Reviews and News on Ultrasound Machines

Imaging technology has progressed greatly, but there is one thing that has not changed: a large part of radiology uses, to some degree, ionizing radiation. While well tolerated outside the womb, it presents several problems for the developing newborn.

Now, with most normal pregnancies, the need for constant or repeated imaging never arises, but in the case of a fetus with prenatal heart problems, the number and intensity of images increases dramatically. Fortunately, ultrasound machines have come to the rescue in the form of fetal echocardiograms.

Fetal echocardiograms are, to be blunt, a targeted ultrasound study that will specifically image the heart and the surrounding cardiovascular system of the developing child. Think about that rather dry statement for a moment. A way has been found to look at the heart of an unborn child in such detail that problems can be discovered before that child is born. And it can do this with little or no danger to either mother or child, and as an added bonus, it doesn’t hurt and is barely uncomfortable.

A fetal echocardiogram can detect the gross abnormalities associated with congenital defects, but it can also find issues with cardiac rhythm that may influence the course of treatment for the rest of the pregnancy.

A single test between 12 and 18 weeks – sometime early in the second trimester – can give a very detailed picture of the heart and a good clinical picture of potentially high risk patients. So, this test can be the linchpin for many diagnostic interventions that add up to a healthy baby. Or, alternatively, it can ease the mind of a high risk mother, eliminating a potential cause for worry.

Mothers who might be good candidates for a fetal echocardiogram are women with the risk factors of insulin-dependent diabetes and advanced maternal age, or a family history of congestive heart disease in a parent or previous child. For the fetus, there are the risk factors of a twin, another less serious malformation previously discovered in another ultrasound test with an ultrasound machine or exposure to certain cardio toxic drugs early in the pregnancy that may cause a heart defect to occur.

In the face of modern medical miracles, we have lost sight that it was not that long ago that the idea of open heart surgery was the height of fantasy. Opening a living heart, fixing it, and then reviving the patient was the stuff of dreams.

Now that this is a reality, there became a new wrinkle – how can be know what is going on in the heart before it is laid open? Could we fix abnormalities as we discover them? Fortunately, ultrasound is giving us both of those abilities.

Catheter technology has been around for a while, but that had to be combined with external radiographic techniques to get a picture, and that was at times only a precursor to more invasive procedures like open heart surgery. And, as amazing as that surgery can be, there should be other, less dramatic options.

This used to be the province of external ultrasound machines only. Even catheter based ultrasounds radiated sound in a circle, a good technology for circular structures like the esophagus or arteries. But in order to image a structure with the complex volume of the heart, there had to be something better.

Fortunately, the researchers at Acuson Corporation of Mountain View, CA have developed an intracardiac ultrasound catheter. It will allow surgeons to see the structures within the heart with greater clarity than ever before. They can now precisely determine any affected area. Gone is the radial pattern of the ultrasound. This new sixty four element transducer projects a sideways wave. Normally, there is some form of focusing lens to direct the ultrasound. That would be too big for the tip of this catheter. This new ultrasound transducer has no need of that to maintain a tight focus that is ideal for such a tight area.

This new technology works across a wider range of sound waves. This allows a cardiologist to determine the amount of penetration they need. The upshot of this is that, even if the catheter is on the right side of the heart, you can still visualize the left side just as well. It just depends on where you set the machine.

This new ultrasound machine technique will undoubtedly provide greater diagnostic specificity for cardiac patients, leading to better care and better outcomes.

One of the most serious and often fatal conditions that can affect a child before it is born and during its first year of life is a congenital heart defect. Birth defects remain the leading cause of death for children in their first year of life, even though overall infant mortality rates are declining.

But there is good news for expectant parents and their babies, thanks to GE Healthcare. GE Healthcare has purchased exclusive rights to a new patented software technology for use in its 3D/4D Voluson ultrasound systems.

According to Dr. Alfred Abuhamad, professor and chairman of the Department of Obstetrics and Gynecology at Eastern Virginia Medical School, finding congenital defects in an infant’s heart can be quite difficult. “This is due to two facts,” he says. “First, the heart is tiny. But in addition, ultrasound relies on the skill of the technician. An infant’s heart is a difficult organ to look at and the experience of the operator matters a great deal.”

