Flat detectors drive advanced applications in R/F and angiography

Digital fluoroscopy need not include flat detectors, a fact demonstrated by continued progress in conventional radiography/fluoroscopy systems. But solid-state detectors took important steps in 2003 toward becoming the engines for driving future high-end applications.

Shimadzu showed it was a player in the new digital age, exhibiting an amorphous selenium flat detector scheduled for release in the first half of 2004. Toshiba talked up its work-in-progress flat detector for the second year. And component supplier Thales Electron Devices introduced a large-field-of-view dynamic detector scheduled for beta testing early this year.

Siemens and Philips gave meeting-goers a feeling for how Thales' new detector might be integrated into high-performance end-user systems, while GE showcased a previously launched large flat-detector system, as well as CCD-based solutions.

GE Medical Systems

Cost-efficiency, performance, and dose reduction are key design elements in GE's digital R/F products. Development has focused on advancing the art of conventional image intensifier technology, such as the 12-bit CCD-based camera developed for its Precision platform, while establishing a position in flat-detector technology with the Innova 4100 (radiology) and Innova 2000 (cardiology).

• Precision MPi, a multipurpose tilt-C R/F system, was designed to meet the siting and performance needs of hospitals and outpatient clinics. The compact system, cleared by the FDA shortly before the RSNA meeting, can be installed in a 12 x 12-foot room. Key features include angulated imaging to separate overlying anatomic structures for clearer viewing, an advanced function typically found on dedicated angiography systems that can be used to perform general R/F, interventional, and angiography procedures.
• Precision 500D features a 12-bit CCD-based camera with a high-resolution image intensifier. AutoEx dynamic exposure automatically adjusts the focal spot, dose rate, and spectral filter in real-time to achieve an optimal contrast-to-noise ratio. Automatic brightness control and extended dynamic range circuitry maintain contrast while minimizing blooming. Radiation exposure of patient and staff is minimized with fluoro store to hard disk and automatic last image hold capabilities. Spectral filtration minimizes the patient's absorbed dose during fluoroscopy.
• Innova 4100 interventional radiology system appeared last year as the company's flat-detector flagship in R/F. The digital fluoroscopic system features a 41 x 41-cm FOV.

InfiMed

The company specializes in providing advanced digital x-ray acquisition, processing, and review solutions for radiography (Stingray DR), as well as fluoroscopy, angiography, and cardiac cath (PlatinumOne). Digital systems can be applied either as retrofits to update existing rooms or for integration into new or refurbished rooms.

• PlatinumOne Cardiac and Combo products are both designed as vendor-neutral, cost-effective upgrades, offering the functionality needed to support advanced cardiac catheterization and interventional procedures. These digital systems give cath labs seamless digital acquisition. The Combo provides high flexibility for angiographic and cardiologic applications. Both Cardiac and Combo are optimized for expanded image storage and fast image processing.

Philips Medical Systems

Film-based and digital systems offer a range of price points and capabilities in Philips' R/F portfolio. The Allura XperFD family characterizes the high end with a flat detector (FD) in place of an image intensifier and x-ray personalized (Xper) technology that customizes workflow with user-programmable settings. The Eleva family offers multifunctional R/F systems that combine conventional imaging chains with electronic workflow tools.

• Allura Xper FD20 is a work-in-progress, large-field-of-view system designed to bring the benefits of flat-detector technology to interventional applications involving cerebral, abdominal, and peripheral vasculature. The FD20 was shown with the company's Integris 3D-RA (rotational angiography) reconstruction tool capable of generating a volumetric reconstruction of 120 images in less than 75 seconds after data acquisition. Additional reconstructions can be performed for more focused images and increased resolution. The Xper FD20 features a 2048 x 2048-pixel imaging chain with 154-micron pixels. Its 30 x 40-cm detector offers selectable fields-of-view, from an FOV that covers the rectangular active matrix of the detector to a 16 x 16-cm-square FOV. Whole-body coverage can be achieved either with propeller rotation or traditional roll movement, affording 240 degrees rotation up to 55 degrees /sec. The MRC x-ray tube and SpectraBeam copper filtration system captures and filters out low-energy x-rays. If a collision with patient, technicians, or other objects is imminent, the BodyGuard electromagnetic sensor system shuts down the system.
• EasyDiagnost Eleva is a conventional R/F system designed to support a range of applications from gastrointestinal and various iodine and vascular procedures to standard radiography. Eleva technology adjusts to the way staff work, allowing individual operators to program exam-, operator-, and patient-related presets. EasyGrip enables single-handed operation and tableside control. A foldout cassette holder, EasyLat, features an integrated grid and automatic exposure control.

