This article is from in the January 2008 issue of DOTmed Business News. A list of registered users that provide sales & service can be found at the end.

Medical imaging is one of the biggest industries in healthcare, and there are many companies in this diverse and competitive marketplace. Some are part of the technology-driven world of X-ray tubes and Image Intensifiers (II). For those OEMs and third party providers - the global market is over a billion dollars. Without question, tubes and intensifiers are critical components in X-ray imaging equipment. When they need to be replaced, buyers may have a service contract with the original seller, or they may need to look at other options. Depending on the type of X-ray tube or II and where it's purchased - and whether it's purchased new or refurbished -- prices range in the thousands to hundreds of thousands of dollars.

For example, German Filgueira, president of Poder Inc., Miami Beach, FL sells Varian and Dunlee X-ray tubes and reloads and sells GE Lunar tubes for bone densitometry. "An OEM densitometry X-ray tube sells for around $9.000," Filgueira states. Poder Inc. will reload a tube and guarantee it with the same guarantee an OEM gives - and sell it for $4,500."




Technical Prospects, LLC in Greenville, WI sells X-ray tubes and IIs. President Jeremy Probst says, "In most cases, reloaded tubes are as good as new tubes. There may be some differences between the OEM insert vs. the aftermarket insert. However, these inserts are manufactured as close to the original as possible. We supply both new and "as is - where is" tubes to the medical imaging market." Probst believes that an end user can save anywhere from 25 to 50 percent when purchasing a reloaded tube or refurbished II.

X-ray tubes are designed for demanding applications including angiography, computed tomography (CT) and for the specific requirements of mammography and dental imaging. An X-ray tube must be replaced when the dose loss reaches a level of 50 percent or when the required exposure time has doubled.

Image Intensifiers convert X-rays into a light image that is recorded with a camera. The performance of an II can be judged by the light intensity produced in the output screen and the spatial resolution. The light intensity is most often expressed using the conversion factor Gx .This conversion factor relates the luminance, measured as:
Total gain = Flux gain (area input screen/area output screen). The spatial resolution of an II has improved over the last two decades. For example, for a pre 1970 II using a ZnCdS:Ag input screen, a spatial resolution of 2 lp/mm was rarely achieved. Modern IIs show values of 5-7 lp/mm.

Jeff Rondeau, president of 5 Star Imaging, Odessa, FL says that his company repairs and evaluates all X-ray tubes and IIs from Dunlee, Siemens, Varian and Thales. They also sell pre owned certified products tested at 5 Star Imaging to meet all OEM specifications. Rondeau said that that the life of an X-ray tube varies depending on its usage. "If an X-ray tube is sitting in a chiropractor's office it's not going to be used as much as it would be in an emergency room," says Rondeau. "Those that are not used frequently can last ten years or more, while those used on a regular basis may need to be replaced in a matter of months." 5 Star Imaging reloads, repairs and evaluates all X-ray tubes and IIs from Dunlee,




New and reloaded tubes

According to Ralph Babcock, general manager at Imaging Affiliates in Rural Hall, NC, refurbished tubes are tubes that have had some repairs done to them, without completely reloading the old housing with a new insert. "It can be as simple as changing and replacing the dielectric oil that is in the housing to replacing grid-switches and even anodes and cathodes," says Babcock. "When a tube is manufactured "new," the original manufacturer takes a housing and an insert and combines them to form a new tube-unit.

This new tube-unit will probably include a housing that has been refurbished to conform to original specifications and has had some parts replaced on it such as stators, gaskets, expansion-bellows, high-voltage receptacles and port-windows." Babcock says that all the original tube manufacturers "reload" x-ray tubes -- that is -- take a refurbished housing and load a new insert into this housing as well as some tube reloaders such as STAT, 5 Star and North American Imaging. "Reloaded tubes are tested to conform to the original performance specifications and are given the appropriate warranty that a so called 'new tube' would have," states Babcock. Refurbished tubes are also tested to this conformity (focal spot sizes, emission, high-voltage stability), but may or may not be given the same warranty as the new or reloaded tubes would have."

