Incorporating MRI Parallel Imaging Technologies

Advantages of MRI Parallel Imaging

MRI parallel imaging technology uses complex software algorithms to reconstruct the signals from multiple channels in a way that can reduce imaging times or increase image resolution, without the corresponding increase in imaging times associated with standard MRI scanner imaging. Although parallel imaging techniques have only recently been introduced into MRI scanners in hospitals and clinics, they have already achieved wide clinical acceptance in many imaging applications. Their considerable advantages in terms of better spatial and temporal resolution and enhanced image quality, have updated the position of MRI in a wide range of abnormality and disease imaging.

Multi-channel technology and parallel imaging allows for significant improvements in most clinical MRI scanner examinations. There is no significant degradation in performance, compared to non-parallel imaging. Faster scanning could increase the patient throughout, as well as dramatically improve patient comfort during scans.

This technology could potentially contribute to the use of MRI scanning as an alternative to CT scanning and play a significant role in radiation protection strategies, particularly in young patients.
MRI scanning offers superb soft tissue contrast. However, high- resolution scans are often excluded, due to long scan times. Parallel imaging offers much shorter acquisition times, while retaining the high resolution necessary for early lesion and/or tumor detection

Phased Array Coil System

MRI parallel imaging takes advantage of the numerous elements of phased array coil system. Each element of the coil system is associated with a dedicated radio frequency channel (a special single-channel radio receiver) whose output is processed and combined with the outputs of the other channels (signals acquired by the other coil elements). This technology improves the signal–to-noise ratio (the signal quality) as compared to a standard MRI scanner coil system; while covering the same explored body volume.

Multi-Channel Radio Frequency and Parallel Imaging

Multi-channel radio frequency and parallel imaging technologies are hardware and software implementations, respectively aimed at improving the coverage signal resolution and speed of MRI scanner examinations. With multi-channel technology, the MRI scanner signal used to form an image is collected by a collection of separate coil elements. Each element relays signal information along a separate channel to an image reconstruction computer. Such arrays of coil elements can improve imaging coverage and the ratio of signal-to-noise in the image. The number of elements in the array of detectors is an important factor in characterizing a parallel imaging system.

Multi-channel coil and receiving systems and parallel imaging technologies were first implemented in brain examinations. Recent developments in both hardware and software have allowed for broader clinical applications of these technologies, such as in cardiac, lung, abdomen, and limb studies. For example, parallel imaging, in partnership with multi-channel radiofrequency systems allows for better visualization of small lesions and blood vessels that may allow for an earlier diagnosis of cancer and cardiovascular disease. Greater imaging coverage is possible with multi-channel radiofrequency system technology facilitating oncology screening and peripheral angiography. Finally, scan times are considerably reduced using parallel imaging, allowing for tolerable breath holds when scanning patients. The most current MRI scanners at 1.5T and 3T all feature multi-channel radiofrequency system technology and parallel imaging.

Locating Parallel Imaging Upgrades on MedWOW

MedWOW, the global medical equipment marketplace, is a good place to look when you are ready to upgrade your imaging department by adding multi-channel technology and parallel imaging to your MRI system.

MedWOW features imaging inventories from dealers all over the world, so locating the specific MRI parts you need from a variety of makes, models and manufacturers in a safe and protected environment, is easy and secure. MedWOW is the leading medical equipment portal for all types of medical equipment trade, and with over 12,000 users visiting the site daily; locating your particular MRI parallel imaging upgrade is a relaxed experience.

Explaining the MRI Receiver

What is the MRI Receiver’s Role?

An RF MRI receiver is used to process the signals from the MRI receiver coils. Most modern MRI systems have six or more MRI receivers to process the signals from multiple coils. The signals range from approximately 1MHz to 300MHz, with the frequency range highly dependent on applied-static magnetic field strength. The bandwidth of the received signal is small, typically less than 20kHz, and dependent on the size of the gradient field.

A traditional MRI receiver configuration has a low-noise amplifier followed by a mixer. The mixer combines the signal of interest to a low-frequency IF frequency for conversion by a high-resolution, low-speed, 12-bit to 16-bit analog-to-digital converter (ADC). In this receiver architecture, the ADCs used have relatively low sample rates below 1MHz. Because of the low-bandwidth requirements, ADCs with higher 1MHz to 5MHz sample rates can be used to convert multiple channels by time-multiplexing the receive channels through an analog multiplexer into a single ADC.

With the introduction of higher-performance ADCs, newer MRI receiver architectures are now possible. High-input bandwidth, high-resolution 12-bit to 16-bit ADCs with samples rates up to 100MHz can also be used to directly sample the signals, thus eliminating the need for analog mixers in the receive chain.

