The customized neonatal MRI system provides state-of-the-art MRI capabilities in the NICU.

In the bone marrow (BM), hematopoietic progenitors (HP) reside in specific anatomical niches near osteoblasts (Ob), macrophages (MΦ) and other cells forming the BM microenvironment. A connection between immunosurveillance and traffic of HP has been demonstrated but the regulatory signals that instruct immune regulation on HP circulation are unknown. We discovered that the BM microenvironment deficiency of p62, an autophagy regulator and signal organizer, results in loss of autophagic repression of macrophage contact-dependent activation of Ob NF-κB signaling. Consequently, Ob p62-deficient mice lose bone, Ob Ccl4 expression and HP chemotaxis towards Cxcl12 resulting in egress of short-term hematopoietic stem cells and myeloid progenitors. Finally, Ccl4 expression and myeloid progenitor egress are reversed by the deficiency of the p62 PB1 binding partner Nbr1. A functional ‘MΦ-Ob niche’ is required for myeloid progenitor/short-term stem cell retention, in which Ob p62 is required to maintain NF-κB signaling repression, osteogenesis and BM progenitor retention.

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Background To eliminate the medical risks and logistical challenges of transporting infants from the neonatal intensive care unit (NICU) to the radiology department for magnetic resonance imaging, a small-footprint 1.5-T MRI scanner has been developed for neonatal imaging within the NICU. MRI is known to be noisy, and exposure to excessive acoustic noise has the potential to elicit physiological distress and impact development in the term and preterm infant. Objective To measure and compare the acoustic noise properties of the NICU MRI system against those of a conventional 1.5-T MRI system. Materials and methods We performed sound pressure level measurements in the NICU MRI scanner and in a conventional adult-size whole-body 1.5-T MRI system. Sound pressure level measurements were made for six standard clinical MR imaging protocols. Results The average sound pressure level value, reported in unweighted (dB) and A-weighted (dBA) decibels for all six imaging pulse sequences, was 73.8 dB and 88 dBA for the NICU scanner, and 87 dB and 98.4 dBA for the conventional MRI scanner. The sound pressure level values measured on the NICU scanner for each of the six MR imaging pulse sequences were consistently and significantly (P=0.03) lower, with an average difference of 14.2 dB (range 10–21 dB) and 11 dBA (range 5–18 dBA). The sound pressure level frequency response of the two MR systems showed a similar harmonic structure above 200 Hz for all imaging sequences. The amplitude, however, was appreciably lower for the NICU scanner, by as much as 30 dB, for frequencies below 200 Hz. Conclusion The NICU MRI system is quieter than conventional MRI scanners, improving safety for the neonate and facilitating siting of the unit within the NICU.

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