CT X-ray tube

The CT X-ray tube is one of the more popular, most used and most replaced. The average useful life of a CT tube is sometimes estimated by the number of slices the CT system has performed. Michael Webster, president of Legacy Medical Imaging, Fort Worth TX, says that tube life depends on the type of tube and which system it's used in. "LMI works with a lot of GE systems and have found the life expectancy on a 3.5MHU tube lasts between 120K to 200K slices and a 6.3MHU Proformix tube can last over one million slices," says Webster. Ralph Babcock at Imaging Affiliates says, "The CT tubes today are called on to perform at a much higher level then we though possible 20 years ago. A typical spiral body scan would be performed at 120 kV, 400mA for 15 seconds or more continuous. This means the tube is performing at 48kw continuous and in the course of that 15 seconds, will emit 720kJ of X-ray energy and heat. Ten to fifteen years ago, CT technology was limited to single exposures of lower techniques and much longer wait times between slices. In order to do the necessary power and through-put demands placed on the scanner, the tube must be comprised of very special components that are designed to take the loads and stresses of the demands placed on the tube. CT tube components such as bearings, targets, cathodes and metal-frames must not only be up to the high heat demands of this technology, but also be able to withstand extremely high G forces as the gantry rotates as fast as two to three times per seconds." Babcock went on to say that everything in the CT tube has gotten much bigger to handle this and a lot of the metals used in the target are strategically desired materials that are in high demand throughout the world such as molybdenum and tungsten and have a correspondingly high price to go with that demand. "When we look at the types of procedures that we can do non-invasively that result in quicker and faster diagnosis, we can justify the higher costs for these tubes," says Babcock.




Greg Kramer, president of C&G Technologies, Inc., Jefferson, IN said that prior to multi-slice CT, the industry standard units for tube wear was the "slice". One rotation under X-ray power, producing one image, equaled one "slice". According to Kramer, "1 slice = 1 image. The term slice and image became interchangeable words." Kramer states, "Toshiba counts rotations whereby one 360 degree scan under power, equals the measure of tube wear in 'rotations'. One rotation can equal as many 'images' as the detector can collect in one rotation, i.e. 1,2,4,8,16,32,64, etc." He went on to say that Philips and Siemens use the 'scan-second' measure of tube wear. "This is the number of seconds the tube is under power while scanning," says Kramer. "One scan-second can equal the same number of images as in rotations, or it can mean more since many scanners can do two or more full 360 degree rotations in one scan-second." "Note that none of the above methods take into account the amount of Voltage or Current put into the tube," states Kramer. "Therefore, two tubes with identical amounts of slices, or rotations, or scan-seconds can have very different amounts of true wear on them." Kramer explained that GE uses Amp-Seconds to measure tube wear. The amount of current (amps), times the duration of the scan (seconds), equals Amp-Seconds. GE CT scanners report this in 'mas," a smaller unit the amp-second. 1 amp second = 1000 mas. "Scanning at 250ma for one second = 250mas. The number of images generated depends on the number of detector rows. This method is more of a "true" measure of tube wear," states Kramer He goes further saying, "having said all this, you can see that the terms 'scans' and 'slices are no longer necessarily the same. It would be easier on all of us if the manufacturers would adopt the same method for measuring tube wear, and my preference would be for amp-seconds." Rick Fow, vice president of sales at C&G said that the company sells new tubes from Varian and Dunlee and also sells refurbished tubes. "We put our used tubes though a "process" checking all parts and replacing the oil in the protective covering," says Fow. "This process will add longevity to the life of the tube."

Many years ago, Dick Dilick, president and CEO of J&M Trading, Goodlettsville, TN had an idea to extend the life of the X-ray tube by attacking the primary element which fails a tube - that being the arcing and/or corona effects which cause the tube to become useless. "We found that the science behind the failure provided a means to correct the problem, in the field, and we received a series of patents for it," says Dilick. "Basically, tube life is not infinite, but because of its high quality and design characteristics, it is much longer than the life of the combination of the insert and housing in an untouched fashion. Simply removing the water, a polar molecule in a DC Field, and gases, which sometimes produce bubbles in the housing, when created in a situation where the gases are produced in a volume greater than the saturation level of the medium used as either/and an insulation/heat transfer mechanism, allows the dramatic reduction of arcing and corona, and - guess what - a long life (with constant care)." Dilick continues, "Not a very rewarding statement to a patent holder, but very rewarding to the site using the process. In one case, the third party service firm produced an annual profit from one CT scanner alone, over a two year period of $820K," says Dilick.




