), which were combined
with truncation (‘*’ or ‘$’)
 searching for catchwords in quote symbols
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 using Boolean operators (‘AND’ and ‘OR’) for joining the key terms (McGowan et al.
2016)
A pre-specified eligibility criteria was used for inclusion of prospective articles in the review.
All articles that failed to match the inclusion criteria was eliminated from the study (Moule,
Aveyard and Goodman 2016). This helped in retrieval of an estimated 25 articles from the
databases. The table given below highlights the criteria, based on which articles were included in
the literature review:
Inclusion criteria Exclusion criteria
Published in English Published in foreign language
Published on or after 2013 Published prior to 2013
Focuses on either MRI, CT or both Focuses on any other scanning modality
Any country of publication Manuscripts, abstracts
Table 1- Inclusion and exclusion criteria for literature review
Literature review
With the objective to analyses the comparison between the two imaging test CT scan and
MRI, it is essential to evaluate it's various advantageous and disadvantageous in relation to
health care sector and care of the person. Therefore, the theme has been analyzed to get the
correct outcome.
Advantageous of CT-scan
Nam, Barrack and Potter (2014) has conducted a systematic literature review and
recognized the comparative analysis of CT-scan and MRI test. With the aim of evaluating the
disadvantages and advantages of CT, MRI, and US as diagnostic tools for assessing wear-
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associated corrosion difficulties, the researchers conducted a systematic literature review. Pieces
of scholarly evidences were collected from electronic databases namely, CINAHL, MEDLINE,
Scopus, and EMBASE, based on evaluation of the quality of evidences, intervention allocation
method, and outcome assessments. In his study they said that CT scan is the most sensitive test
that give information about the component positioning in human body but they are also limited
in giving information regarding soft tissue contrast one. Some of the major advantages of CT
scan modality, in relation to conducting body scans were attributed to the widespread
acceptability and availability of this screening technique across healthcare facilities.
Furthermore, collection of evidence from the databases also suggested that several companies
have formulated metal artifact decrease software and/or protocols, in order to lessen the beam-
hardening artifact, which is typically created at the time of reconstruction of filtered back CT
projection. This systematic literature review also provided evidence for the fact that CT
modalities are less dependant on operators, which acts as a potential advantage of the procedure
over other screening processes. Nonetheless, one major methodological issue with this article can
be accredited to the fact that this secondary research did not take into consideration unpublished
articles that might have added evidence to the research phenomenon. In addition, it is also
difficult to combine results from a plethora of studies owing to different research approaches,
used in the individual studies.
Study of Nanavaty, Alvarez and Alberts (2014) in their study in National Lung Screening
Trial, found that, low dose CT test can be useful in detecting the presence of lung neoplasm in
person. The researchers also conducted a systematic review of numerous randomized clinical
trials and also took into consideration the costs and adverse reactions that were associated with
the screening process. Upon searching for relevant articles in electronic databases, the
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researchers found that Low-dose CT was highly successful in identifying presence of both
cancerous and benign non-calcified nodules. In addition, it also considered benign non-calcified
nodules as false positives. Low-dose CT testing procedure was found to include supplementary
invasive and imaging procedures, either through bronchoscopic fine-needle aspiration,
transthoracic needle biopsy, or surgical approaches, which had a low likelihood. The review of
literature also elaborated on the effects that the screening procedure created on rates of mortality,
among people who had been identified to remain at high-risk, thus elucidating the potential
advantages that CT scan process offered, over other scanning methods. However, one major
limitation can be associated with the role of unpublished literature, and the decision of peer
reviewers and editors that might have resulted in publication bias in the article.
The authors assessed and compared the feasibility of introducing CTP and diagnostic
accuracy with non-contrast CT (NCCT) where total 1152 patients were found with acute stroke.
The patients in the hospital from stroke onset or with wake-up stroke were eligible for CTP
unless glomerular filtration rate is estimated more than 50 ml was highlighted in the patient.
Moreover, CTP was assessed by authors for long until the peak of the cerebral blood flow until
the flow of the cerebral blood is reduced in the patient and obtained the result discussed before.
However, the researchers highlighted few limitations which reduced the accuracy of the study.
The first limitation of the study is that the researchers used 16 slice CT scanner with the spatial
brain coverage along with the limited acquisition duration time. Therefore, this limitation may
increase the generalizability of the result since a considerate number of institutions have better
technology or this technology. In order to avoid the problem discussed before International
consensus guidelines recommend a length of 70–90s CT scan is required to use. Fortunately, the
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most recent scanners have CTP capacity of scanning whole brain and advanced acquisitiontime
which permitted variable interval scanning for focusing on high frequency.
