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the scanner register these signals and turn them into images. Most modern units also include a shield, which prevents the scanner from picking up interference from outside signals sources like televisions and radio stations. MRIs work by aligning the water |
molecules in your body. Radio waves then cause these aligned particles to emit signals, which register on the scanner. The images reflect the amount of activity that is occurring in each internal structure. Each MRI-generated image shows a thin slice |
of the body. The MRI Process The entire MRI process takes about an hour or two to complete. The scan itself takes between 30 and 60 minutes, but the appointment also includes pre-scan positioning and other preparation activities. Once patients |
arrive at the MRI center and fill out their paperwork, they must remove all metal objects from their bodies. The strong magnets in an MRI scanner can attract zippered clothing, jewelry, watches, belts, keys and credit cards. Implanted medical devices |
that contain metal may also cause complications with the scan. Next, patients will put on a hospital gown and ear plugs. Fast FactSome MRI scans use a contrast dye to improve image detail. The most common dye is gadolinium, which |
is safe and effective for most patients with properly functioning kidneys. This magnetic metal ion can visually enhance lesions on MRI images, indicating growths that may be mesothelioma tumors. For contrast-enhanced MRIs, patients will receive an injection of a contrast |
dye. This makes certain areas show up more clearly on the test. After the injection, patients lie down on the imaging table. The technologist then arranges a coil around the part of the body that is being imaged. For pleural |
mesothelioma, this will be the chest. For peritoneal mesothelioma, it will be the abdomen. Once the technician positions the patient’s body correctly for the exam, the patient and table are slid into a tube-like opening in the MRI machine. During |
the scan, the machine makes repetitive knocking sounds as the magnetic field gradients turn on and off. The test itself is painless. Patients should try not to move during the scan, but they can communicate with their technician via microphone |
if they feel scared or claustrophobic. Patients can leave the MRI center immediately after the scan. A post-processing technologist will then highlight abnormal areas on the images. Once the final images are ready for review, a radiologist interprets the results |
and provides the patient’s primary doctor with a report. From there, the physician can examine the scan on a computer monitor, send them electronically to the rest of the treatment team or print them out for the patient’s medical records. |
damage. Because MRIs do not use ionizing radiation, most doctors prefer MRIs for patients who need routine imaging scans. The U.S. Food and Drug Administration (FDA) concludes that as long as the field strengths are kept below 2.0 Tesla, MRIs |
are safe for repeated use. MRIs for Diagnosing Mesothelioma Tumors Magnetic resonance imaging currently plays a limited role in diagnosing mesothelioma. When doctors do prescribe MRI scans to diagnose the disease, they often use them to complement CT scan results. |
MRI-generated images can help differentiate between normal tissue and tumor tissue, which cannot be determined with a CT scan alone. MRI scans produce a visual representation of differences is signal intensity between cancerous and noncancerous tissues. Because cancerous tissues emit |
more intense signals than surrounding healthy tissue, malignant mesothelioma tissues appear as white spots on the scan results with varying brightness. The difference between malignant and noncancerous tissue is even more pronounced in contrast-enhanced MRIs. To arrive at a mesothelioma |
diagnosis, radiologists usually inspect MRI-generated images for a mass on the pleura, which encases the lungs. These masses often emit signals of intermediate intensity. The fluid located between the lungs and pleura can also indicate mesothelioma, as areas of pleural |
bilateral pleural involvement, pleural shrinkage, pleural effusions and pleural calcifications may also show up on MRI-generated images. These features may suggest mesothelioma, but cannot be used to make a definitive diagnosis. MRIs for Staging Mesothelioma Tumors Most studies indicate that |
MRIs and CT scans are equally effective for accurately staging malignant mesothelioma tumors. While MRIs are less effective at detecting lymph node involvement, they are generally superior at detecting the extent of a tumor’s invasion of other local structures – |
one of the key steps in staging a mesothelioma tumor. When radiologists use MRIs to stage a mesothelioma tumor, they look for the following features: - Loss of normal fat planes - Extension into mediastinal fat - Tumor growth that |
