Significant advances in imaging technologies promise to improve healthcare through earlier and more accurate detection of medical conditions.

Computed tomography (CT) scans are now commonplace in medicine, and for good reason. They provide accurate images that improve diagnostic accuracy and guide treatment for a number of conditions. The downside is that they also expose patients to radiation and this is a drawback of increasing concern. Decades ago, patients may have had a few X-rays now and then. Today, they can have numerous scans with each one having a great deal of more radiation than an X-ray.

Four major CT system manufacturers globally released new systems in the past year featuring innovative scanner technology to reduce radiation dose, boost image quality and to be mindful of the current conservative economic climate in healthcare. GE, Siemens, Philips and Toshiba all released their next generation CT systems, each offering significant advances over technology these vendors previously offered. Until recently, hospitals had to decide how many slices they wanted when selecting a CT scanner, ranging from 16-620 slices. Today, several vendors offer upgradeable systems to enhance slice capabilities, and that is driving the market.

Indian Market Dynamics

In 2014, Indian CT scanner market is estimated at Rs.795 crore, a dip from the 2013 market. There was an 8-10 percent growth in the smaller machines, <16 slices, with the sales of 360 units in <16 slices, and 120 units in 16-slice category. The three brands, GE, Philips, and Siemens, have a combined market share of 93 percent. In response to this trend, all the brands are offering models in the unit price range of Rs.20-80 lakh. The high-end cardiac scanners continue to constitute 11 percent of the market, in value terms.

With the launch of the Revolution ACT by GE in April 2015, the CT scanner market is seeing a major shift. The Made in India scan system is the result of the efforts of a 50+ team of Indians, working for four years and a development budget of USD 20 million. In the process, GE engineers claimed 10 patents. Lower radiation dosage, special pediatric settings, and a smaller footprint are other features. GE is looking to market it worldwide starting with emerging markets - not just in India.

Technology Improvements

When 64-slice CT systems were introduced nearly a decade ago, they were purchased in large numbers to upgrade older 16-slice systems and soon became the new standard of care. Soon after that boom period for CT, sales abated due to the economic slowdown and the uncertainty of future reimbursements due to US healthcare reforms. This made many hospitals think hard about replacing CT systems as frequently as they had previously, with many extending the service life from five years to 10 or more. The conversion to a value-based payment healthcare system and concerns over radiation dose also have changed what hospitals look for in return on investment, cost-effectiveness, efficiency and increasing patient safety. This is the setting as many providers now begin thinking about replacements for their older, first-generation 64-slice system.

New detector technology. In the past few years, GE Healthcare, Philips, and Toshiba introduced new detector technology for their CT systems that uses microelectronic circuits. This technology reduces electronic noise and enables sharper images. GE and Philips also have introduced new detectors to enable dual-energy spectral imaging on their newest generation CT systems.

Iterative reconstruction. Until recently, all CT systems reconstructed images based on filtered back projection because it was fast and could be accomplished in a reasonable amount of time using older computer technology. However, with rapid advances in computing power and the reduction in costs for that power, all the major CT vendors now offer iterative image reconstruction. This software revises the image over and over again with multiple iterations to clean up artifacts and clarify the image pixel by pixel. This enables diagnostic image clarity on low-dose scans that was previously not possible. This also enables CT scanning at much lower doses than a decade ago.

Spectral CT imaging. Spectral CT (also called dual-source or dual-energy CT) has the potential to become a major trend in the coming years, as all the major CT vendors are now integrating this capability into their scanners. Similar to the way a prism breaks visible light down into its parent chemical elements on the periodic table for analysis, spectral CT can break down X-ray photons by chemical elements. Spectral CT is based on viewing the same anatomy at two different kV energies. This can be accomplished with a dual-source CT scanner, or newer methods that use fast kV switching between different energies during the scan, or detector elements that record different kV levels during a scan.

Different anatomical features are enhanced at different energy levels. Instead of needing to scan a patient multiple times at different energies to achieve various tissue enhancements, spectral CT allows different energy views to be created from a single scan. Applications for the technology include definitive identification of gout, differentiation between different types of kidney stones to better guide treatment, improved metal artifact reduction and clearer identification of pulmonary embolism. The technology aids vascular image interpretation, especially in calcified vessels or in the presence of thrombus. Additional applications are being researched and vendors have made big investments in the technology in anticipation of its use in next-generation CT diagnostics in the coming years.

Indian Market Dynamics is based on market research conducted by Medical Buyer in September 2015.

"In the present scenario, the CT scanners available are state-of-the-art and conform to various standards required for patient safety in terms of radiation dose and contrast dosage. Low radiation dose and low iodine-contrast usage is becoming the norm. Tube current modulation, dynamic collimation, iterative reconstruction, and dose-efficient low-noise detector make it possible to conduct cardiac exam with an effective dose of 0.22 mSv. Current scanners are complicated, and protocols should be tailored to specific patient size, anatomy imaged, and clinical indications for the exam. There is need for a dedicated CT protocol team to regularly monitor protocols and techniques to further reduce dose. Centers must adopt manufacturer-specific CT protocols developed by subspecialty societies and organizations dedicated to dose reduction."

Dr Dinesh Kapoor,
Director & HOD of Radio Diagnosis,
Fortis Hospital, Noida

10 Diagnostic Imaging Trends for 2018



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