"Feed-and-wrap" technique versus deep sedation for neonatal magnetic resonance imaging: a retrospective comparative study

Abstract

Objectives: Neonatal MRI is usually performed under deep sedation, which is challenging-especially in low-weight premature patients. In addition, long-term side effects, such as neurotoxicity, are of concern. An alternative to sedation is to induce natural sleep by feeding and immobilising the child, the "feed-and-wrap" technique (FWT). The objective of this study was to evaluate differences in image quality between neonates examined under sedation and by using the FWT during the first four months of life.

Materials and methods: We retrospectively assessed image quality (based on a 4-point semiquantitative scale) of all MRI examinations in neonates performed at our institution between July 2009 and August 2022. Differences in image quality between examinations under sedation versus FWT were evaluated.

Results: We included 432 consecutive patients, 243 (56%) using sedation and 189 (44%) using the FWT. Corrected age and body weight (mean ± SD: 3.7 ± 1.1 versus 4.5 ± 1.3 kg, p < 0.001) were significantly lower in the FWT group. The overall success rate in the FWT group was 95%. Image quality was slightly lower when using the FWT (mean ± SD: 3.7 ± 0.43 versus 3.96 ± 0.11, p < 0.001). Multivariate analysis showed a higher risk of acquiring sequences with diagnostic limitations in the FWT group (p < 0.001), increasing with corrected age (p = 0.048).

Conclusion: The FWT is a highly successful method to perform MRI scans in term and preterm neonates. Overall image quality is only slightly lower than under sedation. Especially in immature low-weight preterm patients, the FWT is a reliable option to perform MRI studies without exposing the child to risks associated with sedation.

Clinical relevance statement: The "feed-and-wrap" technique enables high-quality MRI examinations in neonates, including low-weight premature patients. Deep sedation for diagnostic MRI procedures in this age group, which has the risk of short- and long-term complications, can often be avoided.

Key points: Deeply sedating neonates for MR examinations comes with risks. Image quality is only slightly lower when using the "feed-and-wrap" technique. The "feed-and-wrap" technique is feasible even in low-weight premature infants.

Keywords: Infant; Magnetic resonance imaging; Neonate; Sedation; “Feed-and-wrap”.

Fig. 1

immobilisation of a premature patient in the MR preparation room. The child is transferred from the incubator into the vacuum mattress, MR-compatible monitoring is applied (a) and a pacifier (b, red arrow) is used. After vacuum has been applied, the child is taken into the MR scanner (c)

Fig. 2

Examples of the different quality scores based on a T2-weighted turbo spin echo sequence of the brain at the level of the basal ganglia. a Score of 4 with excellent image quality. b Score of 3 with slight motion artefacts, primarily affecting the frontal lobe. c Score of 2 with marked artefacts. Anatomic landmarks are still visible, but details, such as cortico-medullary differentiation, are only partially assessable. d Nondiagnostic image with severe artefacts, corresponding to a score of 1

Fig. 3

Development of examination numbers under sedation versus FWT over time. Since the introduction of the FWT in 2015, the number of examinations under sedation decreased continuously

Fig. 4

Clinical examples of examinations performed using the FWT. a T2-weighted turbo spin echo sequence demonstrating venous congestion bleeding in the periventricular white matter and basal ganglia (red arrows) due to (b) thrombosis in the sinus confluens (red arrowhead, T1-MPRAGE (Magnetization Prepared Rapid Acquisition with Gradient Echoes) postcontrast) in a 13-day old female patient. T2-weighted turbo spin echo (c) and 3D-SPACE (Sampling Perfection with Application optimized Contrast using different flip angle Evolution) (d) sequence demonstrating a large craniofacial teratoma (blue circles) with a large adjacent intracranial arachnoid cyst (blue arrow) in a 4-day-old female patient. T2-weighted Half fourier Single-shot Turbo spin-Echo (e) and T1-weighted 3D stack of stars gradient echo sequence (f) confirming suspected bilateral adrenal gland bleeding (orange arrows) in a 7-day old male patient

Fig. 5

Number of sequences with diagnostic limitations depending on corrected age in the “feed-and-wrap” group. We applied a jitter technique to avoid multiple overlapping data points in order to enhance the visibility and interpretability of the data