encases more than half the circumference of an organ or mediastinal structure Radiologists can exclude patients as good surgical candidates if an MRI scan shows mediastinal or full-thickness pericardial involvement, diffuse or multifocal chest wall disease or involvement of the |
diaphragm or spine. By revealing the stage of a mesothelioma tumor, MRI images can help doctors determine whether or not the patient is a good candidate for invasive surgery. MRIs are especially useful for detecting two primary features of patients |
who are unlikely to benefit from an aggressive operation: chest wall invasion and involvement of the diaphragm. In one study, MRIs detected diaphragmatic spread with 82 percent accuracy, while CT scans detected the same condition with only 55 percent accuracy. |
MRIs are useful for staging mesothelioma with the TNM system. Some studies suggest that MRI scans can differentiate between T3 and T4 disease, but not earlier stages like T1 and T2. One study found that MRIs understaged half of the |
mesothelioma tumors by failing to detect pericardial invasion, which advances tumors from stage T2 to stage T3. However, the same MRIs were effective at detecting involvement of the internal pericardium, which also advances tumors from stage T3 to T4. The |
study correctly identified all of the tumors that were stage T3 or lower (while excluding the T4 tumors) with a positive predictive value of 100 percent. MRIs for Evaluating Response to Treatment Oncologists consider the MRI an accurate and reproducible |
technique for evaluating patient response to mesothelioma treatment. When evaluating the MRI scan results of mesothelioma patients undergoing treatment, radiologists often measure the tumor from several separate sites. This helps account for the rind-like growth pattern of the cancer. The |
primary measurement that the doctors look for is an increase or decrease in pleural thickness. Fast FactIn one study of 50 mesothelioma patients, MRI scans correctly categorized the tumor response in 92 percent of patients. If there is no visible |
disease on the post-treatment imaging scan, doctors call this complete response. If there is a 30 percent decrease in the sum of linear tumor measurements, they generally refer to that as a partial response to treatment. If the MRI indicates |
a size increase of at least 20 percent (or shows a newly developed lesion), the disease is considered progressive. Doctors may prescribe lung spirometry tests when using MRIs as another way to evaluate treatment response. Patients whose MRIs indicate a |
partial or complete response to mesothelioma treatment often display simultaneous improvements in lung function, which can be measured with a spirometer. When doctors study MRI results to determine treatment response, they can adjust their patient’s prognosis accordingly. In one study, |
patients whose MRIs indicated a response to therapy had a median survival of 15.1 months, while patients whose MRIs indicated no response had a median survival of only 8.9 months. |
Are omega-3 polyunsaturated fatty acids derived from food sources other than fish as effective as the ones that are derived from fish? In a recent review in the Journal of Lipid Research, researchers from Oregon State University set out to assess the scientific data we have available to answer that |
question. The review article by Donald B. Jump, Christopher M. Depner and Sasmita Tripathy was part of a thematic series geared toward identifying new lipid and lipoprotein targets for the treatment of cardiometabolic diseases. Interest in the health benefits of omega-3 PUFA stemmed from epidemiological studies on Gree... |
the 1970s that linked reduced rates of myocardial infarction (compared with rates among Western populations) to a high dietary intake of fish-derived omega-3 PUFA. Those studies have spurred hundreds of others attempting to unravel the effects of omega-3 PUFA on cardiovascular disease and its risk factors. |The omega-3... |
acid (PUFA) conversion pathway. Omega-3 in the diet Fish-derived sources of omega-3 PUFA are eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid. These fatty acids can be found in nutritional supplements and foods such as salmon, anchovies and sardines. Plant-derived sources of omega-3 PUFA are alpha-... |
acid is an essential fatty acid. It cannot be synthesized in the body, so it is necessary to get it from dietary sources, such as flaxseed, walnuts, canola oil and chia seeds. The overall levels of fatty acids in the heart and blood are dependent on the metabolism of alpha-linolenic |
acid in addition to other dietary sources. The heart of the matter A study in 2007 established that dietary supplementation of alpha-linolenic acid had no effect on myocardial levels of eicosapentaenoic acid or docosahexaenoic acid, and it did not significantly increase their content in cardiac muscle (3). Furthermore,... |