Siemens Medical Solutions

Advanced development efforts in R/F have focused on the Siemens Axiom Artis platform for interventional angiography and cardiology. Products feature application-specific acquisition protocols called organ programs. Their preprogrammed settings automate operator-intensive actions, with the goal of simplifying routine work.

• Axiom Artis dTA, equipped with a flat detector based on amorphous silicon, permits routine diagnoses using advanced clinical features, including 3D imaging and ease-of-use tools designed to optimize patient throughput. The ceiling-mounted design gives clinicians access to patients from all sides. The C-arm moves 60 degrees /sec in orbital and rotational directions, acquiring data that can be reconstructed in 3D.

Shimadzu Medical Systems

The Japanese company has returned to its century-old roots with an emphasis on x-ray systems. Shimadzu shone the spotlight on high-end R/F products at the RSNA meeting, while exhibiting a work-in-progress dynamic flat detector.

• Digitex Safire (Shimadzu Advanced Flat Imaging Receptor), shown in Japan in October, debuted at the RNSA meeting. The detector is scheduled for release internationally in the second quarter of 2004, designed for use in interventional cardiology. The flat detector, a collaboration involving Shimadzu and two unnamed partners, relies on amorphous selenium.
• MH-200S and MH-300 positioners were showcased for the second year. The MH-200S ceiling-mounted C-arm positioner offers 108 programmable positions. The multipurpose floor-mounted MH-300 vascular/cardiac C-arm features transverse travel, allowing the upper extremities to be imaged without moving the patient or pivoting the table. Both C-arms support rotational digital subtraction angiography and acquire data at sweep speeds up to 60 degrees /sec.
• Digitex Premier vascular digital subtraction system, shown at the 2003 RSNA meeting, acquires and displays up to 30 frames per second in a 1024 x 1024-pixel matrix in single-plane mode.

Thales Electron Devices

Long-time components supplier Thales began exploring flat detectors in 1986. The company entered into a joint venture with Siemens and Philips in 1997 to create Trixell, which two years later began producing a radiographic flat detector based on amorphous silicon. In 2000, the company delivered flat detectors for testing in cardiac cath units. Trixell is now the principal supplier of flat detectors to Siemens and Philips.

• Pixium 4700 debuted as a finished product designed for real-time skeletal and vascular imaging, including digital subtraction angiography. The fluoroscopy flat detector was shown at the 1998 RSNA meeting as a work-in-progress. Its amorphous silicon-based detector measures 12 x 16 inches (30 x 40 cm) and delivers a maximum resolution of 154 microns. Preproduction models are undergoing clinical testing, and production is scheduled for April 2004.

Toshiba America Medical Systems

The pioneer of high-performance CCD technology in R/F is maneuvering for a piece of the new digital pie with a large-FOV flat detector. Software programmers are also advancing the company's 3D agenda in vascular imaging.

• Ultimax, a multipurpose R/F system introduced last year, was showcased with a work-in-progress 14-inch flat detector, also shown a year ago. An image intensifier can be fitted with the system until the flat detector is commercially available.
• Infinix Vci, a single-plane, ceiling-suspended vascular system, was enhanced with a 3D digital angiography protocol. The protocol creates volumetric images for neurovascular interventions that show bone and vascular structures and also allows volumetric measurement of aneurysms. Images are displayed on Vital Images' Vitrea 2 workstation.