Adults can find it very unsettling to be fed into a dark hole within a large, loud, gray box, one that will take pictures to determine why they are ill. For children, the experience can be downright scary. Unfortunately, medical imaging exams of the past could not help but be intimidating, and, as a result, pediatric caregivers used sedation or immobilization to keep the patients still. Although these methods helped to obtain better images, they increased the anxiety of the patients and their families.

Today, however, that scenario is disappearing as manufacturers release new technologies, new protocols, and new and friendlier designs. With technological advances resulting in faster exams, better image quality, radiation-exposure control, and less intimidating machines, the experience has become an easier one for all involved.

More! More! More!
Like their counterparts in the adult world, pediatric radiologists use the same modalities in the medical imaging spectrum, such as CT, MRI, and ultrasound. "Imaging is used to prove or disprove diagnosis," says Terry Snider, RT (R) (CT), supervisor at St Jude Children's Research Hospital (Memphis, Tenn). Advances in all areas are allowing it to do that more quickly, more accurately, and less invasively.

Improvements in resolution and sensitivity allow detection of disease earlier. Physicians can recognize illnesses at early stages and then develop appropriate therapy or treatment courses, even in utero. "Fetal imaging, using MRI or ultrasound, has made great strides in improving the timeliness of diagnosis of congenital abnormalities so that physicians can offer management options, including fetal or immediate newborn surgery," says William E. Shiels, MD, chief of radiology at Columbus Children's Hospital (Columbus, Ohio).

Better spatial resolution helps to detect and localize diagnoses as well as focus treatment. Johann Fernando, PhD, director of PET/CT science at Philips Medical Systems (Andover, Mass), notes that, for instance, a doctor can now tell if a tumor is one mass or two, meaning it has metastasized and requires a different treatment plan.

Simpler diagnoses benefit as well. "Soft-tissue foreign objects in the body, including wood, glass, and metal, previously required surgery to diagnose," Shiels says. "Now, that is a rare approach. Better than 99% of the time, one can diagnose with ultrasound and even perform a removal with this image guidance."

Ken Gray, director of medical imaging at Children's Memorial Hospital in Chicago, was part of the facility's recent renovation of the department, which the patients have welcomed with open arms. He says patients find smaller machines with rounded edges less intimidating.

The simple availability of PACS workstations brings advantages. "Most physicians develop at least one question in the course of a patient's care," shares Michael D'Alessandro, MD, professor of radiology at the University of Iowa's Carver College of Medicine (Iowa City). "Traditionally, those questions remained unanswered, but the Internet now makes it easy to find them. Instead of going to the library, the library comes to them. Having this information at one's fingertips helps to reduce errors."

Intelligent recognition software, which eliminates the transcription portion of the process, allows for fast report generation and quicker turnaround, according to Ken Gray, director of medical imaging at Children's Memorial Hospital (Chicago).

In turn, faster exam times allow more utility and greater access. "CT has become a first tool in the emergency room," says Sholom Ackelsberg, general manager of research for global CT functional imaging at GE Healthcare (Waukesha, Wis). "It quickly provides lots of information, from head to toe, which is especially useful in trauma cases where the entire body must be examined to determine injury and treatment."

With GE Healthcare's Propellor motion-correction technology, used in the lower right study, brain images in pediatric patients have better resolution and more detail.

Hybrid technologies also are increasing speed and accuracy in diagnosis. When combined with PET, the capabilities of CT or MRI alone are expanded. The combination of metabolic and anatomic imaging is particularly useful in oncology-both for diagnosis and follow up-and brain imaging. "Functional MRI can image different cognitive abnormalities and help guide surgical procedures to avoid important areas of the brain," says Lane F. Donnelly, MD, radiologist-in-chief at Cincinnati Children's Hospital Medical Center (Cincinnati).

Less Size, More Control
Many of these advances, such as hybrid imaging, have originated in the adult market and been adapted to meet the special needs of children. "Children are unique, both physiologically and psychologically," says Shiels, adding that the size of pediatric patients defines a huge difference between them and the adult population.

Their small size presents challenges in visualizing anatomy, both for diagnosis and image-guided treatment. "During a pulmonary embolization procedure in pediatrics, the imaging challenge is the small diameter of the blood vessels. To image where they are large enough (about 3 mm–4 mm in diameter), one must do so centrally where the vessels are more difficult to see. In adults, this is achieved on the periphery. Currently, we can't get the resolution down to the size of the vessel you typically need to be able to resolve in children," notes Robert Cleveland, MD, FACR, chairman of the Committee on Pediatric Radiology at the American College of Radiology (Reston, Va).

Small size also provides greater risk to radiation exposure, specifically ionizing radiation. "The increased cancer risk is very low, but epidemiological studies say it cannot be ignored," says Cleveland, elaborating that the danger can be equated to spending a certain number of hours sitting on the beach.

