Obesity is preventing many people from getting hospital tests because they are too large to fit into scanners. More and more patients are consequently missing out on medical treatments they need.

Even if hospital workers manage to scan these obese patients, interpreting results can be problematic when fat tissue is very dense. Certain procedures are unsatisfactory because ultrasound waves do not penetrate all of the body fat.

Small tumors and other problems might be overlooked due to poor image quality, said Raul N. Uppot, MD, lead author of the study and staff radiologist at MGH.

Incomplete examinations can lead to serious consequences for the patient, such as misdiagnosis or failure to make a diagnosis at all.

Diet and Exercise

In order to identify tests that were hindered by patient size, Dr. Uppot and colleagues examined all radiology records from tests done at MGH between 1989 and 2003.

The percentage of problem tests nearly doubled between 1989 and 2003, they found.

The prevailing lifestyle in the United States and other industrialized countries that encourages poor diet and lack of exercise has led to the current obesity crisis, Dr. Uppot believes.

"Americans need to know that obesity can hinder their medical care when they enter a hospital," he said.

Ripple Effect

One approach to the problem is to increase the dose of radiation, but that solution carries its own health risks.

Furthermore, 83 percent of hospital technicians involved in moving obese patients on and off imaging tables told researchers they experienced some pain during those procedures.

There can also be economic consequences. Further testing and increased hospitalization time might be required following an inconclusive exam.

Scanning obese patients taxes imaging systems by requiring increased power output and contributing to more rapid burnout of X-ray tubes, for example.

Cultural Shift Required

"In the short term, the medical community must accommodate these patients by investing in technology to help them," Dr. Uppot explained.

Hospitals may need to replace older equipment in order to accommodate the growing number of large patients, he noted.

Some are reportedly sending people who don't fit into scanners to veterinary facilities.

"In the long term, this country must make cultural shifts that promote more exercise and a healthier diet," Dr. Uppot concluded.