Preliminary experience with an intraoperative MRI-compatible infant headholder: technical note (original) (raw)
Neurosurgery, 2001
OBJECTIVE Preliminary clinical experience with a novel, compact, intraoperative magnetic resonance imaging (MRI)-guided system that can be used in an ordinary operating room is presented. DESCRIPTION OF INSTRUMENTATION The system features an MRI scanner integrated with an optical and MRI tracking system. Scanning and navigation, which are operated by the surgeon, are controlled by an in-room computer workstation with a liquid crystal display screen. The scanner includes a 0.12-T permanent magnet with a 25-cm vertical gap, accommodating the patient's head. The field of view is 11 × 16 cm, encompassing the surgical area of interest. The magnet is mounted on a transportable gantry that can be positioned under the surgical table when not in use for scanning, thus rendering the surgical environment unmodified and allowing the use of standard instruments. The features of the integrated navigation system allow flap planning and intraoperative tracking based on updated images acquired d...
Does the Use of an Immobilizer Provide a Quality MR Image of the Brain in Infants?
Journal of Radiology Nursing, 2012
Magnetic resonance imaging (MRI) provides key clinical and diagnostic information for care of neonates and young infants. However, to obtain quality images, they need to be motionless in the scanner, often with the aid of sedation medications, which put them at risk for complications. An immobilizer device (an airtight, chambered device that safely and securely fastens around the infant without applying pressure) allows the infant to feel snug and warm, sleepy and motionless, and can be used as an alternative to sedation for this population. We conducted a retrospective, descriptive, comparative study at The Children's Hospital of Philadelphia MRI Department in the Division of Radiology. Inclusion criteria were infants less than or equal to 90 days of age, weighing at least 2 kg, requiring a MRI brain scan that is predicted to take no more than 60 min to complete. We obtained data on 36 patients who received sedation medications for their brain MRI scan, and 36 patients who completed their brain MRI scan without the use of sedation medication, but rather were in the "feed and immobilize" group. Results of the study showed that brain MRIs on sedated infants took longer, and those infants were more likely to experience oxygen desaturation and require supplemental oxygen post-MRI. Most importantly, we found that the MR images were considered diagnostic in 100% of the sedated infants and 94% of the immobilized infants, although significantly more immobilized infants had artifact from motion than sedated infants. Implications for practice include potential cost saving and increased patient's safety (e.g., more stable respiratory status). (J Radiol Nurs 2012;31:91-96.)
Intracranial surgery with a compact, low-field-strength magnetic resonance imager
Topics in magnetic resonance imaging : TMRI, 2009
Intraoperative magnetic resonance imaging (iMRI) has been a reality for more than a decade. As technology has begun to mature, the focus on practicality and user-friendliness has sharpened. In addition, the need for well-designed and well-executed outcome studies remains so that expensive new instruments such as iMRI can be justified. We present our experience with the PoleStar system, a compact, low-field-strength iMRI designed to make intraoperative imaging a routine component of intracranial neurosurgery. The advantages and limitations of this approach are discussed in the context of different clinical applications.
Infant and Child MRI: A Review of Scanning Procedures
Magnetic resonance imaging (MRI) is a safe method to examine human brain. However, a typical MR scan is very sensitive to motion, and it requires the subject to lie still during the acquisition, which is a major challenge for pediatric scans. Consequently, in a clinical setting, sedation or general anesthesia is often used. In the research setting including healthy subjects anesthetics are not recommended for ethical reasons and potential longer-term harm. Here we review the methods used to prepare a child for an MRI scan, but also on the techniques and tools used during the scanning to enable a successful scan. Additionally, we critically evaluate how studies have reported the scanning procedure and success of scanning. We searched articles based on special subject headings from PubMed and identified 86 studies using brain MRI in healthy subjects between 0 and 6 years of age. Scan preparations expectedly depended on subject's age; infants and young children were scanned asleep after feeding and swaddling and older children were scanned awake. Comparing the efficiency of different procedures was difficult because of the heterogeneous reporting of the used methods and the success rates. Based on this review, we recommend more detailed reporting of scanning procedure to help find out which are the factors affecting the success of scanning. In the long term, this could help the research field to get high quality data, but also the clinical field to reduce the use of anesthetics. Finally, we introduce the protocol used in scanning 2 to 5-week-old infants in the FinnBrain Birth Cohort Study, and tips for calming neonates during the scans.
