August brings flood of FDA clearances in preparation for RSNA meeting

Three- and five-head PET grabs spotlight

The first wave of products and upgrades likely to be unveiled on the RSNA exhibit floor passed FDA review last month. August typically is the beginning of a high-traffic period preceding radiology's mega-event in Chicago at year's end. It is a welcome, albeit predictable, respite from the worst drought in new technology to strike the industry in years.

Last month the regulatory watchdog passed 27 devices. This marks a dramatic upturn from the 22 devices cleared each month in June and July and the 20 cleared in May. The count jumps one more, to 28, if the two PET systems cleared under a single K number by CTI PET Systems (CPS) are counted separately.

These two systems, the Vision 3000 and 5000, were the stars of last month's FDA clearances. They stand a good chance of stealing the limelight again at the RSNA meeting, since their developer, CPS, is a joint venture between Siemens Medical Solutions and CTI Molecular Imaging and, consequently, feeds PET products to both companies.

The Vision family of scanners, which composed one of three nuc med clearances in August, utilizes rotating flat-panel detector heads, LSO (lutetium oxyorthosilicate) crystal detector technology, and coincidence point source transmission scan capability. The Vision 3000 will be configured with three detector heads; the Vision 5000 with five.

The two systems leverage much of the technology already proven on other CPS-built systems, all of which have been sold under the Siemens label. The flat-panel detectors, LSO crystal, and coincidence point source concepts first appeared on Siemens' e.cam LSO 3111 PET/SPECT system.

The patient handling system is a slightly modified version of the one used on the CPS ECAT Exact and Siemens ECAT Exact HR+ PET systems. They include vertical bed travel and horizontal scanning range. Maximum patient weight is about 400 pounds.

The acquisition computer, an ACS (Advanced Computational System) III, is similar to the one used for the ECAT PET/CT scanner. Image reconstruction is performed using a dedicated computer, which interfaces with a RAID. The operating console, an updated version of the one on the ECAT PET/CT, runs Siemens' syngo software with CPS ECAT PET acquisitions and application software overlaid. The Pentium-based computer runs the Windows 2000 operating system in a syngo-based NT environment. ECAT Vision operating software provides acquisition, display, diagnostics, archive, and retrieval support. Whole-body oncology applications and visualization tools are provided.

GE gained clearance to market its Millennium Mobile MG system, a SPECT camera in a mobile configuration comprising a gantry, patient table, image acquisition system, operator console, and processing and review workstation. GE described the product as a modification of its current Millennium MG and eNTGRA workstation.

The third nuc med application to pass FDA review last month was quantitative blood-pool SPECT software developed by Philips ADAC. The stand-alone application supports the display and analysis of gated short-axis blood-pool SPECT data sets.

Radiotherapy had a surprisingly weak showing with just two devices passing the FDA, one a stereotactic planning software package, the other a dose calibrator. Seven of the eight newly cleared devices were MR coils. (The remaining MR device is an accessory to Odin's neurosurgical tool, the PoleStar N-10. The accessory, called the RF Tent, is designed to reduce electromagnetic interference.)

Two of the seven MR coils were for body imaging. One involved enhancements to the RF transmit coil of the Hitachi 0.7T Altaire. It was accompanied by an upgrade of the RF subsystem that supports the added receive function of the coil and will allow future use of multiple-array receive coils.

The second body coil to pass FDA scrutiny was developed for GE's 3T system. The company described this transmit/receive body imaging coil to the FDA as expanding the imaging capability of the 3T Signa VH/i. It constitutes a modification of that device by combining the MR system with the body imaging coil that was cleared by the FDA in April 2001, the company wrote. GE asserted that the new coil has the same basic technological characteristics and uses the same basic design, construction, and materials as the body coil cleared a little more than a year ago. The new device, like the old one, is intended for imaging the neck, spine, abdomen/thorax, and extremities.

Siemens' subsidiary Acuson gained clearance for the Sequoia Signature II. The FDA filing provided no details about the Acuson product. References on the company Web site, however, hint that the new technology involves upgraded features for the firm's flagship Sequoia ultrasound system. Toshiba's application for enhancements to its Aplio was among the three other ultrasound devices to pass the FDA in August.

Last month, five image management systems were cleared. One stood out: GE's Advantage Windows x-ray/MR fusion software. The package, designed as an option for the Advantage Windows workstation, allows 3D registration of two volumetric acquisitions involving x-ray angiographic and MR anatomic images. The resulting fusion of data may be useful in both diagnosis and therapy planning.

Of the four x-ray devices, two were dental systems. The other two, however, were of substantial radiological importance. Siemens gained clearance for a 3D navigation interface linking its Siremobil Iso-C 3D device and commercially available third-party navigation systems. The software calculates the navigation matrix required by the external system to navigate the 3D image data sets. The matrix is transferred to the navigation system in the DICOM header of the 3D data sets. The interface is designed for surgical applications involving the spine and complex bone or joint fractures of the upper and lower extremities.

The second radiological x-ray system, called Lodox, is a solid-state imager that converts x-rays into visible light using a fluorescent screen, which is optically joined to charge-coupled device cameras. The product, developed by Lodox Systems of Sandton, South Africa, is intended for general radiographic applications. It is based on technology originally developed to combat theft in diamond mines in South Africa. The company displayed the imager as a work-in-progress at the 2001 RSNA meeting (SCAN 12/26/01).