PET Plays Critical Role in Supporting Parkinson's Disease Research

Reston, Va.—A large-scale study conducted to measure the effectiveness of dopamine cell transplantation in Parkinson’s disease patients shows significant improvements in motor skills and brain function, according to research reported in the January issue of The Journal of Nuclear Medicine (JNM). The results of this study demonstrate that transplanted cells were viable and integrated well with the host brain tissue. Furthermore, these cells produced dopamine that helped support the brain and led to an improvement in motor symptoms. These improvements were sustained over a four-year study period.

“This study provided new insights into the time course of transplantation outcome,” said David Eidelberg, M.D., study co-author and director of the Neuroscience Center at the Feinstein Institute for Medical Research in Manhasset, N.Y. “Comprehensive long-term clinical follow-up, together with molecular imaging, allows for a more realistic appraisal of this kind of intervention for Parkinson’s disease.”

Researchers reported long-term clinical and imaging outcomes after transplantation from 33 patients who originally participated in a one-year, double-blind, placebo-controlled trial of embryonic dopaminergic cell implantation for Parkinson’s disease. Clinical improvement in motor ratings, as well as increased brain uptake of 18F-fluorodopa (18F-FDOPA)—the radiotracer that is widely used to investigate the function of dopamine grafts—was evident at one, two and four years after the transplantation surgery.

source: SNM


Physiologic Factors Linked to Image Quality of Multi-Detector Computed Tomography Scans

A large multicenter international trial found that the image quality of multi-detector computed tomography (MDCT) scans, used for the noninvasive detection of coronary artery disease, can be significantly affected by patient characteristics such as ethnicity, body mass index (BMI), and heart rate, according to a study in the January issue of the American Journal of Roentgenology.

The large multicenter international trial study included 291 patients with coronary artery calcification and found that compared with examinations of white patients, studies of black patients had significantly poorer image quality.

“Physiologic factors such as high heart rate, arrhythmia, obesity, and high coronary calcium burden with motion continue to limit the diagnostic accuracy of MDCT as compared with conventional invasive coronary angiography. Our study is significant because we found a relevant influence of BMI, heart rate, ethnicity, and breathing artifact on the degradation of image quality,” said Melvin E. Clouse, MD, lead author of the study.

MDCT scans have been implemented in a variety of patients with suspected coronary artery disease because of its diagnostic accuracy and reliability. However “the diagnostic ability of any imaging method is directly dependent on image quality,” said Clouse.

“With this new knowledge combined with new and advanced CT scanners, we have the potential to improve image quality of coronary CT angiography, further making the test even more accurate and independent of patient characteristics,” he said.

source: ARRS


Cat Scan Radiation Exposure and Cancer Risks

Several recent articles in he Archives of Internal Medicine outline the rapidly growing concerns about cancer risk and radiation exposure from CT scans. Each day there are over 19,500 Cat Scans performed in the U.S. With each scan the patient is exposed to the equivalent of 30 - 443 chest x-rays.

Smith-Bindman and colleagues3 collected actual data on radiation dosages for the most commonly used CT scans at 4 institutions in the San Francisco Bay area in California in 2008. They found a surprising variation in radiation dose—a mean 13-fold variation between the highest and lowest dose for each CT type studied (range, 6- to 22-fold difference across study types). The investigators found a median effective dose of 22 mSv from a typical Cat Scan coronary angiogram and 31 mSv for a multiphase abdomen-pelvis CT scan. At one institution, exposure was a staggering 90 mSv for a multiphase abdomen-pelvis CT scan.

Even the median doses are 4 times higher than they are supposed to be, according to the currently quoted radiation dose for these tests. Just 1 CT coronary angiogram, on average, delivers the equivalent of 309 chest radiographs. From their data, Smith-Bindman et al3 estimated the risk of cancer, taking into consideration age, sex, and study type. By their calculations, 1 in every 270 forty-year-old women undergoing a CT coronary angiogram will develop cancer from the procedure.

In a second study, Berrington de González and colleagues2 determined CT scan use frequency using data from a large commercial insurance database, Medicare claims data, and IMV Medical Information Division survey data. They estimated there were 72 million CT scans performed in 2007. Excluding scans conducted after a diagnosis of cancer and those performed in the last 5 years of life, Berrington de González et al2 projected 29 000 excess cancers as a result of the Cat Scans scans done in 2007. These cancers will appear in the next 20 to 30 years and by the authors' estimates, at a 50% mortality rate, will cause approximately 15 000 deaths annually.