World neurosurgery, 2018
High-field intraoperative magnetic resonance imaging (MRI) has become increasingly available in neurosurgery centers. There is little experience with combined intraoperative MRI and intraoperative neurophysiologic monitoring (IONM). We report the first series, to our knowledge, of pediatric patients undergoing brain tumor surgery with 3T intraoperative MRI and IONM. This pilot study included all consecutive children operated on for brain tumors between October 2013 and April 2016 in whom concomitant intraoperative MRI and somatosensory evoked potentials and motor evoked potentials were used. Neuromonitoring findings and related complications of all cases were retrospectively analyzed. During a 30-month period, 17 children (mean age 8.4 years; 3 girls) undergoing surgery met the study criteria. During intraoperative MRI, 483 IONM needles were left in place. Of these needles, 119 were located on the scalp, 94 were located above the chest, and 270 were located below the chest. Two comp...
Changing the paradigm for diagnostic MRI in pediatrics: Don't hold your breath
Pediatric Anesthesia, 2017
Increasingly complex pediatric patients and improvements in technology warrant reevaluation of the risk associated with anesthesia for diagnostic imaging. Although magnetic resonance imaging is the imaging modality of choice for children given the potentially harmful effects of computerized tomography-associated ionizing radiation, we dare to suggest that certain patients would benefit from the liberalization of our current standard. Incorporating the use of newer computerized tomography technology may improve safety for those that are already at higher risk for adverse events. Furthermore, magnetic resonance imaging is not risk-free-what is often overlooked is the need for controlled ventilation and breath-holding to minimize motion artifact. As physicians at the forefront of the development and sustainability of the perioperative surgical home, anesthesiologists must work to not only optimize patients preoperatively but should also act as gatekeepers for procedural safety.
Neuronavigation in intraoperative MRI
Computer Aided Surgery, 1999
Objective: We describe the development and implementation of an image-guided surgical system combining the best features of conventional h e l e s s stereotactic systems and the recently developed superconductive vertically configured intraoperative magnetic resonance scanner. The incorporation of intraoperatively updated magnetic resonance imaging (MRI) data sets into the neuronavigation computer overcomes one of the main disadvantages of these systems, i.e., intraoperative brain shift. Methods: The integrated system consists of a 0.5-T MRI scanner (Signa SP General Electric Medical Systems, Milwaukee, WI), a neuronavigation computer with associated software (OTS Radionics, Burlington, MA), and an emulation program linking the two. The scanner has a 60-cm-wide vertical gap where both imaging and surgery are conducted, in-bore infrared linear cameras and monitors for interactive surgical neuronavigation, and flexible surface coils specially designed for surgery. Results: Phantom studies showed navigational accuracy to be better than that obtained using conventional preoperative images and surface markers for patient registration. Our initial 17 cases using this integrated system comprised 16 craniotomies and one biopsy, and demonstrated decreased operative duration, greater frequency of interactive image guidance utilization, and better assessment of the progress of surgery compared to the cases previously done in the intraoperative MRI. Conclusion: This initial study of the addition of h e l e s s stereotactic systems to the basic intraoperative MRI concept has demonstrated its clinical usefulness. The use of the intraoperative MRI greatly reduces the basic weakness of neuronavigation inaccuracy due to target shift. The surgical procedure performed in the imaging volume of the MRI scanner eliminates the problems of patient or scanner transport during the procedure. Immobilization of the patient throughout the procedure eliminated the need for reregistration of the patient, by taking advantage of the fixed camera system in the bore of the MRI system. Comp Aid Surg 4:200-207 (1999). 01999 Wiley-Liss, hc.
MRI in the Neonatal ICU: Initial Experience Using a Small-Footprint 1.5-T System
American Journal of Roentgenology, 2014
system is expensive and challenging to site in the NICU. In addition, the long bore of an adult-sized scanner limits visual and rapid physical access to the neonate during the examination. The 3-T systems are also loud and pose greater safety risks associated with ferromagnetic attraction and tissue heating due to a higher specific absorption rate [6]. In addition, the low signal-to-noise ratio (SNR) of the 0.17-T system precludes the use of stateof-the-art MRI techniques (e.g., diffusiontensor imaging and MR spectroscopy) in neonatal MR examinations. At our institution, we have eliminated the logistical challenge of moving NICU patients to the radiology department by installing a small 1.5-T MR scanner in our NICU. The system is based on a commercially available musculoskeletal MRI system and includes custom-built components. A second prototype system is installed in our research center and is being used for preclinical research studies [17]. To qualify these systems for hu
Magnetic resonance imaging protocols for paediatric neuroradiology
Pediatric Radiology, 2007
Increasingly, radiologists are encouraged to have protocols for all imaging studies and to include imaging guidelines in care pathways set up by the referring clinicians. This is particularly advantageous in MRI where magnet time is limited and a radiologist's review of each patient's images often results in additional sequences and longer scanning times without the advantage of improvement in diagnostic ability. The difficulties of imaging small children and the challenges presented to the radiologist as the brain develops are discussed. We present our protocols for imaging the brain and spine of children based on 20 years experience of paediatric neurological MRI. The protocols are adapted to suit children under the age of 2 years, small body parts and paediatric clinical scenarios.