Time-resolved magnetic resonance imaging of contrast kinetics to identify severe tricuspid valve regurgitation.

INTRODUCTION: The gold standard for identifying and grading tricuspid valve regurgitation is transthoracic echocardiography. However, the acoustic window using transthoracic echocardiography is not always sufficient to quantify the amount of regurgitation. Time-resolved imaging of contrast kinetics (TRICKS) is a 4-dimensional magnetic resonance angiography option with high spatial and temporal resolution. The aim of the present study is to find out whether identification of patients with severe tricuspid valve regurgitation by using TRICKS angiography is feasible. METHODS: TRICKS angiography was performed in a 3T-CMR-scanner after antecubital injection of gadolinium dimeglumine during breath hold. Retrograde appearance of contrast agent in the hepatic veins was classified as severe tricuspid regurgitation (TR). Additional semi quantification of retrograde perfusion was performed by temporal signal intensity curve (SIC) analysis in the hepatic veins close to their drainage into the inferior vena cava. Transthoracic echocardiography (TTE) using the actual European guidelines on the management of valvular heart disease served as gold standard forTR grading. RESULTS: 185 patients (57 +/- 17 years) with TR ranging from no to severe TR were analysed prospectively. 14 (7.6%) patients had severe TR, 27 (14.6%) showed moderate, 137 (74.1%) mild and 7 (3.8%) no TR. TRICKSangiography identified 13 patients with retrograde contrast appearance in the hepatic veins, of whom all had severe TR in TTE. No patient with echocardiographic mild or moderate TR was graded as severe TR using TRICKSangiography. One patient with echocardiographic severe TR showed neither in the visual analysis nor in SIC analysis retrograde appearance of contrast agent in the hepatic veins. Overall, the sensitivity for detecting severe TR using TRICKSangiography was 93% with a specificity of 100%. The positive predictive value was 100%, the negative predictive value 99%. For severe TR there was no intra- and interobserver variability. CONCLUSION: MRTRICKSangiography is a very reliable tool to identify patients with severeTR by the imaging of retrograde appearance of contrast agent in the hepatic veins. Sensitivity and specificity of this approach is very high with no intra- and interobserver variability.

Vanadium-Oxide-Based Thin Films with Ultra-High Thermo-Optic Coefficients at 1550 nm and 2000 nm Wavelengths.

In this paper, the temperature-dependent dielectric properties of vanadium-sesquioxide-based thin films are studied to assess their suitability for thermally tunable filters at optical communication wavelengths. Spectroscopic ellipsometry is utilized to measure the optical constants of vanadium oxide thin films at temperatures ranging from 25 °C to 65 °C. High thermo-optic coefficients (dn/dTs) were observed. The highest dn/dTs, measured at approximately 40 °C, were -8.4 × 10-3/°C and -1.05 × 10-2/°C at 1550 nm and 2000 nm, respectively.

Uterine natural killer cells dysregulation in idiopathic human preterm birth: a pilot study.

OBJECTIVE: To compare between uterine natural killer (uNK) cells in the placental samples of preterm birth and term labor. STUDY DESIGN: Two-arm case-control study. This study included 60 participants divided into two groups. The first group included 30 cases of idiopathic spontaneous preterm labor and the other group included 30 women who delivered by a spontaneous term vaginal delivery and with no history of previous preterm labor. RESULT(S): There were no CD16- CD56bright uNK cells in either groups; CD16+ CD56dim uNK cells were present in only 1 case out of 30 term delivery placentae (3.3%), whereas they were found in 21 cases out of 30 (70%) preterm placental samples with a significant statistical difference (p < 0.0001) and OR 67.667, 95% CI (7.95-575.69). CD16+CD56dim uNK cells were found to be invading both the villi and the decidua in 11 cases (70%), whereas those cells were found invading only the villi in 10 cases (33.3%). CONCLUSION: CD16+CD56dim cells are expressed in both the decidua and the villi of patients with idiopathic preterm labor suggesting an association between uNK cells dysregulation and idiopathic human preterm labor.