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ARDMS Recertification Assessment Program to Start in 2012

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Recertification Assessment Program Fast Facts:

• Examinations to begin in 2019
• No charge for 1st attempt for each specialty
• Online Examinations  (not at a testing center)
• Open book/resource
• Specialty content only, no general physics
• Approximately 50 questions
• ARDMS credentials will be valid for 10 years
• Required standard for ARDMS organizational accreditation

Headlines in the News:

Development Efforts Aim to Facilitate Contrast Enhanced Ultrasound (CEUS) for Molecular Imaging

CEUS offers much potential for molecular imaging applications...

High Intensity Focused Ultrasound (HIFU) Treatment for Prostate Cancer Now Available in Bermuda

Bermuda is the newest location to become part of US HIFU's international treatment program, which provides patients from the U.S. access to the Sonablate technology...

Ultrasound-guided Interscalene Block Placement Accurate and Successful

Ultrasound localization can provide accurate anesthetic placement not made possible by other techniques...

Development Efforts Aim to Facilitate Contrast Enhanced Ultrasound (CEUS) for Molecular Imaging

CEUS offers much potential for molecular imaging applications...

CEUS offers much potential for molecular imaging applications such as in vivo imaging of angiogenesis and assessing disease states for therapy monitoring. Researchers described the state of the art in CEUS in a presentation this week at the Leading Edge in Diagnostic Ultrasound conference.

To facilitate the development of this nascent technology, work is under way to address technical hurdles affecting its sensitivity, specificity, field-of-view, and quantitative capabilities, according to a presentation by Paul Dayton, Ph.D., an associate professor of the joint department of biomedical engineering of the University of North Carolina and North Carolina State University.

"I'm hoping it won't be too long in the future that we can see images where we have volumetric information, where we can look at several different molecular targets based on different-sized contrast agents, and, ideally, we would have some idea of about how many cells are expressing these molecular targets," he said.

In contrast to traditional ultrasound viewing of anatomical features or blood flow, molecular imaging requires imaging of cellular and molecular changes. The goal is to gain enhanced detection of pathologies that are not easily detectable with traditional ultrasound or to monitor therapy by assessing disease states, Dayton said.

As an inexpensive, portable, real-time, and safe imaging method, ultrasound offers a lot of advantages in molecular imaging over other modalities, he said. "It makes sense to turn ultrasound imaging into a molecular micro-imaging tool."

Ultrasound molecular imaging takes into account knowledge of the molecular signature of pathology, utilizing targeted contrast agents that incorporate adhesion ligands (such as an antibody or a peptide on the microbubble shell) or other selective mechanisms that will adhere to the diseased cell, Dayton said. These agents are injected intravascularly and then collect at the site of pathology.

This allows for tasks such as in vivo angiogenesis imaging and molecular imaging of therapeutic response.

Challenges

Molecular imaging with ultrasound requires sensitivity -- the ability to detect small numbers of targeted contrast agents that are attached to disease cells. It also must have specificity, to detect only the target area and not be confounded by freely circulating contrast agent that hasn't bound to the target, he said.

It must also have a field-of-view that allows for interrogation of the entire disease area, and it would ideally have a quantitative ability that allows for correlation of image contrast with degree of pathology, Dayton said.

Currently available contrast agents, however, have a mean diameter and polydispersity (i.e., variations in size) that don't fit as well with the requirements of molecular imaging, according to Dayton. Today's contrast agents have a mean microbubble size distribution of 1.8 ± 1.5 microns in diameter.

Different-sized microbubbles react differently to ultrasound signals based on their size. In a recent acoustic experiment involving microbubbles of uniform size, researchers noticed, among other findings, that the larger the microbubble size, the higher its acoustic response.

"So there are definitely ways to optimize the response that we see from microbubbles," he said. "And, quite frankly, most of the commercial microbubbles are not optimized for detection with commercial imaging systems. To date this really hasn't been a problem, because with [traditional] contrast imaging you inject millions to billions of these contrast agents into a patient and you only needed to detect a small fraction of those. So it's not important that you're really sensitive to every single microbubble."

That's not the case with molecular imaging, which requires optimized sensitivity for the small number of microbubbles that are retained in the tissue, he said.

A previous study evaluating kidney perfusion in a rat found that a contrast agent with an optimal size for molecular imaging led to a 10- to 15-fold increase in sensitivity compared to a low dose of a standard contrast agent.

"This is something that we're going to see in the not-too-distant future," he said. "Microbubble diameter and distribution can substantially improve imaging sensitivity, and I'm sure it won't be long until the microbubble manufacturers will be moving in this direction."

As for specificity, one way to improve it is to make better adhesion ligands for the microbubbles. In addition, improved rejection of nontargeted contrast agents could help. An ultrasound molecular imaging signal processing technique would enable real-time detection of microbubbles.

This can be achieved using filtering techniques, separating freely circulating agents from agents bound to pathology, he said. "This is what needs to happen to make molecular imaging a real-time technique in the clinic," he said. "Prior commercial imaging systems are not really optimized to do this yet, but the technology is possible, and I'm sure as we find molecular imaging becomes more of an interest to clinicians, this is something that we'll see available on clinical imaging systems."