OEM X-ray tube manufacturer

GE Healthcare, headquartered in the United Kingdom, is an OEM giant in the X-ray tube business. They manufacture X-ray tubes for every medical imaging application including CT, vascular, radiology, R&F and mammography. Global Tubes manager, David Mliner heads up the X-ray tube division at GE Healthcare and says that there are three production centers for X-ray tubes in Europe, India and the United States. "These centers manufacture thousands of tubes per year," says Mliner. He went on to say that an extensive number of quality control tests are performed through the tube manufacturing process to guarantee a high level of performance and a longer lifespan. Global tube engineer manager or GE tube manufacturing, Thomas Ebben, said that the emergence of cardiac applications in diagnostic imaging requires GE to push the limits of performance with x-ray tubes. "To meet this demand, GE Healthcare engineers have created a new generation of X-ray tubes perfectly adapted to the technical requirements of each clinical segment for a better medical diagnosis," Ebben used the Performix Pro Line, as an example. "It is the only X-ray tube in the world that is able to sustain 100KW of power for better image quality during cardiac examinations. In addition, the extremely high heat dissipation rate makes it possible to increase the number of consecutive exams without being limited by tube cooling," states Ebben. GE Healthcare has exclusive rights to their X-ray tubes and only sells directly from GE Healthcare.

In 2000, GE was the first company to introduce full-field digital mammography for patient use, and today there are more than 1,500 GE Senographe systems in use worldwide. GE Healthcare's Senographe Essential features the largest detector, offering largest field of view. Panel image detectors retain their sensitivity, yielding excellent images over the entire lifespan of the product. The digital flat-panel is more compact than an image intensifier, so it is much easier to incorporate into different system designs, including mobile systems with greater ease of access to the patient.




Heavy hitters in the X-ray tube industry

Without argument - Dunlee and Varian Medical Systems have a huge share of the X-ray tube market.

Dunlee's roots in the X-ray tube business are obviously strong. Dunlee, a division of Philips Medical Systems, with world headquarters in Aurora, IL, stocks tubes at their factory in Aurora, IL, as well as air terminals throughout the United States, Europe and Asia. Their customers include OEMs, service providers and end users. According to David Keuhn, vice president of Global Marketing & Sales, Dunlee offers a full line of replacement tubes including over 70 CT replacements and 50 conventional X-ray replacements. "Dunlee tubes meet or exceed original OEM specifications for fit, form and function, and the warranty conditions are second to none," says Kuehn. Dunlee's prices are lower than the OEMs, but they use the best materials for the construction of X-ray tubes and also use the same vendors (in many cases) as the OEMs. "Streamlined manufacturing, highly experienced workers and an in-depth understanding of CT systems enables us to create products that meet or exceed the specifications of the OEM tube for performance," says Keuhn. As the OEM sales channel for Philips Medical Systems, Dunlee offers a product portfolio that includes X-ray tubes, image intensifiers, collimators, table-tops, grids, etc. Dunlee and Philips are responsible for several industry firsts, including the first 1 MHU CT tube and their exclusive spiral groove bearing technology. Dunlee's Glassware Solutions in an innovative program that allows diagnostic imaging institutions the opportunity to eliminate the unpredictable expenditures associated with glassware replacements by providing complete glassware coverage for a flat monthly fee.

Varian Medical Systems, Inc., Palo Alto, CA is the leading independent manufacturer of X-ray tubes and digital detectors for X-ray imaging in medical, scientific and industrial applications. In its most recent fiscal year ended September 2007, the company reported revenues of $1.8 billion, of which X-ray products contributed $258 million. Varian's X-ray products business based in Salt Lake City, UT supplies powerful and technologically advanced X-ray tubes to many large manufacturers all over the world. David Hurlock, international marketing manager for Varian Interay said that Varian Interay manufactures cost effective replacement medical X-ray tubes in diagnostic equipment made by GE, Hitachi, Philips, Shimadzu, Siemens and Toshiba.

Hurlock explained differences between digital radiographic flat-panel detectors and image intensifiers. The digital radiographic flat-panel detector is a replacement of film in radiographic systems and image intensifiers in fluoroscopy systems. "Flat panels offer several advantages to conventional analog systems," says Hurlock. "Digital radiographic flat panels are more sensitive to X-rays and can potentially reduce the radiation dose to a patient." He also said that the temporal resolution of images from flat-panel detectors is better than that of images from IIs, reducing the potential for blurring due to motion. "We see a trend developing toward significantly larger X-ray tube requirements for digital X-ray systems, including those with flat panels. The equipment operators are getting more through-put with digital systems, increasing the duty cycle of the tubes. These digital systems require greater ability to dissipate heat than do tubes used with analog systems," states Robert Hibdon, vice president and general manager, Varian Interay.