Dr. Abuhamad developed Sonography-based Volume Computer Aided Diagnosis, also known as SonoVCAD. GEHealthcare has licensed this automation protocol and is using it in their Voluson EG ultrasound, designed especially for woman’s health care. Several tools designed to improve clinical workflow are also included in the new ultrasound machine, which has been available less than 12 months.

SonoVCAD automatically acquires the images that are needed for a complete view of the fetal heart. “It makes everything much simpler for the technician,” said Dr. Abuhamad. “It automates the examination of the heart prenatally, ensuring better detection of congenital heart problems.” The image is composed of views of different planes which when viewed together can show fetal heart defects and allow the physician to determine not only what type they are, but how severe they are as well. The ultrasound technician begins the process by identifying the standard starting point for such ultrasound machines, which is the four chamber view of the heart. Algorithms created by Dr. Abuhamad allow the other views to be generated from that starting point view.

The good sides of therapeutic ultrasound hide a big problem: these ultrasound machines are large and expensive. Add to that some focusing issues and therapeutic ultrasound shows definite limitations for clinical use for the here and now. That all may have changed.

A doctoral candidate at Cornell University has just set the world of therapeutic ultrasound on its ear. George Lewis has created ultrasound devices that are pocket sized, instead of the current ones that can top out at thirty pounds. These small devices are more powerful than their large predecessors and the cost? Around USD$100. For comparison, that larger ultrasound we mentioned earlier regularly sells in the neighborhood of USD$20,000.

How was this accomplished? Mr. Lewis (remember he’s not a PhD yet) has increased the efficiency of an existing transducer. In the traditional method, a great deal of the energy used to convert the voltage to sound waves is lost. Lewis has created a way to increase the efficiency of this process. In his versions, up to 95% of the source energy goes into the transducer.

This means that his smaller ultrasound transducer can use less power to make the same output, or use the same power to generate a much more powerful output. Lewis envisions small, cell phone sized devices that can cauterize wounds at the scene of the accident, for example. Smaller probes will be able to get closer to tumors, but have the same output as larger probes.

Clinical trials are currently underway. This is significant because it is the first step toward getting approval of the new technology for patient use. The initial work is being done with a form of drug delivery. Hydrogen sulfide, a substance toxic at high doses, is being administered in small doses that are targeted to a particular area by this new small ultrasound unit. This will cut down the toxic risk of a systemic dose of the medication, but increase the effectiveness by localizing the small dose.

These are only the first tentative steps for this novel technology. FDA approval and widespread clinical use is still years ahead, but the avenues for this new therapeutic ultrasound machine are limitless. This innovation will shift not only the use, but the effectiveness and the accessibility, of therapeutic ultrasound.

Ovarian cancer is a significant woman’s health issue. In the United States alone, more than 21,000 women are diagnosed with ovarian cancer each year, and more than 15,000 of those women die.

When caught in its early stages and limited to the ovary, however, ovarian cancer can be cured in about 90% of patients. Unfortunately, ovarian cancer is seldom diagnosed until it is at an advanced stage. This is because the disease has few symptoms in its earlier stages, and there are no good screening tools. When ovarian cancer is detected at these more advanced stages, the rate of survival drops considerably, with only 20 to 30% of patients surviving.

An ongoing research study, preliminary results of which have just been announced, has found that it is now possible to detect ovarian cancer in its earlier stages—stages 1 and 2 specifically—using the combination of transvaginal ultrasound machine and the CA125 blood test. Preliminary study results are being published in the April issue of The Lancet Oncology.

The United Kingdom Collaborative Trial of Ovarian Cancer Screening is being conducted at University College London, by Ian Jacobs, Usha Menon, and their colleagues. More than 200,000 post-menopausal women, ages 50 to 74, were recruited for the study, which will continue through 2012.

The women were randomly assigned to one of three groups. The control group received no treatment. The second group received screening using both transvaginal ultrasounds combined with the CA125 blood test; this was referred to as multimodal screening. The final group received screening using only transvaginal ultrasound every year. Clinical evaluations and surgery were given to patients who showed consecutive screens with atypical results.

