Purpose To evaluate the safety and efficacy of microwave ablation (MWA) in patients with end-stage renal disease and secondary hyperparathyroidism. Materials and Methods The study protocol was approved by the human ethics review committee. Between March 1, 2014, and June 30, 2015, 51 patients (25 men, 26 women; mean age ± standard deviation, 53.1 years ± 12.9) were enrolled. All patients had at least one enlarged parathyroid gland and secondary symptomatic hyperparathyroidism, which was treated with ultrasonographically (US) guided MWA. The levels of intact parathyroid hormone, serum calcium, phosphorus, and alkaline phosphatase were compared before and after MWA. Paired-sample t tests and paired-sample Wilcoxon signed-rank tests were used to compare treatment outcomes before and after MWA. Results Complete ablation was achieved in all 96 glands in 51 of 120 patients with severe secondary hyperparathyroidism. The mean follow-up time was 11.1 months ± 3.3. The maximum diameter of the glands ranged from 0.5 cm to 4.8 cm (mean, 1.5 cm ± 0.6). The ablation time for each gland was 216.1 seconds ± 130.1. The mean serum intact parathyroid hormone, calcium, and phosphorus levels after MWA (400 pg/mL [400 ng/L; range, 151.3-629.0 ng/L], 2.33 mmol/L ± 0.23, and 1.54 mmol/L ± 0.43, respectively) were significantly lower than those before MWA (1203 pg/mL [1203 ng/L; range, 854.7-1694.5 ng/L], 2.53 mmol/L ± 0.24, and 1.97 mmol/L ± 0.50, respectively; P < .01), while the alkaline phosphatase levels did not change with MWA (P > .05). Ipsilateral recurrent laryngeal nerve injury was seen in one patient (2%). A hematoma developed during one procedure in one patient (2%) and was treated successfully with injection of thrombin. Conclusion US-guided MWA is safe and effective for destroying parathyroid gland tissue in patients with end-stage renal disease and severe secondary hyperparathyroidism. Further experience with the technique is clearly necessary. RSNA, 2016.

The aim of this prospective study was to evaluate the value of the combination of lymphatic contrastenhanced ultrasound (LCEUS) and intravenous contrast-enhanced ultrasound (IVCEUS) for the identification of cervical lymph node metastasis (CLNM) from papillary thyroid carcinoma (PTC). From November 2018 to March 2019, 24 consecutive patients with PTC were evaluated. All patients underwent routine US, LCEUS and IVCEUS. Pathology was used as the gold standard. After injection of a contrast agent into the thyroid parenchyma, lymphatic vessels and lymph nodes (LNs) could be exclusively displayed as hyper-enhancement on LCEUS. Benign LNs displayed a complete bright ring (100%) and homogeneous perfusion (88.9%) on LCEUS, while displaying centrifugal perfusion (66.7%) and homogenous enhancement (88.9%) on IVCEUS. Perfusion defects (94.9%) and interruption of the bright ring (71.8%) were the two characteristic LCEUS signs for diagnosing CLNM. On IVCEUS, CLNM appeared as centripetal perfusion (59.0%) and heterogeneous enhancement (59.0%). After comparison with pathology, perfusion defect was correlated to the metastatic foci in the medulla and interruption of the bright ring to the tumor seeding in the marginal sinus (all p values <0.05). LCEUS had more value (area under the receiver operating characteristic curve [AUC] = 0.850, 95% confidence interval [CI]: 0.682À1.000) in diagnosing CLNM than IVCEUS (AUC = 0.692, 95% CI: 0.494À0.890) and routine US (AUC = 0.581, 95% CI: 0.367À0.796). The combination of LCEUS and IVCEUS has the highest diagnostic value (AUC = 0.863, 95% CI: 0.696À1.000). LCEUS had higher diagnostic value than IVCEUS and US for CLNM from PTC. The combination of LCEUS and IVCEUS has the highest diagnostic value for CLNM.

Plasma shaping effects on temperature gradient driven instabilities and geodesic acoustic oscillations are investigated with gyrokinetic theory and a local magnetohydrodynamic equilibrium model. In particular, we focus on the effect of the elongation κ, including its radial derivative s κ = (r/κ)(∂κ/∂r), in the large aspect ratio limit. An analytical formula of the dependence of the geodesic acoustic mode (GAM) frequency on the elongation is given. It is found that the GAM frequency sharply decreases with increasing elongation by the dependence of [(2 − αs κ)/(κ2 + 1)]1/2 with α = 0.5–1, which comes from the modification of ion classical polarization balanced by that of curvature drift polarization. The dependence of the critical threshold of the ETG/ITG instability on the elongation is numerically studied and a semi-analytical formula is given as (R 0/L Tc)/(R 0/L Tc) s κ=0,κ=1 = (1 + 0.36s κ)[1 + 0.11(κ − 1)], where R 0 is the major radius and L Tc is the critical scale length of the temperature gradient.

MWA may be safe and effective to manage recurrent and persistent SHPT nodules; a definite conclusion needs to expand the sample size with a longer follow-up time.

With Empirical Orthogonal Function (EOF) and trend analysis method adopted, the spatio-temporal variation of total cloud amount is analyzed for 75 stations on the Qinghai-Tibet Plateau during the period 1971-2004. Analysis indicates that the total cloud amount decreases from the southeast to the northwest of the plateau, and that the annual and seasonal variations in total cloud amount both show an apparent declining tendency over the past decades. Correlation analysis demonstrates that the total cloud amount is negative with sunshine duration and diurnal temperature range (DTR), and is positive with precipitation and the relative humidity, respectively. The negative correlation is consistent with the radiative effect of cloud, while the positive correlation between total cloud amount and precipitation is obscured because of the influence of topographic factors. Discussion implies that the decrease of total cloud amount is possibly due to the variation of atmospheric aerosol content and ozone concentration over the plateau, although it is difficult to quantify the driving force mechanism up to now.