As interventional procedures expand radiology beyond diagnostics to treatment modalities, equipment manufacturers are providing the technology to keep up with this trend. This month, the Technology &
As interventional procedures expand radiology beyond
diagnostics, to treatment, equipment manufacturers are providing
the technology to keep up with this trend.
Interventional CT suite
Picker International (Cleveland) recently announced its VenueTM
suite for x-ray computed tomography (CT), designed to meet
interventional radiology and radiation oncology needs. The suite
includes PinPointTM (figure 1), an interventional planning tool;
fluoro-assisted computed tomography (FACTSTM), a C-arm fluoro x-ray
unit integrated into the CT system; continuous CT (CCTTM), a
real-time reconstruction process; and C-ViewTM, which integrates a
C-arm within the CT suite for fluoroscopic and digital-subtraction
PinPoint is a frameless stereotactic device that includes an
articulated stereotactic arm integrated into the CT scanner. The
device enables radiologists to visualize and plan the simulated
instrument path in relation to the target area, according to
Picker. "All possible paths can be considered and critical
structures can be safely avoided," said the company.
With FACTS, fluoroscopy can be used to visualize the delivery of
treatment devices, with follow-up CT confirmation of the
location-in one step, without moving the patient. Continuous CT can
guide minimally invasive therapies involving motion prone areas,
such as the thorax and diaphragm regions. And C-View provides
"complete endovascular capability in the CT suite," according to
New oncology division
In May, Picker announced the formation of an oncology division.
"The new division will incorporate magnetic resonance imaging
(MRI), x-ray, ultrasound, and CT imaging modalities to provide the
most advanced treatment planning system possible for oncology
patients," said Tim Hansen, executive vice president at Picker. The
company's ACQSIMTM, a CT planning system for external-beam
radiation therapy, is a main product in the oncology division.
According to Picker, the ACQSIM has an installed base of 200, holds
70% of the market share, and has led the conversion to
3-dimensional (3D) volume treatment planning.
The new Venue interventional radiology product line is being
incorporated into the oncology systems division "to improve
brachytherapy treatment for cancer patients," said Picker. "The
combination of brachytherapy and external beam radiation gives us
optimal tools for success," said James Hevezi, PhD, of The Cancer
Therapy and Research Center (San Antonio, TX). With the PinPoint
stereotactic arm and FACTS digital fluoro, "we can increase target
precision" with "an innovative way of planning these procedures,"
said Dr. Hevezi.
Picker has established a medical advisory board to work on
developing an oncology-specific CT device, according to Stephen
Whisenhunt, general manager of oncology systems.
Uninterrupted interventional CT
According to GE Medical Systems (Milwaukee), the company's
recently developed software called SmartViewTM allows radiologists
"to conduct interventional CT procedures without interruption."
Previously, high-quality images for CT-guided procedures were
available, but did not match the speed of traditional fluoroscopy
"SmartView was designed to overcome the trade-off between image
quality and speed by reducing extraneous procedure time," said Ken
Denison, manager of Americas CT Marketing at GE. "In a routine
biopsy situation, for example, real-time imaging allows
interventional radiologists to follow the needle all the way from
the entry point to the target." Adjustments in trajectory can be
made by monitoring the images displayed on an in-room image
monitor, he explained, which is particularly helpful when multiple
attempts are needed to place the needle correctly.
GE offers SmartView for its HiSpeedTM CT/i system. The mobile,
flat-screen monitor can be positioned in the physician's line of
sight during an interventional procedure. The real-time images
allow for uninterrupted monitoring of the needle trajectory,
eliminating the need to leave the scanning room to view images and
return to make necessary adjustments. This technology, noted GE,
makes the interventional procedure more efficient and also improves
Monitoring biopsies with CT fluoroscopy
Philips Medical Systems North America Company (Shelton, CT) is
developing CT fluoroscopic capabilities for its line of Tomoscan
Advanced Volume (AV) CT systems equipped with RapidViewTM. CT
BiopsyView will enable physicians to monitor a range of
interventional procedures in real-time. The fluoroscopic feature is
intended for use in nonvascular applications in the lung,
retroperitoneum, skeletal system, spine, and intracranium.