While the transvaginal ultrasound screening alone detected 75 percent of the cases of ovarian cancer, adding the CA125 blood test improved the rate of diagnosis to 90 percent. More importantly, rather than being diagnosed in the later stages, 48 percent of the cases detected were in stage 1. Previously, only 28 percent of the cases of this disease have been detected in stage 1. Using multimodal screening, many women will be able to receive earlier treatment and anticipate improved outcomes. While the researchers could not speak to the effect of multimodal screening on deaths from ovarian cancer at this stage of their research, their results may well represent a significant step forward in this area.

Because transvaginal ultrasound and the CA125 blood test are already in use and approved by the FDA, there will be no lengthy delay to develop new ultrasound machines or new machinery to analyze blood samples. The new screening protocols can be put into use now.

According to a new study from the Thomas Jefferson University Hospital in Philadelphia, PA, the combination of sonohysterography with transvaginal ultrasound improves clinicians’ ability to diagnose adenomyosis. Adenomyosis is a common and benign condition of the uterus. It can cause abnormal vaginal bleeding, dysmenorrhea, and pelvic pain. American Journal of Roentgenology, the monthly journal of the American Roentgen Ray Society (AARS), is publishing study results in its April issue.

Sonohysterography, or SHG, is a technique which involves infusing a fluid, typically sterile saline, through the cervix into the uterus by way of a soft plastic catheter. The uterine cavity is distended by the infusion. The uterine lining is then easier to visualize, allowing for greater diagnostic specificity of uterine and endometrial pathology. The transvaginal ultrasound probe is inserted as usual.

The lead author of the study was Sachit Verma, M.D. The study included 26 women. According to Dr. Verma, “This study describes the presence of ill-defined areas of fluid intravasation extending from the uterine cavity into the myometrium known as fluid containing tracks or so called ‘myometrial cracks’ on SHG. Myometrial cracks have not been described previously as a sign of adenomyosis. The tracks, seen in 26% of our cases, become conspicuous as saline seeps through the ‘myometrial cracks’. They are difficult to characterize on standard transvaginal ultrasound.”

Transvaginal ultrasound machines alone has been the first diagnostic tool used in cases where adenomyosis is suspected. When it fails to provide a diagnosis, an MRI is usually the next step. As Dr. Verma points out, MRIs are expensive and there may be a wait to get the patient scheduled. The combination of sonohysterography together with transvaginal ultrasound appears to provide as much diagnostic specificity as an MRI without the associated costs and delay. In the instant study, 23 women had findings suggestive of adenomyosis when SHG was used. Adenomyosis was confirmed in 22 of the 23 women using an MRI.

Dr. Verma said, “Knowledge of ‘myometrial cracks’ will decrease the errors in interpretation and improve patient care so that specific treatment can be instituted. This additional information for the referring physician can possibly decrease the number of endometrial biopsies – reducing costs in patient management – in cases where SHG shows no uterine abnormality and adenomyosis is the sole cause of abnormal bleeding.” This study provides further proof of the continued utility of ultrasound machine technology.

Researchers have developed a new form of ultrasound that may be able to predict early bone loss. The new form of ultrasound was developed by Yi-Xian Qin, Ph.D., Director of Orthopedic Bioengineering Research Laboratory at Stony Brook University. Dr. Qin developed the new ultrasound form jointly with colleagues at Stony Brook and at the NSBRI (National Space Biomedical Research Institute).

Bone loss, or osteoporosis, affects millions of Americans. The new ultrasound machine called SCAN, for Scanning Confocal Acoustic Navigation, looks at more than just the density of bone. It can look for strength, structure, and stiffness as well. “SCAN uses non-invasive and non-destructive ultrasound to image bone, and the technology enables us to identify weak regions, as well as make a diagnosis and to assist in healing fractures,” says Dr. Qin. “Because with SCAN we can assess bone qualities, such as stiffness, we can predict the risk of fracture, as quality of bone rather than density is more of a predictor of fracture risk.”

The new technology will be more than just diagnostic; it will be therapeutic as well. By stimulating bone regeneration, ultrasound machines can help accelerate the healing of fractures. “We are trying to use ultrasound technology as a way to get an image of the fracture site,” says Dr. Qin. “An integrated probe will directly shoot ultrasound into the region of the fracture. We hope this will result in effective acceleration of fracture healing.”

The NSBRI is funded by NASA. NASA is interested in this technology because astronauts who spend extended periods of time in space suffer from bone loss, and are also subject to stress fractures.

