Too Fat For Mri

Research has shown that doctors may spend less time with obese patients and fail to refer them for diagnostic tests. One study asked 122 primary care doctors affiliated with one of three hospitals within the Texas Medical Center in Houston about their attitudes toward obese patients. The doctors “reported that seeing patients was a greater waste of their time the heavier that they were, that physicians would like their jobs less as their patients increased in size, that heavier patients were viewed to be more annoying, and that physicians felt less patience the heavier the patient was,” the researchers wrote. Dr. Louis J. Aronne, an obesity specialist at Weill Cornell Medicine, helped found the American Board of Obesity Medicine to address this sort of issue.

Drug doses are usually based on standard body sizes or surface areas. The definition of a standard size, Dr. Hudis said, is often based on data involving people from decades ago, when the average person was thinner. Scanners that can handle very heavy people are manufactured, but one national survey found that at least 90 percent of emergency rooms did not have them. Even four in five community hospitals that were deemed bariatric surgery centers of excellence lacked scanners that could handle very heavy people. Yet CT or M.R.I. imaging is needed to evaluate patients with a variety of ailments, including trauma, acute abdominal pain, lung blood clots and strokes.

For imaging studies that use CT or magnetic resonance imaging (MRI), the problem is one of fit. The equipment can only hold a limited amount of weight. MRI equipment is also limited by the size of the tunnel in which a person must enter in order to be scanned. Uppot says obesity affects the quality of all types of imaging.

Advertisement Advertise with NZME. "Ultrasonographers are at risk of wrist and shoulder injuries and this is increased when scanning obese patients as sound waves are absorbed and scattered by fat," Barnard wrote. According to the National Health and Nutrition Examination Survey conducted in 2015-2016, the prevalence of obesity (BMI ≥30 kg/m2) in U.S. adults was 39.8% [2].

The goal is to help doctors learn how to treat obesity and serve as a resource for patients seeking doctors who can look past their weight when they have a medical problem. Uppot says he became interested in how often imaging examinations were less than adequate because Massachusetts General has a number of patients who undergo gastric bypass procedures in an attempt to control obesity. When these patients were sent to radiology to see how well the procedure was doing, several were turned away because they were too big. Uppot says his study indicates that ultrasound is the imaging procedure that is most frequently affected by obesity. He says almost 2% of patients sent for an ultrasound examination are unable to have a satisfactory study performed because of size.

For example, obesity interferes with ultrasound assessment because it is difficult for ultrasound wave signals to penetrate fat to picture the organs underneath. As a result, the image becomes unreadable. Uppot says he reviewed all radiological reports at Massachusetts General Hospital between 1989 and 2003.

Others resort to more extreme measures. Dr. Kahan said another doctor had sent one of his patients to a zoo for a scan.

In 1989, Uppot determined that 0.1% of patients at Massachusetts General could not be imaged because of their obesity. In 2003, that rate had nearly doubled to 0.19%. Under most circumstances, quality CT images can be obtained in patients weighing up to 450 pounds. Most MRI equipment can accommodate patients up to 350 pounds. Wellington region DHBs have previously written to the Health Minister urging a tax on sugary drinks and warning that "for the first time in history, NZ children could live shorter lives than their parents as a result of excess weight and obesity".

That correlates to the increase in obesity in Massachusetts, which rose from 9% in 1991 to 16% in 2001, he said. “Bad outcomes because of inappropriate dosing do occur,” said Dr. Lemmens, who added that 20 to 30 percent of all obese patients in intensive care after surgery were there because of anesthetic complications. Given the uncertainties about anesthetic doses for the obese, Dr. Lemmens said, he suspects that a significant number of them had inappropriate dosing. But, he added, another reason for poor outcomes in obese cancer patients is almost certainly that medical care is compromised.

A persistent myth in the medical community is that morbidly obese patients can be referred to zoos because they have scanners designed for large animals, said both Drs. Uppot and Gunn.

“It was the perfect marriage of the high-quality imaging with the patient comfort,” Day said. Magnetic resonance imaging (MRI)is an imaging procedure that uses a large magnet, radiofrequencies, and a computer to produce detailed images of organs and structures within the body in order for doctors to make or "rule out" medical diagnoses. MRI does not use radiation, as do X-rays or CT scans. Our state-of-the-art MRI scanners have “motion correction” imaging that allows for a faster examination. That means the patient is in the scanner for a shorter time.

