Shockwave Lithotripsy for Blasting Kidney Stones

Exactly what causes kidney stones is not known. There can be many different reasons. The most common type in about 80% of cases is composed of calcium oxalate crystals. Other types of kidney stones are composed of magnesium, ammonium, phosphate, calcium phosphate and cystine. Uric acid stones are another different type of stone in about 5–10% of cases.

Even though calcium is one of the major minerals in kidney stones, research now shows that having a low calcium diet actually increases the incidence of kidney stones. When calcium levels are low your body produces more oxalate which does increase your risk of kidney stones.

Usually kidney stones can pass without assistance or are removed from the body without causing permanent damage. However, if a kidney stone blocks urine flow for a period of time, complications can arise. Prevention of kidney stones is important because repeated occurrences of kidney stones increase the risk of developing chronic kidney disease.

A complication of kidney stones is the need for invasive treatments. If the stone cannot pass on its own, the first treatment tried is often shockwave lithotripsy. The shockwave lithotripsy procedure uses high-energy sound waves directed at the stone to break it up into smaller pieces so that it may be more easily passed.

According to the American National Kidney and Urologic Diseases Information Clearinghouse, more than 5 percent of the US population will have kidney stones, which is probably generalizeable to other countries. Men are more likely than women to acquire kidney stones, particularly between the ages of 40 and 70. For women, the prevalence actually decreases after age 50. Extracorporeal shockwave lithotripsy, or "blasting" of the stones, is a popular treatment for kidney stones.

In extracorporeal shockwave lithotripsy, shockwaves that are created outside the body travel through the skin and body tissues until they hit the denser kidney stones. After the stones have been hit, they will break down into sand-like particles that are easily passed through the urinary tract in the urine.

Extracorporeal shockwave lithotripsy uses shockwaves to break up stones, so that they can easily pass through the urinary tract. Most people can resume normal activities within a few days. Complications of extracorporeal shockwave lithotripsy include blood in the urine, bruising, and minor discomfort in the back or abdomen.

MedWOW features a large selection of new and used lithotripter systems, as well as replacement lithotripter parts from a variety of manufacturers. As the principal international eCommerce platform for all kinds of medical equipment, MedWOW, features a sophisticated searchable catalogue that allows you to filter for make, manufacturer, continent, condition, price range, coupling technique, DICOM 3.0 COMPLIANT, type of motor, transducer type, triggering and shockwave type when shopping for a lithotripter.

Currently MedWOW features lithotripters from the following manufacturers:
Direx, Philips, Siemens, Waltz, Gyrus Acmi, ENGEMED, Dornier MedTech, Fuzhou Secure, MTS and many more. If you don’t find the exact extracorporeal lithotripter system you are looking for, you can post a free buying request which typically will bring you a number of competitive quotes from MedWOW’s global inventories.

Better Diagnoses Thanks to Digital Tomosynthesis

Although it is steadily spreading to more applications, digital tomosynthesis is primarily used in breast imaging, where it offers better detection rates than mammography, with little extra increase in radiation exposure. Suggested uses include: visualization of pulmonary nodules, mammography, angiography, dental imaging and delineation of fractures. Because the image processing is digital, a series of slices at different depths and with different thicknesses can be reconstructed from the same acquisition, saving both time and radiation exposure. Tomosynthesis is preferable to standard planar X-ray in the following applications:

• Nephrology
• Mammography
• Chest imaging
• Orthopedics
• Brachytherapy
• Dental imaging

Digital tomosynthesis is a technique of generating images of slices through the body using a general radiographic X-ray system with a direct digital radiography detector. This is accomplished by obtaining a large, representative number of low-dose acquisitions across a range of projection angles of the X-ray tube. Currently, tomosynthesis is an optional add-on for suitable direct digital radiographic systems (flat panel detectors). The additional software controls the movement of the X-ray tube and the reconstruction of the images.

Modern digital RF equipment with a flat panel detector can be operated in tomosynthesis mode. In order for a flat panel detector system to carry out tomosynthesis, it requires the following:

• Control of the smooth movement of the X-ray tube, at the required speed
• Rapid pulsing generator
• Modern fast flat-panel detector

There are significant advantages, from an economic point of view, for tomosynthesis, as there is a reduction in the numbers of patients needing to have CT, MRI or nuclear medicine scans. Digital tomosynthesis can effectively improve the non CT- based treatment planning in radiotherapy and are especially useful in the following fields: source localization in Brachytherapy; long -term evaluation of treatment based on follow-up and study of complications arising from the possibility to relate dose distribution to anatomy if combined with depth dose data; and cost-effectiveness of treatment planning for clinics by integration of data acquisition and treatment planning processes. However, tomosynthesis is not a replacement for CT. Rather, it is an improvement over conventional radiography by bringing in some 3D information.

