Computed Tomography

No matter how you slice it, CT vendors have continued to push the design and image quality of today's scanners, improving their overall clinical performance and increasing anatomical coverage. To no one's surprise, multi-detector CT continued the buzz it started at last year's Radiological Society of North America meeting in Chicago last week -- however even the vendors were surprised the "other guy" didn't bring along a 128-slice scanner. "I think we're all waiting for healthcare facilities to figure out what to do with the image volume of 64-slice," several vendors voiced. Toshiba did look into the future by demonstrating its 256-slice scanner. The works in progress scanner would be able to image the entire heart in one rotation, but there's no word yet on when it will be commercially available. 

All of the CT vendors showcased their 64-slice systems launched at last year's show, and Siemens also showcased its just-launched dual-source CT (a first of its kind) with two tubes and two generators that touts twice the temporal resolution, acquisition speed and scanning power, while minimizing radiation exposure. Sixty-four slice scanners bring the gantry speed and sub-millimeter volume coverage needed to gather a high-resolution image of a heart, brain or a pair of lungs in about five seconds.

Additional highlights in the reign of CT at RSNA 2005 included a large bore CT scanner from Toshiba America Medical Systems with a 90 cm and a 70 cm acquired field-of-view. GE Healthcare introduced a new series of CT scanners called the BrightSpeed series geared for a broader audience of healthcare facilities, including community hospitals and outpatient imaging centers that may have space constraints and require a quicker return on investment. Philips Medical Systems showcased an ambient experience called CT Halo for improved, efficient workflow in the CT environment, including radiology, cardiology and oncology CT. And a new company to the RSNA showroom floor, NeuroLogica, introduced a mobile CT scanner called CereTom that has a 25-cm field of view that can be brought bedside and used in any hospital room or clinic bay.

If you didn't make it all the way around the floor or not on the show floor at all, here are some details of what CT vendors had on display. Vendors are listed in alphabetical order.


E-Z-EM Inc. introduced at RSNA its works in progress EZ CHEM blood analyzer. It was developed in conjunction with Nova Biomedical, and the company has exclusive rights to market the product to radiologists and gastroenterologists in North America, with additional marketing rights worldwide.

EZ CHEM is a point-of-care device for conducting blood assays in patients prior to certain imaging procedures. Such blood values are often required to determine a patient's kidney function before certain IV contrast agents are administered.

The device performs a simple test from a pin-prick same of blood and produces results in as little as 40 seconds after measuring the blood for levels of creatinine, an important indicator of a patient's renal status.

Evaluating a patient's kidney function can help determine their ability to safely receive IV contrast prior to a CT exam. This can be an important precaution especially for known diabetics, patients with known kidney impairment, and patients over 50. EZ CHEM should present considerable time savings, as such blood tests now must be sent to a lab before a CT exam, the company says.

E-Z-EM expects to submit its application to the FDA for regulatory clearance in the 3rd quarter of fiscal year 2006 with commercialization soon after.


GE Healthcare showcased its LightSpeed VCT 64 channel CT scanner, as well as using the show to spring board a new line of CT scanners that are compact in design and appropriate for a wide range of basic radiology applications.

In a single rotation, GE's LightSpeed VCT creates 64 sub-millimeter images, totaling 40 millimeters of anatomical coverage, which are combined to form a three dimensional view of a patient's anatomy. The LightSpeed VCT is able to capture the image of any organ in one second, perform a whole body trauma scan in fewer than 10 seconds, and capture images of the heart and coronary arteries in as few as five heartbeats, GE said.

Since its introduction at last year's RSNA, the scanner has been installed at more than 500 clinical sites, according to the company.

GE also showcased what it tagged adaptive technologies for its VCT scanner. In the future, GE says the scanner will be able to adapt to a patient's heart rate and anatomy, further personalizing their CT scan. Adaptive technologies also make dose reduction possible, GE said.

GE debuted its new line of BrightSpeed scanners that are available in 4-, 8- and 16-slice configurations. Compact in design and intended for basic radiology applications, the scanners provide the same image quality, productivity capabilities and reliability of the LightSpeed systems. GE said the BrightSpeed series will be attractive to a broader audience of healthcare facilities, including community hospitals and outpatient imaging centers that may have space constraints and require a quicker return on investment.

