Siemens get closer to the heart

Miniaturisation of electronic components has enabled commercialisation of the world’s first echocardiography system to acquire instantaneous, non-stitched full-volume images of the heart in a single heartbeat.

It will give physicians the ability to look inside a patient’s heart in much closer detail for procedures where temporal information is critical. It can, for example, show cardiac wall motion and blood flow. The real-time nature of ultrasound also enables clinicians to have direct, interactive contact with the patient during scanning.

With real-time 3D information available through the Siemens Acuson SC2000 echocardiography system, it should be easier for clinicians to do a better job. ‘The system has unparalleled capabilities in information rate processing that allow us to acquire a full volume of the entire heart with 90º pyramids,’ said Klaus Hambuechen, chief executive, Ultrasound, Siemens Medical Solutions USA, whose parent company developed the device. ‘With a high-volume acquisition rate like this — in one second, every second — acquisition time is dramatically reduced, improving the overall workflow in the echocardiography suite.’

The ‘echo in a heartbeat’ 3D imager has evolved from existing 2D technology, which was first introduced in the 1970s. Instantaneous, non-stitched, full-volume imaging comes 55 years after echocardiography pioneers Inge Edler and Hellmuth Hertz acquired the world’s first cardiac ultrasound recording using Siemens technology in 1953.

‘The latest advances have been possible because of the competence within Siemens which we have acquired over many years working with 2D,’ said Shane Williams, technical consultant with the company. ‘There’s a lot of inherent knowledge here and we have been able to apply it to take advantage of the advances in miniaturisation.’

Siemens’ Acuson SC2000 is claimed to deliver a great deal more information than conventional systems. The breakthrough has been achieved by improving two crucial sub-systems, the beamformer and the patented Coherent Volume Formation technology, which is a critical stage in generating an image from the data.

To acquire data from a beating heart, the beamformer transmits specially shaped and timed pulses into the body thousands of times a second. The receive beamformer then generates multiple beams through parallel and real-time processing of the echo received in response to each of the transmitted pulses. The maximum imaging rate is determined by the number of receive beams the sub-system can generate in parallel.

This is what Siemens has achieved with the Acuson SC2000. Its imaging engine is capable of forming up to 64 beams in parallel. In comparison, its predecessor ultrasound system is able to form up to four beams in parallel. This equates to an increase in information acquisition rate of a factor of 16. Coupled with the system’s high-volume acquisition rate, the imageformer’s Coherent Volume Formation (CVF) moves away from serial line-by-line acquisition towards simultaneous, multiple beams, delivering excellent image resolution, Siemens claims.

The CVF technology aligns the phase of the beams generated by the receive beamformer and applies coherent or phase-sensitive processing across phase-aligned beams. This phase-sensitive processing plays two important roles.

First, it captures the inter-voxel phase information before it is discarded by another stage of the imageformer, the amplitude detector. This early capture allows the imaging system to preserve information and thus sustain the high information rate.

Second, the phase-sensitive processing is key for high quality multibeam operation with up to 64 parallel beams and programmable beam distribution in azimuth and elevation. This is achieved through retrospective transmit focusing, which may, to photographers, sound like an oxymoron but is, in fact, a capability of CVF.

The coherent imageformer is a critical component of high information rate and high image quality imaging. It complements the massive parallel beamformation capability of the front-end subsystem.

The imageformer of the new echocardiography systems can process up to 160 million voxel/second. This translates into an information processing rate increase of 16-fold compared with the company’s existing products.

The Acuson SC2000 system is designed to support advanced cardiovascular applications. The knowledge-based workflow software uses learned pattern recognition technology and an expert database of real clinical cases. This enables the system to recognise anatomical patterns and landmarks, as well as to perform automatic measurements streamlining clinical workflow.

The system automatically derives reference plane images from the full-volume cardiac capture dataset and offers automated full-volume contouring for fast analysis. Customisable, programmable, and protocol-driven workflow sequences deliver repeatability for better outcomes: greater efficiency, accuracy, consistency, and care — from data acquisition to diagnosis.

Max Glaskin