As images are clearer and diagnoses more accurate using digital tomosynthesis, more and more radiography and imaging departments are increasingly taking advantage of its benefits. It is assumed that with time, tomosynthesis will be used in more applications as its effectiveness is tested and proven. If you are interested in purchasing this type of equipment, a sensible place to look is MedWOW, where you can find a large selection of all sorts of radiography and imaging equipment, as well as digital tomosynthesis-related parts from global vendors, which translates into more competitive prices and services for buyers.

When searching on MedWOW for radiographic X-ray systems, digital mammography and direct digital radiography detectors needed for tomosynthesis; go to MedWOW’s all-inclusive and intuitive search engine, which allows you to find the exact used tomosynthesis equipment that you are searching for, using filtering options such as: manufacturer, model, price range, year manufactured, location and many other filters.

Another alternative is to post a buying request for the type of digital tomosynthesis -related equipment you are looking for, by filling out a form and giving as much information as possible. MedWOW attracts sellers from all over the world and so you will likely be sent a few quotes for your selected digital tomosynthesis.

The Function of X-Ray Tubes

An X-ray tube is basically a vacuum tube that produces X-rays, which are used in X-ray machines. X-rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light. X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered in the late 19th century. The discovery of this controllable source of X-rays created the field of radiography: the imaging of opaque objects with radiation that penetrates. X-ray tubes are also used in airport luggage scanners, CAT scanners, X-ray crystallography and for industrial inspection.

As with any other type of vacuum tube, there is a cathode, which emits electrons into the vacuum and an anode to collect the electrons ─ creating a flow of electrical current, known as the beam, through the x-ray tube. A high voltage power source is connected across the cathode and the anode to accelerate the electrons. The X-ray spectrum depends on the anode material and the accelerating voltage.

In many applications, the current flow is able to be pulsed on for between approximately 1ms to 1s. This allows for consistent doses of x-rays, and taking snapshots of motion. Until the late 1980s, X-ray generators were merely high-voltage, AC to DC variable power supplies. In the late 1980s a different method of control emerged, which became known as high-speed switching. This followed the electronics technology of switching power supplies (also known as switch mode power supply), and allowed for: more accurate control of the X-ray unit, higher-quality results, and reduced exposure to X-ray.

Electrons from the cathode collide with the anode material, usually tungsten, molybdenum or copper, and accelerate other electrons, ions and nuclei within the anode material. About 1% of the energy generated is emitted/radiated, usually perpendicular to the path of the electron beam, as X-rays. The rest of the energy is released as heat. Over time, tungsten is deposited from the target onto the interior surface of the x-ray tube, including the glass surface. This slowly darkens the tube and was thought to degrade the quality of the X-ray beam, but research has suggested there is no effect on the quality. Eventually, the tungsten deposit becomes sufficiently conductive that at high enough voltages, arcing occurs. The arc jumps from the cathode to the tungsten deposit, and then to the anode. The arcing causes an effect called "crazing" on the interior glass of the X-ray window. As time goes on, the tube becomes unstable even at lower voltages, and must be replaced. At this point, the x-ray tube assembly (also called the "tube head") is removed from the X-ray system, and replaced with a new tube assembly. The old tube assembly is shipped to a company that reloads it with a new, replacement X-ray tube.

The range of photonic energies emitted by the system can be adjusted by changing the applied voltage, and installing aluminum filters of varying thicknesses. Aluminum filters are installed in the path of the X-ray beam to remove "soft" (non-penetrating) radiation. The numbers of emitted X-ray photons or doses are adjusted by controlling the current flow and exposure time.

In simple terms, the high voltage controls X-ray penetration, and thus the contrast of the image. The tube current and exposure time affect the dose and consequently, the darkness of the image.

Some x-ray examinations (such as: non-destructive testing and 3-D microtomography) need very high-resolution images and therefore require x-ray tubes that can generate very small focal spot sizes, typically below 50 µm in diameter. These tubes are called microfocus x-ray tubes.

There are two basic types of microfocus x-ray tubes: solid-anode x-ray tubes and metal-jet-anode x-ray tubes.