The new BrightSpeed scanners include Volara digital data acquisition system (DAS) and the Xtrex FX workflow platform. The series also offers productivity tools to facilitate review and communication, such as direct volume visualization with direct multi planar reformat (MPR). Included in the BrightSpeed series is the wide open workflow with Xtream FX that provides imaging departments the ability to keep pace with the large volume of data generated by multi-detector CT systems. A tool such as direct multi-planar reformat (DMPR) helps customers improve interpretation efficiency and provides views that may be more familiar to referring physicians and surgeons.

BrightSpeed will be commercially available in early 2006, GE said.

GE also showed as a works in progress the LightSpeed Xtra. The large-bore CT scanner is intended for radiation oncology, bariatrics and interventional applications such as CT-guided biopsies. In addition, the weight capacity of the table has increased from 450 pounds to 600 pounds, GE said.

GE's Stroke Work-Up application for the LightSpeed VCT, which is being used to image the brains of stroke patients at the University of Michigan Health system in Ann Arbor, Mich., was showcased. The scanner's speed and resolution are required for rapid examination of blood vessels in the brain, to provide information to help physicians make an accurate and timely diagnosis of stroke, and to help physicians determine the extent of stroke damage.

GE used RSNA to announce the next generation of application software for analyzing volume data sets called VCAR (volume computer assisted reading).

VCAR automatically finds, segments and measures pathologies and then displays the analytic results. According to GE, VCAR's design enables the software to monitor and manage patient's response to treatment over time.

GE also showcased Lung VCAR that can find, isolate and measure lung nodules over time. Computer-assisted visualization using GE's Lung VCAR software enables auto-visualization of lesions that may otherwise have gone unnoticed. After the software helps doctors find the lung nodules, Lung VCAR then isolates and precisely analyzes the nodules, comparing the measurements to previous results to determine if the nodules are growing.



Medrad introduced Smartflow for its Stellant D CT injection system. Smartflow, built on a similar platform as Medrad's DualFlow, that eliminates the need for manual calculations in tailoring CT injection protocols to specific patients.
   
According to Medrad, Smartflow allows a site to set preferences, such as flow rates or grams over time, in advance. The technologist would then only need to enter a few patient-specific parameters to activate the Stellant to calculate a suggested protocol that can be used as-is or adjusted at the user's discretion, Philips said. Users have the option to include a saline test inject for vein patency, a test for bolus for contrast timing, or a diagnostic injection with contrast, DualFlow, and saline flush.



NeuroLogica Corp. introduced a mobile CT scanner called CereTom that has a 25-cm field of view. The system can be brought bedside and used in any hospital room or clinic bay.
   
According to NeuroLogica, the scanner is capable of performing normal CT, perfusion, xenon perfusion and angiography. It is designed for use in the ER, OR, ICU, MICU, SICU, NICU, interventional suite or any medical clinic. In the future, the company said CereTom may also be used by orthopedic surgeons and dental specialists.



Philips Medical Systems highlighted its Brillance line of CT scanners, as well as introduced new innovations for enhanced CT clinical performance.

Philips' Brilliance CT 64-channel configuration provides expanded anatomical coverage for faster exams performed with shorter breath holds and less motion. The Brilliance CT 64 has 64 x 0.625 millimeter detector banks, giving total z-axis coverage of 40 millimeters, and has a maximum gantry rotation speed of 0.4 seconds. Philips RapidView reconstruction utilizes 3D cone-beam technique for image quality at 20ips. Expanded clinical applications include functional and physiologic imaging, including stroke assessment with 80 millimeter coverage achieved through Jog Scan.

Philips showcased what it calls CT Halo for improved, efficient workflow in the CT environment, including radiology, cardiology and oncology CT. The ambient experience designed for CT is coupled with remote post-processing capabilities that eliminate the need for a separate control room. The design gives caregivers more time to focus on their patients by decreasing procedure steps and increasing patient comfort.