Razek et al. 2014 had done an examination on CT scan test. He reviewed the method of
CT perfusion in head and neck cancer. The analysis of the tumor was done by mean of
deconvolution and compartmental, which has given a clear image of the lesion. They also
analyzed the prediction of response of neck and head carcinoma after given radiotherapy and
chemotherapy through perfusion CT scan. Thus help to identify the effect of the therapy.
However, differentiation was difficult with the convention method of detection. He also used
perfusion CT scan test to know the activity of lymphoma. In his study he concluded various
advantages of CT scan test, highlighting the point that CT scan test is available globally and give
the faster result. It is of lower cost as compared to the MRI test and assists in monitoring patient's
health. He further said that a routine CT scan could help radiologist to assess the information of
cancer and its range of being cured.
Garge, Rao and Bawa (2013) have done a systematic literature review that included peer-
reviewed journal based on preoperative computed tomography. He used PUBMED, MEDLINE
as the search engine to gain information regarding the topic. In result, it was shown that 96
patients were confirmed of tracheoesophageal fistula by examining through CT scan. He
concluded by saying that preoperative CT is useful in cases of tracheoesophageal fistula.
However, the major limitation of the research is that the safety of the method used is
controversial because limited information is given by the author regarding the management of
surgery. Thus it can be said that preoperative CT scan cannot be made generalized as the
standard of care.
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Disadvantageous of CT-scan
Albert (2013) has also highlighted the related risk of cancer due to radiation caused by
CT scan test. He concluded in his study that though CT scan has benefit in screening lung
cancer, their continuous use as an imaging test can cause radiation based cancer in people. The
researchers also conducted a comprehensive literature review of scientific evidences and
suggested that there remains a risk of malignancy among patients who are continuously
subjected to CT scans.
In the study of Sadro and Dubinsky (2013), has deal the related risk in pregnant women
undergoing CT scan test. The author has said that due to emission of X-ray radiation during CT
scan can end up with teratogenic effects in infants. The researchers focused on the fact that
pregnant patients often experience nonobstetrical emergencies during their pregnancy, including
renal colic, hemorrhagic ovarian cysts, appendicitis, and pulmonary embolism. The findings
were based on evidences that had been collected from scholarly articles and suggested that
although CT scan primarily focuses a beam of x-rays on different body parts, it threatens the
health of the person who is subjected to the procedure.
One major disadvantage of CT scan techniques in scanning was established by Nam,
Barrack and Potter (2014) who identified the fact that CT scans have potential limitations in their
capability to deliver improved soft tissue contrast. In addition, the fact that the scanning modality
cannot operate in the absence of ionizing radiation was identified to be a major drawback.
Findings from the systematic literature review also made the researchers conclude that CT scans
are not able to forecast the extent of tissue destruction, which in turn will act as a barrier in
effective stroke imaging. Furthermore, Nanavaty, Alvarez and Alberts (2014) also stated that
although CT scan has been found to play an important role in lowering mortality rates by
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effective screening, lack of access to necessary healthcare amenities that have the scanning
modality, and affordability concerns can act as potential obstacles to screening using CT. This in
turn can be accredited to the fact that most patients do not have adequate insurance or health
coverage, or reside in regions from where it becomes difficult to access multidisciplinary
medical centers having scanning facilities.
Raman et al. 2013 have done a critical analysis on impact of radiation caused by CT scan
test. They said that CT scan examination exposes the person to high-intensity X rays, that causes
risk of cancer. In the paper, the author has suggested recommendation to reduce the radiation
frequency at a minimal level. They highlighted the importance of improving the technology that
lowers the emission of X-ray. Razek et al. 2014 have conducted the research highlighting the
role of perfusion CT scan in which he mentioned the various advantages of it. However, he also
mentioned that CT scan can disrupt radiotherapy because patients get exposed to harmful
radiation which can cause cancer.
Advantageous of MRI
Low, Barone and Lucero (2015) have done a comparative study to detect the accuracy of
MRI and CT for confirming peritoneal cancer index. They employed 22 patients that has
undergone CT scanning and MRI test after cancer surgery. They found that MRI test has
accurately classified tumor volume in 20 patients out of 22 patients and CT scan predicted in 11
patients only, thus he concluded that MRI more correctly confirms PCI than CT scan. However,
major limitations of the study were related to the retrospective nature of the investigation and the
recruitment of lesser proportion of patients who had been subjected to both MRI and CT scans.
