Cardiac Ultrasound Broadens its Reach

Today’s cardiac ultrasound is an ideal modality for frontline diagnostics as well as image-guided procedures throughout the hospital.
By: 
Maureen Leahy-Patano

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June 12, 2008

Heart disease is the leading cause of death in Americans, claiming hundreds of thousands of lives yearly. The ability to diagnose and treat patients sooner and with more accuracy is key to winning the war against heart disease. Advancements in ultrasound — one of imaging technology’s most affordable and available modalities — are leading the charge by bringing enhanced diagnostic and treatment accuracy to more patients.

Cardiologist Wolfgang Fehske, M.D., St. Vinzenz Hospital, Cologne, Germany, relies on GE Healthcare’s Vivid S6 cardiovascular ultrasound for applications throughout the hospital.

What makes the Vivid S6 so attractive, he says, is it is a small, mobile scanner packed with high-end technology. Although specifically designed as a dedicated cardiovascular solution, it can be used at various locations beyond the cath lab, including the ICU, the EP lab, the OR and for ultrasound-guided procedures at the bedside.

“The Vivid S6 is also completely compatible with the advanced network technology of the GE EchoPAC system, which is the benchmark in digital imaging,” said Dr. Fehske. “It is important to be able to review all prior data on a patient no matter where you are.”

When the hospital used exclusively larger ultrasound units, they performed fewer exams in the ICU and the cath lab. In Dr. Fehske’s experience, Vivid S6’s mobility and networking compatibility are strong arguments for better patient care.

For physicians requiring enhanced understanding of real-time, 4D anatomy and function, GE offers the Vivid 7 Dimension complete with LV quantification tools, including 4D LV volume on-board. End-users report the system’s features “support an intuitive impression of morphologic anatomic structures in a 3D image and therefore simplify interpretation and 3D navigation impressively.”

Having worked with ultrasound for nearly 30 years, Dr. Ernesto Salcedo, M.D., associate professor of medicine and director, echocardiography laboratory, University of Colorado Hospital, Denver, has witnessed firsthand the technology’s evolving capabilities. The hospital has been using 3D real-time (3D/4D) TEE echocardiography, the Philips’ iE33 system, since May 2007. In the OR, Dr. Salcedo believes the technology’s greatest potential is for surgical mitral valve repair. Standard therapy for treating severely impaired heart valves used to involve implanting an artificial valve; now the goal is valve repair versus valve replacement, he says. But, you must be able to determine which valve is repairable. 3D/4D TEE gives surgeons views of the heart that aren’t possible with two-dimensional data.

“Surgeons can now determine - before surgery - which valve is affected and in what area, which in turn, helps them determine the best course of treatment. Intraoperatively, the technology allows the surgeon to immediately see the results of the repair, and provides good information on the evolution of ventricular function,” Dr. Salcedo said.


Ultrasound vs. CT, MR

How do the newer features of cardiac ultrasound stack up against the benefits of other imaging modalities?

“Ultrasound is the best modality for frontline, immediate return on diagnostic information,” said John Davidson, senior director, cardiology, ultrasound division, Siemens Medical Solutions.

“Today’s cardiac ultrasound technology offers the benefits of immediate detection and reporting, being able to look at regional wall motion abnormalities in real time and assessment of valve structure and morphology,” Davidson said. Other imaging modalities attempt to acquire these end points but they accomplish them over a period of time and they require the patient to travel to the source of the imaging, whereas ultrasound is transportable to the point of care. As a result, the workflow, costs and turnaround times are much more favorable with ultrasound, he says.

“CT is great for analyzing the coronary arteries and for perfusion, but can’t provide a real-time assessment of heart function. With some scanners you can’t see the entire heart and so you have to stitch it together or use some other type of post-processing technique in order to see what’s going on,” added Gordon Parhar, director of cardiac ultrasound with Toshiba America Medical Systems.

