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Headlines in the News:

Contrast-Enhanced Perfusion Echo Bolsters Treadmill Stress Test

Myocardial perfusion echocardiography with contrast can improve the sensitivity of dobutamine stress tests in detecting coronary artery disease (CAD)...

Ultrasound Can Predict Tumor Burden and Survival in Melanoma Patients

Patients could be spared unnecessary surgery...

Automated Whole-Breast Ultrasound Doubles Cancer Detection

An automated whole-breast ultrasound system doubled the cancer detection rate when used with mammography....

Prenatal ultrasound Does Not Increase Risk for Autism

Antenatal ultrasound does not appear to be associated with an increased risk for autism spectrum disorders (ASD)....

Contrast-Enhanced Perfusion Echo Bolsters Treadmill Stress Test

Developments in imaging technology and software continue to help cardiac MRI exams gain prominence in the medical imaging market...

Myocardial perfusion echocardiography with contrast can improve the sensitivity of dobutamine stress tests in detecting coronary artery disease (CAD) and also improve the performance of treadmill exercise stress echocardiography, according to a study published online in Heart.

The researchers found that real-time perfusion imaging with continuous infusion of microbubble contrast significantly increased the sensitivity of dobutamine stress echocardiography compared to only performing wall-motion analysis. And the technique turned in even better results when used in treadmill exercise stress echocardiography exams.

"During both [dobutamine stress echocardiography] and [treadmill exercise stress echocardiography], the sensitivity of [wall-motion] analysis during [real-time perfusion] imaging is improved because subendocardial wall-thickening abnormalities can be detected," wrote a team led by Dr. Saritha Dodla of the University of Nebraska Medical Center in Omaha.

The researchers wanted to determine the incremental value of real-time perfusion imaging during treadmill exercise echocardiography in assessing myocardial perfusion and contrast-enhanced wall motion, and compare it to the performance of dobutamine stress echocardiography conducted over the same period. The study team retrospectively reviewed 254 patient studies from December 2005 to February 2008. All patients had quantitative angiography within 90 days of the stress test or were considered not to have CAD based on previously established criteria (Heart, August 26, 2009).

During the study period, 155 patients being examined for the presence of significant CAD received real-time perfusion imaging with dobutamine stress echocardiography, while 99 had real-time perfusion imaging with treadmill stress echocardiography. Patients received the Definity ultrasound contrast agent (Lantheus Medical Imaging, North Billerica, MA), and real-time perfusion imaging was performed on either a Sonos 5500 (Philips Healthcare, Andover, MA) or an Acuson Sequoia C512 scanner (Siemens Healthcare, Malvern, PA).

Contrast replenishment, plateau intensity, and wall motion were all examined for the detection of CAD.
During dobutamine stress echocardiography, myocardial perfusion imaging with real-time perfusion was better at detecting CAD, yielding a sensitivity of 85%, significantly better than the 72% turned in when using wall-motion analysis to find CAD (p < 0.05).

"The improvement in sensitivity with [myocardial perfusion] analysis during [dobutamine stress echocardiography] was primarily due to better detection of left anterior descending disease," the authors wrote.

Myocardial perfusion imaging with real-time perfusion showed even more value for detecting CAD during treadmill exercise stress echocardiography, producing 98% sensitivity and a statistically significant improvement versus when the technique was used in dobutamine stress echocardiography (p < 0.05). The study team also found that wall-motion sensitivity during treadmill exercise echocardiography had an 89% sensitivity in detecting CAD, significantly better than wall-motion sensitivity during dobutamine stress echocardiography (p < 0.05).

The improvement in wall-motion sensitivity during treadmill exercise stress echocardiography was due to the detection of subendocardial wall-thickening abnormalities in 48% of the patients with induced subendocardial perfusion defects, according to the study team.

"Large prospective clinical trials are needed to confirm that [real-time perfusion] improves [wall-motion] sensitivity during [treadmill exercise stress echocardiography] and [dobutamine stress echocardiography], by comparing the [wall-motion] sensitivity during [real-time perfusion] with that achieved during conventional harmonic imaging, where ultrasound contrast is currently used only to improve endocardial border delineation," the authors concluded. "Such trials are under way."

View the article online.

