Magnetic resonance imaging-guided injection of platelet-rich plasma for treatment of an insertional core lesion of the deep digital flexor tendon within the foot of a horse

Definitive diagnosis of a deep digital flexor tendon insertional lesion within the right fore foot was made by magnetic resonance imaging (MRI) examination and the lesion subsequently treated by injection with platelet-rich plasma. MRI was used to guide positioning of the needle to achieve highly accurate injection. The volume injected was found to approximate the calculated lesion volume. On the basis of experience with this case, MRI-guided injection of insertional deep digital flexor tendon lesions of the foot of horses under general anaesthesia is practicable. This technique is likely to be more accurate than the other techniques described (computed tomography, ultrasonography) and carries no risk of exposure to radiation (radiography)

An inertial sensor-based system can objectively assess diagnostic anaesthesia of the equine foot

Reasons for performing study: In order for changes in lameness to be accurately and repeatably detected and recorded during diagnostic investigations, an objective measure of lameness is required.<p></p> Objectives: To ascertain whether an inertial sensor-based system can distinguish between a positive and negative response to diagnostic anaesthesia of the foot and objectively assess the effect of a positive response on the trot.<p></p> Study design: Restrospective clinical study.<p></p> Methods: Data obtained during lameness investigations undertaken between August 2011 and December 2012 in which either a palmar digital or abaxial sesamoid nerve block was performed were retrospectively reviewed. Response to diagnostic anaesthesia was categorised as positive (n = 14) or negative (n = 9) by one of 2 evaluators before analysis of kinematic data (i.e. blinded). Changes in maximum and minimum head difference (ΔHDMax and ΔHDMin) and change in head movement asymmetry/change in pelvic movement asymmetry (ΔHMA/PMA, measure of asymmetry) allocated to each limb were calculated. A Kruskal–Wallis one way analysis of variance on ranks was performed. Receiver operating characteristic (ROC) curves were generated for ΔHDMax, ΔHDMin and ΔHMA for the blocked limb to identify cut-off values to distinguish positive and negative responses to the block.<p></p> Results: Median ΔHDMax and ΔHDMin were significantly greater after a positive response to diagnostic anaesthesia (P<0.01). Change in head movement asymmetry allocated to the blocked limb and contralateral forelimb and ΔPMA allocated to the contralateral hindlimb were significantly greater in the positive response group (P<0.05). Change in head movement asymmetry allocated to the blocked limb and ΔHDMax and ΔHDMin are useful diagnostic tests for identifying positive response to anaesthesia (area under the curve = 0.98, 0.83 and 0.96 respectively).<p></p> Conclusions: An inertial sensor-based system can identify a positive response to diagnostic anaesthesia of the foot. Symmetry of movement allocated to the blocked limb, contralateral forelimb and contralateral hindlimb significantly improve, and head movement significantly decreases in horses with a positive response to the block. Cut-off values for a positive response have been identified with good sensitivity and specificity. Forelimb lameness significantly affects contralateral hindlimb movement, which has implications for the investigation of multi-limb lameness

High‐Resolution Infrared Synchrotron Investigation of (HCN) 2

International audienc

Protracted and polyphased gold mineralisation in the Agnew District (Yilgarn Craton, Western Australia)

The Archean orogenic gold deposits exhibits common characteristics including coeval emplacement age often proposed to be associated with a single late tectonic gold mineralisation event. Although valid for a large majority of deposits in the Yilgarn Craton, this model does not account for certain atypical gold deposits. In the world-class Agnew District (Yilgarn Craton, Western Australia) structural and paragenetic relationships, combined with a compilation of geochronology and multiple sulfur isotopes, indicate that mineralisation developed during a two-stage process involving different fluid sources. The initial event dated at c. 2660 Ma is related to the onset of folding during Kalgoorlie Orogeny and presents characteristics compatible with magmatic intrusion related mineralisation. A second mineralisation event dated at c. 2630 Ma presents a mineral and metal inventory typical to Archean orogenic-like gold mineralisation, and developed at a later stage of the orogenesis. Measurements of d 34 S and ? 33 S from spatially constrained samples from the two temporally distinct mineralising events further ascertain contrasting fluid compositions and/or reservoirs. Combined with geochronological data obtained on the poly-magmatic Lawlers granitic complex, we argue for a protracted ore forming process. The first stage of mineralisation has a magmatic affinity and is followed by a second stage of mineralisation whereby Au-bearing hydrothermal solution incorporated an Archean sedimentary sulfur reservoir. We propose that the change in source reservoir for sulfur in hydrothermal fluids may reflect a regional change in tectonic regime from convergent to transcurrent motion, allowing fluids to be first sourced from mantle-derived magmas followed later by metamorphic fluids