T2 mapping of cartilage in the equine distal interphalangeal joint with corresponding histology using 0.27 T and 3.0 T magnetic resonance imaging.

BACKGROUND: Low-field magnetic resonance imaging (MRI) is widely available to equine veterinarians yet is insensitive at detecting cartilage damage in the distal interphalangeal joint (DIPJ). T2 mapping is a quantitative imaging technique that can detect cartilage damage before morphological change is apparent. OBJECTIVES: Validation of a T2 mapping sequence on a low-field MR system. Correlation of the mean T2 relaxation time in sections of cartilage with varying levels of pathology using low- and high-field MRI. STUDY DESIGN: Cross-sectional study. METHODS: Eight phantoms with known (nominal) T2 values underwent low-field (0.27 T) MRI and 38 ex vivo DIPJs were imaged. A further 9 ex vivo DIPJs were imaged on both the low- and high-field MR systems. Immediately after imaging, the DIPJs were disarticulated and samples collected for histology. Histological sections were graded using the Osteoarthritis Research Society International (OARSI) scoring system. Fiji ImageJ software with the MRIAnalysisPak plugin was used to calculate T2 maps and draw the regions of interest (ROIs). RESULTS: There was close agreement between the nominal and the measured T2 values in the phantom study. Spearman's rank correlation demonstrated significant positive correlation between low- and high-field T2 measurements, rho 0.644 (p < 0.001). The intrarater agreement for T2 measurements was excellent, intraclass correlation coefficient (ICC) = 0.99 (95% confidence interval [CI] = 0.99-1.00), the inter-rater agreement was excellent, ICC = 0.88 (95% CI = 0.82-0.92) and there was good intrarater agreement for OARSI scores (к = 0.76). MAIN LIMITATIONS: Only a small number of histological samples were analysed. Both articular cartilage surfaces were measured within the ROI. There were no OARSI grade 0 control samples. CONCLUSIONS: A T2 mapping sequence on a low-field 0.27 T MR system was validated. There was a positive correlation between low- and high-field T2 measurements. The findings suggest a higher mean T2 relaxation time in pathological cartilage tissue examined in this study compared to normal equine cartilage tissue.

Total Ankle Replacement in a Military Jet Pilot.

INTRODUCTION: A total ankle replacement in a jet pilot after an open, high-energy foot and ankle fracture and dislocation with talar extrusion in a plane crash was carefully evaluated before considering fitness to fly.CASE REPORT: A 33-yr-old male test pilot of the Italian Air Force was involved in a plane crash and reported an open high-energy fracture/dislocation of the right ankle, with the expulsion of the right talus due to the impact, and other fractures. A titanium replica was inserted inside the ankle. However, the patient suffered from intolerable pain and developed arthritic changes in the cartilage of the tibial plafond. For these reasons, a decision was made to perform a custom-made total ankle replacement.DISCUSSION: The 2-yr follow-up after the last operation and the evaluation of the pilot's fitness to fly are reported in this case study. The pilot was assessed fit to fly, including high performance military aircrafts.Verde P, Guardigli S, Morgagni F, Roberts S, Monopoli D, Scala A. Total ankle replacement in a military jet pilot. Aerosp Med Hum Perform. 2020; 91(7):597-603.

Elective Single Embryo Transfer: an update to UK Best Practice Guidelines.

A significant number of multiple pregnancies and births worldwide continue to occur following treatment with Assisted Reproductive Technologies (ARTs). Whilst efforts have been made to increase the proportion of elective single embryo transfer (eSET) cycles, the multiple pregnancy rate or MPR remains at a level that most consider unacceptable given the associated clinical risks to mothers and babies, and the additional costs associated with neonatal care of premature and low birth weight babies. Northern Europe, Australia and Japan have continued to lead the way in the adoption of eSET. Randomised controlled trials or RCTs, meta-analyses and economic analyses support the implementation of an eSET policy, particularly in light of recent advances in ARTs. This paper provides a review of current evidence and an update to the eSET guidelines first published by Cutting et al. (2008) intended to assist ART clinics in the implementation of an effective eSET policy.

Imaging of radiation damage using complementary field ion microscopy and atom probe tomography.

Radiation damage in tungsten and a tungsten-tantalum alloy, both of relevance to nuclear fusion research, has been characterized using a combination of field ion microscopy (FIM) imaging and atom probe tomography (APT). While APT provides 3D analytical imaging with sub-nanometer resolution, FIM is capable of imaging the arrangements of single atoms on a crystal lattice and has the potential to provide insights into radiation induced crystal damage, all the way down to its smallest manifestation--a single vacancy. This paper demonstrates the strength of combining these characterization techniques. In ion implanted tungsten, it was found that atomic scale lattice damage is best imaged using FIM. In certain cases, APT reveals an identifiable imprint in the data via the segregation of solute and impurities and trajectory aberrations. In a W-5at%Ta alloy, a combined APT-FIM study was able to determine the atomic distribution of tantalum inside the tungsten matrix. An indirect method was implemented to identify tantalum atoms inside the tungsten matrix in FIM images. By tracing irregularities in the evaporation sequence of atoms imaged with FIM, this method enables the benefit of FIM's atomic resolution in chemical distinction between the two species.

