Quantitative Brain Morphometry of Portable Low-Field-Strength MRI Using Super-Resolution Machine Learning.

Background Portable, low-field-strength (0.064-T) MRI has the potential to transform neuroimaging but is limited by low spatial resolution and low signal-to-noise ratio. Purpose To implement a machine learning super-resolution algorithm that synthesizes higher spatial resolution images (1-mm isotropic) from lower resolution T1-weighted and T2-weighted portable brain MRI scans, making them amenable to automated quantitative morphometry. Materials and Methods An external high-field-strength MRI data set (1-mm isotropic scans from the Open Access Series of Imaging Studies data set) and segmentations for 39 regions of interest (ROIs) in the brain were used to train a super-resolution convolutional neural network (CNN). Secondary analysis of an internal test set of 24 paired low- and high-field-strength clinical MRI scans in participants with neurologic symptoms was performed. These were part of a prospective observational study (August 2020 to December 2021) at Massachusetts General Hospital (exclusion criteria: inability to lay flat, body habitus preventing low-field-strength MRI, presence of MRI contraindications). Three well-established automated segmentation tools were applied to three sets of scans: high-field-strength (1.5-3 T, reference standard), low-field-strength (0.064 T), and synthetic high-field-strength images generated from the low-field-strength data with the CNN. Statistical significance of correlations was assessed with Student t tests. Correlation coefficients were compared with Steiger Z tests. Results Eleven participants (mean age, 50 years ± 14; seven men) had full cerebrum coverage in the images without motion artifacts or large stroke lesion with distortion from mass effect. Direct segmentation of low-field-strength MRI yielded nonsignificant correlations with volumetric measurements from high field strength for most ROIs (P > .05). Correlations largely improved when segmenting the synthetic images: P values were less than .05 for all ROIs (eg, for the hippocampus [r = 0.85; P < .001], thalamus [r = 0.84; P = .001], and whole cerebrum [r = 0.92; P < .001]). Deviations from the model (z score maps) visually correlated with pathologic abnormalities. Conclusion This work demonstrated proof-of-principle augmentation of portable MRI with a machine learning super-resolution algorithm, which yielded highly correlated brain morphometric measurements to real higher resolution images. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Ertl-Wagner amd Wagner in this issue. An earlier incorrect version appeared online. This article was corrected on February 1, 2023.

Bioactive compounds, antioxidant activity, and mineral content of bróquil: A traditional crop of Brassica oleracea var. italica.

Brassicaceae edible plants are rich in bioactive compounds and promote health benefits. However, there is less interest in expanding knowledge about the Brassica cultivars to date. In particular, underutilized species and local cultivars could constitute a source of agrodiversity in adapting to the territory with likely higher contents of nutraceutical compounds. In this context, Bróquil (Brassica oleracea var. italica) is a traditional Brassicaceae crop grown in the Spanish region of Aragón. Currently, it is cultivated mainly in family orchards for autoconsumption and, in minority, in small farms for local markets. This study evaluates a collection of 13 bróquil landraces from the Spanish Vegetable Genebank of the Agrifood Research and Technology Center of Zaragoza (BGHZ-CITA), describing their mineral contents, bioactive compounds, and antioxidant activities, including a broccoli commercial variety "Parthenon" as the control. The study reports data on the health-promoting nutrients and antioxidants of bróquil for the first time. Under our experimental conditions, we found that bróquil has a great variability for these compounds that showed on average similar or higher levels than the broccoli control. The different bróquil landraces also revealed variability in both intraccessions and interaccessions due to the lack of a formal breeding selection. Despite this variability, we highlight accession HB5 that corresponds to Headed Bróquil BGHZ6685. In particular, we can stand out its antioxidant activity of 87.07 ± 0.81%I, total phenolic content of 13.21 ± 0.53 mg GAE g-1 dw, total flavonoid content of 14.50 ± 1.29 mg QE g-1 dw, total glucosinolate content of 43.70 ± 1.09 mg SnE g-1 dw, and vitamin C content of 7.21 ± 0.13 mg AA g-1 dw. Regarding bróquil mineral composition, K was the highest macroelement (22.66-33.62 mg g-1 dw), followed by Ca, P, and S whose values were relatively lower compared to K. Mg and Na showed the lowest values. Among the microelements evaluated (Mn, Zn, and Fe), iron was the most abundant detected, higher in all bróquil accessions than in broccoli, except for one accession. Therefore, the results reported for bróquil landraces show promising nutritional quality. This could lead to an increase in agrobiodiversity and contribute to a more diversified and healthy diet.

Single Plane Illumination Microscopy for Microfluidic Device Imaging.

Three-dimensional imaging of live processes at a cellular level is a challenging task. It requires high-speed acquisition capabilities, low phototoxicity, and low mechanical disturbances. Three-dimensional imaging in microfluidic devices poses additional challenges as a deep penetration of the light source is required, along with a stationary setting, so the flows are not perturbed. Different types of fluorescence microscopy techniques have been used to address these limitations; particularly, confocal microscopy and light sheet fluorescence microscopy (LSFM). This manuscript proposes a novel architecture of a type of LSFM, single-plane illumination microscopy (SPIM). This custom-made microscope includes two mirror galvanometers to scan the sample vertically and reduce shadowing artifacts while avoiding unnecessary movement. In addition, two electro-tunable lenses fine-tune the focus position and reduce the scattering caused by the microfluidic devices. The microscope has been fully set up and characterized, achieving a resolution of 1.50 µm in the x-y plane and 7.93 µm in the z-direction. The proposed architecture has risen to the challenges posed when imaging microfluidic devices and live processes, as it can successfully acquire 3D volumetric images together with time-lapse recordings, and it is thus a suitable microscopic technique for live tracking miniaturized tissue and disease models.