Evaluation of a Flexible 12-Channel Screen-printed Pediatric MRI Coil

Abstract

ediatric MRI is often performed with heavy, large, and relatively inflexible coil arrays designed and built for adult MRI. For awake children, these arrays can be intimidating and uncomfortable, thereby restricting the child's breathing. For parents, they contribute to the stress of the examination. For pediatric caregivers, the coils complicate the placement of medical support equipment, such as mechanical ventilation tubes, pulse oximeters, anesthetic lines, respiratory bellows, blood pressure cuffs, electrocardiogram probes, and video goggles. For sedated or anesthetized children, respiratory compromise from heavy coils on the torso requires more invasive respiratory support or bolstering of the coils away from the patient, with a resultant decrease in signal-to-noise ratio (SNR) and reduced parallel imaging acceleration capability. As a result, much work has been aimed at the design of custom-fitted pediatric coils to maintain SNR. Such efforts have included a flexible cardiac array (1), a set of small head coils for pediatric patients (2), and even a novel pneumatically adjustable head coil to maintain a close patient fit (3). In comparison, flexible arrays have also been proposed by Neocoil (Pewaukee, Wis) and ScanMed (Omaha, Neb). Recently, screen-printed MRI coil technology has been developed to increase SNR due to a more compact fit with respect to the patient. Screen-printed MRI coils allow printing on a flexible substrate (4,5). These coils also have been shown to be printable on fabric, and a 12-channel receive array has been used at 3 T (4-7). In addition to the beneficial SNR increase of large dense MRI coil arrays in general (1,8-14), screen-printed technology (15,16) offers the advantage

Flexible Multi-Turn Multi-Gap Coaxial RF Coils: Design Concept and Implementation for Magnetic Resonance Imaging at 3 and 7 Tesla

“…Further improvement in flexibility was reached with printed and stitched coils on flexible substrate or even elastic textile. Screen-printed MRI coils [17] developed by Corea et al have shown to be a reliable alternative to bulky conventional coils with comparable SNR, suitable especially for pediatric imaging [18]. Stretchable Rx coils produced with copper braids [19], [20], meandered conductors [21], liquid metal printed into neoprene support material [22], liquid metal filled tubes [23], [24] or conductive elastomers [25] mostly target wrist or knee imaging and offer a truly wearable solution.…”

Iterative motion‐compensation reconstruction ultra‐short TE (iMoCo UTE) for high‐resolution free‐breathing pulmonary MRI

“…Both TE and TR (, ) increased compared to adult studies due to smaller FOV and excitation slab. The number of spokes was adjusted between 80 thousand to 90 thousand to keep the total scan time no more than 5 min 30 s. Due to varied scan subject size, different receiver coil arrays were used in pediatric scans to improve SNR: 8‐channel and 32‐channel cardiac arrays (GE Healthcare, Waukesha, WI), as well as a 12‐channel flexible screen‐printed coil array (Inkspace Inc., Moraga, CA) …”

Safety challenges related to the use of sedation and general anesthesia in pediatric patients undergoing magnetic resonance imaging examinations

“…Parallel imaging acceleration is routinely used clinically to accelerate MR acquisition by not sampling some lines of k-space in the phase-encoding direction while estimating missing information from coil sensitivity profiles of adjacent receiver elements. Parallel imaging usually leads to 2- to 3-fold acceleration, although recently developed high channel count and flexible coils offer the promise of higher acceleration factors and are undergoing clinical validation for applications in the pediatric population [ 49 , 50 ]. Higher signal acquired with a 3-tesla (T) versus a 1.5-T scanner, combined with parallel imaging, has the potential to reduce the overall scan time and thus the need for sedation/general anesthesia.…”