"High-frequency ultrasound with elastography has the potential to improve the efficiency of skin cancer diagnosis," said lead author Eliot L. Siegel, M.D., vice chairman of the Department of Radiology at the University of Maryland School of Medicine (UMSM) in Baltimore. "It successfully delineated the extent of lesions and was able to provide measurable differentiation among a variety of benign and malignant lesions."
There are more than one million cases of skin cancer diagnosed in the U.S. every year, according to the American Cancer Society. Melanoma, the most serious type of skin cancer, will account for about 68,720 cases of skin cancer and 11,590 deaths in 2009, despite the fact that with early detection it is highly curable.
Suspicious skin lesions are typically diagnosed by dermatologists and biopsied based on their surface appearance and characteristics. Unfortunately, even to experienced dermatologists, benign and malignant lesions often appear similar visually and on physical examination, and some malignant lesions may have a benign appearance, especially in their early stages. It is not uncommon for patients to have one or more lesions that appear concerning.
"Dermatologists tend to biopsy any lesions that seem visually suspicious for disease," said coauthor Bahar Dasgeb, M.D., from the Department of Dermatology at Wayne State University in Detroit and Pinkus Dermatopathology Lab in Monroe, Michigan. "Consequently, many benign lesions are needlessly biopsied in order to avoid the risk of missing a potentially deadly melanoma."
Elastography was found to distinguish between benign and malignant lesions not by their visible appearance but by measuring their elasticity or stiffness. Since malignancies are stiffer than benign growths, elastography, when added to high-frequency ultrasound imaging of the skin, has potential to improve the accuracy of traditional clinical diagnosis of skin cancers and, in some cases, eliminate unnecessary biopsies of benign skin lesions. The procedure is noninvasive, convenient and inexpensive.
For the study, researchers used an ultra high-frequency ultrasound system to image 40 patients with a variety of malignant and nonmalignant, or benign, skin lesions. Malignant tumors included squamous cell carcinoma, basal cell carcinoma and melanoma. Benign lesions included dermatofibroma, a noncancerous growth containing scar tissue, and lipoma, a noncancerous tumor composed of fatty tissue.
The researchers calculated the ratio of elasticity between normal skin and the adjacent skin lesion, and used laboratory analysis to confirm their diagnoses. Cystic lesions, which are not malignant, demonstrated high levels of elasticity, while malignant lesions were significantly less elastic. The elasticity ratio of normal skin to the various skin lesions ranged from 0.04 to 0.3 for cystic skin lesions to above 10.0 for malignant lesions.
In addition, high-frequency ultrasound with elastography allows for accurate characterization of the extent and depth of the lesion below the surface, which can aid physicians in treatment.
"The visualized portion of a skin lesion can be just the tip of the iceberg, and most dermatologists operate 'blindly' beyond what they can see on the surface," Dr. Siegel said. "High-frequency ultrasound provides almost microscopic resolution and enables us to get size, shape and extent of the lesion prior to biopsy."
Note: Copies of RSNA 2009 news releases and electronic images will be available online at RSNA.org/press09 beginning Monday, Nov. 30.
RSNA is an association of more than 44,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)
Editor's note: The data in these releases may differ from those in the printed abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at 1-312-949-3233.
For patient-friendly information on x-rays, visit RadiologyInfo.org.
PET identifies which prostate cancer patients can benefit from salvage radiation treatment
05.12.2017 | Society of Nuclear Medicine and Molecular Imaging
Designing a golden nanopill
01.12.2017 | University of Texas at Austin, Texas Advanced Computing Center
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
11.12.2017 | Physics and Astronomy
11.12.2017 | Earth Sciences
11.12.2017 | Information Technology