Tertiary care hospitals – Technology needs of MR systems

MRI is an integral part of the healthcare system. The advances in the hardware and the newer and faster sequences have helped MRI foray into all specialties of medicine. The inherent advantage of excellent soft tissue detailing, and no radiation, makes it the preferred option over all other imaging modalities. The longer scanning times, a multitude of artifacts, and claustrophobia are the limiting factors of the past. The present scanners have upgraded systems at every step of the examination. Each vendor has come up with a newer set of innovations. The focus is on faster technologies like AI-enabled pre- and post-processing, higher-channel multipurpose RF coils, sequences with better SNR, obviating use of intravenous contrast, 3D and 4D protocols, co-registration with previous studies, and multi-modality comparative evaluations. The computers employed are getting much faster, the data storage and retrieval is shifting to personalized cloud systems, sub- and super specialty-based protocols are the new norms. A meticulous and detailed evaluation of various vendor products is needed to be able to assess the utility of each scanner in the context of the requirements of a particular hospital, the super specialties catered to by the imaging department, the patient throughput, and the most important factor – the cost.

There can be no such conversation about a fully loaded scanner. There is a myriad of choices, not only from different vendors but even from the same vendor. It is not possible to comprehensively vote for one particular imaging system. The radiologists must first chart out the requirements of every clinical specialty, and then match them with the products available to make a judicious choice. As the number of options available is immense, and the cost of including each option is high, it is advisable to concentrate on what is more suitable, rather than what is more desirable.

The context for the choice of the MR system. The key factor to consider is the rapid advancements in the technology in radiology over the years, and in the future as well, for delivering personalized clinical solutions. For example, image acceleration techniques using AI are enabling clinical applications that were thought not possible in MR and are now a reality.

Clinical applications at the system. MR cases are primarily driven by the medical program that the institution offers and the sub-specialties – MR applications need to be chosen on that basis. For example, a multi-specialty quaternary care institution should always have a whole-body MR system with all clinical applications loaded. These can be broadly classified as anatomical, functional, and quantitative applications. The choice of RF coils is driven by this as well.

Gradient selection. The gradient system is the engine of the MR system – the minimal choice should be at least an amplitude of 45mT/s and slew rate 200 or 220 T/m/s gradient system with very high gradient linearity, fidelity, and endurance. Such an advanced high-performance gradient engine can provide an opportunity to the radiology department to expand clinical offerings by adopting the latest developments in advanced neuro applications, vascular, MSK, etc.

Multi-transmit technology. Conventionally, in early days of high-field MRI, disadvantages of 3.0T MRI used to be the SAR and dielectric shading issues. To overcome these challenges, anatomy-specific and patient-specific multi-transmit technology has been developed and it is a must-have in the 3T system – so that we get the advantage of 3T MRI without issues on certain clinical scans, especially in body, cardiac, etc.

Patient comfort choices. Patient comfort is important to avoid re-scans and hence technologies like ambient experience inside the MR room and inside the MR bore, along with low aquatic noise MR scans and dockable patient carts, must be considered for selection.

The choice of the MR scanners must also include the running cost of the equipment, the regular upgrades on offer, the maintenance services, the ease of availability of spare parts, and the alacrity of the response from the vendor. After all, the machine must work seamlessly for several years and is not just a one-point purchase.

The number of choices in the equipment has gone up exponentially.

The tagline remains – The shoe should fit Cinderella!