Pediatric Hospital Installs Kid-Friendly CT Scanner
Next Generation Nuclear Cardiac Imaging
Mayo Clinic First to Offer CT in a Flash!

Pediatric Hospital Installs Kid-Friendly CT Scanner

For pediatric patients, any imaging exam can be a scary experience. Traditional CT scanning, while necessary, can be frightening, require sedation for children to stay still, and increase radiation exposure at a vulnerable age. As a result, children’s hospitals are always looking for ways to improve the radiology experience for their patients.

Toshiba’s Aquilion ONE CT system promises speedier scans and reduced radiation dose for pediatric patients at Arkansas Children’s Hospital.

Arkansas Children’s Hospital has enlisted a new innovation from Toshiba America Medical Systems to do just that. The hospital has become the first pediatric facility to install the Aquilion® ONE 320-detector row CT system, which promises speedier scans and dramatic reductions in radiation for the littlest patients.  

“Any kind of procedure or exam is scary for children,” said Cindy Holland, VP of Ancillary Services at Arkansas Children’s Hospital. “We are dedicated to finding new procedures and technologies to minimize the usage of drugs, make tests faster, and make the entire experience more pleasurable. We installed the Aquilion for its fast, high-quality results that minimize issues for our patients.”

Arkansas Children’s Hospital is the only pediatric medical center in Arkansas and one of the largest in the United States, serving children from birth to age 21. The facility houses 316 beds, a staff of approximately 500 physicians, 80 residents in pediatrics and pediatric specialties, and more than 4,200 employees. Over the years, the hospital has earned an international reputation for medical breakthroughs, unique surgical procedures, and advanced research, and has been named one of U.S. News & World Report’s best pediatric hospitals three times.

The hospital selected the new Toshiba CT scanner due to their long-held satisfaction with Toshiba products, and their continual desire to improve the imaging experience for their young patients. This system scans an entire organ in a single pass and produces 4D videos that show an organ’s structure, movement, and blood flow. In comparison, a 64-slice, 128-slice, or 256-slice CT scanner can capture only a portion of an organ in a single pass, forcing physicians to “stitch together” multiple scans of an organ to get a full image.

The speed of the new scanner, which covers 16 cm in a single 0.35-second rotation, means pediatric patients won’t have to test their ability to stay still. When children are imaged with multidetector CT, sedation is sometimes required to keep the patient still long enough to obtain a clear diagnostic image. Using the Aquilion ONE, the hospital hopes to sedate fewer patients for these exams.

“Any time we can do scans without drugs, it is preferable for our patients,” Holland said. “This scanner is faster with a larger detector, and since our patients’ organs are smaller, we can capture entire organs in one scan. With cardiac scans, we can more easily time the imaging with the beating of the heart. All of this means scans are faster, patients don’t need to be sedated, and exams are more complete.”

Another benefit of the Aquilion ONE for Arkansas Children’s is the reduced radiation dose. With faster, more complete scans, children can avoid excess radiation exposure. The typical cardiac scan with the Aquilion ONE results in less than 2 millisieverts (mSv) radiation dose, versus 10-15 mSv in a conventional pediatric cardiac exam. In addition to the speed reducing radiation dosage, the scanner comes with a type of software that automatically measures the size and age of each patient and tailors radiation dose to achieve the best and safest image quality for each exam. The SUREExposure Pediatric software uses protocols based on the patient’s age, size, and type of exam to ensure patients receive only the radiation required to obtain a clear diagnostic image.

Since the installation in March, the hospital has used their new scanner for pediatric patients in multiple settings, including cardiology, orthopedics, and neurology. To further make the scan as quick, painless, and even enjoyable as possible, the hospital has incorporated a patient screen with child-friendly animations. Children can more easily follow commands with cartoon animals instructing them how.

The facility plans to use the Aquilion ONE in new dynamic studies focused on joint and respiratory issues, and to further develop pediatric protocols to increase pediatric safety and improve the CT imaging experience.