intake had no protective association with the incidence of coronary heart disease, heart failure, atrial fibrillation or sudden cardiac death (4, 5, 6). In general, it did not significantly affect the omega-3 index, an indicator of cardioprotection (3). Why doesn’t supplementation of ALA affect the levels of fatty acid... |
in the biochemical pathway (see figure)? The data seem to point to the poor conversion of the precursor ALA to DHA, the end product of the omega-3 PUFA pathway. DHA is assimilated into cellular membrane phospholipids and is also converted to bioactive fatty acids that affect several signaling mechanisms that |
control cardiac and vascular function. According to Jump, “One of the issues with ALA is that it doesn’t get processed very well to DHA.” This is a metabolic problem that involves the initial desaturation step in the pathway, which is catalyzed by the fatty acid desaturase FADS2. Investigators have explored |
ways to overcome the metabolic bottleneck created by this rate-limiting step. One approach involves increasing stearidonic acid in the diet, Jump says, because FADS2 converts ALA to SDA. While studies have shown that increasing SDA results in significantly higher levels of downstream EPA and DPA in blood phospholipids,... |
of DHA were not increased (7). FADS2 also is required for DHA synthesis at the other end of the pathway, where it helps produce a DHA precursor. Consumption of EPA and DHA from fish-derived oil has been reported to increase atrial and ventricular EPA and DHA in membrane phospholipids (3), |
and heart disease patients who consumed EPA and DHA supplements had a reduction in coronary artery disease and sudden cardiac death (8). “Based on the prospective cohort studies and the clinical studies,” Jump says, “ALA is not viewed as that cardioprotective.” He continues, “It is generally viewed that EPA and |
DHA confer cardioprotection. Consumption of EPA and DHA are recommended for the prevention of cardiovascular diseases. The question then comes up from a metabolic perspective: Can these other sources of omega-3 PUFA, like ALA, be converted to DHA? Yes, they can, but they’re not as effective as taking an EPA- |
or DHA-containing supplement or eating fish containing EPA and DHA.” (Nonfish sources of EPA from yeast and DHA from algae are commercially available.) It’s important to note that omega-3 PUFAs are involved in a variety of biological processes, including cognitive function, visual acuity and cancer prevention. The mole... |
bases for their effects on those systems are complex and not well understood. “These are very busy molecules; they do a lot,” Jump says. “They regulate many different pathways, and that is a problem in trying to sort out the diverse actions these fatty acids have on cells. Even the |
area of heart function is not fully resolved. While there is a reasonable understanding of the impact of these fatty acids on inflammation, how omega-3 fatty acids control cardiomyocyte contraction and energy metabolism is not well understood. As such, more research is needed.” Elucidating the role of omega-3s in the |
heart: the next step At the University of Maryland, Baltimore, a team led by William Stanley has made strides toward elucidating the role of PUFAs in heart failure. Stanley’s research group focuses on the role of substrate metabolism and diet in the pathophysiology of heart failure and recently identified the |
mitochondrial permeability transition pore as a target for omega-3 PUFA regulation (9). The group is very interested in using omega-3 PUFAs to treat heart failure patients who typically have a high inflammatory state and mitochondrial dysfunction in the heart. “It seems to be that DHA is really the one that |
is effective at generating resistance to stress-induced mitochondrial pore opening,” which is implicated in ischemic injury and heart failure (10), Stanley says. “It also seems to be that you’ve got to get the DHA in the membranes. You have to ingest it. That’s the bottom line.” Stanley points out that |
ingesting DHA in a capsule form makes major diet changes unnecessary: “You can just take three or four capsules a day, and it can have major effects on the composition of cardiac membranes and may improve pump function and ultimately quality of life in these people. The idea would be |
that they would live longer or just live better.” The impact and implications of omega-3 in the food industry The big interest in DHA over the past 30 years has come from the field of pediatrics. Algae-derived DHA often is incorporated into baby formula for breastfeeding mothers who do not |
eat fish or for those that do not breastfeed at all. “In clinical studies, you see that the visual acuity and mental alertness of the babies are better when they’re fed DHA-enriched formula over the standard formula,” says Stanley. Stanley continues: “The current evidence in terms of vegetable-derived omega-3s may |