In other words, 15 000 persons may die as a direct result of CT scans physicians had ordered in 2007 alone. Presumably, as the number of Cat Scans scans increase from the 2007 rate, the number of excess cancers also will increase. In light of these data, physicians (and their patients) cannot be complacent about the hazards of radiation or we risk creating a public health time bomb.


New MRI Safety Risk For Patients With Pacemakers Identified By FDA Researchers

FDA researchers have found that certain cardiac pacemakers may inadequately stimulate a patient's heart while undergoing a magnetic resonance imaging (MRI) scan due to the magnetic pulses mixing with the electronic pulses from the pacemaker. This inadequate stimulation is potentially dangerous for the patient undergoing the MRI scan, according to research published in BioMed Central's open access journal BioMedical Engineering Online.

MRI is an imaging technique that uses a magnetic field instead of ionizing radiation to produce a detailed image of internal body structures. MRI systems expose patients to very strong magnetic fields that can interfere with implanted cardiac pacemakers. Physicians are instructed by pacemaker manufacturers and MRI system manufacturers not to expose patients with pacemakers to MRI scans. MRI can damage the pacemaker's electronic system and cause burning of heart tissue at the tip of the pacemaker lead, due to an increase in temperature from the MRI. Both risks can result in incorrect or absent stimulation from the pacemaker.

source: Medical News Today


Studies quantify radiation doses, cancer risks from CT scans

Doses of radiation from commonly performed computed tomography (CT) scans vary widely, appear higher than generally believed and may contribute to an estimated tens of thousands of future cancer cases, according to two reports in the December 14/28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

CT scans have become increasingly common in the United States—about 70 million were performed in 2007, up from 3 million in 1980, according to background information in one of the articles. "While CT scans can provide great medical benefits, there is concern about potential future cancer risks because they involve much higher radiation doses than conventional diagnostic X-rays," the authors of one report write. For example, a chest CT scan exposes the patient to more than 100 times the radiation dose of a routine chest X-ray. "The risks to individuals are likely to be small, but because of the large number of persons exposed annually, even small risks could translate into a considerable number of future cancers."

It is important to understand how much radiation medical imaging delivers to help balance benefits and risks, the authors note. In one paper, Rebecca Smith-Bindman, M.D., of the University of California, San Francisco, and colleagues studied 1,119 patients undergoing the 11 most common types of diagnostic CT scans at four area institutions in 2008. Using hospital records, they calculated the radiation dosage involved with each scan and then estimated lifetime risks of cancer that could be attributed to those scans.

Radiation dosage varied widely between different types of CT studies; median (midpoint) doses ranged from 2 millisieverts for a routine head CT scan to 31 millisieverts for a multiphase abdomen and pelvis scan. "Within each type of CT study, effective dose varied significantly within and across institutions, with a mean [average] 13-fold variation between the highest and lowest dose for each study type," the authors write.

The estimated number of CT scans that would lead to the development of one cancer case also varied by type of CT scan and also by each patient's age and sex.

source: Eurekalert

Variable Doses of Radiation Raise Safety Concerns for CT Procedures

Radiation doses from common CT procedures vary widely and are higher than generally thought, raising concerns about increased risk for cancer, according to a new study led by University of California, San Francisco (UCSF) imaging specialists.

San Francisco, CA (Vocus/PRWEB ) December 14, 2009 -- Radiation doses from common CT procedures vary widely and are higher than generally thought, raising concerns about increased risk for cancer, according to a new study led by University of California, San Francisco (UCSF) imaging specialists.

In day-to-day clinical practice, we found significant variation in the radiation doses for the same type of computed tomography procedures within institutions and across institutions," said lead investigator Rebecca Smith-Bindman, MD, a professor of radiology at UCSF. Our results highlight the need for greater standardization because this is a medical safety issue."

Computed tomography imaging, known as CT, is a diagnostic procedure that uses special x-ray equipment to obtain cross-sectional pictures of the body that provide detailed images of organs, bones, and other tissues. CT is associated with higher radiation exposure than conventional x-rays, yet radiation dosages that patients receive from the newer CT scanners have gone largely unregulated, according to Smith-Bindman, who also is a UCSF professor of epidemiology and biostatistics and obstetrics, gynecology and reproductive sciences.