Solid-anode microfocus x-ray tubes are in principle very similar to the Coolidge tube, but with the important distinction that care has been taken to focus the electron beam into a very small spot on the anode. Many microfocus x-ray sources operate with focus spots in the range 5-20 µm, but in rare cases spots smaller than 1 µm may be produced.

The major drawback of solid-anode microfocus x-ray tubes is the very low power in which they operate. To avoid melting of the anode, the electron-beam power density must be below a maximum value. This value is somewhere in the range 0.4-0.8 W/µm depending on the anode material. This means that a solid-anode microfocus source with a 10 µm electron-beam focus can operate in the range 4-8 W.

In metal-jet-anode microfocus x-ray tubes, the solid metal anode is replaced with a jet of liquid metal, which acts as the electron-beam target. The advantage of the metal-jet anode is that the maximum electron-beam power density is significantly increased. Values in the range 3-6 W/µm have been reported for different anode materials (gallium and tin).[4][5] In the case with a 10 µm electron-beam focus a metal-jet-anode microfocus x-ray source may operate at 30-60 W.

The major benefit of the increased power density level for the metal-jet x-ray tube is the possibility to operate with a smaller focal spot to increase image resolution, and at the same time acquire the image faster, since the power is higher (15-30 W) than for solid-anode tubes with 10 µm focal spots.

MedWOW’s inventories feature X-Ray tubes from most of the major manufacturers including: Shimadzu, Varian, Dunlee, Fischer Imaging, GE Healthcare, Philips, Siemens, Picker and Raymed, with more being added all the time, so finding exactly what you need is efficient and simple for busy medical professionals. With dozens of types of x-ray tubes currently featured through MedWOW’s comprehensive online catalogue ─ finding and purchasing your next x-ray tube is trouble- free and as thousands of medical professionals use the MedWOW portal on a daily basis, the prices are always competitive.

How Cone-Beam CT Can Enhance Your Practice

Cone-Beam CT is a fairly new imaging technology that produces 3-dimensional image data. Using a cone-shaped x-ray beam rather than the linear fan beam of conventional CT, a cone-beam CT scanner takes just one revolution around the patient to create multiple views. For example, in a dental setting, cone-beam CT can take images of both jaws in 3.6-6 seconds of actual exposure time. This represents significantly less radiation than one would receive with a full series of digital periapical radiographs, and is comparatively the same as bite-wing radiographs. With imaging software, the data may be reconstructed to provide 3D views that can easily be manipulated to show different angles, varying depths and thicknesses, and be selective for the particular tissues that need to be examined. The dose of radiation needed for a cone-beam CT scan is much lower than for a standard CT.

3D CT scans created from the cone-beam CT allow the surgeon and restorative dentist to best plan and place dental implants. Their uses and superior benefits are present throughout care, beginning with diagnosis to treatment and including post-op examinations. This can include: locating and determining the distance to vital anatomic structures; measuring alveolar bone width and visualizing bone contours; determining if a bone graft or sinus lift is needed; selecting the most suitable implant size and type; optimizing the implant location and angulation; increasing case acceptance; reducing surgery time and more. With the use of guided implant placement based on 3D cone-beam CT scans, all the above benefits are improved to the point that the surgeon can approach each case with the confidence that comes from knowing that the best available image data and technology have been used to guarantee success.

Some of the benefits of Cone Beam CT over regular CT include:

• X-Ray radiation exposure to the patient is up 10 times less than a standard CT scanner.
• Much faster scan time. Scans on a Cone-Beam CT take between 10-40 sec, while on a regular CT scanner, it takes a few minutes.
• Cheaper, as the average price of a Cone-Beam CT scan is up to 50% less than a conventional scan.
• You can already find Cone-Beam CT's throughout the US at various imaging centers and in many dental offices.
• Any dentist can utilize the Cone-Beam CT technology through 3rd party image processing centers that read the CT and electronically convey the data to the treating dentist.

The foremost eCommerce platform for all kinds of medical equipment, including Cone-Beam CT systems and other imaging equipment, MedWOW, has positively established its #1 position in the global imaging marketplace. MedWOW provides good-quality Cone-Beam CT systems in a safe and secure trading environment. When purchasing or selling a Cone-Beam CT, MedWOW can provide the market, the platform and the buyers, as well as a large variety of support services for both buyers and sellers. MedWOW has recently upgraded its medical equipment catalogue with various manufacturers, refurbished equipment and new and used Cone-Beam CT systems for medical and dental practices worldwide.