December issue of RSNA News Now Available
Dont's Miss the Latest News
The December issue of RSNA News is now available at RSNAnews.org
Highlights include:
Stanford Lab Emerges as 3D Imaging Leader
Biomarker Identification Accelerates Alzheimer Research
Negative Perception of Pediatric Radiology May Explain Workforce Shortage
Study Reinforces Concerns about CIN
iPhone Application Tracks Radiation Exposure, Risk
Headlines
Leading the News
Research
Technology
Clinical Practice
Leading the News
Imaging Test Detects Alzheimer Disease That Is Likely to Progress
Preclinical Alzheimer disease can be detected by screening an individual's cerebrospinal fluid for set biomarkers and by using PET imaging with the Pittsburgh Compound B (PiB) to detect the presence of beta-amyloid in patients. Washington University School of Medicine Professor John C. Morris and colleagues recently assessed 159 adults with an average age of 71.5 years who had undergone PET scans using PiB, but did not have symptoms of dementia. These patients were then followed for between 0.8 and 5.5 years after the initial scan. During that time period a total of 23 patients progressed to clinically detectable dementia and nine were diagnosed with dementia associated with Alzheimer. The PiB PET scans allowed researchers to identify patients who would develop Alzheimer disease-related dementia; however, it did not predict which individuals would develop dementia not associated with Alzheimer.
From "Pittsburgh Compound B Imaging and Prediction of Progression From Cognitive Normality to Symptomatic Alzheimer Disease"
Archives of Neurology (12/09) Vol. 66, No. 12, P. 1469; Morris, John C.; Roe, Catherine M.; Grant, Elizabeth A.
Research
Benefits of Shortened Breast Radiation Course Presented at SABCS
New research presented at the 32nd Annual CTRC-AACR San Antonio Breast Cancer Symposium (SABCS) focuses on the benefit of a shortened radiation course in patients with the most common type of non-invasive breast cancer. The study, which focuses on patients with ductal carcinoma in situ (DCIS) who have had a lumpectomy, was led by the Cancer Institute of New Jersey's Sharad Goyal, MD, instructor of radiation oncology at UMDNJ-Robert Wood Johnson Medical School. In DCIS, the cancer cells are inside the milk ducts of the breast and have not spread to surrounding breast tissue. The study looked at 69 patients between 2002 and 2004. Following a lumpectomy, patients were offered accelerated partial breast irradiation (APBI), a one-week course of treatment that targets the specific area of the breast cavity where the cancer was removed. Investigators found that APBI greatly reduces the rate of local recurrence for low-risk DCIS patients. Considering the shortened course of radiation (one week of APBI versus the traditional seven or eight), Goyal notes such treatment not only lessens the chance of recurrence, but also could have great benefit to a patient’s quality of life in not having to travel continuously to the treatment site.
From "Benefits of Shortened Breast Radiation Course Presented at SABCS"
Newswise (12/11/09)
CT-Slices Connected by Means of a Path Search Algorithm for Fused Joint Segmentation
Researchers used a rough surface model of the shoulder to extract a loop that encircles the joint. The intersection points of this loop and separate CT slices were then connected by means of a path search algorithm. Inaccurate sections were corrected by iteratively applying a Hough transform to the segmentation result. The researchers found that combining surface curvature, limited user interaction, and iterative refinement via a Hough transform forms a satisfactory approach for the segmentation of severely damaged arthritic shoulder joints.
From "Combined Surface and Volume Processing for Fused Joint Segmentation"
International Journal of Computer Assisted Radiology and Surgery (12/05/2009) Krekel, Peter R.; Valstar, Edward R.; Post, Frits H.; et al.
First-Trimester Placental Volume and Vascularization Measured by 3-Dimensional Power Doppler Sonography in Pregnancies With Low Serum PAPP-A
Low serum pregnancy-associated plasma protein A (PAPP-A) levels are associated with altered 3-D placental Doppler indices, while both factors are also associated with the subsequent development of intrauterine growth restriction (IUGR) and adverse pregnancy outcomes. These conclusions are based on 3-D power Doppler sonography of placentas performed at gestational ages between 11 weeks and 13 week six days in 84 pregnancies with PAPP-A concentrations of less than 0.4 multiple of the median. Pregnancy outcomes for these cases included 57 pregnancies with birth weights at or above the 10th percentile group, 16 pregnancies with birth weights below the 10th percentile and normal Doppler findings in the umbilical artery throughout gestation, and one pregnancy with a birth weight below the 10th percentile and abnormal umbilical Doppler findings later in gestation. No differences were found in PAPP-A levels among these groups.
