Micro-bubbles and CPS technology improve ultrasound cancer detection
A new generation of ultrasound contrast media, micro-bubbles, combined
with a new pulse sequencing technology, can enable ultrasound scanners to
distinguish healthy tissue from malignant tumours and metastases better than
previously.
The bubbles are microscopically small gas bubbles that are injected into
the patient's vein from where they circulate around the body and start to
concentrate in characteristic patterns in especially suspicious areas. The
new agent has a high contrast from body tissue and can even highlight areas
of concern that could not previously be detected.
Siemens Medical Solutions is now tracking cancer and metastases with a
new ultrasound technology developed especially for this purpose, Cadence
Contrast Pulse Sequencing Technology or CPS. CPS transmits certain sound
sequences that make the bubbles oscillate. The echoes of the contrast medium
bubbles are separated from those of the tissue by using a special processing
method. This makes it possible to watch the inflow of the contrast medium
on-screen.
The new, patient-sparing method has been used in several European
hospitals with the focus on diagnosing liver cancer and other liver lesions.
Additional medical fields of application are currently in the research
phase.
Contrast media for ultrasound imaging are becoming more important for
clinical examinations. Their use facilitates detection of smaller metastases
(for example, in the liver), as well as benign and malignant tumours, that
was not possible with previous ultrasound methods.
“Using CPS technology from Siemens, we are able to accurately display the
smallest tumour vessels even with low quantities of contrast medium," said
Assistant Professor, Dr. Deike Strobel, Head of the Ultrasound Department at
the Medical Clinic I of the University Hospital in Erlangen, Germany. For a
number of years now, she has been working and performing research with this
effective and cost-efficient method. “Earlier, patients with inconclusive
liver tumours were sent from Ultrasound to Computed Tomography, and if all
else failed, to Magnetic Resonance Tomography or other examinations.
However, using contrast medium sonography, provides for a safe and fast
diagnosis of most liver tumours. Contrast media with ultrasound is a truly
revolutionary concept."
Siemens uses, among others, the Sonovue contrast medium by Bracco in
Milan, Italy. Microscopic gas bubbles are approximately ten times smaller in
diameter than that of a human hair.
Different from contrast media of the first generation which burst after
their initial contact with sound waves and supplied a one-time image only,
the new generation micro-bubbles remain in the patient’s circulation for
approximately 15 minutes, preserved by utilization of a lower sound output.
As confirmed by a number of studies, they enable physicians to detect
tumors, benign or malignant, in a highly reliable manner through certain
blood circulation patterns. On-screen, liver tissue filled with contrast
medium is shown as bright, for example, while metastases are displayed
considerably darker in colour.
Dr. Christoph Dietrich, Chief Physician of Internal Medicine at the
Caritas hospital in Bad Mergentheim, Germany, for example, has been working
for a number of years with this method. He successfully used the Siemens
Technology together with Sonovue in many cases. “This new ultrasound method
using micro-bubbles is a safe and fast method to diagnose liver tumors,“
comments Dietrich. “The so-called echo signal amplifiers consist of air and
gas bubbles that are encased in different shells. The micro-bubbles are a
strong reflector for ultrasound. The substances remain in the blood flow for
a few minutes only and are exhaled through the lungs. Through improved
ultrasound systems, it is possible to use this technology today, effectively
reducing more complex, expensive or dispensable imaging methods. This
applies in particular to differentiating benign and malignant liver tumors.”
For many years the use of contrast media has been a common method for
other imaging modalities such as Computed Tomography, Magnetic Resonance
Tomography and Nuclear Medicine. The use of contrast medium in ultrasound
has been growing in importance. Previous problems were, on one hand, the
inability of existing methods to separate contrast medium signals from
tissue signals — resulting in images with limited diagnostic usefulness. On
the other hand, contrast medium of the first generation was not visible long
enough and generated one single image only. The objective of the studies
under way in different hospitals across Europe is to improve cancer
diagnostics with contrast media for ultrasound. In addition, efforts are
being made to optimize the method for visualizing the bubbles. The German
Society of Ultrasound in Medicine (DEGUM) is participating in this work in
progress. Also, additional application areas, e.g. in cardiology, breast,
are under investigation.
To top |
|