Bernard Glas, vice president of marketing and sales at Adam Medical Sales, Inc. in Brooklyn, NY says that Adam offers short warranties on CT tubes - 60, sometimes 90 days. "If also depends on customer's usage too," says Glas. "If we know the CT tube will have 'light use," we may extend the warranty to 90 days." Glas went on to stay that companies like STAT Medical would give a longer warranty because they have better capabilities to test and forecast the life of an X-ray tube. "I can light the tube up and visually check it, but a company like STAT has all the equipment necessary to disassemble a tube and test all components," says Glas.

STAT Medical X-ray Tubes, Inc. does offer a warranty of 12 months pro rated and some 24 month warranties on their new X-ray tubes. Remanufactured tubes usually carry a 90-day to 12 month warranty depending on the tube. Tim Davis, president of STAT Medical X-ray Tubes, Inc. has found a true nitch in the X-ray tube market and its working. STAT specializes in unique, hard to find tubes including stationery anode, monoblocs, cath/angio, and CT tubes. "We have the ability to reload and source hard to find tubes," says Davis. "When I started this business in 1993, I had 1,250 square feet of space and last year we moved into a 2 million dollar building." Davis attributes some of his success to the fact that there aren't many tube loading facilities left in the United States and that has helped his business grow. He also said that STAT deals with tubes that other companies choose not to deal with. "There's a need out there for hard to find angio and CT used tubes and we will provide them, or fix them and add a significant warranty," says Davis.

As far as Image Intensifiers go, Davis said that he is not involved.

He is, however, researching flat-panel detectors, which he feels have a way to go in terms of repairability. "When the time is right, and I feel that flat-panel detectors are worth investing in, I'll consider it," says Davis.

DOTmed Business News did an Industry Sector Report on Flat Panel systems in its February issue.

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DOTmed Registered X-Ray Tube and Image Intensifier Sales and Service Companies
Names in boldface are Premium Listings.

Domestic
Doug Anderson, BIS Technologies, AZ
Kurt Bringolf, Eclipse Medical Imaging, CA
DOTmed Certified
Sajjad Tirmzi, National Liquidation, CA
Terry Michel, Radiology Systems Engineering, Inc., CA
Jeff Rondeau, 5 Star Imaging, FL
Larry Dewey, Dewey X-Ray, FL
German Filgueira, PODER, Inc., FL
DOTmed Certified/100
Stan Hightower, SH Enterprises, GA
Greg Kramer, C&G Technologies, Inc., IN
DOTmed Certified/100
Martin Nash, A2X-ray, KS
Kevin Blaser, Coast to Coast Medical, MA
William Brooks, Salem Medical Electronics, Inc., NC
Won Choi, DRGEM USA, NJ
Joseph Hauschildt, Metropolitan Medical Imaging, LLC, NJ
Gary Bischoff, Electronic Control Concepts, NY
Hugh Cotty, JC Medical Equip.Co., Inc., NY
Gregg Jones, Accurad Medical Imaging, OK
Peter Chen, Global Medical Equipment, PA
DOTmed Certified/100
Jason Botko, APlus Medical, SC
DOTmed 100
Michael Webster, Legacy Medical Imaging, TX
DOTmed 100
Tom Howard, Radiographic Service, Inc., WI
Jeremy Probst, Technical Prospects LLC, WI
DOTmed Certified/100
Bernard Glas, Adam Medical Sales, Inc., NY
DOTmed Certified/100

International
Helio Dibax, Eletromedica, Ltda., Brazil
Luiz Carlos Oliveira, LRX Medical Service, Brazil
Hui Zeng, Beijing Lado Technology Co., Ltd., China
Alexander Prox, Medtec GmbH Germany, Germany
DOTmed Certified/100
Suraj Tuteja, Export Import Consortium, India
Felix Donoghue, FX Rays & Imaging, India
DOTmed 100
Girish Chandarana, Hem-Tech Services, India
Sanjiv Goyal, RadMedical, India
Abdul Radjak, PT Alkeslab Primatama, Indonesia
Mohammad Hashemi, Abzar Teb Asman Co Ltd, Iran
Hossein Shirazi, Baresh Partov, Iran
Eli Barkai, BeMedical, Israel
Diaa Alhindaoui, M&TEC - Group, Syria
Hani Alzayat, Medical System Experts, Ltd., Syria
Ali Damla, Sefer Medikal, Turkey
Jose Morillo, J Morillo Sistemas Biomedicos, Venezuela

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