Medical Device Dailys

A 120-patient study conducted at the University Hospital Zurich (Zurich, Switzerland) has found that a novel non-invasive step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis provides highly accurate results compared to the conventional clinical practice requiring invasive coronary angiography while significantly reducing radiation exposure to patients.

The results of the study were published in the June issue of Heart, the journal of the British Cardiovascular Society (London).

The single-center study marks the first clinical trial of the Somatom Definition from Siemens Healthcare (Erlangen, Germany), equipped with two X-ray tubes and support software capable of characterizing tissue and their densities (Medical Device Daily, March 13, 2008).

The study, "Low-Dose CT Coronary Angiography in the Step-and-Shoot Mode" found the SAS mode successful for all 120 patients with 100% sensitivity, 93% specificity, 94% positive predictive value (PPV) and 100% negative predictive value for the diagnosis of significant stenosis.

Significantly, the dual-source computed tomography (DSCT) uses a greatly reduced radiation dose and also reduces the life-threatening complications associated with invasive coronary angiography.

The primary end point for the study was reduction of radiation doses a goal made possible with new algorithms introduced by Siemens with the Adaptive Cardio Sequence (ASC) software coupled with the two-step image acquisition.

The ASC monitors the heart frequency of patients adjusts the recording window, responding, for example, to arrhythmia by postponing the recording phase to avoid image errors due to the sudden movement.

The resulting images were of "excellent diagnostic quality in patients with stable heart rates up to 70 bpm," according to Dr. Hatem Alkadhi, the specialist who led the research team.

Alkadhi said, "The dosage reduction achieved in comparison to previous CT angiography is also remarkable."

He said the effective dose was 2.5 millisievert (mSv), on average, where a normal average effective dose for heart scans is between 9 and 21 mSv.

Dr. Sami Atiya, chief executive for computed tomography at Siemens Healthcare, said the innovations for dose reduction, in conjunction with improved diagnostic image quality, are central to Siemens' approach to a market estimated at $5 billion in products sales for the U.S alone.

The introduction of 64-slice CT technology rapidly emerged in recent years as a promising tool for the clinical assessment of many cardiac conditions.

A CT scan is considered essential for identifying or ruling out hemorrhagic strokes with image acquisition and interpretation required within an hour of a patient arriving at a hospital.

Earlier this year, clinicians at the Erasmus Medical Center (Rotterdam, the Netherlands) noted several scanner generations have been introduced leading to progressive improvements in the detection of coronary artery stenosis.

The increasingly powerful post-processing software allows even high-resolution imaging free of artifacts winning widespread acceptance and demand despite a lack of clinical trials, they note.

Multidetector CT provides an even more robust and reliable non-invasive tool to assess cardiac pathology, clinicians with the British Institute of Radiology saying that as the equipment becomes increasingly available these scanners potentially can play a significant role in the assessment of coronary syndrome in the emergency setting.

Ultrasound market expanding

In another imaging sector report, global consulting firm Frost & Sullivan (London) said in a recent report that advancements in obstetrics and gynecology ultrasound, hand-carried ultrasound, other smaller market segments such as urology and surgical ultrasound are driving the European ultrasound market.

In European Markets for Ultrasound, F&S finds that the market was worth $900 million in 2007, estimating this to reach $1.4 billion in 2014.

"Increased demand from private practitioners as well as the growing number of breast and prostate ultrasound procedures will boost market growth," said Frost & Sullivan Research Analyst Krishanu Bhattacharjee. "With the use of hand-carried ultrasound units for the anesthesia and emergency wards, the European market for ultrasound is set to experience sustained growth."

With advances in technology, particularly in the form of miniaturization of transducer probes, elastography ande 3-D and 4-D imaging, the report says the market is poised to grow at a steady rate.

Advances in volume-rendering technologies in ultrasound will spur market growth. The market will witness substantial growth due to the widespread acceptance of hand-carried ultrasound by European hospitals as well as private diagnostic settings.

"Hand-carried and portable ultrasound, coupled with advancements in breast ultrasound, will promote market expansion," Bhattacharjee said. "At the same time, growing demand from private practitioners to promote volume sales, together with volume-rendering technology for ultrasound, will drive the uptake of new equipment."

However, F&S said the market for radiology ultrasound will experience gradual decline in the coming years owing to high levels of saturation. Continuous price erosion as well as the rising demand for refurbished equipment among private clinicians will also hamper market growth.

The overall ultrasound market will be driven by companies that can provide enhanced value-added offerings and cater to the untapped potential in surgical, urology and musculoskeletal ultrasound.

Sustaining competitive pricing alongside advancements in technology, competition from multi-slice CT and low-cost manufacturers that will fuel price erosion will pose major challenges to market expansion.

"With the influx of low-cost manufacturers, price sensitivity will continue to be a cause of concern for vendors," Bhattacharjee cautioned. "The lack of complete reimbursement for several clinical applications of ultrasound may also hamper the market's growth, providing an edge to other imaging modalities such as multi-slice CT."

FDA okays Inion systems

Inion (Tampere, Finland) said it has received FDA clearance for its biodegradable graft containment systems for spinal fusion procedures.

Marketing approvals have been received for the S-1 anterior cervical fusion system, S-1 double-level plate and S-2 anterior thoraco-lumbar fusion system.

These systems consist of biodegradable plates and screws, which are designed for bone graft containment in spinal fusion procedures. Such procedures are carried out as a treatment for a range of spinal conditions including ruptures and displacement of inter-vertebral discs.

Inion's S-1 and S-2 graft containment systems include implants intended for use along the entire length of the spine in conjunction with traditional rigid fixation.