Looking into its crystal ball, Philips unveiled a new technological innovation that portrays a vision about the future of CT.  The first, already in clinical trial at Hadassah Medical Organization in Jerusalem, Israel, is a simultaneous multi-energy detector. The detector is comprised of layers designed to simultaneously detect both low-energy and high-energy x-rays. Simultaneous imaging of both soft and hard radiation improves tissue characterization, Philips said. Combining signals from both detector layers provides a conventional CT image consisting of the full energy of the beam. Simultaneous multi= energy detectors do not require a second beam of radiation and thus avoid the potential pitfalls of time lag, registration artifacts and unnecessary radiation dose.

Another technology Philips showcased in the CT arena was new full coverage detector platform based on Nano-Tile technology that will image an entire organ such as the heart or head in a single rotation. The whole organ detector is based on tiles that can be integrated into panels of any size.

Philips also highlighted its new Philips Brilliance Workspace Portal that transforms conventional computers into a radiology workspace. Clinicians can view CT images and case information via Brilliance Workspace's software applications from various locations, and without having to load the CT dataset onto the PC. The interactive portal can be used as a primary image review station or as a method to share results remotely with referring physicians or specialists, such as in the surgical suite or emergency department.

In addition, Philips displayed its Philips Brilliance Workspace 2.0, which was developed for multi-slice CT and is adaptable across the entire Philips Brilliance family. The system features direct integration from the console to a hospitals' health information system and radiology information system (RIS), displaying all patient information on the screen and helping to eliminate paperwork. Information is made available with a click of a button, in many cases eliminating the need to run a dedicated HIS/RIS terminal in the CT suite. Features include auto mapping, in which the specific scan protocol for the requested study is automatically populated, and an auto-launch application that automatically opens the software application. Once the scan is complete, the Workspace communicates with HIS/RIS systems to finalize coding and billing, providing improved workflow and patient care.

Showing a number of works in progress, Philips featured a virtual colonoscopy application that includes computer-assisted reader (CAR) to automatically segment and find intracolonic polyps. The technology, which is pending FDA 510K clearance, automatically segments data and provides measurements that are designed to aid physicians in the detection of polyps. Philips electronic cleansing algorithm, also pending clearance, automatically segments and subtracts tagged contrast enhanced intra-colonic stool and fluid. This allows clear inspection of the entire colonic surface on both prone and supine datasets while maintaining and potentially improving lesion detection when they are located under fluid or make it easier to rule-out lesions where residual stool could mimic a polyp, Philips said.
            
In addition, Philips previewed an analysis tool designed for cardiologists, cardiac radiologists and CT technologists to perform detailed evaluation of the coronary arteries and advanced ventricular functional analysis. The comprehensive cardiac analysis (CCA) package aims to reduce the time and complexity of a cardiac evaluation, Philips said. Based on automated total heart segmentation technology, Philips CCA provides visualization of the entire coronary tree, morphological analysis of the vessel lumen and cross-sectional views of the artery in question allowing for free lumen diameter/area analysis.



Siemens Medical Solutions introduced the Somatom Definition, a dual-source CT system that provides twice the temporal resolution, acquisition speed and scanning power, while minimizing radiation exposure. According to Siemens, the scanner can image full cardiac detail with as much as 50 percent less radiation exposure compared to traditional CT scans.
 
Siemens' Definition, which uses two x-ray sources and two detectors at the same time, features a 31-inch (78-cm) bore opening and a 79-inch (200-cm) scan range. The system is equipped with z-Sharp technology, the Straton x-ray tube and CARE solutions, which benefit in earlier detection, faster evaluation, and more precise follow-up of disease states.

In the area of cardiac diagnosis, the dual-source CT scanner can image patients with high or irregular heart rates, or even arrhythmia, without beta blocker medications, Siemens said. The system also enables physicians to better identify and characterize plaque, an early indicator of heart disease. In acute care, Siemens said the new scanner will enable the assessment of patients with acute chest pain, abdominal pain, and suspicion of stroke. In clinical research, the scanner's ability to image with two different x-ray energies simultaneously will allow physicians to better differentiate, characterize, isolate and distinguish bone, soft tissue and fluid. 