What are the Basic Elements of an MRI Receiver?

The basic elements of an analog MRI receiver chain are a pre-amplifier, a one- or two-staged modulator, aquadrature-phase-sensitive detector, low pass filters, two second-stage audio amplifiers with variable gain, and two analog-to-digital converters. As a result, the MRI receiver is very similar to a conventional superheterodyne radio receiver.

What to Look for in MRI Receivers When Purchasing

When dealing with MRI scanner receivers, it is important to take a good look at the signal-to-noise ratio and the bandwidth. In general, a wider bandwidth includes more noise. Decreasing the bandwidth by a factor of 4 results in an increase in the signal-to-noise ratio by a factor of 2 (less noise in the image).

When decreasing the bandwidth, we gain a better signal quality. However, there are also some trade-offs:

• the chemical shift artifact increases.
• longer echo time (TE) means some reduction.
• longer echo time means that fewer slices can be fitted into the repetition time (TR) period.

In the signal-to-noise ratio however, the overall effect of the reduction of the bandwidth is an improvement in the signal-to-noise ratio.
The initial bandwidth of the MRI signal produced by the MRI scanner is a function of the special encoding readout gradient strength, and the chemical shift.

Where to Buy MRI Scanner Receivers

MedWOW, the global medical equipment portal, specializes in imaging equipment, including an impressive selection of MRI scanner receivers. Currently, there is a broad selection of MRO scanner receivers for both stationary and mobile MRI units from GE Healthcare, Siemens, Marconi, Picker and Toshiba. MedWOW’s revolutionary search engine allows you to browse their catalogue in a number of ways, so finding the MRI scanner receiver you need is a simple procedure. You can filter by manufacturer, make, model, condition, location, year manufactured, Seller’s business type and more. So, when buying or selling MRI scanner receivers, MedWOW is a good place to find a varied selection at competitive prices, as well as safe and protected transactions.

The Beginners Guide to Finding MRI Parts

For an MRI system to work perfectly there must be synergy between the various MRI parts. Very frequently, MRI parts need to be exchanged, and certainly much before the entire system needs replacing. Keeping your imaging department in safe, patient-oriented and nowadays, even competitive shape is not an easy task, but it's important if you hope to offer the kind of services your patients need and expect. You're very much aware of how expensive used MRI parts can be. Yes, even seemingly simple MRI parts can run into thousands of dollars for good quality replacements.

The main functioning MRI parts of an MRI system include: one external magnet, RF (radio frequency) equipment, gradient coils and a computer. Other MRI part mechanisms include: an RF shield, a power supply, NMR probe, display unit, and a refrigeration unit. All of these MRI parts will need upgrading or replacing during the lifetime of the the MRI system, so it is important to do some basic research and know how to go about replacing these MRI parts on short notice, so you don’t cause any down time which can harm the function of your department, at the very least.

Many times, MRI parts of all kinds can be serviced and repaired, but when that isn’t possible, finding a trustworthy source is imperative. Since MRI systems are relatively complex, and quite unlike other imaging systems, it is important to find an imaging equipment expert who can guide you through the process.

A site that features MRI parts specialists from all over the world is MedWOW, which is a global platform for buying and selling medical equipment. In order to meet their goal of providing comprehensive medical equipment services, with a strong emphasis on used imaging parts, MedWOW developed three methods for locating and purchasing good-quality and guaranteed used MRI parts, all of which are available in a multilingual format which translates communications between buyer and seller, so it is possible to get competitive prices on MRI parts and related imaging equipment and services, even if it is on the other side of the world.

MedWOW’s unique Part Finder Service was created in order to best serve its global user base of medical equipment professionals. MedWOW partnered with dozens of the major used imaging parts suppliers in the world. In this way, they are able to supply healthcare professionals with any available used MRI part from any manufacturer, makes and model from anywhere in the world. This means that if you are searching for a specific used MRI part and you can’t find it anywhere, the MedWOW Parts Finder team will take over your search, and probably find it for you. This imaging parts finder service is completely free, so just fill in your request in as much detail as you can, and then you can sit back and relax and wait for quotes for your used imaging part.

Your second option in used MRI parts finders, is to use MedWOW’s all-inclusive search engine, which is built using copious filtering options, so you can search for just about any used imaging part and find it, even if it has changed names or manufacturers over the years.

Finally, the third ingenious choice is to post an MRI part buying request, by filling out a form and giving as much information as possible about the used imaging part that you seek. The portal attracts sellers from all over the world (10,500 visitors a day) so you will likely be sent a few competitive quotes for your selected MRI part to choose from.