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

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Ultrasound Can Predict Tumor Burden and Survival in Melanoma Patients

Patients could be spared unnecessary surgery...

Researchers have shown for the first time that patterns of ultrasound signals can be used to identify whether or not cancer has started to spread in melanoma patients, and to what extent. The discovery enables doctors to decide on how much surgery, if any, is required and to predict the patient's probable survival.

Dr. Christiane Voit said "We have identified two ultrasound patterns of lymph node metastasis in melanoma patients which can identify correctly any amount of tumor cells in the sentinel lymph nodes in 75-90% of cases before proceeding to surgery on the sentinel lymph nodes."

Dr. Voit, who is a dermatologist and head of the diagnostic unit at the Skin Cancer Centre at Charité - Universitätsmedizin Berlin, the Medical University of Berlin, Germany, said that although her research needs to be confirmed in multi-centre, randomized clinical trials, it had the potential to spare patients unnecessary surgery, especially if it was combined with ultrasound-guided fine needle biopsy of lymph nodes rather than conventional surgery.

Since 2001 Dr. Voit and her colleagues in Germany and The Netherlands have included 850 melanoma patients in a prospective study to investigate the use of ultrasound in diagnosis and treatment planning. They have already demonstrated that ultrasound-guided fine needle biopsy of sentinel nodes before conventional sentinel node surgery can identify up to 65% of patients in whom the cancer has started to spread. The study presented today shows how far ultrasound patterns correlate with disease progression, tumor burden, survival and prognosis in the first 400 of these patients with stage I/II melanoma and with the longest follow-up.

Before having sentinel node surgery the patients were investigated using ultrasound, and these results were checked against the results of the subsequent surgery. The researchers found that two ultrasound patterns together could correctly identify the amount of cancer cells in the lymph nodes in 80% of cases.

A balloon shape ultrasound pattern with or without loss of central echoes (where the lymph node has lost central echoes or still has some residual central echoes, but these are wandering toward the rim, giving an asymmetrical shape to the centre) was an indicator in up to 83% of cases of a large amount of cancer cells in the sentinel node. "This ultrasound pattern was a late sign, only occurring in cases of advanced metastasis," said Dr. Voit.

A pattern of peripheral perfusion (where small blood vessels start to surround the lymph node) was an early sign of a small number of cancer cells present. "The early signs are signs of first disruption of the normal lymph node architecture by an early stage metastasis.

The most important one is peripheral perfusion, which shows angiogenesis (the formation of new blood vessels) is occurring," she explained.

The researchers found that these two ultrasound patterns could predict overall survival. Estimates for overall survival after five years for patients with stage I/II is between 50-90% depending on the state of the tumor. Dr. Voit found that 93% of patients with neither of these ultrasound patterns, 87% of patients with peripheral perfusion, and 56% of patients with balloon shapes with or without loss of central echoes, survived for at least five years; survival without cancer spreading to other parts of the body was 74%, 60% and 26% respectively.

Dr. Voit said: "For the first time we have established that ultrasound patterns can be used as criteria for diagnosing disease progression and tumor burden. Balloon shaped lymph nodes with or without loss of central echoes and peripheral perfusion are independent prognostic factors for survival."

Discovering if cancer has spread to the lymph nodes is the most important factor influencing the prognosis and treatment of melanoma patients. Doctors usually cut out one or two key lymph nodes, called sentinel nodes, and use these as an indicator of whether or not the cancer has spread to the other lymph nodes. If the sentinel node is free of cancer, patients don't need to have more extensive lymph node removal. However, only 20% of patients who have a sentinel node biopsy have cancer that has spread there, and so the operation, which can be accompanied by side effects such as chronic swelling and seroma, is unnecessary for 80% of patients. Using ultrasound first to detect the presence or not of sentinel node metastases could be a non-invasive way of limiting the numbers of patients who require subsequent surgery or simply watchful follow-up care.

View the article online.

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

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Automated Whole-Breast Ultrasound Doubles Cancer Detection

An automated whole-breast ultrasound system doubled the cancer detection rate when used with mammography....

An automated whole-breast ultrasound system doubled the cancer detection rate when used with mammography to screen a population of women with dense breasts and/or an elevated breast cancer risk, according to a multi center study published online this month in European Radiology.