be of particular value in developing countries where supplements for DHA (fish oil capsules) or access to high-quality fish may not be readily accessible.” Food manufacturers in developing countries are beginning to shift to plant-derived omega-3 PUFAs, which are relatively cheap and widely available. Despite those mov... |
be limited by the inefficient biochemical processing of the fatty acid — an issue that researchers have yet to resolve. - 1. Dyerberg, J. et al. Am. J. Clin. Nutr. 28, 958 – 966 (1975). - 2. Dyerberg, J. et al. Lancet. 2, 117 – 119 (1978). - 3. Metcalf, |
R. G. et al. Am. J. Clin. Nutr. 85, 1222 – 1228 (2007). - 4. de Goede, J. et al. PLoS ONE. 6, e17967 (2011). - 5. Zhao, G., et al. J. Nutr. 134, 2991 – 2997 (2004). - 6. Dewell, A. et al. J. Nutr. 141, 2166 – 2171 |
(2011). - 7. James, M. et al. J. Clin. Nutr. 77, 1140 – 1145 (2003). - 8. Dewell, A. et al. J. Nutr. 141, 2166 – 2171 (2011). - 9. GISSI-Prevenzione Investigators. Lancet. 354, 447 – 455 (1999). - 10. Khairallah, R. J. et al. Biochim. Biophys. Acta. 1797, 1555 |
research focuses on the molecular mechanisms that control salt balance and blood pressure in health and disease. She is a native of Washington, D.C., and in her spare time enjoys cooking, thrift-store shopping and painting. |
Courtroom atmospheres, deposition testimony, and cross-examinations have long-standing oral traditions and culture. How does an individual who does not speak participate in such traditions? Individuals who have severe communication impairments |
of speech and/or writing may accomplish their communication potential through the use of augmentative and alternative communication (AAC). Communication through AAC techniques, symbols, and strategies, however, is not familiar to |
judges, attorneys, and court recorders within most courtrooms. How do speech-language pathologists adequately prepare persons with complex communication needs (PWCCN) to participate within a cultural environment that is entrenched and |
centered on the spoken word? What graphic symbols best represent legal concepts such as "oath," "testimony," "swearing in," and "legal capacity"? How do PWCCN achieve their right to access justice |
when their "voice" is communicated through a communication assistant and/or through assistive technology? How may SLPs facilitate modifications within the justice system that allow for an appropriate amount of time |
for persons with severe physical challenges to respond to a rapid series of questions from attorneys or police? At present, access to justice for persons with severe expressive disorders is |
difficult. The Legal Arena Suppose that an SLP is invited to serve as an expert witness in a case involving a PWCCN. The SLP will work with police, lawyers, and |
judges in connection with a client. It will be necessary to establish an assessment tool that describes the capacity of the client to testify in court. As an expert witness, |
the SLP will be challenged immediately by opposing counsel regarding the SLP's competence as an expert as well as his or her choice of assessment tool(s). SLPs also need to |
understand the key differences between the clinical and legal arenas. The justice system is centered on "winning" and "losing." Insurance companies participate in determining when to settle and "walk away" |
and end the case. Another difference is the process of evaluation of the client's communication skills. For example, sometimes a proposal for an evaluation must first be submitted to the |
court and both attorneys for approval before any contact with an individual is permitted. Thus, the SLP may prepare by reading hundreds of pages of clinical and educational reports regarding |
an individual with an expressive communication disability, and may then need to seek approval for each proposed diagnostic strategy before the actual evaluation. Modifications to the proposed plan may be |
suggested by either attorney or the judge. Experts in litigation today must be familiar with the origin and significance of the Daubert case (Bernstein & Hartsell, 2005). This 1993 landmark |
decision (Daubert v. Merrell Dow Pharms. , 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed.2d 469) resulted in specific instructions for expert testimony introduced into the courtroom. Basically, |
Daubert's rule established requirements for admissibility of expert testimony, including whether or not the employed technique has been peer-reviewed and published, has a known error rate, can be tested, and |
is a generally accepted practice within the field. As expert witnesses, SLPs need to prepare for testimony with the understanding that their scientific knowledge will be tested by the opposing |
attorney, challenged regarding peer reviews and publications, and examined for potential errors and general acceptance by their own scholarly community. Every word and comma in their expert reports will be |
