Category Archives: Health Care

Sheet metal workers, welders, and others exposed to tiny metal fragments face particular risks during an MRI scan. An adequate screening questionnaire will ask patients if they’ve been exposed to metal fragments well before they enter the MRI suite. In order to minimize anxiety both before and during imaging procedures, physicians should educate patients who work with metal early in the conversation.

Here are the key things to communicate to metal workers when referring them to a diagnostic imaging provider:

• The presence of metal in the body may not present a health risk, but may still contraindicate MRI as an imaging modality.Even if metal fragments don’t react to the magnet in ways that can cause harm, they can still disrupt magnetic field homogeneity. This can cause visual artifacts and signal loss, limiting the diagnostic value of the resulting images.Senol and Gumus present a novel example of this distortion in a brief submission to the journal Quantitative Imaging in Medicine and Surgery. The patient they describe was a metal worker; despite the fact that he had showered and washed his hair prior to his MRI scan, some metal dust remained on his scalp. These fragments created strange circular objects, like water bubbles, on the resulting images. (These images were obtained on a 1.5 Tesla MRI scanner.)


• Sheet metal workers are more likely than others to have tiny metal shards in their eyes, and these objects may not produce any symptoms at all.Patients are often unaware of the presence of intraocular foreign bodies. For instance, see this article from the American Journal of Ophthalmology Case Reports.Even if patients aren’t experiencing discomfort or pain, physicians may elect to obtain images of the eyes via nonmagnetic means before progressing to the MRI study.


• Standard procedure is to order a CT orbit scan prior to MRI for patients who face higher risks of metal fragments in their eyes.CT scans don’t use magnets at all, and are safe for patients who have metal shavings in their eyes. The orbit CT scan is a quick, noninvasive way to make sure patients can safely receive an MRI in scanners of any strength.


• Regardless of the findings of preliminary scanning, patients will always have a way to stop the MRI procedure for any reason.Patients will always have a route of communication with the attending technologist. If they have any concerns during the procedure, they can always tell their technologist, who will stop the scan and evaluate the situation before proceeding.


• If the MRI scan poses any health threat at all, plenty of alternative imaging modalities are available to meet diagnostic goals.In the rare event that technologists and radiologists do find ferromagnetic metal fragments within the patient’s eyes or body, they can always use an alternative imaging technique. Scans involving X-rays don’t create magnetic fields, and won’t interact with metal implants or particles.

The pre-MRI screening process is designed to ensure safety for patients, and a big part of the effort is discerning the presence of ferromagnetic metallic objects within the body. The high-powered magnetic fields involved in an MRI scan can cause these objects to heat up, vibrate, or even shift location — clearly, this presents a health risk for patients, contraindicating MRI as a diagnostic imaging modality.

Despite these risks, physicians can help to provide a more comfortable treatment experience by discussing the above issues with qualifying patients from the beginning of the diagnostic process. Doctors can continue to order the MRI for metal workers with a high degree of confidence in the safety, efficacy, and comfort of their patients, and communication plays a central role in the process.

References:

Platt AS, Wajda BG, Ingram AD, Wei XC, Ells AL. Metallic intraocular foreign body as detected by magnetic resonance imaging without complications- A case report. Am J Ophthalmol Case Rep. 2017;7:76-79. Published 2017 Jun 22. doi:10.1016/j.ajoc.2017.06.010

Senol S, Gumus K. A rare incidence of metal artifact on MRI. Quant Imaging Med Surg. 2017;7(1):142-143.

Researchers suspect that the true rate of mild traumatic brain injuries remains much higher than reported, suggesting the need for broader awareness of the condition. Diagnosis through imaging studies can help.

Neuroradiologists possess powerful tools for revealing the presence of traumatic brain injury (TBI): the CT scan and the MRI scan. Not every patient with suspected TBI requires imaging studies, but for those who do, these two techniques can greatly improve outcomes through prompt diagnosis.

Each of these diagnostic techniques carries its own strengths and hazards, and physicians order them in different cases. A thorough understanding of brain imaging studies can help the medical community identify cases of TBI more readily, leading to better, faster interventions.    

This is a subject of increasing concern among doctors; traumatic brain injuries — especially of the mild variety, more commonly known as concussions — are fairly common. In 2013, around 2.5 million people visited an emergency room with TBI-related complaints. Most cases in the 15-24 age range are related to motor vehicle accidents, but among causes, there’s a close second: playing sports.   

Measuring TBI in the Sports Community

The sports community is particularly interested in improving treatment for TBI, and for good reason. Remember that more concussions and brain injuries come from playing sports than any other cause except for car accidents.

A brief glimpse through the numbers paints an alarming picture:

• In 2009, the Centers for Disease Control and Prevention estimate that nearly 250,000 children and teenagres visit emergency departments for concussions received while playing sports.
• The reported risk of concussion among football players is as high as 75 percent, reports Radiology Today, citing the Sports Concussion Institute.   
• The University of Pittsburgh’s Brain Trauma Research Center estimates that about 300,000 concussions are associated with sports in a given year.
• The same institution lists the chance of concussion for athletes in contact sports to be up to 19 percent per year of play.

These statistics explain why researchers are working so hard to find fast, field-side imaging tests that can pinpoint the severity of TBI immediately following the event. Promising options include stadium MRI rooms and highly portable ultrasound; still, for most players at all levels, radiology-assisted diagnosis of TBI will involve a trip to the imaging center. This places us firmly back in CT/MRI territory.  