The influence of temperature and age on the T1 relaxation time of the equine distal limb.

The extent of fat suppression using short tau inversion recovery (STIR) imaging is variable between horses. Our aim was to determine if patient's age and/or hoof temperature have an influence on the T(1) relaxation time of bone marrow in the equine distal limb, thereby affecting the suppression of fat signal. Magnetic resonance imaging was conducted on standing horses and cadaver samples using a low-field magnet (0.27 T). The hoof temperature was measured at the lateral side of the coronary band. A modified inversion recovery fast spin-echo (IR-FSE) sequence was used to measure the signal intensity for a range of inversion times (TIs) at six different regions of interest (ROI): (1) distal aspect of the proximal phalanx, (2) proximal aspect of the middle phalanx, (3) distal aspect of the middle phalanx, (4) navicular bone, (5) proximal aspect of the distal phalanx, and (6) distal aspect of the distal phalanx. The T(1) of the bone marrow in the equine distal limb was calculated from the results and was found to increase by 3.13 ± 0.08 (SE) ms/°C. There was no significant effect of age (2-16 years) but the T(1) values measured from the limbs of young (< 1 year) animals were considerably longer (32.6 ± 1.7 (SE) ms). Similar effects of temperature and age were found for all measured ROIs but there were significant differences in the mean values of T(1) , ranging from +7.7 (distal aspect of the distal phalanx) to -13.2 ms (distal aspect of the proximal phalanx).

Severe visual loss and orbital infarction following periorbital aesthetic poly-(L)-lactic acid (PLLA) injection.

Visual loss following esthetic treatment of the face is a rare but devastating iatrogenic complication. The authors report a case of a 43-year-old man with blindness and ophthalmoplegia of the left eye following a treatment of the left periorbital region with the subcutaneous filler poly-(L)-lactic acid. The patient's symptoms began immediately following one of the tunneled injections. On presentation, the patient had clear signs of ocular and orbital ischemia. Angiography and further history suggested an embolic orbital infarction as the mechanism of injury. The increased usage of subcutaneous fillers for facial rejuvenation had introduced a small but proven risk of embolization of these viscous materials to the eye and orbit.

Anti-Müllerian hormone levels and antral follicle count in women enrolled in in vitro fertilization cycles: relationship to lifestyle factors, chronological age and reproductive history.

The aims of this prospective study were to investigate the relationship between anti-Müllerian hormone (AMH) and antral follicle count (AFC), and to determine whether these markers of ovarian reserve correlate with lifestyle factors, ethnicity, chronological age and reproductive history. Participants were 136 normo-ovulatory women undergoing infertility work-up within 3 months of their first ovarian stimulation cycle for in vitro fertilization. On day 3 of a spontaneous menstrual cycle, a blood sample for measurement of plasma AMH levels was taken and a transvaginal ultrasound scan to determine the AFC (follicles measuring 2-5 mm in diameter) was performed. Information about smoking, body mass index, alcohol consumption, ethnic origin, chronological age, age at menarche, years since menarche and gravidity were recorded using a case report form. The main outcome measures were plasma AMH concentrations and total number of small antral follicles (AFC). Median plasma levels of AMH were 2.0 ng/ml (interquartile range 1.1-3.6) and AFC was 10 (interquartile range 7-15). A positive correlation between AMH and AFC (r = 0.54, p < 0.0001) was found. AMH and AFC correlated negatively with age (r = -0.30, p < 0.001 and r = -0.27, p = 0.001 respectively) and number of years since menarche (r = -0.23, p = 0.007 and r = -0.21, p = 0.015 respectively), but not with any of the other measures. Circulating AMH levels and AFC correlated with each other and declined significantly with age. There were only weak, non-significant, correlations with lifestyle factors and reproductive history. These putative markers could be used individually or together to assess the age-related decline of ovarian function in normo-ovulatory candidates for IVF.

Ultrasonographic guidance in pediatric regional anesthesia. Part 2: techniques.

The benefits of regional anesthesia are well documented. The downsides of such techniques have been a significant failure rate and a potential for serious complications. Nearly, all regional blocks were first described as essentially 'blind' techniques. The development of high-resolution portable ultrasound (US) has made the use of US for regional anesthesia possible. Improved understanding of sonographic anatomy should lessen both the failure rate and the possibility of incurring serious complications. Natural caution has dictated that only a selection of blocks used in adults has been commonly used in pediatric practice, but with the aid of US, the repertoire of blocks for infants and children may be widened. The second part of this review will concentrate on the practice of both peripheral and central blocks.