“While there is a lot of buzz in the market about CTA, ultrasound is here to stay,” he said. “It’s faster and more cost effective than CT and provides physiological images and data — things that CT cannot, and it does so without any radiation.”

MR tagging has long been considered the gold standard for detecting wall motion abnormalities. But the technology is very expensive, has gating problems and is not always tolerated well by patients. With John Hopkins University, Toshiba is trying to validate strain measured by ultrasound against strain measured by MR.

“Echocardiographic wall motion assessment is still largely subjective. Toshiba’s goal is to find a quantitative way of determining wall motion abnormalities that may lead to earlier diagnoses,” said Parhar.

He said they developed a wall motion tracking technique that is not subject to angle-dependent Doppler limitations and can detect and quantify wall motion defects that are too subtle to be picked up by the naked eye.


Getting the “Full” Picture

“Cardiology is all about temporal resolution,” said Davidson. “Ultrasound has prospered in the imaging world because it provides immediate return on diagnostic information in a real-time mode.”

He said Siemens is developing an architectural capability to enable acquisition of 90-by-90 degree pyramids at 20 volumes/second, every second; in other words, full-volume, true volumetric imaging in real time. This capability is expected to greatly enhance current 3D/4D ultrasound imaging, because it eliminates the need for ECG gating.

Sidebar

New Views

Several advancements in cardiac ultrasound were highlighted at the recent 2008 American College of Cardiology’s Annual Scientific Session in Chicago.

Siemens ACUSON X300 To
www.usa.siemens.com/medical

In addition to the standard quantification tools, the ACUSON X300 Premium Edition for cardiovascular and general imaging boasts advanced capabilities for comprehensive cardiac assessment. These include syngo Velocity Vector Imaging technology for detailed assessment of myocardial mechanics, and syngo Auto Left Heart with progressive pattern recognition for expert-like measurements of ejection fraction and volumes of the left ventricle and atrium extend routine evaluation.
It also offers transesophageal echocardiography (TEE) for evaluation of heart valves and chambers, left ventricular opacification for LV chamber wall definition, as well as intracardiac procedures with the ACUSON AcuNav ultrasound catheter.

Vivid S5 (GE Healthcare)
www.gehealthcare.com

Created for multiple care areas, the new mobile Vivid S5 cardiovascular ultrasound system features a full-sized 17-inch LCD monitor, three active transducer connectors and room for on-board peripherals retained in a miniaturized console weighing less than 160 pounds.

Backward data compatible with the entire GE Vivid family and inspired by the Vivid I, Vivid 7 and Vivid 4, the Vivid S5 boasts stress echo capabilities and raw data DICOM to expand the reach of patient examinations.

Ergonomic features include: constant pivoting height adjustment of the control panel; horizontal swiveling keyboard, a “flex key” that can be assigned to assume the function of more distant keys; and a high contrast wide-angle display monitor designed to minimize eyestrain.

Toshiba Aplio Artida
www.medical.toshiba.com
Artida's real-time multiplanar reformatting capabilities allows physicians to quantify global and regional LV function, including LV ejection fraction, volume and severity of regurgitation. Arbitrary views of the heart can also be obtained to help in surgical planning.

It is engineered to track and display myocardial motion in 3D images. This wall motion tracking feature reportedly allows the user to obtain angle-independent, quantitative and regional information about myocardial contraction. This ability to identify wall motion defects aims to improve cardiac resynchronization therapy (CRT) using pacemakers by determining who will respond to CRT.

Aloka ProSound Alpha 7 and Alpha 10
www.aloka.com

Boasting dedicated platforms for advanced cardiac and vascular imaging, the ProSound Alpha 7 and Alpha 10 systems offer Directional eFLOW, a blood flow capture and display mode offering increased accuracy in blood flow detection of low velocity flow and acute acceleration. An edge optimizer function improves the edge differentiation without compromise in temporal resolution.

  • Toshiba America Medical Systems' Aartida