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Imaging Advances in Endoscopy

Modern technology advances at a lightning pace. Computers become obsolete before they even hit the consumer market. The trendy iPhone is already on its second or third iteration. And BlueRay just beat out HD in the effort to supplant the traditional DVD format.

Just as in the consumer market, medical imaging is advancing by leaps and bounds. Many of these tools are not restricted to physicians’ use — nurses and technicians may be asked to handle these high-tech devices as well.

Image courtesy of Given Imaging

Given Imaging has focused its attention on capsule endoscopy, and the field is growing exponentially. One of the latest offerings is the PillCam video capsule. "Capsule endoscopy is designed to help physicians see what is happening inside the gastrointestinal (GI) tract," says a Given Imaging spokesperson. "During the procedure, the patient swallows a vitamin-sized pill with a camera inside. Transported smoothly and painlessly through the GI tract by the body’s own natural peristalsis, the PillCam video capsule transmits images of the small intestine and the esophagus."

Several versions of this product are now available. The first is the PillCam ESO. Cleared by the U.S. Food and Drug Administration in November 2004, PillCam ESO was developed for patients suffering from esophageal disorders, such as esophageal varices, which can result in fatal bleeding, and Barrett’s esophagus, which is an early indication for esophageal cancer. "The PillCam ESO provides a patient-friendly alternative to esophageal endoscopy and the associated sedation and discomfort," says a Given Imaging spokesperson. PillCam ESO contains an imaging device and light source at both ends of the capsule and takes up to 14 images per second, a total of 2,600 color images, as it passes through the esophagus.

The second option is the PillCam SB. Cleared by the FDA in 2001, PillCam SB is used to visualize the small intestine when diagnosing disorders such as Crohn’s disease, small bowel tumors, malabsorption disorders (such as celiac disease), GI injuries induced by extended nonsteroidal anti-inflammatory drugs (NSAID) use and suspected GI bleeding of the small bowel. "PillCam SB transmits images at a rate of two images per second for approximately eight hours, resulting in more than 50,000 pictures. To date, more than 500,000 patients worldwide are benefiting from this innovative procedure. Given Imaging is also developing a next-generation PillCam SB capsule that will incorporate new optical and image sensor technology to provide superior image quality," says the spokesperson.

Image courtesy of SmartPill Corp.

Finally, there is the PillCam COLON video capsule. This product was developed to visualize the colon and was cleared for marketing in the European Union in 2006. It is not yet cleared for marketing or available for commercial distribution in the U.S. — 510(k) approval is pending. Multi-center clinical trials are underway in Europe and the U.S. PillCam COLON measures 11 mm by 31 mm and contains imaging devices at each end that capture four images per second during the procedure. Each camera utilizes automatic lighting control and a frame rate and depth of field that have been specially adapted for the wider lumen and high degree of compartmentalization that characterizes colon physiology.

This tool is something nurses may assist with in the GI suite. "Given the proper training, nurses commonly prep the patient and assist physicians in administering the PillCam video capsule. Given Imaging hosts several comprehensive training programs for nurses and allied healthcare professionals in different cities throughout the year. These courses are intended to educate nurses and other healthcare professionals on the clinical, technical, and procedural aspects of capsule endoscopy. During these courses, various modules are offered to address the needs of the technician pertaining to administration, applications and software utilization," says the spokesperson.

KARL STORZ Endoscopy-America, Inc., has added high-definition (HD) technology to its Image 1® family of products, says Jeffrey Yates, group marketing manager, video imaging, at Karl Storz. "The launch of Image 1® HD gives surgeons in virtually every specialty the best viewing experience by combining the highest resolution available (1080p) with a more natural widescreen view of endoscopic images (16:9). FULL HD technology begins with the optics of the company’s Hopkins II® rod-lens telescopes. Surgical images are captured on three 16:9 CCDs (charge coupled devices) in the camera head, and then displayed on 16:9 WideView™ HD monitors. Because surgical images are acquired and displayed as 16:9 1080p60 images, Image 1 HD exceeds consumer broadcast standards for HDTV," he adds.

The FULL HD is designed with superior resolution, Yates adds, offering users optimum clarity, color contrast and depth perception during endoscopy. This enables surgeons to better distinguish between anatomical planes. "It enhances landmark recognition and identification of suspect tissue. Progressive scanning at 60 frames per second produces images with less distortion — especially during rapid instrument movement," he explains.