In addition to doubling the detection rate for all cancers, the system tripled the detection rate for very small cancers -- those smaller than 10 mm. The authors believe the technology's effectiveness could justify adding it to the screening routine for some women.

"Additional detection and the smaller size of invasive cancers may justify this technology's expense for women with dense breasts and/or at high risk for breast cancer," wrote a research team led by Dr. Kevin Kelly of Huntington Memorial Hospital in Pasadena, CA (European Radiology, September 3, 2009).

Kelly is also the founder, board chairman, and majority shareholder of SonoCiné of Reno, NV, which developed the whole-breast ultrasound technology used in the study. Statistical analyses in the study were conducted by independent researchers, however.

Given mammography's relatively low sensitivity in women with dense breasts, the researchers sought to compare the performance and diagnostic yield of mammography alone versus a combination of automated whole-breast ultrasound and mammography in this challenging patient population. The study included 4,419 women undergoing routine mammography between January 2003 and January 2007 at eight facilities in California, New Mexico, Georgia, and Utah.

The asymptomatic participants in the study had BI-RADS density of 3 or 4, heterogeneously or extremely radiographically dense breasts, and a family or personal history of breast cancer and/or implants. They were also at least 35 years old unless they had a family or personal history of breast cancer. Women with compressed breast thickness at mammography of greater than 7 cm were specifically not recruited because of ultrasound's limited effectiveness at these depths, according to the study team.

A total of 6,425 automated whole-breast ultrasound exams and mammograms were performed on the women. Of these, 4,991 mammograms were routine screening studies; 1,434 were annual asymptomatic diagnostic immediate-review studies, conducted on 776 patients with previous breast cancer, 399 with implants, and 159 with nonlocalized findings such as diffuse nodularity or diffuse breast tenderness.

Thirty-six percent (2,297) of the mammograms were digital studies, while the rest were analog. Patients had the option of receiving the whole-breast ultrasound study concurrently with mammography (selected by 3,951 women) or alternating mammography and whole-breast ultrasound every six months (chosen by 468 women).

With the SonoCiné system, a transducer from a conventional ultrasound scanner is attached to SonoCiné's computer-guided mechanical arm, which acquires images in longitudinal rows (transverse images), overlapping 7 to 10 mm to ensure complete coverage, according to the researchers. The system's software then creates a cine loop of the images for interpretation. The system was cleared by the U.S. Food and Drug Administration in October 2008.

For the study, SonoCiné was used with multifrequency transducers within at least the 7- to 12-MHz range on several different ultrasound scanners, including the iU22 (Philips Healthcare, Andover, MA), Acuson Sequoia (Siemens Healthcare, Malvern, PA), Logiq 9 (GE Healthcare, Chalfont St. Giles, U.K.), and HDI 5000 (Philips).

One of 10 radiologists with at least 10 years of experience in breast ultrasound interpreted each whole-breast ultrasound study; the mammograms were interpreted by a single radiologist in that institution's usual manner. Although the radiologists were blinded to the results of the corresponding mammograms or whole-breast ultrasound studies, they did in some cases interpret both exams.

To ensure that the original reader had not missed a mammographically detectable cancer, the researchers retrospectively reviewed the mammograms of all participants with cancers detected by whole-breast ultrasound. They also reviewed the mammograms and whole-breast ultrasound studies of all participants with clinically detected interval cancers occurring within one year of a normal mammogram.

There were 57 cancers in 56 study participants. The positive predictive value for biopsy was 39% based on mammography findings, compared with 38.4% for automated whole-breast ultrasound. When whole-breast ultrasound findings were added to mammography, the number of detected invasive cancers 10 mm or less in size tripled from seven to 21, according to the authors. Cancer detections for invasive tumors measuring 11 to 20 mm increased from eight to 14 with the addition of automated whole-breast ultrasound.

In other findings, whole-breast ultrasound detected 32 of 49 cancers (65%) in women with dense or extremely dense breasts, compared with 19 of 49 (39%) by mammography alone (p = 0.02). By adding whole-breast ultrasound to mammography, cancer detections more than doubled, from 19 to 39.

"Limiting [automated whole-breast ultrasound] examinations to a high-risk group with dense breasts, similar to the BRCA1/2 studies with MRI, would dramatically reduce the cost per cancer diagnosis," the authors wrote. "In our study 87% of cancer detections added by [whole-breast ultrasound] were found in the 68% of studies in women with dense/very dense breasts."