In October, the first Somatom Definition was installed at the University of Erlangen in Germany. Siemens said the system is being used for technical and clinical research as well as regular patient care. The first U.S. installations will take place in early 2006 and will include Mayo Clinic, Rochester, Minn.; Cleveland Clinic Foundation, Ohio; William Beaumont Hospital, Royal Oak, Mich.; and New York University Medical Center. 

Siemens also revealed new CT clinical engines for acute care, cardiology, neurology and oncology. The clinical engines are available on Siemens' Somatom Definition, Sensation and Emotion CT scanners.

The CT acute care engine, intended for emergency and trauma imaging, provides an extended field-of-view and scan range up to 200 cm for full body diagnosis. The CT cardiac engine, with imaging applications that range from coronary arteries to peripheral vessels, provides clinicians with motion-free imaging. The CT neuro engine can assist in evaluating complex vascular structures by subtracting bones, differentiating brain tumors and detecting strokes, all in less than 10 minutes. The CT oncology engine assists in detecting, localizing, visualizing and differentiating tumors earlier.

The syngo computer-assisted reading tools, combined with intelligent evaluation, automated follow-up, and image-guided intervention, present higher diagnostic confidence for preventive care, staging, follow-up exams, and real-time guided biopsies. Additionally, comprehensive tumor perfusion enables a fast and easy visualization of tumor enhancement and aids in differentiating tumors.

According to Siemens, the CT clinical engines are available in two workplace configurations - a dedicated CT Workplace and a MultiModality Workplace. CT clinical engines are driven by syngo CT, Siemens said. syngo MultiModality Workplace can be configured with up to four CT clinical engines. In addition, special syngo applications modules can be added for each clinical field and imaging modality, such as molecular imaging or radiation therapy planning.



Toshiba America Medical Systems showcased a large bore CT scanner with a bore opening of 90 cm and a 70 cm acquired field-of-view, making it possible to scan patients of all sizes in various positions. The Aquilion LB CT received FDA marketing clearance over the summer.

According to Toshiba, the system's QuantumPlus detector provides three different slice-width acquisitions, enabling the Aquilion LB CT to acquire isotropic images in all anatomical planes while achieving low-contrast resolution using the lowest dose. Clinical applications include oncology, bariatrics and interventional CT. The system was recently installed at Beth Israel Deaconess Medical Center in Boston, Toshiba said.

In the arena of multi-detector CT scanning, Toshiba highlighted its Aquilion 64 CFX CT scanner that is dedicated to cardiac imaging. The scanner utilizes Toshiba's 64-row Quantum detector that acquires 64 simultaneous slices of 0.5 mm with each 400-millisecond gantry revolution. According to Toshiba, the system allows physicians to capture precise, motion-free images of the heart and coronary arteries to identify soft plaque or measure coronary blockage, and detect signs of disease at its earliest stages, reducing the need for high-risk interventional procedures. 

The slices will continue to increase, according to Toshiba, who previewed for meeting goers a 256-slice CT scanner. The works in progress, which Toshiba said is the future of CT imaging, would be able to image the entire heart in one rotation.

Toshiba also announced at the show that new workflow, security and dose exposure enhancements have been added to its Sure line of automated scan applications for its full line of Aquilion CT systems. 

New Sure enhancements include: SureWorkflow  Image Accelerate, a works in progress that doubles reconstruction speed and allows reconstruction of up to 28 images per second; Enhanced DICOM Data Transfer allows data transfer from the Aquilion 32/64 CT systems to Vital Images workstations; SureSupport Enhancements Physician Education, which is a visiting fellowship program at Shands Hospital, University of Florida; Enhanced NEMA (National Electrical Manufacturers Association) software designed to add an additional firewall between the CT scanner and the hospital or organizational network for added protection; SureExposure enhancements designed to reduce overall dose up to 40 percent and improve patient care; and SureCardio Enhancements that includes adaptable dose modulation software for cardiac CT available to the marketplace, ECG modulation is designed to reduce dose by up to 50 percent for improved patient care.

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