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Obtaining high quality images of the spinal cord with MRI is difficult, partly due to the fact that the spinal cord is surrounded by a number of structures that have differing magnetic susceptibility. This causes inhomogeneities in the magnetic field, which in turn lead to image artifacts. In order to address this issue, linear compensation gradients can be employed. The latter can be generated using an MRI scanner's first order gradient coils and adjusted on a per-slice basis, in order to correct for through-plane (“z”) magnetic field gradients. This approach is referred to as z-shimming. The aim of this study is two-fold. The first aim was to replicate aspects of a previous study wherein z-shimming was found to improve image quality in T2*-weighted echo-planar imaging. Our second aim was to improve upon the z-shimming approach by including in-plane compensation gradients and adjusting the compensation gradients during the image acquisition process so that they take into account respiration-induced magnetic field variations. We refer to this novel approach as realtime dynamic shimming. Measurements performed in a group of 12 healthy volunteers at 3 T show improved signal homogeneity along the spinal cord when using z-shimming. Signal homogeneity may be further improved by including realtime compensation for respiration-induced field gradients and by also doing this for gradients along the in-plane axes.

Major fluctuations in carbon-isotope composition (−2.8 to +5.4‰), as well as in oxygen-isotope composition (−10.2 to −2.1‰), are documented for Hauterivian–Albian shallow-water platform carbonate deposits in Pădurea Craiului (Apuseni Mountains, Romania). A composite carbon- and oxygen-isotope curve reveals the OAE1a and OAE1b as the main oceanic anoxic events (OAEs). Black shales or organic-rich levels, generally associated with such events, are poorly developed in Pădurea Craiului, testifying to slightly different responses to the carbon cycle perturbation between shallow- and deep-water environments. Palaeotemperatures of about 16–35 °C can be envisaged for the Late Hauterivian and Barremian in Pădurea Craiului, similar to those inferred from belemnite stable-isotope data from the Bersek Quarry (Gerecse Mountains, Hungary). For the Early Aptian interval, the δ13C variation pattern in Pădurea Craiului is similar to that documented in the Rochovica section from the Slovak Western Carpathians, developed in a deeper-water environment, although the interval of variation in Pădurea Craiului corresponds better to other shallow-water environment sections in the western Tethys.