The Aquilion ONE was introduced in November 2007, and has since been named Popular Science magazine’s “Best of What’s New 2008—Personal Health Category,” rt Image’s 2008 Most Valuable Product (MVP), Frost & Sullivan’s Global CT Systems Product Differentiation Innovation Award 2007, and AuntMinnie.com’s “Minnies 2008—Best New Radiology Device.”

Next Generation Nuclear Cardiac Imaging

A new entry in the cardiac CT field, one promising low-dose radiation and significant reduction of artifacts, has received FDA 510(k) clearance. As a result, the nuclear cardiology imaging field may find a powerful new push forward.

The Cardius X-ACT from the Digirad Corporation is a rapid cardiac SPECT imaging system, using a 24-inch detector array to eliminate truncation and generate high-precision SPECT studies. But the X-ACT also incorporates a low-dose volume-computed tomography (VCT) attenuation correction system, reducing artifacts caused by overlying tissues. Together, the SPECT/VCT imaging system is touted to increase interpretive ease and accuracy.

“The X-ACT system is an important step forward in our strategy to drive the evolution of nuclear cardiac imaging,” said Todd P. Clyde, chief executive officer of Digirad. “By introducing a series of advanced solid state cameras that are distinguished by their ability to increase diagnostic accuracy, make earlier detection of disease possible, and provide new clinical information that raises sensitivity or specificity of nuclear cardiology procedures, we’re doing this.”

The VCT technology incorporated in the X-ACT helps to reduce radiation dosage for patients. At the same time, the increased speed of the system further reduces radiation. The system’s high-speed triple-head solid-state design combined with nSPEED® software allows the combined cardiac SPECT emission and transmission acquisitions to be performed in as little as 5 minutes. The resulting dose averages 5 mSv per study.

To study this technology and gain evidence for FDA clearance, Digirad has worked with a number of top nuclear cardiology sites, including the Biomedical Institute in Los Angeles, Jefferson Heart Institute in Philadelphia, and University Cardiovascular Medical Group of UCLA in Los Angeles. Results of an extensive multicenter evaluation of the X-ACT technology will be presented during upcoming events including ACC in Orlando, ICNC 2009 in Barcelona, SNM 2009 in Toronto, and ASNC 2009 in Minneapolis.

Digirad believes that the Cardius X-ACT system increases diagnostic confidence in nuclear cardiology and raises the standard in the industry for overall SPECT system performance.

“The X-ACT system can provide cutting-edge VCT technology to a broader range of practices and facilities, allowing higher patient throughput and a better level of care at pricing comparable to that of less accurate technologies,” Clyde said.

Mayo Clinic First to Offer CT in a Flash!

Continuing its long tradition of CT innovation, the Mayo Clinic is the first facility in the United States to install a new CT scanner that promises unprecedented speed and radiation reduction, along with improved capabilities for individual patient care. The new Siemens SOMATOM Definition Flash dual-source CT scanner has been installed in the CT Clinical Innovation Center, with a second system to be installed in the Mayo Clinic emergency department this summer. With the Flash, the researchers and clinicians plan to expand the abilities of CT usage for the benefit of patients and radiologists worldwide.

“Our mission is to develop new CT applications that benefit patients while minimizing risks,” said Joel G. Fletcher, MD, associate professor of radiology at the Mayo Clinic. “CT technology is offering unprecedented advances, and the Flash is helping us push the envelope, optimizing scans for individual patients.”

The new Flash CT system will benefit patients at the Mayo Clinic and beyond in three major areas. First and foremost, the Flash drastically reduces radiation dose. For imaging of the coronary arteries, the Flash can reduce radiation dose by over a factor of 10 due to its dual-source geometry and increased scan speed. With the Flash, a complete CT scan of the coronary arteries can be performed with an effective dose of less than 1 millisievert (mSv), a significant reduction from the typical dose of 8 to 20 mSv.

