Hybrid imaging takes next logical steps with 64-slice PET/CT, multislice SPECT/CT

PET/CT stepped up to 64-slice scanning, while many visitors to the RSNA meeting got their first close-up look at the next generation of gamma cameras. Hybrid SPECT/CT was first publicly seen in June 2004 at the Society of Nuclear Medicine meeting.

GE and Siemens took the high ground in PET/CT, exhibiting 64-slice versions of their hybrid scanners. The Discovery VCT may not appear, however, for another 12 to 18 months. The souped-up biograph is scheduled for delivery in mid-2005. Both are intended for cardiac applications, which vendors hope will boost sales of PET/CT, which, until now, have risen largely on the shoulders of oncologic applications.

The developers of multislice SPECT/CT hope their new products will do for gamma cameras what hybrid imaging has done for PET. Siemens' TruePoint Symbia and Philips' Precedence attracted large crowds and raised questions about which hybrid modality - SPECT/CT or PET/CT - would win the hearts of physicians.

CTI Molecular Imaging

CTI Molecular Imaging made the transition this year from provider to supplier. The company cut its direct sales efforts in PET/CT in favor of making PET systems for other OEMs: Siemens and Hitachi in the U.S. and, in early 2005, Toshiba in Japan. Siemens and Hitachi are also licensing software from CTI subsidiary Mirada Solutions. In 2004, CTI purchased Concorde Microsystems, a developer of micro-PET systems, and ImTek, a provider of micro-CT systems. Both types of products are used to image laboratory animals. The company's PETNET subsidiary operates more than 40 cyclotron-equipped centers, providing FDG and other PET probes to end users.

• PET.connect, an IT product newly released by PETNET, includes software for PET image analysis, education and marketing, and practice management. The suite of products spans oncology, neurology, and cardiology.

GE Healthcare

The company pioneered hybrid imaging five years ago with the first commercial introduction of SPECT/CT. Since then, 500 such hybrid systems have been installed. Then, as now, the CT onboard this system is nondiagnostic, designed primarily for attenuation correction and simple localization of the radiopharmaceutical. The company's latest Infinia Hawkeye featured an upgraded gamma camera. GE also exhibited advancements in PET/CT, notably a work-in-progress 64-slice version.

• The Infinia single-head gamma camera, available separately or linked to GE's PET/CT, incorporates a revised detector design that permits scanning in more patient positions and an intuitive camera-controlled graphic user interface to enhance productivity. GE's Ignite feature, available through its integrated Xeleris workstation, gives operators a single-click scan-and-review option.

• Discovery VCT marries the company's high-performance PET scanner and latest 64-slice CT. The work-in-progress is not expected to enter production for 12 to 18 months.

• PET/CT software called HeartFusion aligns the coronary tree created using CT angiography with PET perfusion data, providing the means to quantify and analyze the impact of atherosclerotic lesions on the heart. HeartFusion requires GE CardIQ Analysis software, which postprocesses data to display, reformat, and analyze 2D and 3D cardiac CT images.

Hitachi Medical Systems America

Earlier this year, at the Society of Nuclear Medicine meeting, Hitachi unveiled a homegrown quadslice CT linked to a CPS-supplied PET scanner. The PET/CT system, called Sceptre P3, passed FDA review weeks before the RSNA meeting began. The design of the hybrid product affords Hitachi's installed base of PET scanners a nonforklift upgrade path to hybrid scanning. Through the company's "Evolve" program, owners of the Sceptre PET can add the Hitachi quadslice CT and swap out the existing table, while keeping the PET scanner in place. External cowling turns the two end-to-end scanners into one.

• Sceptre P3, an LSO (lutetium oxyorthosilicate)-based rotational PET scanner outfitted with a quadslice CT, is now commercially available. The system is the next logical step for the company, which two years ago began marketing the Sceptre PET scanner under a supply agreement with CPS. The name Sceptre P3 (power of three) reflects the presence of three technologies: the LSO-based partial-ring PET detector supplied by CPS, composed of LSO blocks that rotate on a slip-ring gantry; Avia workstation, which controls CT and PET scanners, and postprocesses their data sets (and, potentially, MR data from an outside source) utilizing Fusion7D software provided by CPS subsidiary Mirada; and Hitachi's quadslice CT. A novel feature is the use of cesium as a backup means for calculating attenuation correction in case the CT goes down or metal implants preclude its use.

Philips Medical Systems

Variety characterized the company's hybrid offerings in the form of its multislice Precedence SPECT/CT and enhanced 16-slice Gemini PET/CT. Members of the PET/CT family can be configured for six, 10, and 16 slices.

• Precedence SPECT/CT combines a dual-detector Skylight gamma camera with six- and 10-slice CT for oncology and 16-slice for cardiology. Commercial shipments are expected to begin in April.

• The 16-slice version of its Gemini PET/CT combines the Brilliance CT 16 and Allegro PET. Philips began routinely shipping the system in late September.

• Gemini GXL features enhanced detector, processing, and reconstruction capabilities.

• Gemini 16 Power supports cardiovascular evaluations, as well as Alzheimer's disease assessment.

• The Molecular Imaging Suite on Philips gamma cameras offers multimodality fusion and advanced algorithms designed to improve image quality. JETStream, shown last year and highlighted again this year as an upgrade to Forte gamma cameras, streamlines workflow by allowing concurrent imaging to acquire multiple image sets simultaneously. Astonish, seen last year as a work-in-progress, offers a resolution recovery technique and noise suppression capabilities.

Siemens Medical Solutions

The company exhibited multislice configurations for both forms of hybrid imaging.

• TruePoint Symbia SPECT/CT can be configured with the company's e.cam dual-detector gamma camera to include either a dual- or a six-slice CT. Full production is slated for the first half of 2005.

• A 64-slice version of its LSO-based biograph PET/CT, featuring a 330-msec gantry rotation, is designed specifically for cardiac applications. The combination of CT coronary angiography and PET may improve the selection of patients for percutaneous coronary intervention. The system will also allow rest/stress perfusion and function analysis.

Toshiba America Medical Systems

The company has chosen not to play in the PET/CT market in the U.S., opting instead to offer gamma cameras sourced from Siemens bearing some of Toshiba's own software.

• e.soft version 4.0 includes larger icons and a larger font for easier viewing.

• New release of the e.soft express allows remote viewing of cases.

• PET/CT software called HeartFusion aligns the coronary tree created using CT angiography with PET perfusion data, providing the means to quantify and analyze the impact of atherosclerotic lesions on the heart. HeartFusion requires GE CardIQ Analysis software, which postprocesses data to display, reformat, and analyze 2D and 3D cardiac CT images.