Parallel to the roadmap of clinical CT technology, dedicated systems for high-resolution preclinical CT are seeing a considerable growth taking advantage of the modern technology of high-granularity flat-panel X-ray detectors (FPDs).

The manufacturers of computerized tomography (CT) equipment are stepping off the trodden path and taking the medical community with them. Ahead is a world of changing workflows, decreasing times from diagnosis to treatment, and improving patient care. Current healthcare reform efforts have radiology departments trying to make the most of their current systems to increase productivity while keeping costs down. In some cases, this may mean they are not able to purchase the most up-to-date, high-end scanners that boast premium features. Vendors are recognizing this and are working to give their customers some of those same capabilities at a lower price point.

The high-efficiency CT scanners for both the entry-level and mid-tier markets are being developed by various manufacturers. Multiplanar reconstruction (MPR) speed for images is boosted by automating several normal operator functions. Parallel to the roadmap of clinical CT technology, dedicated systems for high-resolution preclinical CT are seeing a considerable growth, taking advantage of the modern technology of high-granularity flat-panel X-ray detectors (FPDs). While the basic principles have stayed the same, manufacturers are expanding on these principles to offer enhanced performance and image quality.

Technology Updates

CT has evolved from a research tool to an important diagnostic investigating tool. Several improvements in technology with growing detection-efficiency and faster response have led to the current configuration of modern ultra-fast, low-dose whole-body CT scanners. The complex detector is also getting miniaturized, improving signal quality at lower radiation level. Such developments have brought great advantages in the clinical settings in terms of image-quality, dose-effectiveness, imaging-throughput, and also extending considerably the field of clinical application that was initially foreseen.

Iterative reconstruction techniques. The widespread use of CT has raised concerns about potential radiation risks, motivating diverse strategies to reduce the radiation dose associated with it. Iterative reconstruction techniques allow significant improvements in image-quality in terms of noise and contrast and provide distinct strength levels and settings which permit a substantial reduction in effective radiation dose. It has been increasingly integrated into clinical CT practice and has been particularly important in the field of cardiac CT with multiple vendors introducing cardiac CT-compatible IR algorithms.

Innovations in cardiac CT. The advancements in cardiac CT have now enabled coronary assessment with a high degree of accuracy at low levels of radiation for both acute and stable lesions. The ability of cardiac CT to detect significant coronary stenosis has been validated against conventional coronary angiography and intravascular ultrasound. The evolution of this imaging technology has continued, with the number of detectors increasing, resulting in wide availability of 128, 256, and 320 detector row scanners in clinical practice. This progression is ongoing, with 640 detector row scanners now citing even less radiation and scanning time as well as improved image quality.

Spectral imaging. Spectral CT is a relatively new concept in diagnostic imaging, allowing physicians to use CT scanning to assess the material composition of the target area, which can be accomplished at the scanner or in the course of post-processing. Spectral analysis is accomplished in the picture archiving and communication system (PACS) using the magic-glass visualization tool, which upon activation will generate the spectral data side-by-side with the original grayscale image.

Photon-counting detector CT. The prototype technology is expected to replicate the image-quality of conventional CT scanning, but may also provide healthcare specialists with an enhanced look inside the body through multi-energy imaging. Patients could receive a minimum amount of radiation, while the maximal amount of information needed would be delivered to healthcare providers. In collaboration and through a partnership known as a cooperative research and development agreement with the manufacturer, Siemens Healthcare, and researchers in the CT technology field, the clinical center at the National Institutes of Health is testing this technology to help the healthcare field optimize the scanner for clinical use across the U.S. and around the globe.

Multidetector CT. Multidetector computed tomography (MDCT) scanners with improvement of spatial resolution and ability to obtain multiplanar and 3-D reconstructions have greatly improved the diagnostic performance of CT in characterizing renal cell carcinoma (RCC) and estimating the extent of the disease. Important information for treatment planning is provided by CT examination, including tumor location and size, renal arterial and venous anatomy, and relationship to the pelvicaliceal system.

Cone beam CT. Cone beam computed tomography (CBCT) has been introduced as a diagnostic tool utilizing cone-beam geometry, flat panel detectors, and 3-D reconstruction algorithms. The recent advances in CBCT techniques have led to its use in surgical and postoperative planning, especially for head and neck procedures and for detection and quantification of bisphosphonate-related osteonecrosis of jaw. CBCT imaging provides high-resolution hard-tissue diagnosis while offering a large field of view. As such, it can serve as a guide toward management planning with cross-sectional slices allowing identification of the true extent of affected marrow and thus facilitated transfer from the 3-D images to the surgical topographical landmarks.

Challenges and Opportunities

Growing prominence of image-guided interventions against the backdrop of the rising need for early and accurate diagnosis is providing lucrative opportunities for the CT scanner market. Likewise, increasing incidences of cancer and chronic diseases, increase in the global aging population, technological advances, and growing public awareness for healthcare are instrumental factors in the growth of the market.

As the industry emerges from decades of clinical use of CT, some challenges still remain. High price of CT scanners, radiation hazards, and competition from other diagnostics imaging techniques are the main challenges to the market. Awareness and rightful use of diagnostics procedures is also the continuous challenge as technology is moving to smaller towns. Though there is overall growth in the healthcare sector, which was earlier restricted to major cities, there is still a big opportunity in terms of spread. Reimbursement issues and regulatory framework concerns coupled with expensive procedures and instruments are hindering the growth of the market.

Looking Ahead

Even though technology will develop further, the trade-off between image quality and dose will remain, with any technical improvements likely to be mainly used to reduce patient exposures rather than increase image quality. Image quality has improved so dramatically that any further increments may prove to be of only marginal value. Instead, other considerations such as safety and cost will take precedence. Moreover, it may be able to characterize the pathology rather than just finding size and location. Different approaches in terms of technology adopted by all vendors are to get spectral reading as kV switching, dual source, and spectral detectors. Thus, multiple images of tissue can be achieved from various energies. There might be the development of contrast medias suitable at low-dose energy systems, thus giving the metabolic basis on CT, which is currently only on MRI. Novel innovations in preclinical spectral CT devices have paved the way for CT-based molecular imaging.

In the near future, CT using protons to document the location, direction, and energy loss from a proton beam as it passes through the human body could be used to produce a 3-D image of the body that assists in the diagnosis and treatment of a range of diseases. It might offer a number of benefits for patients, but perhaps the most notable could be the active focus on developing CT technologies that use low-dose radiation.

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