CT perfusion imaging of the liver provides functional information about the microcirculation of normal parenchyma and focal liver lesions and is a promising technique for assessing the efficacy of anticancer treatments. Many limitations of early CT perfusion studies performed in the liver, such as limited coverage, motion artifacts, and high radiation dose, are being addressed by technical advances. While other issues must still be solved, CT perfusion has now reached technical maturity, allowing for its use in larger-scale prospective clinical trials.
In a review in the August issue of Radiology (RSNA.org/Radiology), Se Hyung Kim, M.D., of the Molecular Imaging Program at Stanford University, and colleagues discuss the basic principles, current acquisition protocols and pharmacokinetic models used for CT perfusion imaging of the liver. In addition, various oncologic applications are discussed in detail:
The authors also discuss possible solutions to challenges that remain in CT perfusion of the liver, including radiation dose, reproducibility, motion correction and protocol standardization.
“The lack of standardization in image acquisition and the methodologies applied for data analysis is an acknowledged issue by researchers in the field of perfusion imaging, and there is fortunately increasing efforts toward the standardization and harmonization of both data acquisition and analysis,” the authors note. “Such developments are of paramount importance for the wider clinical acceptance of the technique and industry-academia collaborations are being developed to address such challenges.”
In light of the limitations of mammography, including low sensitivity in detecting some cancers and high false-positive recall rates, controversy exists over when and how often screening mammography should occur. Digital breast tomosynthesis (DBT) is rapidly being implemented in breast imaging clinics around the world as early clinical data demonstrate that it may address some of the limitations of conventional mammography.
In an article in the July-August issue of RadioGraphics (RSNA.org/RadioGraphics), Robyn Gartner Roth, M.D., of the Department of Radiology at the Hospital of the University of Pennsylvania, and colleagues detail the clinical applications of digital breast tomosynthesis in both screening and diagnostic settings. Specifically the authors:
“This article focuses on our early clinical experiences with DBT in both screening and diagnostic settings,” the authors note. “One year after implementing DBT for all screening patients, we demonstrated a substantial reduction in our overall callback rate and a trend toward increased cancer detection … As with any new technology, several issues must be considered when implementing DBT into daily practice. Ongoing large-scale prospective trials will help guide the evidence-based utilization of this new technology.”
In an accompanying invited commentary, Stephen A. Feig, M.D., of the Department of Radiology at the University of California Irvine Medical Center, notes that while many supplementary screening modalities, including breast US and MR imaging, have been developed to supplement digital mammography, DBT could perhaps provide the most clinically significant benefit for most women.
Listen to Radiology Editor Herbert Y. Kressel, M.D., deputy editors and authors discuss the following articles in the June issue of Radiology at RSNA.org/Radiology-Podcasts:
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