By Dr. Richard Towbin

The field of radiology is evolving at a breakneck pace, paving the way for new discoveries in diagnoses, treatments and outcomes.

At Phoenix Children’s Hospital, we are working to harness the full potential of radiology to improve, and ultimately transform, patient care.



New technologies enable us to image patients with an unparalleled degree of precision, whether it’s using 3-D to measure the size of a tumor or pioneering a new procedure that allows cardiologists to evaluate a heart patient’s risk of ischemia. Meanwhile, diagnostic tools are rapidly evolving, helping us to reduce patients’ exposure to ionizing radiation while continually improving image quality.

As division chief of the Department of Pediatric Radiology at Phoenix Children’s, my team and I are constantly looking for new ways to improve pediatric practice. Our efforts run the gamut, including first-of-a-kind projects in radiation dose reduction, new imaging paradigms in MR, new technology such as spectral CT and avant-garde approaches to interventional therapy like 3-D imaging and real-time navigation of needle placement for biopsies.

Our culture is one of innovation and ingenuity, but it’s rooted in a commitment shared by each of the 145 staff members in our radiology department: to help and heal the patients in our care.

Reducing radiation exposure
Radiation dose is a consideration for all providers whose patients must undergo multiple scans, but the concern in pediatrics is even greater. When you consider that children with complex or chronic conditions will require imaging throughout their lives, you must take into account the cumulative lifetime dose. In the past few years, we have introduced several new technologies that allow us to achieve our aim of making accurate diagnoses using the lowest possible radiation dose. Among them are:

• EOS imaging system: Phoenix Children’s providers now have access to the world’s most advanced full-body imaging tool to diagnose musculoskeletal disorders and spinal deformities in pediatric patients. The EOS takes simultaneous frontal and lateral images of patients in just 15 seconds. It provides high-quality, 3-D scans that allow us to see the entire body in one image, negating the need to stitch together multiple images. Only one EOS scan is needed to confirm or rule out common conditions such as scoliosis and lower limb abnormalities.

In addition to image quality and 3-D output, the EOS’ radiation dose is two to three times less than a general computed radiography X-ray and 20 times less than basic computed tomography (CT) scans. The dose delivered in a full spine exam is equivalent to just one week’s worth of natural radiation.

• MAGEC rods: Kids with early onset scoliosis are typically treated using growing rods, which require multiple X-rays over the course of their treatment. Historically, X-rays are needed before treatment begins, and are used to measure progress and determine rod adjustment over time. Understanding the radiation exposure with this approach, Phoenix Children’s began using the MAGEC System (magnetically controlled growing rods), created by Nuvasive, Inc.

MAGEC rods give providers a noninvasive option for treating patients with early onset scoliosis. The system includes an adjustable growing rod with innovative magnetic technology and an external remote controller to elongate or shorten the implanted device. With MAGEC, we now monitor rod adjustments and patient progress with ultrasound instead of X-rays, eliminating radiation exposure for patients.

In addition, children with MAGEC undergo significantly fewer surgeries than traditional growing rod patients, all while achieving the same clinical outcomes. It is a win-win all around.

• IQon Spectral CT: Through our strategic partnership with Philips Healthcare, Phoenix Children’s is the second pediatric hospital in the nation and the fourth in the world to use the IQon Spectral CT scanner in a clinical imaging setting. It provides dual-energy imaging on traumatic injuries, tumors, vascular structures and infections – all in a single scan.

Located in our new emergency department and Level I pediatric trauma center for patients in need of a quick diagnosis, the scanner provides very low-dose, highly detailed images. This enables our radiologists to make faster, clearer diagnoses and ensures our physicians have the information they need to create the best possible treatment strategy.

New learning in magnetic resonance imaging
Beyond our day-to-day work, Phoenix Children’s strives to be at the forefront of research, particularly in understanding the effects of imaging on our young patients. We know that dose is a critical consideration, but we’re looking beyond dose to safeguard the health of the children in our care.

• Impacts of free gadolinium: A subject that’s heating up in the medical field is the impact of free gadolinium in the brain.

Gadolium contrast is a chemical substance commonly used in MR scans. Evidence shows that gadolinium can cause problems, especially in children who undergo multiple MR examinations over a long period of time. In an effort to build awareness of the issue and minimize the impact on children globally, we published two of the first studies on gadolinium deposition in the brains of children, which appeared in Pediatrics and Pediatric Radiology.

Locally, we have altered our protocols at Phoenix Children’s to mitigate the effects of gadolinium. We have moved away from using Magnevist contrast, a linear agent with a high probability of creating free gadolium, in favor of Doterum, a macrocyclic agent with a much lower probability of deposition and untoward effects.