Additional features further reduce radiation, including an adaptive dose shield that blocks unnecessary radiation before scanning is initiated. While previously patients would receive the small amounts of radiation coming from the tube at both ends pre- and post-scanning, the shield blocks this radiation, reducing doses by 20%. Finally, another piece of hardware known as the X-Care modulates the tube current to reduce the radiation dose specifically to radiosensitive organs, particularly the breast. Rather than use breast shields, which can decrease image quality, this tool modulates the x-ray tube current to avoid artifacts and extra radiation.

Another major patient benefit of the Flash technology is faster scan time. With two x-ray tubes and two scanners, the new Flash device increases table speed to 43 cm per second, the fastest in CT technology today, but keeps a temporal resolution of 75 ms, enabling complete scans of the entire chest region in 0.6 seconds. A scan of the entire heart can be performed in 250 ms, or about a quarter of a heartbeat. Small pediatric patients who have trouble holding still can be scanned more easily by freezing patient motion. Overall, a full 2-meter scan requires less than 5 seconds total.

The third major benefit to patients from the Flash scanner derives from the dual x-ray tube design. Patients can undergo two simultaneous scans at two different energies, making possible a number of new and improved clinical analyses.

“Other manufacturers have dual energy modes, but do it with one tube,” Fletcher said. “The technology optimizes this process with dual tubes, which offers a high degree of flexibility for different dual energy applications, making everyday use of dual energy CT now possible. We use dual energy for two reasons: One is material classification, especially important in kidney stones and gout. Another key use is with hard-to-detect pathologies.”

The dual energy CT capabilities of the Flash have been optimized by selecting different x-ray beam filters for each of the two tubes, enhancing the ability of the system to differentiate materials that otherwise look identical in single energy CT. This means that clinicians can pinpoint uric acid versus calcium stones in the kidney, allowing for better treatment. They also can identify the differences in uric acid crystals versus calcium in the joints for gout patients, preventing unnecessary joint aspirations or surgeries. They can separate iodine in blood vessels from calcium in plaques or bone, saving processing time and improving visualization of vascular anatomy. And clinicians also will be able to better detect small tumors or areas of inflammation by identifying the presence of iodine contrast within lesions.

Overall, the Mayo Clinic expects improved individualization of patient care through the Flash. The new scanner, with its reduced radiation dose, blazing speed, and dual energy capabilities, allows quick and thorough CT scanning for hard-to-image patients like the morbidly obese, those with bad IV access or renal impairment, coronary CTA patients, and pediatric patients. But it also will allow radiologists to target and hone their work, making the most of every CT scan for each patient.

“As a practice, we are very passionate about this aspect of the new technology,” Fletcher said. “Anybody in medical practice, in or out of radiology, can push a button. But with the Flash and newer tools, we have the ability to maximize patient benefit and tailor every CT scan for each patient’s disease or suspected disease, comorbidities, and diagnostic challenges.

“It’s important for radiologists to be physicians rather than simply an imaging factory,” Fletcher continued. “We need to adapt for patients, and as a specialty, we are really the only group of people that has all the understanding of radiology technology and human pathophysiology to integrate all of the decisions that can be made. I think that we’re the best solution, and the flexibility offered by the new Flash technology is a way that radiologists can highlight the types of unique contributions they can make. Radiologists can demonstrate all the work that goes into preparing and analyzing a scan, and show how patients and their health care providers benefit as a result.”

With more than 35 years of experience in CT imaging, Mayo’s recent addition to its CT scanner fleet continues the ongoing collaborations between Siemens and the CT Clinical Innovation Center. The addition of the Flash to the Innovation Center will provide in-depth usage experience by the Mayo team, and through their publications and educational efforts, increased understanding for radiologists worldwide—another step to using the latest imaging science and CT technology for the benefit of patient care.