Up to six staff can be needed to move a patient from bed to an examination table, and the weight of patients means injuries can be sustained. Advertisement Advertise with NZME. About 36,000 people living in Counties Manukau are morbidly obese, nearly twice the number of any other DHB.

Medical device companies say they’re doing just that to cope with a projected increase in the number of obese patients in the next decade. By 2010, if present trends continue, 50% of Americans could be classified as obese. Two weeks ago at the annual meeting of the Radiological Society of North America, Raul Uppot, a fellow in abdominal imaging and interventional radiology at Massachusetts General Hospital in Boston, presented a study documenting the effect of obesity at the Harvard teaching hospital. Uppot and his colleagues examined 15 years of tests and found that between 1989 and 2003, the number deemed inconclusive because of obesity almost doubled, from 0.1% to 0.19%.

While exceeding the weight limits risks breaking the scanner's table or motor, the cost of fixing or replacing the equipment is typically much less than the cost of a potential lawsuit for misdiagnosis, they noted. T he rising prevalence of obesity has created not only health dangers for patients, but also new challenges in diagnostic testing for hospitalists. The rising prevalence of obesity has created health dangers for patients and new challenges in diagnostic testing for hospitalists. Image Getty Images Some health boards have been forced to buy extra-large scanners or send patients to out-of-area hospitals for examinations.

In an article in the May 2006 American Heart Journal, Dr. Daniels concluded that for patients with the highest BMIs (35 or over), a lower BNP cut-point of ≥54 picograms per milliliter (pg/mL) should be used to maintain the same level of diagnostic sensitivity as for non-obese patients, for whom a cut-point of ≥100 pg/mL is recommended. However, the normal cut-points at which CHF is suspected in non-obese patients have been found not to apply to obese patients, she said. Possible reasons include that the rate that BNP is cleared from the body increases with excessive fat tissue and that obese people produce less BNP than non-obese people.

UCSF has invested in the latest MRI machines that have wider openings and better lighting in the scanner tunnel. These machines greatly improve patients’ comfort during the exam and also yield higher resolution so the images are clearer.

Botts said that due to the increased comfort, patients request to have their tests done in the wide bore scanners. “At one site we have two different scanners.

Dr Stuart Barnard, clinical director of radiology at the hospital, has reported on how that's changing his team's work. Anaesthetists are also struggling to guide needles through layers of body fat, ultrasounds can be clouded by excess weight, and staff risk injury trying to move patients, with up to six people sometimes needed. A report last year warned the NHS is ‘poorly prepared’ to deal with obese patients, lacking staff and equipment to care for them safely. Briatin’s fire crews have spent millions on callouts by the NHS in recent years shifting obese patients who have got stuck in the bath or their bedrooms, or who cannot be safely lifted by ambulance staff. CT scans are used by doctors to assess body fat as well as for more general health checks to see if anything is wrong.

One in three Americans is obese, a rate that has been steadily growing for more than two decades, but the health care system — in its attitudes, equipment and common practices — is ill prepared, and its practitioners are often unwilling, to treat the rising population of fat patients. New MRI scanners were bought last year, one of which can take up to 220kg and has an internal diameter of 70cm. A DHB spokeswoman said that let all patients be scanned.

Patients come in, look at one and look at the other, and specifically ask to go on the bigger bores. Similarly, failing to refer morbidly obese patients to appropriate imaging alternatives can have negative repercussions, said Dr. Uppot. Four years ago, he conducted an informal study looking at what happened to 14 patients who came to the ED with an acute condition and could not fit onto the hospital's scanners.

UCSF Radiology is committed to providing the highest level of imaging quality and radiation safety to our patients through our nationally accredited practices. The Department of Radiology and Biomedical Imaging is committed to maintaining the highest possible standards of patient care and safety. More information about our commitment can be found at on theMRI Safety page. The MRI machine is a large, tube-shaped machine that patients lie within, and the MRI creates a strong magnetic field around the patient. The magnetic field and related pulses of radio waves produce signals from the body that are detected and converted into images by a computer.

Similarly, almost 1% of patients sent for chest X-rays were unable to have useful examinations performed. In a separate study, he tracked 28 obese patients during 2004 who could not be imaged.

The patient was removed from the magnet and the cover sheet was replaced. The patient was reinserted into the magnet, the exam was successfully completed, and the patient was returned to brachytherapy for her treatment.

