Faster MRI?

May 15, 2012

 

Researchers from the Children’s National Medical Center in Washington, D.C (principal researcher: Stanley Fricke) have recently published a study in Medical Physics where they show that ultra-fast magnetic gradients (pulse sequences with rise times 100 times faster than conventional MRI) do not produce nerve stimulation or muscle twitching. According to the researchers, MRI limiting speed should be revisited taking into account the new developments, and they expect MRI to allow imaging of small children in seconds rather than minutes.

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I wrote in my previous post about smart phones and how they are getting more and more common among Radiologists. Well, tablets are not far behind. Actually, the new iPad’s Retina display, which has raised the tablet’s resolution to the level of a 3-megapixel PACS monitor, is generating a lot of expectation, especially for reading Digital Radiography images. The new iPad offers 2,048 x 1,536-pixel resolution at 264 pixels per inch, up from the iPad 2’s 1,024 x 768-pixel resolution at 132 pixels per inch. This, together with the easy-to-handle features, such as zoom and scroll, make this device very suitable for checking images on the fly.

However, this increased resolution is only beneficial when the images also have a high resolution. This is not the case for tomographic images such as CT, MRI, SPECT or ultrasound, which have a much lower resolution. Nonetheless, the portability of the device, together with the new speed capabilities (e.g. the new iPad utilizes the A5X chip, with quad-core graphics processing capability), make the tablet a very attractive tool for Radiologists.

3T MRI in pediatrics

May 17, 2011

3T MRI is being increasingly performed for clinical purposes. The increased SNR is a significant advantage in pediatrics – improved spatial and temporal resolution assist in overcoming the major anatomic, physiologic and behavioural challenges of imaging children. 3T MRI has the potential to image all the systems in pediatrics. However, optimising the parameters with due consideration to specific pediatric features, such as the increased water content of non myelinated brain, is essential. The neonatal brain and pediatric spine are difficult to image at 3T. Several factors also limit cardiac imaging at present. Further improvements in coil technology and newer sequences may help overcome the challenges that remain. On the other hand, some 3T artefacts inherent to specific anatomic regions, like the dielectric effects encountered in adult abdominal imaging, are less problematic in pediatrics due the smaller size.
For more information, see this white paper

MR keeps bringing exciting images of the human body. Who would have expected to have a woman in labor having an MR scan? Well, last November, physicians at the Charité University Hospital in Berlin followed the birth of a child on an open MR system. The movements of the baby in the birth canal to the exit of the head, were monitored through MR imaging.
This is part of a study that tries to show some light into the fact that 15% of pregnant women need a C-section because of the baby not moving properly into the birth canal.

Themed imaging suites

November 15, 2010

Any radiographer can tell how challenging is to image children. X-ray, CT or MR imaging scans require patient’s cooperation in order to get good images.This is not always easy. Children are specially difficult, mainly because they are scared of the whole procedure. Therefore different pediatric hospitals in the UK have started a new concept: the themed imaging suites.
According to Dana Etzel-Hardman, an advanced practice nurse in Children’s Hospital’s radiology department, a thematic room adds to the distraction techniques employed to try to increase productivity of the CT scanner and decrease the number of sedations required for the patients having CT exams. The number of children requiring sedation for a CT scan has declined and the waiting lists too.
Imaging vendors are now working together with children’s hospitals to create themed imaging suites. For more information, check the article aunt minnie

MRI is a powerful tool to assess neurological abnormalities in preterm babies. However, performing an MR scan on a neonate can be hazardous: positioning the baby inside the scanner, sedation, making sûre only MR-compatible material is used… Anyone that has performed or seen an MR exam of a neonate knows how cumbersome it is. This is where an MRI-compatible incubator comes in handy.
MRI-compatible incubators preserve the environmental cocoon of the incubator, maintaining temperature and ventilation stability and reducing the need to handle infants in the MRI environment. This reduces risks, increases the number of infants that can benefit from an MR exam and saves time in the MR suite. Researchers from the Medical University of Vienna in Austria have just published the results of a study on how the MRI-compatible incubator affects clinical management. Read more on the September issue of the European Journal of Paediatric Neurology (2010, Vol. 14:5, pp. 410-417).

Having your patients hold their breath properly during a MR or CT scan is always a challenge, especially when your patients are infants. Mueller et al. have come up with a simple volume-monitored (VM) method for performing reproducible, motion-free full inspiratory and end expiratory chest CT examinations in children. They tested the method on
fifty-two children with cystic fibrosis (mean age 8.8 ± 2.2 years). They underwent pulmonary function tests and inspiratory and expiratory VM-CT scans (1.25-mm slices, 80–120 kVp, 16–40 mAs) according to an IRB-approved protocol. The VM-CT technique utilizes instruction from a respiratory therapist, a portable spirometer and real-time documentation of lung volume on a computer. CT image quality was evaluated for achievement of targeted lung-volume levels and for respiratory motion. Overall, 94% of scans were performed at optimal volumes without respiratory motion. This method is applicable to children older than 4 years-old.
A drawback of the method, though, is the fact that the respiratory therapist has to stay in the room while the scan is being performed, with all the risks of radiation.

For more information you can read the whole article, published online in Pediatric Radiology (May 28, 2010): Volume-monitored chest CT: a simplified method for obtaining motion-free images near full inspiratory and end expiratory lung volumes