Our study provides some initial data documenting the doses that patients receive when they undergo actual CT examinations and this is different than the doses when phantoms-- sophisticated plastic models typically used to quantify CT scanner dose-- are used. We believe documenting the actual doses that patients are exposed to is the first step to reducing those doses and any attendant risk," she emphasized.

complete article: PR Web


Repligen Reports Phase 3 Clinical Trial Results of RG1068 in Pancreatic Imaging

WALTHAM, MA - December 9, 2009 - Repligen Corporation (NASDAQ: RGEN) reported today top-line results from a Phase 3 clinical trial to evaluate the safety and efficacy of RG1068, synthetic human secretin, to improve magnetic resonance imaging (MRI) of the pancreas in patients with a history of pancreatitis. The study's co-primary endpoints were improvements in sensitivity of detection of structural abnormalities of the pancreatic ducts using RG1068 in combination with MRI compared to MRI alone with minimal loss in specificity (<7.5%). The study design used endoscopy as the standard for determination of structural abnormalities. The predetermined criteria for a successful study were achievement of a statistically significant improvement in sensitivity with minimal loss in specificity from two of the three central radiologists reading the MRI images. In this study, one radiologist achieved a statistically significant improvement in sensitivity with RG1068 (p<0.001) while a second radiologist showed a trend but did not achieve statistical significance (p=0.088). There was minimal loss in specificity for all radiologists. While it was not a pre-specified endpoint, pooled data from all three radiologists resulted in a statistically significant improvement in sensitivity with RG1068 (p=0.005) with minimal loss in specificity.

source: Repligen


MRI Detects Breast Cancer at Earlier Stage

SAN ANTONIO - Magnetic resonance imaging (MRI) coupled with mammography detects almost all cancers at an early stage, thereby reducing the incidence of advanced stage breast cancer in high-risk women.

"Earlier stage breast cancers are more likely to be curable," said lead researcher Ellen Warner, M.D., M.Sc., medical oncologist in the Department of Medicine, Division of Medical Oncology at Sunnybrook Health Sciences Center, in Toronto, Canada.

"We can be fairly confident that if screening with MRI finds cancers at a much earlier stage, it probably also saves lives," added Warner, who presented details of these results at the CTRC-AACR San Antonio Breast Cancer Symposium, held Dec. 9-13.

The researchers separated 1,275 women at high risk for breast cancer into two groups: One group was screened with MRI plus mammography, and the second, a control group, received conventional screening by mammography. Participants had the defective BRCA1 or BRCA2 gene mutation, which suggests a very high lifetime risk of developing breast cancer.

Warner and colleagues followed the women over several years to determine which screening method detected cancer at a significantly earlier stage.

source: AACR


CT Brain Perfusion Scans Safety Investigation: Initial Notification

[UPDATED 12/07/2009] The FDA, working with state and local health authorities, has identified at least 50 additional patients who were exposed to excess radiation of up to eight times the expected level during their CT perfusion scans. These cases so far involve more than one manufacturer of CT scanners. Some of these patients reported hair loss or skin redness following their scans. High doses of radiation can cause cataracts and increase the risk of some forms of cancer.

On the basis of its investigation to date, the FDA is providing interim recommendations for imaging facilities, radiologists, and radiologic technologists to help prevent additional cases of excess exposure.

These recommendations include:

* Facilities assess whether patients who underwent CT perfusion scans received excess radiation.
* Facilities review their radiation dosing protocols for all CT perfusion studies to ensure that the correct dosing is planned for each study.
* Facilities implement quality control procedures to ensure that dosing protocols are followed every time and the planned amount of radiation is administered.
* Radiologic technologists check the CT scanner display panel before performing a study to make sure the amount of radiation to be delivered is at the appropriate level for the individual patient.
* If more than one study is performed on a patient during one imaging session, practitioners should adjust the dose of radiation so it is appropriate for each study.

source: FDA


CT Imaging Taken Post Avastin May Predict Survival in Patients With Metastatic Colorectal Cancer

ScienceDaily (Dec. 2, 2009) — Using routine computed tomography (CT) imaging to analyze form and structural changes to colorectal liver metastasis after bevacizumab and chemotherapy may predict overall survival, according to research from The University of Texas M. D. Anderson Cancer Center.

The findings are published in the Dec. 2 issue of JAMA.

When combined with chemotherapy, the angiogenesis inhibitor bevacizumab, also known as Avastin, is associated with both improved survival in those with metastatic colorectal cancer and higher rates of pathologic response in patients undergoing surgical resection of colorectal liver metastases. The monoclonal antibody was approved for use in the front line setting of metastatic colorectal cancer in 2004.

However, the therapy presents a unique set of challenges, explains Jean-Nicolas Vauthey, M.D., professor in M. D. Anderson's Department of Surgical Oncology.

source: Science Daily Release


Smart Phones Allow Quick Diagnosis of Acute Appendicitis

CHICAGO — Radiologists can accurately diagnose acute appendicitis from a remote location with the use of a handheld device or mobile phone equipped with special software, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

"The goal is to improve the speed and accuracy of medical diagnoses, as well as to improve communications among different consulting physicians," said the study's lead author, Asim F. Choudhri, M.D., fellow physician in the Division of Neuroradiology at Johns Hopkins University in Baltimore. "When we can make these determinations earlier, the appropriate surgical teams and equipment can be assembled before the surgeon even has the chance to examine the patient."

