Introduction
"Currently if you have just 30 minutes to do a comprehensive brain examination, you've got to make some choices as to how much time to spend on any particular part of that study - whether it be diffusion weighted imaging, MRA or brain structural scanning," says Dr. Nievelstein, radiologist at Utrecht Medical Center, Netherlands, the site of the world's first Achieva. "Our new Achieva reduces sacrifices all around and we get better quality and more information in the same time slot."
Better image quality, faster examinations, and simpler operation - the new Achieva 1.5T and 3.0T offer solutions to imaging challenges often faced by radiologists in busy hospitals like Utrecht Medical Center. How does the Achieva MR meet these challenges?
FreeWave - The Heart of Achieva
Philips' pioneering development of parallel imaging or 'SENSE' technology provides an increase in acquisition speed far greater than the conventional method of increased gradient strength. With SENSE™, multiple MR receiver channels are paired with multi-channel coils to reduce acquisition time and improve sensitivity. FreeWave, a totally new data acquisition system, takes that breakthrough technology to new heights with a scalable, 32-channel modular architecture. 8 and 16 channels are available on the Achieva today, with 32-channel capability built-in and ready for the advanced application opportunities of tomorrow.
Dr. Nievelstein's colleague, Dr. Theo Witkamp sees impressive results when using the new 8-channel SENSE™ knee coil for joint studies. "With the new knee coil the images are fantastic, I must say. The cartilage is especially impressive. The high detail gives you the ability to very easily see small chondral lesions."
This totally new data acquisition system also offers direct digital sampling that provides unequaled signal-to-noise ratio (SNR) by eliminating all analog filtering of the originating signal and it boasts an impressive 3 MHz bandwidth per RF channel for the shortest TE's and TR's (echo times, repetition times) in the industry.
Expanded Applications
FreeWave capabilities extend well beyond data acquisition to the automatic integrated control of many elements of MR imaging - gradients, spectrometer, table movement, user interface, and Internet enabled protocols. As such FreeWave is able to offer a full range of complex sequences and packages for various applications. They include:
MobiScan (click to enlarge) | 
MobiFlex (click to enlarge) |
Total body imaging with Mobiscan - Head-to-toe imaging providing a virtually unlimited field-of-view, with multiple contrast studies in a single scan. Mobiscan optimizes every step - set-up, scanning and viewing - all within a few minutes.
Peripheral MRA with MobiFlex - Combines SENSE™ with moving bed imaging to allow the use of multiple resolutions throughout a single rapid study. Now it's possible to have 'run-off' scans from the renal arteries to the feet with the resolution optimized where it's needed, and the whole result displayed as one seamless image.
IViewBold (click to enlarge) |
Workflow Enhancements
Bringing all these advancements together through a new Vequion user interface called ScanForum allows Achieva users to accomplish their work efficiently and effectively. This Windows XP-based operating system organizes the scanning and viewing process into a simple user-friendly work environment.
A key feature of ScanForum is ExamCards. An entire MR exam often consists of 5 to 10 different MR studies executed in a specific order with a certain slice orientation. Now ExamCards enable that whole exam to be performed as a single customized sequence, at a single touch. For example, just by dragging and dropping an icon called 'angio study', a whole clinical procedure can be initiated - including planning, BolusTrak and scan protocols.
Because part of an MR department's workload is repeating the same exam for patient follow-up, the new Achieva offers a unique time saving feature called SameScan. Once a previous exam is loaded, a quick acquisition is done to identify several anatomical reference points. Then with the push of a button, SameScan repeats the entire exam ensuring exact replication of slice location.
Outstanding Initial Impressions
Eight weeks after installation of the first Achieva 1.5T at the Utrecht Medical Center, approximately 500 patients have been scanned. 70% were brain and spine studies with the remaining 30% split between abdominal and musculoskeletal scans.
"These initial applications show the influence of the multi-channel architecture on SNR, scan time, and resolution," says Dr. van Leeuwen. "Usually it's a trade-off among those criteria, but with Achieva, the whole curve has shifted upward while maintaining the same scan time."
Utrecht technologist Greet Bouwman is excited about ExamCards. "I think they will make scanning tremendously easier," she says. "Instead of building an examination protocol every time, now you can have just one header file under which all required scans are listed or grouped - that makes a lot of sense."
Leadership in Whole Body 3.0T
Achieva is a true 'family' of products, including the world's most compact whole-body 3.0T MR. Achieva demonstrates strong commonality between the 1.5T and the 3.0T - from footprint to FreeWave - similarities that bind and strengthen both systems.
In Manchester, UK, at Hope Hospital, the site of the first clinical installation of a high-field Achieva 3.0T, Professor Alan Jackson, Professor of Neuroradiology, commented on two of the areas that will benefit patients, "One is that for routine scans, for screening brains and so on, it's just incredibly quick, so it's a very quick, clean procedure for them. The main thing I think though is that diagnostic accuracy is going to go up, particularly in vascular diseases."
Dr. Charles Hutchinson consultant radiologist with a special interest in musculoskeletal radiology indicates that the images acquired the first week have "exceeded expectations". He is "particularly impressed with the cervical spine and cranial angio images."
According to Dr. Hutchinson, "Philips has provided us a 3.0T system to be truly proud of."
3.0T hi-res abdomen with THRIVE fat suppression (click to enlarge) | 
3.0T hi-res angio in brain (click to enlarge) |
Future Safe Design
It's not only today's results from Achieva that are causing heads to turn. It's also Achieva's forward-looking design philosophy.
The Achieva platform with Freewave means "hardware without hard lines," offering a scalable number of receiver channels, transmitters and processors to ensure a flexible, exciting and future-safe investment.
This excitement is exemplified by a works-in-progress technique called kt-BLAST (Broad-Use Linear Acquisition Speed-Up Technique), which promises a further revolution in ultra-fast MR - the ability to increase MR speed 5 to 8 times further*. kt-BLAST -- developed with Philips' support at the Institute for Biomedical Engineering, University and ETH Zurich -- is under clinical evaluation at a number or Philips luminary sites.
(* Works in Progress. Results validated.)
The Philips Achieva is truly an MR system built for today and ready for tomorrow.
Following a splashy debut at the 2003 RSNA in Chicago last December, the newest members of the Philips MR family have been shipped and installed. The first Achieva 1.5T has been operational at the Utrecht Medical Center in the Netherlands since early March and the high-field Achieva 3.0T has recently been installed in the UK at University of Manchester's Hope Hospital. Both sites are experiencing the benefits of enhanced multi-channel imaging performance. (5/6/04)
(Published May 11, 2004)