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November 25, 2011

ARDMS Updates and Headlines in the News:

ARDMS: Important Testing Center Update

A New Ultrasound Tool Promises to Reduce Caesarean Section

New Pacemaker Needs No Wires

Ultrasound Guidance May Suffice for Renal Radiofrequency Ablation (RFA) Guidance

ARDMS: Important Testing Center Update

• At the test center, you must present two current, valid signature IDs, one of which must be a non-expired government-issued photo ID with your signature; see the accepted list of IDs here.
• The name on your application must EXACTLY MATCH the name on both current, valid signature IDs.
• Jane R. Doe and Jane Rachel Doe DO NOT EXACTLY MATCH.
• Failure to present two acceptable IDs will prevent your admission to the test center. If this happens, you will be marked absent and you will forfeit the entire examination fee and seat.
• If the names do not EXACTLY MATCH, update your ARDMS name of record. 

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A New Ultrasound Tool Promises to Reduce Caesarean Section

At a medical conference in southern Italy in 2006, bioengineer Sergio Casciaro asked a group of gynecologists what they used to monitor birth. One doctor replied, “We rely on the digital method.”

And “by digital,” continued the doctor, “I mean the digits that extend from my palm,” and waved his fingers in the air.

Casciaro was dumfounded. “I couldn’t believe that we still had no technology to provide objective monitoring of birth,” he said.

Attempting to fill this gap, Casciaro and his team of researchers introduced AMOLAB — Automatic Monitoring of Labor. By strapping a transducer belt over a woman’s pelvis, the device is able to transmit live images of the position and angle of the fetus up to the moment of birth.

Conceived by the scientists at the National Council of Research in their spare time, AMOLAB has already won Italy's National Innovation Award. This summer, its first clinical trials began.

In providing continuous recorded evidence of the progression of birth, Casciaro said the 3-dimensional ultrasound instrument could discourage doctors from performing unnecessary Cesarean sections.

“If the national average of C-sections has reached 40 percent, and peaks to 65 percent in southern Italy, there must be a problem,” said Casciaro. “I think the situation is out of control.”

For decades, obstetricians and midwives have relied heavily on their own clinical intuition. They combine their expertise with a number of instruments — including their bare hands — to help monitor everything from fetal heartbeat and contractions, to the size and angle of the baby.

But these traditional tools, as shown by a recent study published in the American Journal of Obstetrics and Gynecology, expose even seasoned doctors to high margins of error.

Doctors know this, so at the sign of any complication during labor, many prefer to make an incision, rather than endanger the baby and mother or face a lawsuit.

“These days, there is definitely an excessive use of Cesarean sections,” said Dr. Gianfranco Nacci, head of Gynecology and Obstetrics at the Perrino Hospital in Brindisi, a major medical center in the heel of Italy’s boot. “This situation doesn’t only affect Italy, but all countries in the world, unfortunately even developing countries,” he said.

Throughout the Western world, the number of C-sections performed has increased dramatically.

Since the 1980s, the World Health Organization has insisted that all countries limit Cesarean procedures to no more than 15 percent of all births. In the United States, rates have reached a national record high of 37 percent, according to a recent report by the National Center for Health Statistics.

Today in Italy, the number of babies born through C-sections has reached 38 percent. This figure has doubled in just 15 years.

This doesn't necessarily mean that the level of medical intervention in childbirth has increased. At the Perrino Hospital, where Nacci has delivered babies for 20 years, precise C-sections have replaced older and more risky procedures — such as using forceps or vacuum extractors to move a baby along the birth canal.

“But we have gone too far now,” said Nacci. “We have arrived at percentages of C-sections that have no clinical justification."

To complicate matters, doctors say patients’ expectations around natural birth have shifted, too.

“In the past, mothers were more willing to wait and labor lasted more hours,” said Laura Bruno, an obstetrician who works with Doctor Nacci at the Brindisi Hospital. “But now, some women come to the hospital expecting C-sections."

To Sergio Casciaro, however, it’s not the mothers’ expectations, but the doctors’ desire to make it home for dinner that influences the final outcome. Also, said Casciaro, in most Italian regions, hospitals can charge double fees for a C-section, which continuously tips the balance against vaginal birth.

“The ability to have tangible, solid evidence to demonstrate that they made the best decision in that scenario is what I want to provide for doctors and mothers,” said Casciaro. While C-sections certainly can save the lives of mothers and babies, the intervention also leads to a longer recovery for the mother and the possibility of other side effects.

“Right now it’s all subjective,” continued Casciaro, who thinks doctors’ discretion doesn’t always safeguard mothers during birth. However, AMOLAB could also have a benefit for doctors, providing information that would shield them from unfair lawsuits.

The AMOLAB team has registered their invention under an international patent and is now in talks with private investors to fund a leap into the commercial market.

View the article online.

Article written by staff at globalpost.com and adapted for the purposes of this newsletter.

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New Pacemaker Needs No Wires

A pacemaker that regulates the heart by wirelessly zapping it with pulses of ultrasound from outside the organ is currently undergoing human trials in Europe.

Conventional pacemakers stimulate the heart tissue via electrical leads that are fed into the heart through a vein. But leads can fail, requiring additional surgery to remove and replace them. The conventional approach also restricts where the therapeutic shock can be delivered.

The new device uses focused acoustic waves that are picked up by a small receiver implanted permanently inside the heart, converting the energy into electricity. Unlike radio waves, ultrasound can pass through tissue at high-enough energy levels without causing any heating.