From "First-Trimester Placental Volume and Vascularization Measured by 3-Dimensional Power Doppler Sonography in Pregnancies With Low Serum Pregnancy…"
Journal of Ultrasound in Medicine (12/01/09) Vol. 28, No. 12, P. 1615; Rizzo, Giuseppe; Capponi, Alessandra; Pietrolucci, Maria Elena; et al.
Parallel MRI Provides a Reliable Assessment for Pediatric Knees
Parallel imaging provides faster scanning at the cost of reduced signal-to-noise ratio (SNR) and increased artifacts. A recent study aimed to compare the diagnostic performance of two parallel MRI protocols (PPs) for assessment of pathologic knees using an 8-channel knee coil (reference standard, conventional protocol [CP]) and to characterize the SNR losses associated with parallel imaging. Two radiologists blindly interpreted 1.5 Tesla knee MRI images in 21 children, ranging from nine to 18 years old, with clinical indications for an MRI scan. Sagittal proton density, T2-W fat-saturated FSE, axial T2-W fat-saturated FSE, and coronal T1-W images were obtained using both CP and PP. Images were studied for soft tissue and osteochondral findings. The study found there was a 75 percent decrease in acquisition time using PP in comparison to CP. The CP and PP protocols fit within excellent or upper limits of substantial agreement. The sensitivity of two PPs was similar for assessment of soft and osteochondral tissues. Phantom data indicated an SNR of 1.67, 1.6, and 1.51 on axial, sagittal and coronal planes, respectively, between CP and PP scans. The researchers conclude that parallel MRI provides a reliable assessment for pediatric knees in a significantly reduced scan time without affecting the diagnostic performance of MRI.
From "The Use of Parallel Imaging for MRI Assessment of Knees in Children and Adolescents"
Pediatric Radiology (12/01/2009) Doria, Andrea S.; Chaudry, Gulraiz A.; Nasui, Cristina; et al.
Technology
Researchers Develop Motion Correction Technique for Cardiac (15)O-Water PET Study Using an Optical Motion Tracking System
Researchers have developed a technique that provides reasonable information for correcting the global movement of the subject of (15)O-water PET studies. This system was found to be applicable to both detect and correct subject movement in cardiac PET studies at rest. In order to test the system, PET studies were carried out on a cardiac phantom and healthy volunteers at rest. Three-dimensional locations of markers attached to the subjects during scans were measured using the optical-motion tracking system. (15)O-water dynamic scans with a transmission and axially 30 mm-shifted transmission scans were also conducted. Motion of the subject for these scans was estimated by the information from the motion-tracking system and was corrected on each sinogram using attenuation maps realigned to dynamic frames. Reconstructed dynamic images were then realigned to the transmission data. Regional myocardial blood flows were then calculated for nine segments and myocardial images from the emission images, which were reconstructed with the first attenuation map and with the misaligned attenuation map before and after corrections were made.
From "Development of Motion Correction Technique for Cardiac (15)O-Water PET Study Using an Optical Motion Tracking System"
Annals of Nuclear Medicine (12/09) Koshino, Kazuhiro; Watabe, Hiroshi; Hasegawa, Shinji
Quantitative In-Capromab Pendetide SPECT/CT May Be Able to Noninvasively Grade Prostate Tumors
The results of a recent study indicate that quantitative In-capromab pendetide SPECT/CT has the potential to noninvasively grade prostate tumors. Researchers' experiments focused on the robustness of an advanced iterative reconstruction algorithm that involves corrections for photon attenuation, scatter, and geometric blurring caused by radionuclide collimators. The conversion factors between image values and tracer concentrations were calculated from a uniform phantom filled with an aqueous solution that used the same acquisition protocol and reconstruction parameters as patient studies. By doing so, researchers were able to determine that reconstructed SPECT images further corrected by the deconvolution-based partial-volume-error correction could recover tracer concentrations up to 90 percent of true values in measurements of phantom volumes as small as 7.7 mL.