Appendicitis, or inflammation and infection of the appendix, is a medical emergency requiring surgical removal of the organ. Undiagnosed or left untreated, the inflamed appendix will rupture, causing toxins to spill into the abdominal cavity and potentially causing a life-threatening infection. Appendicitis can occur at any age but is most common in people between the ages of 10 and 30, according to the National Institutes of Health.

Typically, a patient arriving at the emergency room with suspected appendicitis will undergo computed tomography (CT) and a physical examination. If a radiologist is not immediately available to interpret the CT images or if consultation with a specialist is needed, diagnosis is delayed, increasing the risk of rupture. Transmitting the images over a mobile device allows for instant consultation and diagnosis from a remote location. It can also aid in surgical planning.

"This new technology can expedite diagnosis and, therefore, treatment," Dr. Choudhri said.

For the study performed at the University of Virginia in Charlottesville, CT examinations of the abdomen and pelvis of 25 patients with pain in the right lower abdomen were reviewed over an encrypted wireless network by five radiologists using an iPhone G3 equipped with OsiriX Mobile medical image viewing software. All of the patients had surgical confirmation or follow-up evaluations to confirm whether or not they had appendicitis.

source: RSNA News Release


RevMed Successfully Introduces MRI Product Suite at Radiology Society of North America Conference

CHARLESTON, SC--(Marketwire - December 3, 2009) - Revolutions Medical Corporation ("RevMed" or the "Company") (OTCBB: RMCP), producers of the RevVac safety syringe, RevColor, RevDisplay and Rev3D MRI Technology, today announced that it introduced its proprietary suite of MRI software products at this week's Radiology Society of North America (RSNA) annual meeting with great success. Radiologists and universities world-wide received presentations at the RMCP booth. A number of these contacts could play an important role in the Company's ongoing efforts to clinically validate specific applications of its MRI tools prior to the 2010 commercial launch.

"I could not be more pleased about the overwhelming interest that our MRI tools generated at this first introduction of our technology, and moreover at the premier imaging conference in the world," stated RevMed CEO Ron Wheet. "Introducing our proprietary MRI product offering at this conference was a dramatic step forward to commercialization in 2010. Radiologists immediately understood the utility of our products. Universities, OEM and VAR providers requested follow-up discussions regarding clinical collaboration. They also want to explore delivery options, i.e. embedding our product content into their existing commercially available products. Timely hot topics at the show included MRI analysis in breast disease, and brain abnormalities such as the depth of injury in concussion (as reported by the NFL); these led to discussions as to how our unique MRI color software would aid in image analysis, thereby enhancing diagnostic confidence in an entirely different way."

source: MarketWire


Unindicated CT Series Result in Unnecessary Radiation Exposure for Patients

CHICAGO, Nov. 30 /PRNewswire/ -- A large proportion of patients who undergo abdominal/pelvic computed tomography (CT) receive unindicated and unnecessary additional image acquisition resulting in excess, avoidable radiation exposure, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

"It is the responsibility of all physicians who work with ionizing radiation to ensure that the dosage is as low as reasonably achievable without compromising the patient's well being," said Kristie Guite, M.D., radiology resident at the University of Wisconsin (UW) in Madison. "Our study found that this principle is not being followed in many practices."

A CT examination consists of imaging the patient using a CT scanner and sometimes involves the injection of an intravenous contrast agent. Imaging can be performed at multiple time points before and/or after the injection of the contrast material. Each image acquisition is referred to as a "series." Although having multiple series can be helpful for some conditions, they are not generally necessary.

Because it provides valuable diagnostic information, CT use has risen rapidly. In recent years, a number of reports have highlighted the increasing radiation exposure to patients through the use of medical imaging, particularly CT. While these reports have often focused on general and screening uses, little attention has been paid to radiation from additional series, including routine non-contrast or delayed-phase CT, which may or may not be indicated by the patient's condition but are sometimes performed so that nothing is overlooked.

To determine the frequency of unindicated additional scanning and the resultant excess radiation exposure to patients, the researchers reviewed the appropriateness and radiation dose of abdomen and pelvis CT exams for 500 patients performed at outside institutions and submitted to UW - Madison for interpretation. The patients ranged in age from nine months to 91 years, with most between 30 and 50 years old.
complete article