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

Abstract

Background Screen-printed MRI coil technology may reduce the need for bulky and heavy housing of coil electronics and may provide a better fit to patient anatomy to improve coil performance. Purpose To assess the performance and caregiver and clinician acceptance of a pediatric-sized screen-printed flexible MRI coil array as compared with conventional coil technology. Materials and Methods A pediatric-sized 12-channel coil array was designed by using a screen-printing process. Element coupling and phantom signal-to-noise ratio (SNR) were assessed. Subjects were scanned by using the pediatric printed array between September and November 2017; results were compared with three age- and sex-matched historical control subjects by using a commercial 32-channel cardiac array at 3 T. Caregiver acceptance was assessed by asking nurses, technologists, anesthesiologists, and subjects or parents to rate their coil preference. Diagnostic quality of the images was evaluated by using a Likert scale (5 = high image quality, 1 = nondiagnostic). Image SNR was evaluated and compared. Results Twenty study participants were evaluated with the screen-printed coil (age range, 2 days to 12 years; 11 male and nine female subjects). Loaded pediatric phantom testing yielded similar noise covariance matrices and only slightly degraded SNR for the printed coil as compared with the commercial coil. The caregiver acceptance survey yielded a mean score of 4.1 ± 0.6 (scale: 1, preferred the commercial coil; 5, preferred the printed coil). Diagnostic quality score was 4.5 ± 0.6. Mean image SNR was 54 ± 49 (paraspinal muscle), 78 ± 51 (abdominal wall muscle), and 59 ± 35 (psoas) for the printed coil, as compared with 64 ± 55, 65 ± 48, and 57 ± 43, respectively, for the commercial coil; these SNR differences were not statistically significant (P = .26). Conclusion A flexible screen-printed pediatric MRI receive coil yields adequate signal-to-noise ratio in phantoms and pediatric study participants, with similar image quality but higher preference by subjects and their caregivers when compared with a conventional MRI coil. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Lamb in this issue.

Figure 1:

Screen-printed 12-channel coil array for pediatric applications allows for ease of construction, flexibility, lighter weight, and smaller size arrays, offering easy access to monitoring equipment. A, Interior coil construction (anterior and posterior components are constructed equally). B, Complete array demonstrates flexibility by the anterior component being folded in the longitudinal direction.

Figure 2:

A, Pediatric phantom highlights the location of axial signal-to-noise ratio (SNR) maps produced with the 12-channel printed coil (i) and the 32-channel printed array (ii). Blue and red dotted lines indicate location of SNR profile highlighted in B. A, Plots comparing SNR through the phantom for the 12-channel printed coil and the 32-channel coil to that of the screen-printed coil.

Figure 3:

Comparison of clinical MR images obtained with commercial (left) and 12-channel screen-printed (right) coils. A, Abdominal image in a 3-month-old subject with cavernous transformation of the portal vein. B, Chest image in a 7-year-old subject with a chest wall vascular malformation. C, Forearm image in a 12-year-old subject. Good field of view coverage and high signal-to-noise ratio are demonstrated.