This reduced generalizability of the study. The advantages of MRI were also elaborated in the
systematic literature review conducted by Nam, Barrack and Potter (2014) who found that MRI
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provides an enhanced image of soft tissues in detail, in addition to the possiblepotential that it
holds in predicting the severity and presence of adverse local cells and tissues.
Aspelund et al. (2014) conducted a retrospective cohort study that focused on assessment
of children aged less than 18 years, in relation to screening by CT, ultrasonography and MRI
modalities. Conduction of a retrospective analysis helped the researchers in categorizing the
participants based on their exposure to a particular scanning modality. The participants had been
subjected to CT scan procedure following the administration of intravenous and oral contrast
material, using a General Electric Lightspeed scanner. 2% diatrizoatemeglumine solution was
intravenously administered to the patients, an hour prior to the scanning procedure. This was in
contrast to MRI scans that used a 1.5-T MRI system that contained 8-channel torso coil.
Intravenous gadobenatedimeglumine was used for obtaining post-contrast MRI sequences. This
made the researchers conclude that MRI diagnosis was more feasible and gave higher proportion
of positive result for appendicitis than done by CT scan. However, one major limitation the
failure in specifying diagnosing accuracy as the principal research question. In addition, failure
in determining the actual specificity and sensitivity of MRI scans was a major drawback.
Benefit of MRI was recognized by Lee et al. 2014 highlighting its role in detection of
benign tumor. They conducted a research to differentiate benign and malignant tumor in
gallbladder with help of diffused-weighted MRI test. When the author has used only T2
weighted imaging, it showed only 86.7% of positive predicted value, however, when the MRI
test was combined with T2 imaging test, the result showed 92.2% of positive value. Thus, he
concluded by his finding that diffused weighted MRI test gives more accurate diagnosis for
distinguishing benign and malignant tumor in gallbladder. However, the study had several
limitations. One potential source of limitation is related to the presence of selection bias owing to
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retrospective design of the research. Taking into account the fact that the researchers had
included cases that report gallbladder lesions that were confirmed by surgery or biopsy, they
failed to consider benign lesions, thereby reducing representativeness of the research findings. In
addition, failure to interpret DWI signal intensity might have also affected the results.
In relation to detection of different type of cancer, a study conducted by Rais‐Bahrami et
al. (2014) has showed the role of parametric MRI in detection of prostate cancer. The objective
of the study was to determine the diagnostic yield of analyzing bi-parametric magnetic resonance
imaging for comparing prostate cancer detection and prostate-specific antigen based screening.
In this study author has used, prostate-specific antigen based screening and confirms that MRI
alone can detect high number of lesion and when it is coupled to PSA give more accurate result.
The authors conducted retrospective review of 696 patients who enrolled in a protocol for
undergoing MP-MRI followed by MR/ultrasound (US) fusion-guided prostate biopsyand used
statistical analysis undertaking Fisher’s exact test and paired, two-tailed Student’s t-tests. How,
the limitation of the study is that the study has limited number of patient who fit the inclusion
criteria because of referral of the institution. Moreover, the reference test was limited to the
biopsy findings. Future study is required to conduct using large-scale, long-term screening trials
for validating these findings.
On the other hand, Bhattacharya et al. (2013) conducted a research with help of potential
database of adult person suffering from Ischemic stroke, and found information about the time
when MRI was performed in above person. 53.2% of people had MRI test within 48hrs and they
showed low incidence of misdiagnosis. The researchers conducted reviewed prospective
database of young adults aged in between 16–49 years where they collected various information
with inclusion criteria of race, age, ethnicity, arrival time in the hospital by ambulance, whether
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the MRI was conducted or not within 48 hours of arrival. The variables were tested against
emergency misdiagnosed or diagnosed using the multivariable methods and obtained the result
discussed before. Thus, they said that, early MRI test give accurate result of stroke analysis.
However, study had several limitations such as, in terms of ambulance a considerate amount of
data was missing because records from outside hospitals may have been incomplete. Moreover,
referral bias in the patients was observed who are visiting at hospital, particularly stroke clinical
which further led to the inaccurate result of the study. Besides, the authors also suggested that
Sample size was limited for obtaining accurate result for the study and therefore, further study is
required in this case.