• Amide proton transfer: Kids who undergo brain tumor removal receive a traditional MR after the surgery to determine whether the entire mass was removed. However, traditional MR uses gadolinium, problematic in its own right, but the contrast also lights up the inflamed tissue surrounding the tumor site and makes it difficult to determine whether the surgery was a success.

To minimize gadolinium exposure and improve image quality, Phoenix Children’s is the first pediatric site in the world to utilize amide proton transfer (APT) MR in a clinical setting as a diagnostic tool.

APT assists in the initial diagnosis of a brain tumor and allows providers to determine whether the tumor has been removed. Moreover, APT MRs require no contrast and negate the continued need for gadolinium. Through our use of APT MR, we are amassing unique data that we believe will change imaging practice in pediatric populations.

Advanced imaging
We are committed to building a better future for children with chronic and complex illnesses. A large part of our work focuses on improving existing practice and pioneering new approaches, particularly for the most vulnerable patient populations.

• Drug-induced stress test: Cardiologist Tabitha Moe, M.D. collaborated with pediatric radiologist Dianna Bardo, M.D. to create a new procedure for assessing the coronary arteries in patients with congenital heart disease such as individuals with an arterial switch, Kawasaki disease and other congenital heart conditions, without invasive testing.

Understanding the potential of fractional flow reserve coronary artery computed tomography angiography (FFR CCTA), a procedure that was approved in 2011 for use in adult patients, the team adapted FFR CCTA for pediatric patients.

The test, designed for young adults with congenital conditions who cannot complete exercise-based EKGs, is a noninvasive procedure that allows us to determine whether surgery is required to correct coronary insufficiencies. The test has the potential to transform treatment of children with coronary artery disease worldwide, giving them hope for long-term survival – something that was not possible even a decade ago.

Equally exciting, the dose of ionizing radiation in this test is drastically lower than other modalities. The amount of exposure from FFR CCTA is only 1/20 that of myocardial profusion imaging, making FFR CCTA an especially good option for pediatric heart patients.

• 3-D tumor tracking: Tumors are notoriously difficult to measure given their irregular shapes. Current protocols call for measuring tumors using length, width and height – or xyz – data. This method is problematic because the margin of error is as high as 200 percent, creating a significant challenge in determining appropriate therapies in patients with malignant tumors. At best, xyz provides a guesstimate of a tumor’s true volume.

At Phoenix Children’s, we are using 3-D volume measurements to determine a tumor’s size. The superior precision of 3-D allows oncologists to more precisely identify the most viable course of treatment and determine whether treatments are shrinking a patient’s tumor. Considering that cancer kills more children than any other disease, reliable data is critically important in identifying the best course of treatment, and may even mean the difference between life and death.

Moreover, because 3-D provides precise feedback to physicians about the effectiveness of treatment, the data also can serve as evidence to payors that treatments are working and must be continued, especially in cases where changes are difficult to measure.

New frontiers in radiology
I believe we have only scratched the surface in delivering medical care. Brilliant minds all around the world are racing to discover new cures for conditions that were once a death sentence. For kids with congenital diseases, the future is within our grasp.

• Spinraza therapy: When I was a pediatric resident in the 1970s, the prognosis for children with spinomuscular atrophy (then known as Werdnig Hoffman disease) was grim. Their brains were fully functional, but their bodies were not, and often they would die before their first birthday.

At that time, the medical community did not understand the genome. We were helpless in caring for children with congenital conditions. Today, breakthroughs in molecular therapy are a game-changer for children with SMA and other genetically based diseases. At Phoenix Children’s, we are engaged in new research and treatment using a molecular therapy called Spinraza, which is injected in the cerebrospinal fluid and absorbed in the spinal cord. At the simplest level, the drug gives a child the DNA coding his/her cells are missing. The cells then begin to produce the material that has been missing. It is nothing short of amazing.

Molecular therapies like Spinraza are a harbinger of tomorrow and a hope that congenital diseases will soon become a thing of the past.

The road ahead is an exciting one. Radiology stands at the forefront of medical advancement, leading the way for new innovations in diagnoses and treatments, and providing life-saving care for patients worldwide.

About the author: Dr. Richard Towbin is an internationally renowned pediatric radiologist and Phoenix Children’s division chief of radiology. He is an expert in pediatric interventional radiology, pediatric neuroradiology and an avid researcher, has published over 300 papers, has patented four medical devices and has served as president and chairman of the board of the Society for Pediatric Radiology and treasurer of the Society of Interventional Radiology.