December 15, 2008
RSNA 2008 Reporter’s Notebook
Vol. 9 No. 25 P. 10
Editor’s Note: This article was produced from information provided by the media relations staff of the Radiological Society of North America (RSNA) and presented at press conferences at RSNA 2008 in Chicago.
Exercise Increases Brain’s Blood Flow, May Reduce Age-Related Decline
Older adults who exercise regularly show increased cerebral blood flow and a greater number of small blood vessels in the brain, according to findings presented at RSNA 2008.
“Our results show that exercise may reduce age-related changes in brain vasculature and blood flow,” said presenter Feraz Rahman, MS, currently a medical student at Jefferson Medical College in Philadelphia. “Other studies have shown that exercise prevents cognitive decline in the elderly. The blood vessel and flow differences may be one reason.”
The study, conducted at the University of North Carolina (UNC) at Chapel Hill, is the first to compare brain scans of older adults who exercise with brain scans of those who do not. It was funded by the UNC Biomedical Research Imaging Center and a grant from the National Institutes of Health.
The researchers recruited 12 healthy adults aged 60 to 76. Six had participated in aerobic exercise for three or more hours per week over the last 10 years, and six exercised less than one hour per week. All the volunteers underwent MRI to determine cerebral blood flow and MR angiography to depict blood vessels in the brain.
Using a novel method of 3D computer reconstruction developed in their lab, the researchers made 3D models of the blood vessels and examined them for shape and size. They then compared the blood vessel characteristics and how they related to blood flow in both the active and inactive groups.
The results show that the inactive group exhibited fewer small blood vessels in the brain, along with more unpredictable blood flow through the brain.
“The active adults had more small blood vessels and improved cerebral blood flow,” said the study’s senior author, J. Keith Smith, MD, PhD, an associate professor of radiology at UNC School of Medicine. “These findings further point out the importance of regular exercise to healthy aging.”
Imaging Shows Sound Processing Abnormalities in Autistic Children
Abnormalities in auditory and language processing may be evaluated in children with autism spectrum disorder by using magnetoencephalography (MEG), according to a study presented at RSNA 2008.
“Using MEG, we can record the tiny magnetic fields associated with electrical brain activity,” said Timothy P. L. Roberts, PhD, vice chair of research in the radiology department at the Children’s Hospital of Philadelphia. “Recorded brain waves change with every sensation, thought, and activity. It’s like watching a movie of the brain in real time.”
Typically used for epilepsy evaluation, MEG can also be used to identify timing abnormalities in the brains of patients with autism.
“We found that signatures of autism are revealed in the timing of brain activity,” Roberts said. “We see a fraction of a second delay in autistic patients.”
Ultrasound-Guided Treatment for Plantar Fasciitis Shown Effective
Combining an ultrasound-guided technique with steroid injection is 95% effective at relieving the common and painful foot problem plantar fasciitis, according to a study presented at RSNA 2008.
“There is no widely accepted therapy or standard of care for patients when first-line treatments fail to relieve the pain of plantar fasciitis,” said lead author Luca M. Sconfienza, MD, from Italy’s University of Genoa. “Our new technique is an effective, one-time outpatient procedure.”
Plantar fasciitis, the most common cause of heel pain, is an inflammation of the connective tissue called the plantar fascia that runs along the bottom of the foot from the heel to the ball. The condition accounts for 11% to 15% of all foot symptoms requiring professional care and affects 1 million people annually in the United States.
Conservative treatments, which may take up to one year to be effective, include rest, exercises to stretch the fascia, night splints, and arch supports.
When the condition does not respond to conservative treatments, patients may opt for shockwave therapy, in which sound waves are directed at the area of heel pain to stimulate healing. Shockwave therapy is painful, requires multiple treatments, and is not always effective. Complications may include bruising, swelling, pain, numbness or tingling, and rupture of the plantar fascia. In the most severe cases of plantar fasciitis, patients may undergo invasive surgery to detach the fascia from the heel bone.
Guided Steroid Injection
For this study, Sconfienza and colleagues used a new ultrasound-guided technique along with steroid injection on 44 patients with plantar fasciitis that was unresponsive to conservative treatments.
After injection of a small amount of anesthesia, the anesthetic needle is used to repeatedly puncture the site where the patient feels the pain. This technique is known as dry needling. Dry needling creates a small amount of local bleeding that helps to heal the fasciitis. Lastly, a steroid is injected around the fascia to eliminate the inflammation and pain. The technique is performed with ultrasound guidance to improve accuracy and to avoid injecting the steroids directly into the plantar fascia, which could result in rupture.
After the 15-minute procedure, symptoms disappeared for 42 of the study’s 44 patients (95%) within three weeks.
“This therapy is quicker, easier, less painful, and less expensive than shockwave therapy,” Sconfienza said. “In cases of mild plantar fasciitis, patients should first try noninvasive solutions before any other treatments. But when pain becomes annoying and affects the activities of daily living, dry needling with steroid injection is a viable option.”
MRI Shows New Types of Injuries in Young Gymnasts
Adolescent gymnasts are developing a wide variety of arm, wrist, and hand injuries that are beyond the scope of previously described gymnastic-related trauma, according to a study presented at RSNA 2008.
“The broad constellation of recent injuries is unusual and might point to something new going on in gymnastics training that is affecting young athletes in different ways,” said lead author Jerry Dwek, MD, an assistant clinical professor of radiology at the University of California, San Diego and a partner of San Diego Imaging at Rady Children’s Hospital and Health Center.