"This represents a significant breakthrough, eliminating the lead in the heart," said Paul Skjefte, marketing strategist for EBR Systems, the company that created the pacemaker. The startup, based in Sunnyvale, California, was spun out of research by founder Debra Echt, a former professor of medicine and a cardiologist at Vanderbilt University.

The new device, called the wireless cardiac stimulation (WiCS) system, works like an RFID tag in that the receiver has no power supply of its own, and instead gets all its power and signal wirelessly, but with ultrasound instead of radio waves, said Andy Diston, head of global medical technology practice at U.K.-based Cambridge Consultants, which has partnered with EBR Systems to help commercialize the technology. "The receiver is tiny, about 10 millimeters long and one millimeter in diameter. It's like a grain of rice and entirely passive. It gets its energy from the transmitter," he said.

The ultrasonic signal comes from a pacemaker-like box implanted in the chest above the ribs. The box contains an array of ultrasonic transducers that steer and focus the beam toward the receiver. The receiver picks up the signal and converts it into an electrical signal that regulates the heart.

WiCS is initially being tested with conventional pacemakers—with both devices implanted—as a way to provide a form of treatment for chronic heart failure called cardiac resynchronization therapy (CRT), where chambers on both sides of the heart need to be paced. Because it is not safe to place a lead permanently in the femoral aorta—the only main entry point to the left ventricle—surgeons normally have to painstakingly thread one through blood vessels running on the outside of the heart in order to reach the left side.

The WiCS system avoids this by embedding the ultrasonic receiver in the left ventricle. This is the first time that physicians can choose where in the heart this CRT therapy can be delivered, which means it can be optimized, said Skjefte.

Lead placement is an issue with CRT, said Andrew Grace, a consultant cardiologist at Papworth Hospital in Cambridge, U.K. "If one could place the pulse where you wanted in the heart, that would be good. If it is made to reliably work, then this will be an advance," he said.

This is not the first leadless cardiac device. Grace was one of the first cardiologists to try out a device called the subcutaneous implantable cardioverter-defibrillator (S-ICD), made by Cameron Health of San Clemente, California. The S-ICD became available in 2009. But although it doesn't require the placement of leads inside the heart (instead it uses an external one to deliver shocks), it can only deliver the type of powerful shocks that are used for defibrillation, so it's not capable of pacing. "But other companies like Medtronic are also developing systems that have no leads," said Grace.

EBR Systems has not said how many patients have so far been implanted with the device, or when it will be approved for clinical use. "Our initial clinical sites are in the Netherlands, Germany, and Switzerland. We have successfully treated heart-failure patients who were previously left with few options," he said.

View the article online.

Article written by staff at technologyreview.com. and adapted for the purposes of this newsletter.

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Ultrasound Guidance May Suffice For Renal Radiofrequency Ablation (RFA) Guidance

While CT remains the preferred modality to guide renal radiofrequency ablation (RFA) procedures, ultrasound provides a safe and effective method for preselected cases, according to a retrospective study published in the American Journal of Roentgenology. The authors suggested the protocol could decrease CT utilization and cut radiation exposure when applied in an appropriate patient population.

Multiple imaging modalities, CT, MRI and Ultrasound have been used to guide percutaneous renal RFA. John P. McGahan, MD, of the department of radiology at University of California, Davis Medical Center in Sacramento, and colleagues sought to determine whether preablation imaging could be used to triage patients to RFA with ultrasound alone (group 1) or to CT and ultrasound combined (group 2). The researchers examined ablation effectiveness and complication rates in each group of patients.

In the retrospective study, which covered procedures that took place from 2002 until 2009, pretreatment imaging was used to determine whether the mass was well visualized by ultrasound and if the mass was in close proximity to structures that might be injured by ablation. If those two criteria were met, RFA was performed with ultrasound alone (27 patients). In the remaining 29 patients, RFA was performed using CT and ultrasound guidance.

In the ultrasound cohort, 93 percent of masses were initially successfully ablated without recurrence, compared with 84 percent in the combined imaging group. One patient in each group had one major complication, for an overall major complication rate of 3.3 percent. Univariate and multivariate analysis showed no statistically significant difference in complication rates.

Ultrasound guidance was technically unsuccessful for one patient: a 50-year old, 141-kg man with a mass that could not be reliably visualized after the patient was anesthetized. A second patient in this group required a repeat ablation after the six-month follow-up exam.

Five masses in the CT group were not completely ablated on the first attempt: four tumors had nodular enhancement on CT imaging and one revealed abnormal enhancement on CT 26 months after treatment.

“Our results show better technical effectiveness and nearly equal major complication rates for RFA guided by ultrasound alone compared with RFA guided by combined CT and ultrasound, a finding possibly attributable to selection bias,” wrote McGahan et al.

The researchers outline multiple advantages to the ultrasound alone method. These include:

• Eliminating ionizing radiation;
• Reducing CT scheduling pressures; and
• Ability to transport ultrasound throughout the hospital.

In addition, “the use of color-flow ultrasound with ultrasound may help avoid vessels in the path of the needle, within the lesion or note postprocedural bleeding,” wrote the researchers. Furthermore, contrast-enhanced ultrasound may be employed to assess the success of ablation.

However, unlike CT, ultrasound cannot verify needle position in relation to other structures, and ultrasound guidance may be difficult in large patients.

Although McGahan and colleagues concluded that ultrasound guidance alone can be used for guidance of RFA, the researchers issued a caveat, noting that prescreening is important to select patients who may require CT guidance to avoid risk of injury to adjacent structures.

View the article online.

Article written by staff at healthimaging.com and adapted for the purposes of this newsletter.

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