Image courtesy of Karl Storz Endoscopy America, Inc.

Because the Image 1 is a platform rather than a stand-alone camera system and is both forward- and backward-compatible, the technology can offer savings over many years, for a lower cost of ownership, he adds. In addition, the workflow is optimized because there is no need to purchase, maintain and store separate carts for each specialty.

The Image 1 benefits not just surgeons, but also the rest of the surgical staff, Yates says. "With a greater depth of field, color and contrast, the HD image allows visualization of minute structures and abnormalities that were previously unrecognizable with earlier standard definition endoscopic video technologies. Additionally, the 16:9 display provides a 30 percent larger view of the operative area and a more ergonomic display. This results in less eye fatigue during long cases and earlier visualization of instruments," he adds.

Olympus America also offers several new options for the endoscopy suite; the company has been focusing on innovative imaging developments to provide a higher-definition experience. The PCF-H180AL/I video colonoscope offers 1080i high definition and Narrow Band Imaging™ in a slim design. The pediatric PCF-H180AL/I high definition video colonoscope is the newest offering in the EVIS EXERA II™ universal platform. NBI utilizes narrow bands of light within the spectrum of white light, which are highly absorbed by hemoglobin to improve the observation of mucosal morphology and possibly improve the detection of lesions in the colon. The scope’s Close Focus function enables an enlarged, close-up image by moving the scope tip within 2 mm of the site. The four-way angulation, large inner channel, and auxiliary water jet are combined with Innoflex™ variable stiffness technology so that flexibility of the scope’s insertion tube can be adjusted to suit each patient’s anatomy.

The Endo Capsule is Olympus’ offering for observation of the small bowel. Recently introduced to the U.S. market, the Endo Capsule is designed for non-invasive observation of the small bowel mucosa. Endo Capsule offers high resolution, a wider field of view and an enhanced depth of field, automatic brightness control, advanced color reproduction and structure enhancement. There is also a portable, lightweight real-time viewer that allows physicians to verify the device is fully functional before the patient ingests the capsule. Endo Capsule is part of Olympus’ EnteroPro brand.

For bronchoscopy, Olympus offers the EVIS EXERA II™ 180 series bronchoscope platform with NBI technology. NBI improves visual contrast of vessels and other anatomical structures on mucosal surfaces during observation of the bronchial tree, offering clear views of anatomical tissues and vascular patterns of the bronchial mucosa, which are generally difficult to distinguish using conventional, white-light systems. And the endobronchial ultrasound (EBUS) system offers advanced technology in diagnostic bronchoscopy. Olympus has introduced a hybrid fibervideoscope (the BF-UC160F-OL8) with linear-scanning ultrasound imaging capability and a dedicated aspiration needle, specifically for diagnostic biopsies and staging in the lung. EBUS enables the bronchoscopist to visualize the lymph node and surrounding vessels in real-time through an ultrasound image display, which can be viewed simultaneously with the endoscopic image during the procedure. EBUS-TBNA with the BF-UC160F-OL8 permits visualization of the needle on the video monitor as well as on the ultrasound image in real-time, enabling the physician to more accurately guide the needle into the lymph node to obtain pathology samples. Power Doppler mode, made possible by electronic linear scanning, offers bronchoscopists the ability to check blood flow conditions before needle biopsy. And a specially designed "dimpled" needle tip enhances the view of the needle on the ultrasound image, making it easier to distinguish and position for biopsy.

Then there is endoscopic ultrasound (EUS). The Aloka ProSound SSD-Alpha10 processor is Olympus’ newest addition to the EUS product line. ProSound transmission controls the bandwidth and dominant frequency, offering outstanding performance by combining superior spatial and contrast resolution with high frame rates, providing a sophisticated beam control for high resolution and penetration.

Finally, there is the enteroscope. The single balloon enteroscope (SBE) system is designed to provide physicians with increased efficiencies for the examination and treatment of small bowel abnormalities, while maintaining high quality patient care. The SBE can be used in antegrade or retrograde fashion. The SBE can be used with a broad range of EndoTherapy devices used in tissue sampling, hemostasis and foreign object removal.