Further research should focus on better defining the combination of risk factors and imaging characteristics that warrant supplemental use of automated whole-breast ultrasound, the authors concluded.

View the article online.

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

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Prenatal ultrasound Does Not Increase Risk for Autism

Antenatal ultrasound does not appear to be associated with an increased risk for autism spectrum disorders (ASD)....

Antenatal ultrasound does not appear to be associated with an increased risk for autism spectrum disorders (ASD), according to a study published online this month in the Journal of Autism and Developmental Disorders.

California researchers found that there was no relationship between the number of ultrasound scans and autism risk when a group of children with autism was compared to a group of normal controls. They believe their results may refute anecdotal theories that have connected rising autism rates with the increased use of prenatal ultrasound.

The research team, led by Judith Grether, Ph.D., from the California Department of Public Health in Richmond, CA, retrospectively evaluated singleton and control children enrolled in the Kaiser Permanente of Northern California (KPNC) healthcare system who were born between 1995 and 1999 (J Autism Dev Disord, September 1, 2009).

ASD cases were defined as singleton children with at least one diagnosis of an autism spectrum disorder (i.e., autism, Asperger's syndrome, or pervasive developmental disorder not otherwise specified) based on International Classification of Diseases criteria. Each ASD case was matched to a singleton control case from a cohort of KPNC births without an ASD diagnosis, with researchers trying to match ASD cases and control children based on gender, birth year, and hospital of birth, according to the researchers.

The study team then obtained clinical data from multiple sources within KPNC to identify the antenatal ultrasound examinations that children had received, the date and time of scans, gestational age at time of scans, and the type of scans.

The final study included 362 children with ASD from simplex families (in which a child has autism but parents and other siblings are unaffected) and 393 control children. The mothers of children with ASD had significantly greater mean maternal age than mothers of children in the control group, although the age was not significantly different when evaluated in five-year categories.

The mothers of children with ASD also had more years of education than mothers of children in the control group. In addition, the mean birth age of children with ASD was somewhat less than for the control children, a difference which approached statistical significance, the researchers noted.

Of the children with ASD from simplex families, 13% had no exposure to ultrasound examinations, compared with 12.5% in the control group. The majority of ultrasound exams were performed in the second trimester; 77.9% of ASD cases and 79.2% of the control group had one or more scans during this period. Approximately 28% of both ASD cases and controls had at least one scan in the first and third trimester.

From unadjusted analyses using a chi-square trend test, the study team determined that the number of ultrasound examinations was not significantly associated with ASD status during the entire gestational period or for any trimester.

Using logistic regression models, the researchers observed no significant or consistent increased risk of ASD with increasing numbers of antenatal ultrasound examinations for the total gestation or any trimester when ultrasound frequency was used as a continuous variable. They did note an elevated risk for females, however, in the second trimester when ultrasound was treated as a continuous variable in adjusted models, but not when ultrasound was treated as a categorical variable.

"This finding cannot be attributed to one or two outliers but could represent a chance finding among the large number of comparisons we conducted; alternatively, there may be risk associated with multiple [ultrasound exams] for girls in the second trimester or with medical indications for repeated [ultrasound exams] during this window of gestation," the researchers wrote.

In models that treated the frequency of ultrasound as a categorical variable, the researchers did not find a statistically significant elevation in risk with increasing numbers of antenatal ultrasound examinations for the total gestation or any trimester.

"When boys or girls were evaluated separately in models that treated frequency as a categorical variable, no significant elevations in risk were seen for the total pregnancy or for any trimester," they wrote.

The researchers noted that studies of phenotypic subgroups remain to be conducted and as antenatal ultrasound technologies and procedures change, further evaluation of potential risks may be warranted. In addition, the study did not address other possible risks to fetuses associated with antenatal ultrasound. But overall, use of prenatal ultrasound does not appear to be linked to autism, they concluded.

"The predominately null findings of this investigation of fetal exposure to antenatal ultrasound and risk of autism spectrum disorders may provide assurance that antenatal ultrasound examinations, when performed in a clinical setting according to established guidelines, do not appear to put fetuses at increased risk for developing ASD," the researchers wrote.

View the article online.

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

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