In ischemic stroke it is difficult to differentiate between the ischemic stroke and mimic
stroke, though much research has been conducted in this relation. Previous use of CT scan often
fails to distinguish between the two strokes. Kim et al. 2014 has studied use of MRI in testing
acute ischemic stroke in patients. The authors suggested that with the use of multimodal MRI,
generally accurate and differentiated result of stroke. Within the therapeutic time window, One-
third of acute ischemic strokes that have occurred, which prevented through using this
Multimodal MRI since MRI is a tool, which has the ability to identify the critical or minor stroke
that may be benefited from thrombolysis. Multimodal MRI uses various useful parameters for
deciding treatment route for acute stroke, especially for the patient when the stroke is very
uncertain or patient is showing early symptoms of stroke. The study, authors conducted literature
review which highlighted that on a single or a few parameters are not sufficient data for
obtaining result since it can give bias and in accurate result. The authors further suggested that
instead of considering one or more than one parameter for diagnosed the patients with stroke,
comprehensively combining the information from the pattern of MRI sequence along with the
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mismatching and mixing parameter such as PWI-DWI can be used for obtaining indication of
MRI-based thrombolysis in the patients who experienced stroke. However, the limitation of the
method is that door-to-needle time is longer in case multimodal MRI which further require
extensive study. Further, with the use of diffuse weighted image the prediction of the result of
stroke can be made.
The finding was supported by Quenardelle et al (2016) where they examine the use of
proteins known as plasminogen activator in ischemic stroke and characteristic of stroke mimic.
The authors found that 38% of the stroke mimic created problem in detecting clinical stroke.
They employed the use of cerebral MRI and found that it was able to distinguish neurovascular
disease from stroke mimcs. The authors conducted prospective study including the patient with
accurate stroke within a 1-year period. Majority of the patients had sudden onset of neurological
focal deficit within the time window less than 4H30 as which is accepted as the indicator of
intravenous thrombolysis and obtained the results discussed before. However, the study has
several limitations. The main limitation of the study is thatfor the cohorts study, monocentric
recruitment was done which was further highlighted the bias of the study. Moreover, the authors
preselected the patients who had onset of symptoms within the thrombolysis time window.
Gupta et al. (2018) conducted MRI test in cryptogenic stroke patients of total 54 carotid
arteries in 27 unique patients where authors compared the presence of IHIS on the ipsilateral
versus contralateral side and for correlated proportions McNemar’s test was used. The authors
found that MRI can help in imaging of carotid plague in patients having problem with stenosis.
They further said that, it helps in stratification of stroke risk which is helpful for future clinical
practice. However, author highlighted few limitation of the study such as clinical data was
collected by authors prospectively but classification of TOAST stroke subtypes was made
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retrospectively. Moreover, since in the limited subset of patient, numerous causes of stroke were
present, it further hindered the accurate interpretation of result.
Park et al. (2015) have conducted the research on knee arthroplasty in order to investigate
the role of MRI in the diagnosis of the disease. He has undertaken IRB retrospective review that
recognizes 300 patients having the problem of knee arthroplasty. He took three-year period cases
total number ranging to 28 which has gone through standard radiographic testing as the mean for
diagnosis. He found that many of the tests showed a negative result, though the person faces the
problem of knee arthroplasty. He then conducted an MRI test to see the diagnosis that was not
detected in the radiograph. He saw that a total of 36% of the patient showed the disease and has
undergone surgery. He concluded it form his finding that MRI is the most valuable test for
managing the knee arthroplasty as it gives confirm the result of it. However, his outcome was not
that justified because the protocol taken by the author is not relevant to the study. His finding is
also controversial because other methods are also available to detect knee arthroplasty.
Disadvantageous of MRI
Lempel et al. (2014) has done research on aortic angiography where, he found that CT
angiography give better resolution than MR angiography.They also identified a limitation of
MRI in aortic angiography that, the aortic arch is not detected in the test. The authors identified
two cases of intramural hematoma, five cases of aortic dissection with the AAI incidence of
2.9/100. The aim of the study to determine the incidence of non-traumatic acute aortic injury
which is extended from pelvis or the abdomen in emergency department of acute aortic
syndrome (AAS) for estimating the authentic dose of the abdomino-pelvic portion The authors
performed the study for determining the frequency of acute aortic arch dissections and all of the
study was performed in between 2010 to 2012. Only those patients were included in the study
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who was reported to have a dissection flap or an intramural hematoma at CT angiography and
patients with localized penetrating ulcers were excluded and obtained the result discussed before.
