Super‐resolution Reconstruction MRI Application in Fetal Neck Masses and Congenital High Airway Obstruction Syndrome

Abstract

Objective Reliable airway patency diagnosis in fetal tracheolaryngeal obstruction is crucial to select and plan ex utero intrapartum treatment (EXIT) surgery. We compared the clinical utility of magnetic resonance imaging (MRI) super-resolution reconstruction (SRR) of the trachea, which can mitigate unpredictable fetal motion effects, with standard 2-dimensional (2D) MRI for airway patency diagnosis and assessment of fetal neck mass anatomy. Study Design A single-center case series of 7 consecutive singleton pregnancies with complex upper airway obstruction (2013-2019). Setting A tertiary fetal medicine unit performing EXIT surgery. Methods MRI SRR of the trachea was performed involving rigid motion correction of acquired 2D MRI slices combined with robust outlier detection to reconstruct an isotropic high-resolution volume. SRR, 2D MRI, and paired data were blindly assessed by 3 radiologists in 3 experimental rounds. Results Airway patency was correctly diagnosed in 4 of 7 cases (57%) with 2D MRI as compared with 2 of 7 cases (29%) with SRR alone or paired 2D MRI and SRR. Radiologists were more confident ( P = .026) in airway patency diagnosis when using 2D MRI than SRR. Anatomic clarity was higher with SRR ( P = .027) or paired data ( P = .041) in comparison with 2D MRI alone. Radiologists detected further anatomic details by using paired images versus 2D MRI alone ( P < .001). Cognitive load, as assessed by the NASA Task Load Index, was increased with paired or SRR data in comparison with 2D MRI. Conclusion The addition of SRR to 2D MRI does not increase fetal airway patency diagnostic accuracy but does provide improved anatomic information, which may benefit surgical planning of EXIT procedures.

Clinical Assessment of Fetal Well‐Being and Fetal Safety Indicators

“…Fetal movements can cause artifacts in MRI, but various approaches can be used to reduce their negative effect on images, such as the adjustment of acquisition parameters. Super‐resolution reconstruction (SRR) is another tool that combines images captured in the 3 orthogonal planes to generate 1 volume for analysis of the fetal brain and neck masses 48,49 . Similar application of motion‐corrected slice‐to‐volume registration software has been shown to improve the diagnosis of fetal cardiac lesions when compared with 2D MRI 50 .…”

“…Super-resolution reconstruction (SRR) is another tool that combines images captured in the 3 orthogonal planes to generate 1 volume for analysis of the fetal brain and neck masses. 48,49 Similar application of motion-corrected slice-to-volume registration software has been shown to improve the diagnosis of fetal cardiac lesions when compared with 2D MRI. 50 MRI volumetry can provide precise estimates of total lung volume, which may have a potential role in predicting the outcome of congenital diaphragmatic hernia, congenital lung lesions, and potentially neonatal lung function.…”

Super-resolution reconstruction in ultrahigh-field MRI

“…While SRR is not a novel technique, it has recently gained a high degree of focus from the imaging community. There are a variety of methods in which to employ SRR, from neural networks to a variety of algorithms that utilize low-resolution (LR) inputs to reconstruct a high-resolution (HR) image ( 8 , 9 , 15 , 19 ). The predominant focus of this study was to utilize the basic idea that low-spatial-resolution images acquired at an offset contribute new, unknown information to the previous data set acquired that can be estimated and used to generate higher-spatial-resolution data sets and assess the accuracy of the HR estimate against directly acquired counterparts for scans acquired with rapid imaging with refocused echo pulse sequences (rapid acquisition with refocused echo [RARE]).…”

Assessment of longitudinal brain development using super‐resolution magnetic resonance imaging following fetal surgery for open spina bifida

“…Despite technical developments in MRI, in terms of rapid‐pulse sequences and advances in coil design, it is still limited by fetal motion artifacts 15 . In this study we used novel post‐processing techniques, including super‐resolution reconstruction (SRR), which can reduce fetal motion effects 2 , 8 , 10 , 14 , 26 , 27 , 28 , 29 , 30 . We hypothesized that this may improve quantitative cerebral assessment to aid our understanding of the impact of fetal OSB closure on brain development, which could be useful in ascertaining its outcome.…”