GONE ARE THE DAYS OF SIMPLE ONE- AND TWO- DIMENSIONAL SCANS. MEDICAL IMAGING
HAS COME A LONG WAY OVER THE PAST FEW YEARS, AND TORRANCE MEMORIAL IS
LEADING THE WAY WITH ITS CUTTING-EDGE RADIOLOGY DEPARTMENT.
If you’ve ever reclined inside a
magnetic resonance imaging (MRI) machine or had a
computed tomography (CT) scan, chances are you weren’t thinking about how the machine worked or
whether it was the latest model. Most of us aren’t well versed in
the types of imaging equipment at hospitals, and even if we were, it’s
likely we’re too busy clutching a broken arm or hoping that something
is benign to care.
But the field of radiology is a critical part in understanding, from a
visual perspective, what is happening beneath the surface of our skin
and inside our bodies. It can hold the key to diagnosis and treatment.
Advancements in the field of radiology have moved beyond simple X-rays
to utilizing equipment that can give doctors detailed, three dimensional
images in mere seconds. But not all machines are alike. While most hospitals
utilize CT, MRI, ultrasound and other modalities, changes in technology
can make a big difference when it comes to deciphering disease.
“We pay a lot of attention—and capital—to getting the
most state-of-the-art equipment in our department, and we rely heavily
on it,” says
George So, MD, a radiologist at Torrance Memorial Medical Center. One of the most distinctive
aspects of the radiology department at Torrance Memorial is the focus
on cutting-edge equipment, says Dr. So. This focus is something you are
not likely to encounter at most community hospitals.
One of these advanced machines is the dualtube,
64-slice computed tomography (CT) scanner. “The machine is very, very fast. If a patient is moving—maybe
because they are in pain or trauma—the faster you can scan them,
the better detection you can get,” says Dr. So.
Scanning from head to toe can take just seconds. Speed is also important
to capture organs in motion—like the heart—where physicians
want to get an image frozen in time.
Another feature of the CT scanner is its dualenergy source. Dr. So notes
that the benefit of having two different energy sources (as opposed to
one—common in conventional CT scanners) is that you can reduce the
number of artifacts, or noise, that the machine picks up. Because artifacts
can mimic pathology or interfere with the interpretation of a scan, their
reduction is critical to successful imaging.
Speed is also important when doing magnetic resonance imaging (MRI), a
non-invasive means to construct pictures of the body that is especially
useful for soft tissue like the brain, muscles and heart. Like the name
implies, this machine uses a magnetic field; the strength of the magnetic
field is measured in a unit called a Tesla.
Most conventional scanners are 1.5 Tesla, but Torrance Memorial has a 3.0
Tesla machine. The greater strength results in a faster, more detailed
and higher resolution scan, says Dr. So. Because the MRI also has more
“channels” or ways to pick up these signals, the scanners
are able to get more resolution.
These advancements in machinery don’t just mean a faster scan for
the patient. They can also result in fewer invasive procedures. Traditionally,
if a patient had an aneurysm or a blockage of a blood vessel, it would
have required a conventional angiogram and catheterization.
But with a 3T MR scanner or dual-source, high-speed CT scanner, physicians
have a better picture of the problematic area, and patients may be able
to avoid biopsies and other invasive procedures like catheterization.
Fixing the blood vessel also becomes more streamlined, because physicians
now have a “map” of where to direct the treatment, notes Dr. So.
Another area where Torrance Memorial stands at the cutting edge of imaging
is at the medical center’s
Breast Diagnostic Centers. Recognized as centers of excellence by the American College of Radiology,
the breast imaging centers now have two digital tomosynthesis (TOMO) machines,
also known as
3-D mammography, currently in Torrance and Manhattan Beach.
A normal mammogram creates a two dimensional picture of the breast, taking
images from top to bottom and side to side. With three dimensional imaging,
the breast is positioned the same way it is with a normal mammogram, but
an X-ray moves around it while images are taken in layers.
While normal mammograms are very useful, they can “hide” or
obscure fine details. “It’s like the princess and pea,” says
Patricia Sacks, MD, medical director of the Vasek and Anna Maria Polak Breast Diagnostic
Center at Torrance Memorial. “If the pea, or lump, is between mattress
number 71 and 72 and you take a twodimensional picture of it, you’re
not going to find it. But if you’re able to cut between the mattresses,
you can find it.”
In addition, the size of the “pea” is unknown unless you have
a way of photographing above and below it. This is what 3-D TOMO allows
physicians to do.
Dr. Sacks notes that the breast is much more like a ball than a circle,
so it only makes sense to image it in a way that reflects the true shape.
“A breast is a 3-D structure, and up to this point we’ve been
using a 2-D image to look it,” she says. The benefits of this become
clear when comparing scans. “If, after taking a 3-D mammogram, you
go back to look at the 2-D, you often don’t see the lump.”
According to Hologic, which manufactures the 3-D mammography machines,
the technology can detect 41% more invasive breast cancers and reduces
false positives by up to 40%.
Dr. Sacks notes that use of 3-D mammography has decreased the number of
recalls for patients, which is normally around 9% to 10%.
Although tomography isn’t a new technology, its use in breast imaging
is—and its availability in hospitals is limited. Dr. Sacks notes
they currently use the TOMO for “all comers,” though it may
prove to be particularly advantageous for some people, like those with
dense breasts or subtle areas of “architectural distortion”—areas
that are hard to image using traditional techniques.
Reading these 3-D mammograms takes longer than a traditional mammogram,
and physicians are required to take an online training course in order
to become proficient in the machine and interpreting results. Dr. Sacks
notes that one of the most important parts about reading a mammogram is
comparing subtle changes over time.
Luckily the 3-D imaging can be used to make a 2-D image and compared to
previous traditional mammograms. “It really is a fantastic advance
for women,” says Dr. Sacks.
USING IMAGING FOR TREATMENT
Beyond diagnostic imaging—using imaging to find or diagnose a disease
or problem—is the field of
interventional radiology, or treating disease while using imaging to help guide physicians through
a procedure. It is commonly used in cancer therapy, spine intervention
and neurology and can result in more targeted treatment.
“A very common procedure for a patient with liver or kidney cancer
is to find the blood supply to the tumor and implant a bead embedded with
a drug—like chemotherapy—so the bead blocks off blood supply
to the tumor and slowly releases a chemotherapy or other drug to kill
the tumor,” says Dr. So.
A similar procedure is done for
uterine fibroids, which require a large amount of blood. Using interventional radiology,
radiologists can implant the beads (this time without drugs), which will
block off blood supply and the fibroid will shrink.
Perhaps the most exciting area of interventional radiology is stroke treatment,
says Dr. So. Stroke can be devastating not only medically but psychologically
too—for both patients and their caregivers. “Stroke patients
come in, and sometimes they have slurred speech, are drooling or paralyzed
on one side of their body,” he says.
With guided imaging, interventional radiologists can go in and remove the
clot. For the radiology team, the rapid recovery is inspiring. “They
can regain function on the [operating] table. They start talking; they
make sense. The before-and-after is amazing,” says Dr. So.
While the equipment is a critical tool in putting the radiology department
at the forefront of medicine, the main strength is the people. “We
have all the hardware, but the staff helping out day-to-day are the most
important parts of the department,” says Dr. So.
Even though imaging is sometimes a behind-the-scenes pursuit, Dr. So doesn’t
mind. But the time has come to shed light on its importance: “Our
radiology department is the best kept secret in the South Bay!”