Two major limitation of the study are retrospective study design and the small number of arch
dissections. Moreover full extent of arch dissection may have led to inclusion bias which further
limited the accuracy of the study. Further detailed study Is required in this case to obtain accurate
result of the study.
James, Karacozoff and Shellock (2013) have talked about the severe outcome of MRI
screening. In the study, the author has reflected the risk associated with the patients who undergo
MRI test focusing on the presence of ferromagnetic bodies. He said that MRI uses a magnetic
field to get the clear image of the stroke or any related damage tissue. He conducted the MRI test
in patientsand recognized that the presence of any metal in the body of patients gave false result
and caused severe health issue in them. Richard et al. (2013) have studied the incremental value
of MRI and CSF to test the Alzheimer disease. He included 181 patients in his study and
conducted the memory test in each of them. In the result, he got that incremental value of MRI
was very high. He concluded by saying that, with the examination of MRI the Alzheimer patient
may undergo more deterioration of their memory because this test uses a magnetic field.
However, in his study, no clear justification is given to order to highlight the issue of CSF in
losing the memory in such patients.
Russo et al. (2017) have studied the risk of MRI test in patients who have undergone
surgery of the heart and have implanted a pacemaker. The research was done by taking the MRI
test before and after the implantation of a pacemaker in the heart. The standard protocol of the
trial was adopted for this. In his research, he conducted 1000 MRI test and founded that in 30%
of the patients, the MRI test has led to lethal effect. Firstly, the analysis did not show any
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positive result, and instead disrupted the function of the artificial pacemaker. The reason for the
finding by the author was highlighted stating that the magnetic field of the MRI has disrupted the
metallic part of the pacemaker. Due to this, the action potential was not generated, and heart
functioning got interrupted. The finding of the author was relevant to the finding as because the
reason given by him was justified with the known theory of electromagnetic theory.
Conclusion
The review of literature thus helped to highlighted several important aspects of the MRI
and CT scan. Some of the advantage of the CT scan includes sensitivity, modality and
widespread acceptability. It also promotes successful identification of the cancerous and benign
nodules. However, it is associated with sudden limitations like its inability to extract information
about soft tissues. It also fails to highlight the level of tissue destructions. In the domain of MRI,
the main advantages highlighted are accurate analysis of the soft tissues. It also helps in the
elimination of the false positive results by making use of its sensitivity. Other benefits if MRI
highlighted in the literature review include effective and accurate detection of the benign and
malignant tumors. However, this advantage coincides with the CT scan but the level of
sensitivity in MRI is higher than CT scan. MRI however, is found to be associated with certain
disadvantages like risk associated with the patients undergoing the MRI scan. The presence of
the ferromagnetic particles in the body of the individuals who are subjected to the MRI scan are
found to be harmful. Moreover, the magnetic field used in the MRI scan is harmful for the
people with pacemaker due to repulsion of the magnetic field. However, in spite of this threats
to the individuals undergoing MRI scan, the review of literature highlighted that MRI scan is
preferred for the imaging of the stroke over CT scan and this preference is done based on the
level of sensitivity.
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MRI VS CT SCAN TEST FOR STROKE IMAGING
Recommendation
U.S Food and Drug Administration (FDA) in association with the Society for Magnetic
Resonance Technologists (SMRT) have developed a series of the guidelines in order to promote
safety aspects during the conduction of the MRI scan. In order to prevent MRI burn it is
recommended to ensure that any objects entering inside the MRI room is conditional or MRI
safe. Moreover, the patients are require to change out of street clothes before the conduction of
the MRI scan. The patient is required to be positioned in such a way that it avoids direct skin to
skin contact. Use of the manufacture padding is always recommended in to insulate the patients.
While conducting the MRI scan with patients with implants, only MRI conditional implants must
be used and if the MRI conditioning is not met then scan must be strictly avoided. FDA also has
a separate set of guidelines in order to understand the MRI safety labeling and this include cross-
checking of the static field strength, maximum spatial gradient of the filed and proper assessment
of the limitations of the implants. US FDA has a separate set of posters which have a detail
subdivisions of the MRI safety guidelines is important for the health professionals who are
conducting the MRI scans have a detailed knowledge about the safety measures for the
conduction of MRI. Use of trained professionals will help to ensure the safety of the patients
during the MRI. However, further research is required to be undertaken in order to further
increase the sensitivity of the MRI scan.
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MRI VS CT SCAN TEST FOR STROKE IMAGING
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