PET/CT shines with enhancements emphasizing speed and resolution

PET/CT dominated nuclear medicine offerings, as it has for several years. Citing opinions expressed by academic luminaries, vendors spoke about the prospect of this hybrid technology replacing stand-alone PET. The increased speed and demonstrated ability of PET/CT to deliver information crucial to patient management provided the impetus for this prediction. All but lost in the shuffle was the mainstay of nuclear medicine, the gamma camera. Upgrades continue to appear, but the gamma camera's contributions to clinical medicine continue to be overshadowed by PET/CT.

CTI Molecular Imaging

The company was a pioneer in PET development, but until the last few years it seemed content to work in the shadows. CTI supplied PET scanners to Siemens Medical Solutions through CTI PET Systems, a joint venture with Siemens that has been renamed CPS Innovations. The exclusive agreement between CPS Innovations and Siemens ended in 2001, paving the way for CPS to begin supplying other companies, such as Hitachi, as well as selling PET systems directly. CPS is best known for its proprietary lutetium oxyorthosilicate (LSO) crystal technology. CTI also designs and manufacturers cyclotrons and PET chemistry systems.

• LSO Hi-Rez Reveal PET/CT scanner, introduced at the RSNA meeting, offers resolution up to three times higher with up to twice the sensitivity and speed of previous-generation scanners, according to the company. Improved resolution is due to advanced LSO crystal technology.
• Pico-3D boosts performance further. The improved data pipeline, showcased on the RSNA exhibit floor but shown first in June at the Society of Nuclear Medicine meeting, is optimized to handle the faster count rate possible with the new LSO detector technology. Pico-3D was developed by CPS' sister company, Concord Microsystems of Knoxville. Its name reflects its ability to capture and route data in picoseconds instead of nanoseconds, as was the case with earlier generation electronics.

CTI/Mirada Solutions

Last year, CTI Molecular Imaging acquired software developer Mirada Solutions, principally for its image analysis and fusion software. Advanced versions have been integrated into a PET scanner workstation.

• Reveal-MVS debuted as a workstation dedicated specifically to molecular imaging. It includes a personal review workstation, cardiac analysis algorithms, and software to support radiation oncology and surgery. The personal workstation allows clinicians to take cases with them to review or present outside the reading room.
• RTist, the oncology and surgical software onboard Reveal-MVS, combines structural information from CT and MR images with functional information from PET and SPECT as part of therapy planning. RTist is configured to allow this planning from a terminal other than the planning workstation. Automated tools contour fused images and export the contours and referenced planning CT to the planning workstation.
• Image review and image fusion are completed using PET, PET/CT, MR, CT, and SPECT data sets. Tools and options to streamline clinical workflow support the quick review of cases and allow advanced DICOM query and retrieve.
• Emory Cardiac Tool Box has been integrated into Reveal-MVS as part of an agreement with Syntermed. The toolbox is a comprehensive package of software for processing, displaying, interpreting, analyzing, and reporting myocardial perfusion studies.
• ImageChecker CT system was added to the Reveal-MVS package as part of a deal with R2 Technology. The addition of computer-aided detection and analysis of lung nodules is a step toward providing a complete thoracic radiology solution, according to CTI.

GE Medical Systems

The company was among the first to integrate CT and PET, helping to precipitate a major new avenue of oncologic evaluation and patient management. Advanced technologies now drive the development of GE's PET/CT products, as the company has trimmed the footprint of its flagship hybrid Discovery LS scanner and tweaked its performance and that of other fusion-based systems, such as the Hawkeye SPECT/CT platform.