This figure is thought to be greatest with CT scanners; modalities, such as MRI and ultrasound, have been found to hold very little risk. Cleveland notes, "The high-tech, modern era of CT has been at a cost of producing moderately high radiation doses-not necessarily dangerous-but higher than one would like in pediatrics. We operate with the 'ALARA' concept-as low as reasonably achievable."

Incorporating this concept means that occasionally, image quality is sacrificed for a reduction in dose. Other steps to reduce exposure include assuring the CT exam is necessary, conducting faster scans, and varying radiation protocols. "Current modulating software allows us to set the dose level to reduce the amount of exposure. We do so by setting the level of noise that is acceptable," says St Jude's Snider.

Donnelly of Cincinnati Children's points out that many of the CT manufacturers now offer better dose profiles with less exposure per image. "Many [systems] feature software protocols to avoid overdosing and errors, which can result in extra exams."

Fernando notes that Philips' hybrid PET/CT scanner, the Gemini, has pediatric protocols targeted to provide the lowest possible dose without compromising image quality. GE Healthcare's Ackelsberg explains the company's four-step approach, which includes color coding based on the Broselow-Luten system; automatic exposure control set with the scout scan; pediatric clinical application and detail set software protocols; and faster speeds.

The Columbus Pediatric Radiography Board, developed by Columbus Children's Hospital in Ohio, allows children to be positioned just once and remain in place during the entire imaging exam; it's the equipment that moves.

Less Motion
Faster CT speeds have definitely reduced the need for sedation during these exams; this is also true for MRI, though not to the same extent. "During many pediatric radiology studies, particularly MRI and to a lesser extent CT, children need to be sedated because they can't stay still," Donnelly reveals. "This is definitely true of babies-at 2, they don't understand; for 4 to 7 year olds, it's borderline."

Speed provides one solution. "Restricting motion is always a challenge, but multislice detectors are quicker now, presenting less of a challenge and reducing the need for sedation," Snider says.

Another solution is immobilization. This could be as simple as the swaddling of infants who, once comfortable and warm, might drift off to sleep. Position-specific products like the Octostop Chair and the Pigg-O-Stat Infant Immobilizer and Positioner help to comfortably hold children still.

Other methods are less certain but have met with great success. Donnelly reports that the Cincinnati Children's Hospital Medical Center has successfully used both a light show and MRI video goggles to examine children without sedation. The MRI video goggles, which play DVDs and/or tapes brought in by the patients, were introduced in the spring to provide relaxation and decrease claustrophobia. During the first 6 weeks of use, 35 children who had been scheduled for sedation were able to forgo it. "Formerly, it was common practice to sedate any child under age 7," Donnelly says. "We have now been able to avoid sedation with the goggles on patients as young as 3 years old."

More Comfort
Seemingly small innovations can make a large difference in the patient experience. "These options relax the patient, reduce the need for sedation, and allow the exam to proceed faster. In addition, greater patient satisfaction was found to be an immediate result," Donnelly says.

Improved patient experiences also were the result at Children's Memorial Hospital in Chicago. "We recently renovated our department, and visitors-particularly oncology patients, who make frequent visits-have shared their appreciation for the new space," Gray says.

Even as facilities consider redesigning their pre- and postprocedural rooms, manufacturers are working on the equipment itself. Gray notes that the rounded edges and smaller sizes make the machines less intimidating to patients. Both GE Healthcare and Philips have introduced open MRI and CT models, which allow the patient to see a caregiver in close proximity.

Less Scary
The demand for less intimidating designs, faster speeds, and greater resolution has pushed technological advances. Snider observes that manufacturers look for more speed and accuracy when clinicians and diagnosticians are ready to use the equipment.

For instance, David Weber, manager of the global high-field MR business at GE Healthcare, notes that in an effort to improve differentiation in the brain, new surface coils were developed, boosting signal contrast. "In the adult brain, one gets good differentiation between gray and white matter and other differential structures. But the differences are smaller in pediatric patients if you don't do anything different during the exam," he explains.

MRI manufacturers are looking at ways to increase speed, and CT manufacturers continue to refine techniques for reducing radiation exposure. Weber notes that machines simply won't be purchased unless they make a difference in the quality of care or the bottom line.

Quality of care in general continues to encourage innovation. "Physicians and the imaging community as a whole want to provide better diagnosis as well as improved methods of curing disease," says Fernando of Philips.

Shiels of Columbus Children's Hospital sums it up, stating, "Better outcomes with fewer complications and accurate diagnosis with minimal invasiveness drive the new technology." More quality with less discomfort? Now that doesn't seem so scary.

Renee DiIulio is a contributing writer for Medical Imaging.