After the MRI incident, it was discovered that the patient received cone-beam CT (CBCT)-guided external beam radiation therapy with the lighter present in her right pelvic pannus. The radiation therapists were not aware of the MRI incident and assumed the source of the CBCT metal artifact was located inside the body cavity due to its apparent depth (Fig. 3 ). The lighter was located in 1 of the radiation beam paths during 2 fractions, but the impact to treatment was minimal. A note about the patient's penchant for storing her lighter in her pannus was placed in her electronic medical record. The radiation therapists, brachytherapists, and simulation therapists were instructed to search for the lighter before subsequent treatments and simulations.

Wide bore magnetic resonance imaging (MRI) systems have allowed radiologists to offer patients the optimized comfort of conventional open bore systems, as well as the high-quality imaging of conventional closed bore systems. Because wide bore MRIs have broadened the demographic of patients who can be tested, the systems have gained widespread adoption in use, with many practices opting to equip their offices solely with wide bore systems.

London Zoo also denied taking obese patients but a spokeswoman for the Royal Veterinary College confirmed they have been approached. The Royal Veterinary College (RVC)yesterday said its CT scanners, customised for horses, could be used to accommodate patients weighing 30 stone or more but they would need to get a special licence to scan humans. The bizarre requests to use CT scanners, normally intended for four-legged animals, at the UK’s leading veterinary college in north London were revealed as hospitals face pressure to adapt beds and wards for an increasingly obese population. MRI machines have weight limits ours is 330 lbs (fairly standard) and our bariatrics one (fatty machine) at a nearby hospital has a limit of 550 lbs. The phenomenon of a patient storing items in their body habitus (known as the “Human Couch”) was previously reported for an obese ER patient who had an asthma inhaler, dime, paper towels, and a TV remote control hidden on the exterior of her large body habitus [18].

She was so humiliated that she declined requests for an interview. For many, the next step in a diagnosis involves a scan, like a CT or M.R.I. But many extremely heavy people cannot fit in the scanners, which, depending on the model, typically have weight limits of 350 to 450 pounds. That happened to a patient who eventually went to see Dr. Scott Kahan, an obesity specialist at Georgetown University. The patient, a 46-year-old woman, suddenly found it almost impossible to walk from her bedroom to her kitchen. Those few steps left her gasping for breath.

A main reason these new wide bore machines have become so widely popular is because they have allowed those patients who cannot fit into conventional MRI machines — for example, obese patients or patients with wide shoulders — the option to have MRI tests done. “The population of the country, and certainly in our area, continues to grow in regards to body habitus,” said Botts when discussing PinnacleHealth’s decision to purchase a wide bore scanner. “Our ability to serve certain people in the population was starting to decrease with the smaller bore scanners and with the weight limits that they started out with.” With the addition of a new wide bore scanner to the practice, PinnacleHealth has been able to provide the best service for the largest number of people possible.

Instead, the MRI Technologist removed the lighter. The patient was reinserted into the bore and another set of surveys was acquired. The susceptibility artifact was reduced, but still significant.

HUNDREDS of patients have had MRI scans cancelled because they are too fat to fit in the tube. Before Day adopted wide bore systems at his practice, his dilemma was whether to market conventional open MRI systems to the patients for their increased comfort, or to buy a 1.5 Tesla, high field, tunnel, claustrophobic magnet because referring physicians preferred the image quality. With the acquisition of Siemens’ Magnetom Espree, he was able to talk with patients about comfort and to referring physicians about quality.

One of the most frequent medical problems in obese patients is arthritis of the hip or knee. It is so common, in fact, that most patients arriving at orthopedists’ offices in agonizing pain from hip or knee arthritis are obese. But many orthopedists will not offer surgery unless the patients first lose weight, said Dr. Adolph J. Yates Jr., an orthopedics professor at the University of Pittsburgh School of Medicine. The difficulties range from scales and scanners, like M.R.I. machines that are not built big enough for very heavy people, to surgeons who categorically refuse to give knee or hip replacements to the obese, to drug doses that have not been calibrated for obese patients.

Of all the imaging modalities, CT scanning is usually the best option if a person can fit on the scanning table, he said. CT scanning tables typically have a higher weight limit than MRI tables (450 lb vs. 350 lb).

A large magnetic susceptibility artifact was detected near the right pelvis during the MRI scout indicating the presence of ferrous material. The source of the artifact turned out to be a disposable lighter that was stored inside the patient's pannus.