• Second-generation Discovery ST was showcased for its compact design and 70-cm-wide patient bore. Work-in-progress respiratory gating is being developed to reduce motion artifact by obtaining PET data at specific times in the breathing cycle.
• Infinia Hawkeye, a hybrid SPECT/CT shown at the June meeting of the Society of Nuclear Medicine, features an advanced 1-inch Elite detector. Elite is composed of 95 photomultiplier tubes enabling the imaging of high- and medium-energy isotopes.
• Millennium gamma cameras offer a new common user interface and Ignite workflow software, which automates exams.
• Xeleris, GE's high-performance image review workstation, is now available for use in nuclear medicine.
• eXplore Vista scanners were showcased as GE's answer for small-animal PET imaging. The scanners are manufactured by Suinsa Medical Systems of Madrid. An agreement announced at the RSNA meeting makes GE the exclusive worldwide distributor of the product. (Suinsa also has manufactured components on contract for GE's nuclear medicine and x-ray businesses.) The scanners, available in single- and dual-ring configurations, will serve drug discovery and development in academia and pharmaceutical labs.

Hitachi Medical Systems America

Hitachi is a relative newcomer to PET, having begun marketing its Sceptre PET system only about 18 months ago. The value-priced PET scanner is supplied by CPS Innovations.

• Sceptre was showcased as providing an LSO-based detector that rotates around the patient.
• Avia workstation processes and displays data from any diagnostic imaging facility, allowing centralized diagnostic interpretation of discrete or fused PET, CT, MR, and nuclear medicine images.

Philips Medical Systems

Merger and acquisition fever brought ADAC Laboratories to the Philips family in 2000. The corporate acquisition provided Philips with one of the most extensive lines of gamma cameras and PET scanners in the industry. Only in the last few years, however, has Philips been able to capitalize on its CT and PET holdings, introducing the Gemini PET/CT in 2001. The unique dual-ring configuration of the Gemini allows the hybrid scanner to operate as one unit or be divided into separate CT and PET scanners. SkyLight was introduced in 2000 as the first gantryless gamma camera, buoying gamma cameras with conventional designs, such as the company's Forte product.

• With the Brilliance CT, Gemini joined the ranks of PET/CTs that offer a 16-slice CT configuration.
• JetStream, released as an upgrade to Forte, accelerates and streamlines the imaging process, featuring concurrent imaging to acquire multiple image sets simultaneously.
• Astonish debuted as an advanced image processing technology designed specifically for molecular imaging. The work-in-progress offers a resolution recovery technique and noise suppression capabilities.
• Syntegra 2.0 autofusion toolkit was introduced with algorithms that automatically coregister metabolic and anatomic data.
• Mosaic was showcased as an advanced "small-bore" animal PET imaging system for preclinical research.

Siemens Medical Systems

Siemens has benefited from a long-time investment in CPS Innovations, its joint venture with CTI Molecular Imaging. An advanced scintillator and faster electronics, provided by CPS, have allowed the company to produce one of the most evolved PET systems. Siemens has returned the favor to CTI, providing its multidetector CT scanners for integration into that company's PET/CTs. Siemens' own line of PET/CT scanners, called biograph, gained a new family member at the RSNA meeting, and its flagship capabilities were enhanced.

• A six-slice CT setup joined two- and 16-slice configurations of the biograph.
• Hi-Rez, an advanced form of LSO crystal technology and Pico-3D electronics (see CTI Molecular Imaging) were presented as optimizing signal and lesion detectability.
• Leonardo, Siemens' workstation, was enhanced with imaging applications, including workflow improvements and CT applications addressing radiation therapy planning and lung analysis.

Toshiba America Medical Systems

A strategic alliance with Siemens provides the cornerstone for Toshiba's t.cam variable-angle, dual-detector gamma camera, as well as the e.soft Signature Series workstation. Toshiba's e.soft version 3.0 for nuclear medicine was introduced with workflow enhancements and 3D imaging tools.

• Fusion Slice Display manages data sets of different matrix sizes, while Matrix Transformation serves as an image rendering technique to display the data.
• 3D processing options include Flash 3D general and cardiac, CT attenuation correction, and advanced image fusion with syngo 3D.
• A dual-monitor option on t.cam allows the connection of two flat-panel monitors to an e.soft postprocessing workstation. Also optional is the Clinical Wizard, designed to help create and set up basic workflows for t.cam.