Mathematicians at the University of Liverpool (United Kingdom) have found that it is possible to gain full control of sound waves that could lead to improved medical scans for technology such as ultrasound machines.

Working in partnership with the Indian Institute of Technology in Kanpur, they tested the numerical properties of a flat lens made out of "meta-material" — a material that gains its properties from its structure rather than its composition. This material is thought to defy the laws of physics, allowing objects to appear exactly as they are rather than upside down as seen in a normal convex or concave lens.

Sebastien Guenneau, from Liverpool’s department of mathematical sciences, explains, "We know that light can be controlled using ‘meta-material,’ which can bend electromagnetic radiation around an area of space, making any object within it appear invisible. Now we have produced a mathematical model that proves this theory also works for sound.

"This theory becomes particularly interesting when considering ultrasound, which is a sound pressure used to penetrate an object to help produce an image of what the object looks like inside. This is most commonly used in pregnancy scans to produce an image of a fetus. We found that at a particular wave frequency, the meta-material has a negative refraction effect, which means that the image produced in the flat lens appears at a high resolution in exactly the same way it appears in reality.

"What surprised us most of all, however, was that at the point where negative refraction occurs, the meta-material becomes invisible, suggesting that if we were to use this in sonogram technology, it could be possible to make the image appear in mid-air like a hologram rather than on a computer screen. We also found that if we arranged the meta-material in a checkerboard fashion, sound became trapped, making noisy machines, for example, quieter."

The scientists predict that the technology could be adapted for tests at higher sound frequencies such as when drilling for oil, where a more accurate image of the earth could be made in order to pinpoint where drilling should take place. The research is published in the New Journal of Physics.

DURHAM, N.C. — A high-energy form of ultrasound imaging developed by researchers at Duke University’s Pratt School of Engineering produces pictures of liver tumors that are better than those made with traditional ultrasound, according to results of a clinical study.

The study suggests that the imaging method known as acoustic radiation force impulse (ARFI) ultrasound might offer a new tool for screening patients at increased risk for liver cancers, according to the researchers. They say it might also play a useful role in guiding biopsy procedures and minimally invasive therapies aimed at destroying cancerous tissues found deep in the abdomen.

The researchers reported their findings Jan. 7 in the journal Physics in Medicine and Biology. The work was funded by the National Institutes of Health with system support from Siemens Medical Solutions.

First developed six years ago by Duke biomedical engineers Gregg Trahey and Kathy Nightingale, ARFI uses high-energy sound waves to push on tissues like sonic fingers. A tracking beam then captures the movement of the tissue, providing a measure of its elasticity or stiffness.

"To our knowledge, these are the first images of abdominal malignancies in humans that show tissue elasticity," says Trahey, professor of biomedical engineering, radiology and medical physics at Duke. The preliminary findings, which represent the PhD thesis work of Trahey’s former graduate student Brian Fahey, have already led Siemens to pursue a product prototype that will combine traditional ultrasound with ARFI, he added.

In general, primary liver cancers are soft, while those that have spread from other organs are hard. ARFI may be able to tell the difference between hard and soft tumors, Trahey says. "If borne out in further studies, [that discriminating ability] suggests that ARFI may be useful in guiding treatment decisions. All current imaging methods — including CT, MRI and ultrasound — have mediocre performance in the detection of early liver cancers," he adds. "There is a potential role for ARFI because it is low-cost and can be built on conventional ultrasound machines."

Traditional ultrasound is now the guidance method of choice in many hospitals for procedures targeting the liver, kidneys, pancreas and lymph nodes, Trahey says. Ultrasound has advantages in that it is widely available, low-cost and doesn’t expose patients to ionizing radiation. However, a significant number of tumors are difficult to see with this method, requiring physicians to resort to alternatives such as computed tomography (CT) and magnetic resonance imaging (MRI), which add to the complexity and cost.

In the new study, the researchers captured ARFI images of 12 tumors in nine patients, including seven liver and two kidney tumors, and compared them to traditional ultrasound. The ARFI pictures showed greater contrast than standard ultrasound, providing clearer definition of the edges of cancerous masses.

Collaborators on the study included Rendon Nelson, vice chairman of radiology at Duke, along with David Bradway, Stephen Hsu and Douglas Dumont, all biomedical engineering graduate students at Duke’s Pratt School.

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