This study evaluated the ability of T2 mapping magnetic resonance imaging at 3 T, in addition to morphological sequences, to assess efficacy of platelet-rich plasma (PRP) injections, characterizing qualitatively and quantitatively the grade of knee cartilage repair in patients with patellofemoral chondropathy. We retrospectively studied 34 patients (22 men, 12 women, mean age 41.8 years, including 22 men) with patellofemoral knee chondropathy, who underwent intra-articular PRP injections and completed a clinical and instrumental follow-up. As control group, we evaluated 34 patients who underwent non-operative therapy. All patients were submitted to clinical (using VAS and WOMAC index) and imaging studies with 3 T magnetic resonance with cartilage analysis with T2 mapping sequences for cartilage analysis before and after treatment. In the study group, mean pre-treatment T2 relaxation time values were 44.2 ± 2.5 ms, considering all articular cartilage compartments, with significant reduction at the follow-up (p < 0.001). At the index compartment, mean pre-treatment T2 relaxation times values were 47.8 ± 3.6 ms, with statistically significant reduction at the follow-up (p < 0.001). Evaluation of focal cartilage lesions reported pre-treatment mean T2 value of 70.1 ± 13.0 ms and post-treatment mean value of 59.9 ± 4.6 ms (p < 0.001). From a clinical point of view, the pre-treatment WOMAC and VAS scores were 18.3 ± 4.5 and 7 (IQR:6–7.2), respectively; the post-treatment values were 7.3 ± 3.2 and 2 (IQR: 1.7–3.0), respectively (p < 0.001). In the control group, despite clinical improvement, we didn’t find significant T2 values change during the follow-up period. In conclusion, T2 mapping is a valuable indicator for chondropathy and treatment-related changes over time.

In recent years, ultra-low field (ULF)-MRI is being given more and more attention, due to the possibility of integrating ULF-MRI and Magnetoencephalography (MEG) in the same device. Despite the signal-to-noise ratio (SNR) reduction, there are several advantages to operating at ULF, including increased tissue contrast, reduced cost and weight of the scanners, the potential to image patients that are not compatible with clinical scanners, and the opportunity to integrate different imaging modalities. The majority of ULF-MRI systems are based, until now, on magnetic field pulsed techniques for increasing SNR, using SQUID based detectors with Larmor frequencies in the kHz range. Although promising results were recently obtained with such systems, it is an open question whether similar SNR and reduced acquisition time can be achieved with simpler devices. In this work a room-temperature, MEG-compatible very-low field (VLF)-MRI device working in the range of several hundred kHz without sample pre-polarization is presented. This preserves many advantages of ULF-MRI, but for equivalent imaging conditions and SNR we achieve reduced imaging time based on preliminary results using phantoms and ex-vivo rabbits heads.

No abstract

In recent years, Ultra Low Field (ULF) MagneticResonance Imaging (MRI) is being given more and more attention, thanks to the possibility of integrating ULF-MRI with MagnetoEncephaloGraphy (MEG) in the same set-up. A MEGcompatible Very Low Field (VLF) MRI device working in the hundreds of kHz, without sample prepolarization and with room temperature receiving channel, is presented. Considering the same imaging conditions and SNR value, the system has better performances in terms of scan time if compared with existing ULF devices while preserving many of the ULF-MRI advantages.

Static magnetic field effect in the framework of the radial pair mechanism (RPM) theory was studied on the biologically significant chemical reaction between ascorbic acid and Fremy's salt. The data indicate that the reaction rate depends on the applied magnetic field strength. The time scale of the studied reaction and the improved continuous-wave electron paramagnetic resonance system allowed for the first time the direct comparison of the amplitude differences between exposed and control samples in the strictly same boundary conditions. Until now the RPM was studied in a different time scale, focusing only on faster reactions by time-resolved techniques or by spectrophotometer measurement. The magnetic field effects presently measured can not be extended tout court to living systems; however the understanding of magnetic field sensitivity in basic chemical reaction in vitro could help clarifying the underlying basic step of interaction between magnetic fields and biological systems.