As the elderly population in American continues to grow, finding affordable, easy to use ways to provide excellent care will be an increasingly important goal. Dr. Qin and his colleagues believe SCAN technology will not only be easier and less expensive to use than current x-ray based measures of bone density, but that it will also be easier and have more robust capabilities. It is possible that patients may be able to use a small, mobile SCAN device themselves. Currently SCAN is in clinical evaluation.

Early detection and diagnosis of breast cancer is crucial to minimize invasive treatment and improve outcomes. Unfortunately, women with dense breast tissue have been at a disadvantage when receiving traditional mammography, making it harder for them to receive that all important early diagnosis. According to the New England Journal of Medicine, these women have a five times greater risk of breast cancer. Now a new automated breast ultrasound system, ideally suited for such women, is available from Siemens Healthcare.

Called the Acuson S2000 Automated Breast Volume Scanner (ABVS), this new technology is a multi-use ultrasound breast system. It uses user-independent, standardized image acquisition to produce volume images of the breast. A study by the Radiological Society of North American (RSNA) showed a 42 percent improved detection rate of non-palpable, invasive breast cancer when ultrasound followed traditional mammography. It is possible that with improved ultrasound technology, such as that provided by the Acuson S2000 ABVS, the detection rate may improve even more.

Klaus Hambüchen, CEO, Ultrasound at Siemens Healthcare, said, “I am convinced that automatic ultrasound volume imaging with the Acuson S2000 ABVS can make a significant contribution in diagnostic confidence for women with dense breast tissue or inconclusive mammography findings.”

The Acuson S2000 ABVS ultrasound machine provides a complete view of the anatomical, coronal plane of the breast, which includes tissue from the nipple to the breast wall. This is a much more complete view of the entire breast than that available through conventional ultrasound imaging. Additionally, the Acuson S2000 ABVS system completes its examination in less than 15 minutes, considerably less time than the typical 30 minutes for hand-held ultrasound examinations. This will not only prove more convenient and comfortable for the patient, but will also allow the health care facility to provide care to a greater number of patients, increasing profits. The system uses BI-RADS® ultrasound reporting capabilities; the American College of Radiology developed the BI-RADS ultrasound reporting classification for mammography reporting.

Fatty Tissue and eSie Touch elasticity imaging are innovative breast imaging applications also supported by the Acuson S2000 ABVS system. This further improves the ability of clinicians to rely on diagnostic data provided by the system.

One of the largest suppliers of health care technology in the world, Siemens Healthcare Sector provides medical solutions in diagnostic and therapeutic technologies.

The ultrasound transducer is a highly sensitive and technical piece of medical equipment. As with any equipment which comes into contact with a patient, it requires special care and handling.

The most important thing to remember when caring for your ultrasound transducer is that you must follow your manufacturer’s directions for care and cleaning. If you do not, you run the very real risk not only of irreparably damaging your transducer, but of also voiding your warranty. So step one is, alas, read the manual.

That said, there are some general guidelines for care and safety of transducers in general.

1. Properly store transducers when not in use. Most machines have a designated storage place for transducers, such as a dedicated holder.
2. Avoid dropping the ultrasound transducer or subjecting it to any kind of impact.
3. Mind the cable. The cable is, in essence, an electrical cord. Unnecessary bending or folding of the cable can damage the cable insulation, which may lead to electrical shock.
4. Always inspect the transducer apparatus, including lens and cable, before each use. If the transducer is damaged, it can cause injury to the patient or operator. If you notice a problem with a transducer, do not use it and contact the manufacturer for service and/or replacement.
5. Use only approved coupling gels to avoid damage to the equipment and discomfort for the patient.

Now that you know how to care for your transducer, how about cleaning?

1. Step one is read the manual and follow the manufacturer’s instructions. The importance of this step cannot be overstated.
2. Use the manufacturer’s specified cleaning products and germicides. To do otherwise can damage your equipment and void your warranty.
3. Do not allow the connector end of the cable or transducer to become immersed in the cleaning product.
4. If your transducer must be soaked in germicide, follow the manufacturer’s instructions as to length of soaking time.
5. Steam cleaning, using a heat autoclave or gas process, is generally not recommended.

As long as you follow the proper procedures for ultrasound transducer care, use and cleaning, your equipment will serve you well, allowing you to better serve your patients.