CT Scans in the Diagnosis of TBI

Computerized tomography (CT) scans take multiple X-rays and combine them into cross-sectional “slices” of internal structures. While this exposes the patient to small doses of ionizing radiation, but it’s also the fastest, most accurate way to identify bleeding and swelling in the brain.

Clearly, edema (brain swelling) and hematoma (bleeding in and/or around the brain) are serious conditions. The faster doctors discover them, the better for the patient. Typically, then, physicians order CT scans for suspected acute injuries to the brain. The CT scan is the modality of first access.

Later, doctors may order more CT scans to track healing in TBI instances that don’t require surgery. As with every order of an X-ray procedure, physicians weigh the benefits of the treatment against the risks posed by exposure to radiation before making a referral.  

MRI Scans in the Diagnosis of TBI

Magnetic resonance imaging (MRI) is the go-to tool for identifying subtle effects of injury, including bruising, scarring, and microscopic damage to nerve fibers. Images produced by CT scan won’t reveal these conditions, though nerve fiber injury is a common cause of stubborn symptoms.

Sometimes brain tissue is injured too severely to recover, so MRI scans can track the results of a TBI for years following the precipitating event. This imaging modality is another powerful tool in the neuroradiologist’s brain-injury kit.  

Schedule Diagnostic Imaging for Patients with TBI

Ultimately, health care providers will determine the appropriate imaging technique for each patient showing signs of TBI. Plenty of non-radiological tests exist; these may be enough to recognize and begin treatment for milder injuries to the brain.

Physicians who need fast access to radiology services in cases of TBI can make referrals through the Precise Imaging physician’s portal. This online tool provides anytime access to the crucial services we provide.

Call Precise Imaging at 800-558-2223 to make a referral or schedule an appointment today.

References:

“Centers for Disease Control and Prevention Justification of Estimates for Appropriation Committees, Fiscal Year 2016.” CDC. Centers for Disease Control and Prevention, U.S Department of Health and Human Services, 2016. PDF. 2 Jan. 2019.

Orenstein, Beth. “A Closer Look at Concussions.” RadiologyToday. Great Valley Publishing Company, Inc., Sept. 2016. Web. 2 Jan. 2019.

Prince, Carolyn and Maya Bruhns. “Evaluation and Treatment of Mild Traumatic Brain Injury: The Role of Neuropsychology.” NLM. Brain Sciences, Aug. 2017. Web. 2 Jan. 2019.

“Traumatic Brain Injury (TBI) and Concussion.” ASNR. American Society of Neuroradiology, n.d. Web. 2 Jan. 2019.

Gadolinium Retention Research Roadmap Now Available

 

On February 15, 2018, The National Institute of Biomedical Imaging and Bioengineering brought together an international group of researchers, scientists, and medical doctors to look at the current and future concerns regarding the human body’s retention of gadolinium-based contrast agents (GBCAs). Ultimately, they wished to identify any potential safety hazards associated with this common MRI contrast agent. In September, the results were published, mapping out a path for future research into this subject. Physicians can now access the work for a greater understanding of GBCAs used in diagnostic imaging settings.   

 

The report states that “in spite of more than 30 years of use of GBCAs, important information about the biodistribution and tissue interactions of each GBCA in clinical use remains unknown. It is clear that gadolinium retention in a number of tissues, including bone, skin, and brain, beyond 24 hours may occur with all types of GBCAs, although the magnitude of observed retention is greater with linear GBCAs than with macrocyclic GBCAs.”

What Researchers Know About GBCAs Today

 

More simply put, the researchers found the body does have a tendency to retain GCBAs for more than 24 hours after injection, although the degree to which they are retained depends upon the GBCA type as well as the specific organ. Another finding by the authors of the report essentially states that much more research is needed to determine more exactly how much the body retains GCBAs, and what, if any, safety risks accompany this retention.

 

Despite an estimated 450 million or more intravenous doses of GCBAs, very little is understood regarding their potential health consequences. While the substance is largely regarded as safe, some types of GCBAs have been linked to nephrogenic systemic fibrosis in patients with advanced forms of kidney diseases. This is why the use of GCBAs is usually contraindicated for patients with serious kidney problems.

 

The GBCA Research Roadmap Plots a Course Forward for Researchers

 

The new roadmap illustrates key concerns and identifies certain subsets of the population that need to be more closely studied. Populations of study include pregnant women, the elderly, younger patients, and lactating women. Research efforts should be aided by utilizing large database sets such as those at the Mayo Clinic, or studies in which patients underwent contrast aided imaging using GCBAs. Use of large amounts of data could help to uncover inconsistencies or particularly vulnerable groups when it comes to GCBA retention.   

 

The study acknowledges that future research will bridge important gaps in knowledge. The roadmap generated by the researchers prioritizes discovering  “(a) if gadolinium retention adversely affects the function of human tissues, (b) if retention is causally associated with short- or long-term clinical manifestations of disease, and (c) if vulnerable populations, such as children, are at greater risk for experiencing clinical disease.”

 

While this new document does not offer any answers to these questions, it does lay the groundwork for future research efforts in order to fill in these gaps. In fact, by plainly stating what is not known regarding GCBA retention, the authors of the “roadmap” have already taken an important first step.  

 

Access the full text of this special report here.