The U.S. Food and Drug Administration has just updated the regulations regarding warning labels on gadolinium-based MRI contrast agents, due to the risk of NSF.
From now on, Magnevist, Omniscan, and Optimark would be required to carry labels with the following warning: “inappropriate for use among patients with acute kidney injury or chronic severe kidney disease.” The labels will emphasize the importance of screening patients to detect kidney dysfunction before MRI contrast administration.
According to the FDA, the latest review of the safety of the most widely used gadolinium-based contrast agents “determined that Magnevist, Omniscan, and Optimark are associated with a greater risk than other [gadolinium-based contrast agents] for NSF in certain patients with kidney disease.” However, all gadolinium-based contrast agents are under study, as data suggests that NSF may follow the administration of any of them.

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With the help of cardiac MR, German researchers have found out that he human heart adapts to triathlon training by developing greater muscle mass and wall thickness, as well as larger left atria and larger right and left ventricles.
The researchers carried out cardiac MR exams on 27 triathlon elite athletes and 27 controls, and measured the ejection fraction, myocardial mass, and atria and ventricles volumes. A comparison between triathlon athletes and the control group showed significant differences. The results of this study will be published in the October issue of Radiology (multicenter study led by researcher Michael Lell, MD, and colleagues at the University of Erlangen-Nuremberg in Erlangen).

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).

The American Academy of Neurology has weighed in heavily on the side of MR as opposed to noncontrast CT for the diagnosis of stroke patients in its newly published practice guidelines. However, the practice may not be feasible in the real world.

According to the president of AHA, it is clear that MR has more diagnostic accuracy than a CT scan for stroke assessment. The latest studies reviewed in the article demonstrate the superiority of MRI for detecting a stroke at an early stadium. However, considering the current situation in most hospitals, it is always faster to do a CT than an MR scan on an acute stroke patient. There are always extra arrangements to be made before the patient can get into the MR scanner and many places do not have more than one MR scanner, which is fully booked the whole day.
As a conclusion, if hospitals are going to implement these guidelines, they probably need to get themselves an MR scanner at the emergency department.

Back pain is very common among the adult (and young) population. However, it is not always easy to diagnose the source of the pain. Currently, patients with lower back pain must undergo an invasive procedure known as provocative discography to help determine where the pain comes from. A die is injected into the disk via a needle until the patient reaches his or her pain threshold. Based on the level of pain expressed by the patient, the physician forms the diagnosis.
Nocimed (a Californian-based company) is currently testing Nociscan, a software that combines an MR spectroscopy sequence and postprocessing to identify chemical biomarkers of painful disks (degenerative disk disease MR – DDD MR).
There are two metabolites associated with painful disks: lactate and proteoglycan:
– Lactic acids build up in painful disks (the same phenomenon that makes muscle hurt).
– Proteoglycan holds water in the disks. A normal disk has a high content of water and proteoglycan. However, disk degeneration involves dehydration and proteoglycan breaks down. This also prevents nerve in-growth, creating a permissive environment for innervation of nociceptors [pain reporting nerves] that has been observed in the inner nuclei of degenerative painful disks (not found in healthy disks). In general, nocireceptive nerves and acidity means pain.
This technology is not yet commercially available. A two-year study has shown very good results and no false positives, but further investigation is still necessary.
Nevertheless, this new technology represents a step forward to diagnose lower back pain in a more efficient, non-invasive manner.
For more information, refer to:
– Keshari KR, Lotz JC, Link TM, et al. Lactic acid and proteoglycans as metabolic markers for discogenic back pain. Spine. 2008;33(3):312-317. PMID: 18303465
– Carragee EJ, Don AS, Hurwitz EL, et al. 2009 ISSLS Prize Winner: Does discography cause accelerated progression of degeneration changes in the lumbar disc: a ten-year matched cohort study. Spine. 2009;34(21):2338-2345. PMID: 19755936
– O’Neill C, Kurgansky M, Kaiser J, Lau W. Accuracy of MRI for diagnosis of discogenic pain. Pain Physician. 2008;11(3):311-326. PMID: 18523502
– Serena S et al. Modified Magnetic Resonance Spectroscopy Diagnosis of Painful and Non-Painful Lumbar Intervertebral Discs :Abstract

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

A couple of days ago, a young male, aged 22, was fitted with a new Advisa MRI safe pacemaker in the South West in the US. This is a state-of-the-art MRI-compatible pacemaker, which means he will be able to have an MRI scan in the future should he need one. This is not possible with an ordinary pacemaker, and there are different records of patients dying in the MR suite all over the world, because of the effects of the magnetic field on the pacemaker.
Those are good news to patients who have a pacemaker: the MR suite could now be open to them.

More information can be found at: http://www.diagnosticimaging.com/europe/content/article/113619/1570949