Field-of-view also represents a challenge for ultrasound molecular imaging. Single-slice imaging may not provide reliable information in nonhomogeneous tissue. In addition, while 3D contrast imaging will provide essential data about the distribution of molecular targets in tissue, high-resolution, contrast-specific 3D tissue imaging is just starting to be developed, he said.

Quantitative ability represents yet another challenge. Right now, most molecular imaging is based on relative measurements, mostly generated from image video intensity.

"Ideally, we would want to know the exact relation between video intensity and the number of microbubbles that are retained in the tissue, so we can more quantitatively assess disease states," he said. This task has been difficult, due in part to the polydisperse nature of current microbubbles.

"Development of uniformly sized contrast agents in the future may allow the creation of algorithms to estimate the number of contrast agents retained in the acoustic intensity," he said.

View the article online

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

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High Intensity Focused Ultrasound (HIFU) Treatment for Prostate Cancer Now Available in Bermuda

Bermuda is the newest location to become part of US HIFU's international treatment program, which provides patients from the U.S. access to the Sonablate technology...

US HIFU, a worldwide leader in the development, distribution and use of minimally invasive high intensity focused ultrasound ("HIFU") technologies, is pleased to announce that its HIFU treatment for prostate cancer is now available in Bermuda. King Edward VII Memorial Hospital in Bermuda joins more than 100 centers in 30-plus countries to offer the innovative treatment with the Sonablate® 500 medical device. 

Bermuda is the newest location to become part of US HIFU's international treatment program, which provides patients from the U.S. access to the Sonablate technology ("Sonablate HIFU") in international facilities where it is approved or authorized, since Sonablate HIFU is in the final phase of the FDA clinical trials and not approved for use in the U.S. As part of the US HIFU international treatment program, which began in 2004, patients and physicians travel to the Bahamas, Mexico, Canada and other jurisdictions outside the U.S. for the procedure. 

"We were strategic in our selection of Bermuda so we could open up access to Sonablate HIFU for interested patients and physicians in the northeast," said US HIFU's CEO Steve Puckett, Jr. regarding the company's decision to introduce Sonablate HIFU in Bermuda at this time. "For ease of transportation, we expect to see a good number of patients and doctors from that area and eastern seaboard in general, but Bermuda's King Edward VII Memorial Hospital is just one more high-caliber choice open to any patients and doctors throughout the country." 

Dr. Donald Thomas, the hospital's chief of staff, said, "We are very pleased to be able to offer this treatment. As we are only about a two-hour flight from the eastern U.S., we can offer this high-tech procedure very close to home for some U.S. patients in a stunningly beautiful island setting." 

The first two patients were treated at the beginning of May by Dr. Stephen Scionti, NYU clinical associate professor of urology, who has been involved with Sonablate HIFU since 2006. 

"The hospital is a modern, first-rate organization staffed by world-class physicians. As with the other US HIFU facilities, I believe patients can feel as confident in traveling offshore for the treatment as they can in going to their local hospital for an already approved procedure," said Scionti. "As a physician working away from my regular office, I am able to focus on my patients and their treatment when everything in the venue is in perfect order; King Edward VII Memorial Hospital was no exception."

View the article online

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

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Ultrasound-guided Interscalene Block Placement Accurate and Successful

Ultrasound localization can provide accurate anesthetic placement not made possible by other techniques...

Ultrasound localization can provide accurate anesthetic placement not made possible by other techniques, according to investigators. Anshuman Singh, MD, presented his group’s findings at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons in New Orleans.

Singh noted that a more accurate placement of anesthetic leads to high patient satisfaction and a low rate of adverse events. Still, he said, there are those who are wary of its use.

“Some surgeons advise against the use of interscalene block with their particular patients, probably because early literature had a high rate of catastrophic events,” he said. “The anesthesiologists went back to the drawing board and basically came up with a list of things that facilitates the placement of interscalene blocks … ultrasound guidance essentially has been unstudied in the orthopedic literature.”

According to Singh, the purpose of the investigation was to evaluate the safety and efficacy of ultrasound-guided interscalene block (ISB).

A prospective evaluation

The study involved the prospective evaluation of a cohort of 1,333 patients undergoing shoulder arthroscopy from 2005 to 2008 at a single private ambulatory surgery center. Ultrasound-guided ISB was performed by an experienced anesthesiologist, and preoperative complications, block failure and time to discharge were all recorded.

A physician queried patients 24 hours after surgery, recording onset of pain, pain level, emergency visits and patient satisfaction. The patients were then screened for a comprehensive register of adverse events, and those with complications were followed until resolution.

Low failure rates                          

“Only five patients failed,” Singh said. “Two of these were re-blocked preoperatively with success, for a low failure rate. These were done in the pre-op area, and patients left about an hour and a half after they left the operating room. They went home, and the blocks lasted about 14 hours.”

The five immediate failures and two re-blocked patients led to an ultimate success rate of 99.6%, Singh said. Thirty-eight major and minor complications (2.85%) occurred overall, although Singh reported most of these were not major. “This was a very sensitive study,” he said. “Over half of the problems were ear numbness and digital numbness that was very transient.” Three patients with medical comorbidities had permanent issues – two with brachial plexus palsy and one with myocardial infarction the day after surgery.

Singh reported that 99.07% of patients were satisfied or very satisfied, with 0.97% responding they were unsatisfied. “Ninety-eight percent of people said they would have it again, if they could,” he said.

View the article online

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

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