Previous studies have reported on numerous injuries to the growing portion of adolescent gymnasts’ bones. However, this study uncovered some injuries to the bones in the wrists and knuckles that have not been previously described. In addition, the researchers noted that these gymnasts had necrosis of the knuckle bones.
“These young athletes are putting an enormous amount of stress on their joints and possibly ruining them for the future,” Dwek said.
The radius is the bone in the forearm that takes the most stress during gymnastics. Due to damage to the radial growth plates, the bone does not grow in proportion to the rest of the skeleton and may be deformed. Consequently, it is not unusual for gymnasts to have a longer ulna than radius. Some former gymnasts must undergo surgery to shorten the ulna and regain the proper fit of the wrist bones into the forearm.
Dwek and coauthor Christine Chung, MD, used MRI to study overuse injuries seen in the skeletally immature wrists and hands of gymnasts. The researchers studied wrist and hand images of 125 patients aged 12 to 16, including 12 gymnasts with chronic wrist or hand pain.
“We were surprised to be looking at injuries every step down the hand all the way from the radius to the small bones in the wrist and on to the ends of the finger bones at the knuckles,” said Dwek. “These types of injuries are likely to develop into early osteoarthritis.”
Dwek said further study is needed to understand how gymnastic stresses are causing these injuries.
“It is possible that by changing the way that practice routines are performed, we might be able to limit the stress on the joints and on delicate growing bones,” he said.
Patient Photos Spur Radiologist Empathy and Eye for Detail
Including a patient’s photo with imaging exam results may enable a more meticulous reading from the radiologist interpreting the images, as well as a more personal and empathetic approach, according to research presented at RSNA 2008.
“Our study emphasizes approaching the patient as a human being and not as an anonymous case study,” said lead author Yehonatan N. Turner, MD, a radiology resident at Shaare Zedek Medical Center in Jerusalem.
Many radiologists have limited contact with patients. A referring physician will order imaging exams, and the radiologist interprets the results without meeting the patients.
Technological advances have further distanced the radiologist from interaction with the patient. With the advent of teleradiology, radiologists are now able to view images from remote locations via the Internet or satellite.
“We feel it is important to counteract the anonymity that is common in radiologic exams, especially with the growth of teleradiology,” Turner said. To study this, the researchers set out to determine whether the addition of a patient’s photograph to a file would affect how radiologists interpreted the results.
For the study, 318 patients referred for CT agreed to be photographed prior to the exam. The patients’ images were added to their files in the hospital’s PACS. The photograph appeared automatically when a patient’s file was opened.
After interpreting the exam results, 15 radiologists were given questionnaires to gather data about their experience. They all admitted that they felt more empathy toward the patients after viewing their photos. In addition, the photographs revealed medical information such as suffering or physical signs of disease.
More importantly, the results show that radiologists provided a more meticulous reading of medical image results when a patient photo accompanied the file.
To assess the photographs’ effect on interpretation, 81 examinations with incidental findings were shown in a blinded fashion to the same radiologists three months later but without the photos. Approximately 80% of the radiologic incidental findings reported originally were not reported when the photographs were omitted from the files.
The radiologists involved in the study commented that while the addition of the photo did not lengthen the time spent reading, it was a factor in how meticulously they interpreted the images. All 15 radiologists agreed that the inclusion of a photograph in a patient’s file should be adopted into routine practice. The photos can also be included in long-distance teleradiology practices.
“The photos were very helpful both in terms of improving diagnosis and the physicians’ own feelings as caregivers,” Turner said. “Down the road, we would like to see photos added to all radiology case files.”
Robotic Technology Improves Stroke Rehabilitation
Research scientists using a novel, hand-operated robotic device and functional MRI (fMRI) have found that chronic stroke patients can be rehabilitated, according to a study presented at RSNA 2008. This is the first study using fMRI to map the brain in order to track stroke rehabilitation.
“We have shown that the brain has the ability to regain function through rehabilitative exercises following a stroke,” said A. Aria Tzika, PhD, director of the NMR Surgical Laboratory at Massachusetts General Hospital and Shriners Burn Institute and an assistant professor in the department of surgery at Harvard Medical School in Boston. “We have learned that the brain is malleable, even six months or more after a stroke, which is a longer period of time than previously thought.”
According to the Centers for Disease Control and Prevention, stroke is the third leading cause of death in the United States and a principal cause of severe long-term disability. Approximately 700,000 strokes occur annually in the United States, and 80% to 90% of stroke survivors have motor weakness.
Previously, it was believed that there was only a short window of three to six months following a stroke when rehabilitation could make an improvement.
“Our research is important because 65% of people who have a stroke affecting hand use are still unable to incorporate the affected hand into their daily activities after six months,” Tzika said.
To determine whether stroke rehabilitation after six months was possible, the researchers studied five right-hand dominant patients who had strokes at least six months prior that affected the left side of the brain and, consequently, use of the right hand.
For the study, the patients squeezed an MR-compatible robotic device for an hour per day, three days per week for four weeks. fMRI exams were performed before, during, upon completion of training, and after a nontraining period to assess permanence of rehabilitation. fMRI measures the tiny changes in blood oxygenation level that occur when a part of the brain is active.
The results show that rehabilitation using hand training significantly increased activation in the cortex, the area in the brain that corresponds with hand use. Furthermore, the increased cortical activation persisted in the stroke patients who had exercised during the training period but then stopped for several months.
“These findings should give hope to people who have had strokes, their families, and the rehabilitative specialists who treat them,” Tzika said.