scrutinized. Although SLPs may feel confident in their professional knowledge base and clinical skills in AAC, writing and defending the expert report within the legal system is very different from |
preparing a clinical report for a public school or medical facility. To prepare a report for testimony, SLPs need to translate their clinical knowledge into a legally useful form without |
using jargon, and to follow the rules, roles, and procedures for written reports according to legal tradition. These evaluations and reports must be precise so as not to introduce any |
reasonable doubt. Failure to understand the purpose and use of a written report may result in a damaging cross-examination and may undermine the SLP's credibility. One example of potential difficulty |
is establishing a legal capacity for expressive communication when that expression is an alternative form to speech. As yet, there is no legal definition of "capacity" for testimony if not |
through speech. The definition of "capacity" is important—a client must be judged to have the "capacity" to participate, because a legal case may set a precedent. When assistive technologies, such |
as speech-generating devices (SGDs) or voice output communication aids (VOCAs), are introduced, the question arises: Does the legal capacity (or definition of expressive communication competence) shift when an SGD is |
used? In other words, if an individual communicates through technology, is the individual legally more capable as a witness than if he or she communicates without an SGD? Might SLPs |
need to perform two evaluations for the court? One evaluation might be conducted to determine "communication capacity" without technology and another evaluation might determine "communication capacity" with technology or AAC |
strategy. Courtrooms may not be accustomed to working with people who use AAC systems. During depositions and testimony, court recorders transcribe speech, but now they must transcribe the language of |
graphic symbols as reported through communication assistants or through synthetic or digitized speech available within the various technologies. Legal counsel typically examines and cross-examines clients on the witness stand in |
the courtroom. However, the witness stand may not accommodate a person with a disability seated in a power wheelchair and his or her communication partner; SLPs may need to suggest |
modifications to courtroom seating arrangements. Judges may not accept testimony by a communication assistant in lieu of actual testimony by the client. Training programs for judges and attorneys may be |
necessary for greater acceptance of communication through AAC systems and other strategies. Attorneys often challenge the origins of the communication messages; i.e., the "independence" of each communication message may be |
examined and cross-examined if programmed by the SLP. The "author" of each communication expression emerging from a synthesized or digitized SGD may be scrutinized. SLPs may be accused of speaking |
for individuals whom they are assisting. Such challenges can be addressed if the SLP orients attorneys and judges prior to the trial to the person's disabilities, use of AAC, types |
of vocabulary, and characteristics of appropriate questioning techniques for PWCCN. SLPs will need to understand that individuals are eligible for accommodations, and that they may be responsible for requesting accommodations |
on behalf of the individual and his or her assistants. Scope of Practice Issues Responsibilities for SLPs are expanding as public agencies are processing an increasing number of complaints on |
behalf of consumers. Cases of abuse, fraud, malpractice, and denial of basic services to PWCCN impact speech-language pathology practices because communication is often at the core of each case. In |
an administrative or court proceeding, SLPs may become involved in legal practices and procedures that extend beyond their education and training. SLPs need to acquire the knowledge and skills to |
assist individuals who use AAC in pursuing their basic human right to access justice (Huer et al., 2006). An SLP preparing to testify in these types of court cases should |
acquire knowledge and skills such as: - Becoming familiar with the legal process, including understanding the steps and procedures for pre-trial processes, discovery, and investigation - Learning the basic rules |
of law, including definitions such as legal "capacity" to testify, and consistency and reliability of testimony by PWCCN - Identifying the various challenges to testimony and to evaluation - Advocating |
for accommodations for PWCCN, when appropriate, throughout the legal process SLPs who enter the legal arena must coordinate their activities with the attorney with whom they are working. "Full disclosure |
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