From "In Vivo Tumor Grading of Prostate Cancer Using Quantitative In-Capromab Pendetide SPECT/CT"
Journal of Nuclear Medicine (12/09) Seo, Youngho; Aparici, Carina Mari; Cooperberg, Matthew R.; et al.
X-ray Scans Gain Color Mode
Technology that can produce color x-rays has been developed by an international project involving the participation of New Zealand researchers, and University of Canterbury professor Phil Butler says this milestone "gives more information for diagnosis and treatment which will improve healthcare, and save lives." The Medipix All Resolution System (MARS) scanner utilizes technologies first devised for particle physics research at the European Organization for Nuclear Research, and it will allow researchers to gain a better comprehension of frequently fatal conditions. The additional color information means that multiple types of scans can be performed simultaneously, reducing the dose of radiation administered to the patient, according to University of Otago radiologist Anthony Butler. "In addition ... these advanced contrast agents, coupled with multi-energy [computed tomography], will provide similar information to what is currently only obtainable on [magnetic resonance imaging] or [positron emission tomography]," he says. The MARS scanner is being shipped to the United States, where it will be employed in medical imaging.
From "X-ray Scans Gain Color Mode"
ScienceAlert (Australia) (12/17/09)
Clinical Practice
OPN May Play a Role in the Formation of Calcifications Associated With Breast Cancer
Osteopontin (OPN) may play a role in the formation of calcifications that are often associated with breast cancer, according to a retrospective review published online in Radiology on December 17. The review evaluated 141 women with breast cancer using mammographic features and clinicopathologic characteristics correlated with tumor OPN expression. X2 and Fisher exact tests were conducted to evaluate the association of OPN expression with mammographic and clinicopathologic features. They found that calcifications on mammograms, spiculated margins of mass on mammograms, triple-negative phenotype, and lymph node metastasis were significantly associated with OPN status. In contrast with OPN-negative tumors, OPN-positive tumors were more likely to have spiculated margins, to be associated with calcifications, to be a triple-negative phenotype, and to have axillary lymph node metastasis.
From "Primary Breast Carcinoma: Association of Mammographic Calcifications With Osteopontin Expression"
Radiology (12/17/09) Wang, Xiao; Chao, Lan; Ma, Guohui; et al.
Renal Mass Biopsies More Cost-Effective, Prevent Unnecessary Procedures
Massachusetts General Hospital researchers report that using a renal mass biopsy to guide treatment choices for small renal tumors is more cost-effective than direct surgery and can prevent patients from undergoing unnecessary surgical procedures. Most small renal masses are detected incidentally in imaging, and the current treatment is direct surgery, according to lead researcher Dr. Pari Pandharipande, a radiologist in the abdominal imaging and interventional radiology department at MGH. However, many small renal masses are benign, or indolent if malignant, so less invasive surgery options should be considered, according to Pandharipande. The researchers created a cost-analysis schematic and determined that surgery was about $3,500 more expensive than biopsy and resulted in comparable minimally lower life expectancy. If a strategy dropped below $75,000 per quality adjusted life year, that treatment was considered cost-effective. The researchers assumed a biopsy sensitive of 90 percent and specificity of 100 percent, as well as a post-surgery mortality rate of 1.6 percent. Among imaging-detected masses, 77 percent would reflect renal cell carcinoma, either benign or malignant, under the researchers' model. Biopsy was not cost-effective when sensitivity and specificity were lower than 78 percent, when surgical mortality was lower than 1 percent, and when prevalence of renal cancer was 87 percent. A competing-choice cost-effectiveness analysis was used to compare biopsy with surgery, and if one treatment had a lower life expectancy and a higher cost than another, it was considered better.
From "Renal Mass Biopsies More Cost-Effective, Prevent Unnecessary Procedures"
Diagnostic Imaging (12/14/09) Moan, Rebekah
RSNA Weekly is a briefing of the latest radiology-related news selected from hundreds of sources by the editors of Information, Inc. While care is taken to use good sources, inaccuracies in source material are not the responsibility of RSNA or Information, Inc.
Abstract News © Copyright 2009 INFORMATION, INC.
Radiological Society of North America, Inc.,
820 Jorie Blvd, Oak Brook, IL 60523-2251
|
