Faster* MRI throughout the whole body with Compressed SENSE

The new Philips Compressed SENSE technology is a powerful acceleration technique for a wide variety of MRI sequences in a broad range of anatomies. The method combines compressed sensing and sensitivity encoding as in SENSE into one, more powerful, acceleration technique called Compressed SENSE.

Kantonsspital Winterthur (KSW) was one of the first 10 sites in the world to receive Compressed SENSE on their Ingenia 1.5T and Achieva 3.0T MRI scanners. Neuroradiologist Dr. Sabine Sartoretti and radiologist Dr. Rene Patzwahl have been using it since September 2017 and are very satisfied with the results.

“As Compressed SENSE works in virtually all anatomical areas and with many different scan techniques and contrast types, it has the potential to help us reduce the scan time per patient. We can, for example, accelerate a routine brain protocol with 6 sequences (DWI, transverse T2, transverse T1 IR, SWIp, 3D FLAIR, 3D T1 TFE with gadolinium) by 22% by accelerating three sequences (SWIp, 3D FLAIR, 3D T1 TFE with gadolinium) between 30 and 40%. That shorter scanning time will then benefit our patients and in addition, it will allow us to scan more patients.”

In order to get there, Compressed SENSE has to be incorporated into KSW’s customized set of ExamCards. “Our goal is to reduce scan time, but we want the same image quality as before, because most of our ExamCards have been meticulously optimized to our preferences.”

“Our approach for the last weeks has been to add an additional sequence with Compressed SENSE to the original exam, and then compare the images. In this approach we have initially been using a Compressed SENSE (CS) factor as recommended by Philips, then followed by applying either higher or a lower CS factors. Repeating this in a next patient and for the different sequences, and carefully looking at the images afterwards, helps us decide what the best Compressed SENSE factor is for us.”

Dr. Sartoretti remembers how Compressed SENSE immediately impressed her in the first scans. “Our first sequence with Compressed SENSE was a 3D FLAIR in the brain on the Ingenia 1.5T, where we used a Compressed SENSE factor of 8.2. Then we tried a 3D TSE mDIXON post-contrast sequence with a CS factor of 7. In both cases the quality was really good.”

In the neuroradiology area, Dr. Sartoretti initially focused on using Compressed SENSE in 3D imaging. “We use it now for 3D FLAIR, 3D DIR, 3D T1 TFE, 3D mDIXON T1 TFE, 3D TOF, 3D PCA and also for SWIp and 3D T1 Black Blood. We decided to first concentrate on 3D because of the large effect with 3D sequences, but of course we also want to try it with 2D sequences.”

Examples that Dr. Sartoretti mentions to particularly stand out are the venography with 3D PC that is 50% faster, and also the 3D T1 TFE without contrast, where speed was increased by 50%. Their TOF sequences were accelerated by 40%.

“Our aim for the spine is to use Compressed SENSE to help us make the switch to using 3D SpineVIEW. In lumbar spine, for example, we can reduce scan time for 3D T2W SpineVIEW by 27% to 4:46 minutes, voxel size 0.8 x 0.8 x 1 mm."

“In the end, we would like to just perform a 3D T2W, and 3D T1W, and a STIR T2W for cervical and lumbar spine imaging, and then do secondary reconstructions. That’s why we need high resolution for the 3D sequences, and combining with Compressed SENSE then helps to reduce scan time. In this way, replacing the 2D sequences with 3D sequences is much better for the patient, because we can reduce the time of the scan. Another advantage is that if sometimes a scan is not done properly, we have more freedom to do reconstructions afterwards with the 3D sequences and still make a confident diagnosis from the exam.”

The KSW team also started implementing Compressed SENSE in ankle, elbow, knee and wrist MRI exams, for replacing the 2D PD fat sat with 3D PD fat sat. So far, results look good: it’s possible to obtain a good acquisition time with a high resolution.

The team envisions to finally end up with musculoskeletal ExamCards consisting of three sequences, for example 3D PD-weighted fat sat – which is the most important sequence in MSK – plus a T1 and a STIR sequence. Or alternatively two T1 sequences and the 3D sequence.