Real-time monitoring will allow radiologists to correct for
depth and direction of the needle puncture during the procedure,
without having to wait for image reconstruction to check needle
placement. In addition, the fine-needle control should reduce
complications and increase accuracy. According to Philips, CT
fluoroscopy should reduce the need for multiple scans to localize
the lesion and needle tip. Additionally, a high frame-rate should
nullify the impact of patient motion on image quality. The company
predicts that CT fluoroscopy would reduce the biopsy procedure time
by one-half to one-third.
Cook Inc. (Bloomington, IN) recently acquired Global
Therapeutics (Broomfield, CO) to acquire new devices for
interventional radiology, cardiology, and critical care. The Cook
product line will now include a cold-laser, catheter-based system
to treat neointimal hyperplasia (restenosis), a balloon for
percutaneous transluminal coronary angioplasty (PTCA), and several
Usually, when radiologists discuss a three-dimensional (3D)
volume created from tomographic data, they mean a 3D image on a
workstation monitor or laser printout. Now, that image can become
truly volumetric, transformed into a plastic anatomic model based
on data generated from an x-ray computed tomography (CT) or
magnetic resonance (MR) study (figure 2).
"Fused deposition modeling" technology
MedModeler, based on "fused deposition modeling" technology, was
recently granted 510(k) pre-market clearance by the U.S. Food and
Drug Administration (FDA). Indicated as an "image processing
accessory," the device uses 3D surface-representation data or 2D
contour data to create models made of medical-grade, nontoxic
plastic. It can be used in a hospital or office environment. The
build area is up to 10 ¥ 10 ¥ 10 inches, and the device is
compatible with Windows NT and UNIX systems. According to Stratasys
(Eden Prairie, MN), the manufacturer, MedModeler interfaces with
"qualified CT/MR converter software packages."
The device can "support the needs of the surgeon and radiologist
by providing a modeling system that can create patient-specific
models," said Lisa Crump, vice president of business development at
Stratasys. "A physician can gain additional information for making
a diagnosis by examining a 3D model. The surgical team can utilize
the model to formulate or rehearse operating techniques in advance
of surgery, or as an aid in communication," she added.
Rapid prototyping technology replaces machine
Stratasys, founded in 1989, manufactures rapid prototyping
devices for medical, industrial, and consumer applications.
Traditionally, engineers created 3D models and prototypes with
conventional fabrication methods, such as machine tooling. With
rapid prototyping, an engineer (or radiologist, technologist, etc.)
can develop a model directly from computer data within minutes or
Instead of carving a model from a larger piece of material,
rapid prototyping is based on layering together thin, horizontal
cross-sections of a computer-generated model. The layers may
consist of plastic, wood, ceramic, or metal. With this
layer-building approach, rapid prototyping machines can build
almost any shape, including anatomic structures.
In the fused deposition modeling used by MedModeler, a
temperature-controlled head extrudes thermoplastic material layer
by layer, like a stack of CT or MR slices. As the material
solidifies, it laminates to the preceding layer. S. Scott Crump,
chairman and chief executive officer (CEO) of Stratasys, developed
fused deposition modeling in 1988. Its U.S. patent was issued in
Did you ever wonder what consultants say to health maintenance
organizations (HMOs) and managed care organizations (MCOs) when
they're pitching to win the business of managing radiology services
and to cut imaging costs? Here are excerpts from a brochure and
cover letter sent to Applied Radiology from a "managed care imaging
"Establish clinically appropriate practice patterns and cost
reductions will come."
"Simply cutting services will not reduce costs; changing
practice patterns will."
"One of the most effective tools for reducing costs, our
precertification program applies nationally recognized protocols to
imaging requests-and fast."
Comparing utilization with "peer norms"
The company uses "comparative analysis and reporting software"
to provide in-depth analyses of radiology practices that allow HMOs
and MCOs to "compare practice patterns, utilization, and costs to
similar provider groups or organizations." The company analyzes
"cost and frequency of imaging services by diagnosis groups,
clinical indicators (positivity, negativity, appropriateness),
usage of multiple modalities or repeated imaging exams across a
given diagnosis," as well as other data.
Reports can be generated that compare the statistical and
clinical results of referring physicians. These comparative data
help "in understanding how the imaging dollar is distributed
relative to peer norms." The company "will then issue a letter to
physicians who are ordering procedures unnecessarily, and will
educate them on proper ordering for specific diagnoses."
The company predicts "it is able to save healthcare
organizations up to 30% in imaging costs-without compromising
quality of care."