As CT technology advances, the new premium scanners now provide more detailed information in cardiac, oncology, and emergency imaging, while reducing the radiation dose delivered to the patient. Learn about the latest premium features, explained in the article below.
In the upper echelon of the CT market are scanners packed with the newest, most advanced technology available. Most of the recent innovations in CT focus on improving image quality by making acquisition times as short as possible. The goal is to capture a true snapshot of the patient’s anatomy — specifically, moving anatomy. This capability has paved the way for new features such as dynamic cardiac and cerebral imaging that are designed to widen CT’s range of clinical applications. Another key focus is on features to improve workflow by integrating the scanner with peripheral systems such as IT systems and contrast injectors.
Manufacturers also continue their efforts to reduce and control X-ray radiation, which is associated with cancer. CT is the largest single contributor to radiation dose from a man-made source. While the magnitude of the cancer risk is uncertain, it is widely accepted that more could be done to control the dose. Over the last few years, all manufacturers have taken major steps in this direction. In most cases, the latest developments have first been introduced on premium systems.
The main drivers of CT technology advances are demand for:
- New clinical applications:
- Dual-energy CT and spectral CT
- Dynamic imaging
- Further dose optimization
- Workflow integration
New Clinical Applications: Dual-Energy CT and Spectral CT
Dual-energy CT (DECT) and spectral CT are two advanced image acquisition techniques that, while they go about it differently, both aim to achieve the same result: to allow radiologists to more accurately distinguish between different types of tissue and thereby help provide more definitive diagnoses. In most respects, the two technologies are equivalent — what you can do with DECT you can do with spectral CT. Currently, only DECT is commercially available; however, spectral CT is expected to become available in the near future.
Although DECT imaging was introduced a few years ago and has known clinical benefits, it is not yet widely used in clinical settings due to some technical challenges. However, interest in the technology is growing. This is evidenced by the fact that today all the commercially available premium systems are capable of DECT imaging and it is an option on some lower-cost systems.
Each manufacturer has a different DECT or spectral technique available or in development, and differences should be expected in how these techniques perform.
Dynamic Imaging
Dynamic imaging (also known as 4-D imaging) refers to the ability to obtain a series of snapshots of anatomy over a few seconds to a minute in order to show organ function. The resulting images can be quantitatively analyzed to help clinicians determine an accurate diagnosis when, for example, blood flow through an organ (perfusion) is clinically relevant. Dynamic imaging capabilities are particularly useful in emergency imaging, where the top indications for CT use are suspected stroke and trauma.
Any CT scanner can provide a series of static images. The advantage of premium CT systems is that they all provide extensive anatomical coverage, which allows serial images of entire organs to be acquired easily. All the major vendors offer very similar 4-D imaging capability.
Dynamic CT imaging has a wide range of applications; for example:
- In cardiology, research has shown that dynamic CT angiography could reveal conditions that are not found by conventional techniques.
- In dynamic joint studies, preliminary research has shown that dynamic CT technique can generate images of high temporal and spatial resolution without requiring repeated joint motion, which is used for assessment of joint instabilities.
- Perfusion CT imaging can provide diagnostic information in diagnosis of cancers, vascular malformations, etc.
Further Dose Optimization
As CT’s high patient radiation dose continues to receive attention, CT manufacturers continue to take steps to control and reduce dose without affecting image quality.
Detection System
The goal of CT designers is to develop detectors that provide the highest spatial resolution with the lowest noise. As detector performance improves, it is possible to reduce the radiation dose. Incremental refinements are being made by improving the scintillation detector material or solid-state detector material and the electronics.
Dose Reporting
To gain the full benefits of the dose information, it may be necessary to install dose monitoring systems. The main benefit of dose reporting is that the dose data can be more easily tracked and audited. All new CT systems have dose reporting features as standard, and older systems should be upgradable to include this feature.
Workflow Integration
Currently, most CT scanners have tools designed to improve workflow efficiency, as well as patient management and safety. User interfaces have been designed to automate as many steps as possible and, therefore, reduce the number of mouse clicks and user errors in routine workflows. Such features include automated preprocessing/launch, auto 3-D generation, and automated scan settings based on patient information.
Also, all major CT manufacturers have introduced new technologies that aim to enhance integration with peripheral systems such as contrast injectors and IT systems, the latter including conformance to IHE (Integrating the Healthcare Enterprise) profiles.
Recently, manufacturers have paid more attention to integration with CT injection systems. Seamless integration between the injector and scanner improves the workflow, since approximately 50 percent of CT studies require injection of contrast media. In contrast-enhanced studies, the contrast is injected first, then after a short delay, the scan starts; the length of the delay depends on the time it takes for the contrast medium to reach the organ of interest, which, in turn, depends on the patient. Traditionally, the user would need to start both devices, with a delay between start times. The contrast injection parameters are manually set on the injector’s control console, which is usually adjacent to the CT scanner’s console. The optimal injection parameters depend on the type of scan and the patient’s characteristics.
Basic scanner-injector integration, which only allows the scanner and injector to communicate their status with each other, is widely available. In basic integrations, the interface simply ensures that the injector will only start the injection when the CT scanner is ready, using the Controller Area Network (CAN) class 1 or 4 message-based protocols. Such an interface does not endow any significant workflow benefits.
Integration beyond CAN class 4 is now becoming available between some CT scanners and injectors (advanced integration). This level of integration enables the scanner to control the injector. This means that the injector’s control console is no longer needed, the contrast parameters can be automatically set based on the CT parameters, and the injector is started from the CT control console. Also, the electronic injection report can be included in the exam summary and sent to a PACS automatically. This has several potential advantages in addition to those already noted:
- Patient-specific characteristics can be shared between systems to help optimize the scan.
- If a problem emerges with one device, the other can be automatically stopped, thereby improving safety.
- Automatic documentation of all relevant parameters is available in one place.
This article is an excerpt from a Health Devices article posted on ECRI Institute’s Health Devices System, Health Devices Gold, and SELECTplus membership websites on March 18, 2014. The full article includes more guidance on CT technology advances process, several supplements, and corresponding graphs. To purchase this article and its supplementary materials or to learn more about membership programs, visit www.ecri.org, contact clientservices@ecri.org, or call (610) 825-6000, ext. 5891.
