Radionuclide analyses, and sedimentation and accumulation rates of sediment core PS2319-1

There is increasing evidence indicating that syndepositional redistribution of sediment on the seafloor by bottom currents is common and can significantly affect sediment mass accumulation rates. Notwithstanding its common incidence, this process (generally referred to as sediment focusing) is often difficult to recognize. If redistribution is near synchronous to deposition, the stratigraphy of the sediment is not disturbed and sediment focusing can easily be overlooked. Ignoring it, however, can lead to serious misinterpretations of sedimentary fluxes, particularly when past changes in export flux from the overlying water are inferred. In many instances, this problem can be resolved, at least for sediments deposited during the late Quaternary, by normalizing to the flux of 230Th scavenged from seawater, which is nearly constant and equivalent to the known rate of production of 230Th from the decay of dissolved 234U. We review the principle, advantages and limitations of this method. Notwithstanding its limitations, it is clear that 230Th normalization does provide a means of achieving more accurate interpretations of sedimentary fluxes and eliminates the risk of serious misinterpretations of sediment mass accumulation rates.

Radionuclide measurements in sediments and water of the Kara Sea

In this report, the results of a 2000-2001 radiogeoecological investigation are presented for the region of the Ob and Yenisei estuaries and the adjacent Kara Sea. In order to study the behaviour and migration of Cs, Sr and Pu radionuclides in a river - sea system experimental research on the distribution of these radionuclides in the water column and surface sediments has been carried out. In addition, the role of suspended and dissolved organic matter on the behaviour of radionuclides in water solutions has been studied. The 137Cs and 239,240Pu concentrations in the upper 0-2cm layer of the sediments varied between 1,4 and 50,0 Bq/kg, with a mean of 12,4 Bq/kg, and between 0,065-1,96 Bq/kg, with a mean of 0,62 Bq/kg, respectively. There is a direct relationship of a specific radioactivity of 137Cs and 239,240Pu in the sediments and the content of clay fraction. The 137Cs, 90Sr and 239,240Pu concentrations in the water samples varied between 0,4 and 7,0 Bq/m**3 (mean of 3,6 Bq/m**3), 0,4 and 9,7 Bq/m**3 (mean of 3,3 Bq/m**3), and 0,01-0,3 Bq/m**3 (mean of 0,02 Bq/m**3), respectively. In the water samples the concentration of the water-soluble species l37Cs increases with increasing salinity, whereas the concentration of the 90Sr-radionuclide decreases with increasing salinity. This may be related to the physico-chemical behaviour of these radionuclides in water solutions and the influence of several sources on radioactive pollution in this basin. In sea water the suspended matter may absorb up to 10% 137Cs, 90Sr and 239,240Pu, in river water samples these values may reach 15-30%. More than 50% 90Sr and 239,240Pu is able to form complexes with dissolved organic matter. This effect is smaller in saline water. The comparison of the data of 137Cs radioactivity in the surface sediments in 1995 and 2000-2001 showed that the level of radioactivity has decreased.

Sequential Morphological Changes in the CNV Net after Intravitreal Anti-VEGF Evaluated with OCT Angiography

PURPOSE: To assess and describe sequential morphological changes in the choroidal neovascularization (CNV) net using optical coherence tomography angiography (OCTA) in patients undergoing treatment with intravitreal antivascular endothelial growth factor (VEGF). METHODS: Prospective cohort study. OCTA was performed sequentially: before (t0), 1 h (t1), 1 week (t2) and 1 month after the injection (t3), using Avanti RTVue XR equipped with the AngioVue® software (Optovue, Calif., USA). All images were classified by two independent graders. RESULTS: Ten eyes of 10 patients, with a mean age of 72.4 ± 10.5 years, were included. CNV morphology was described as tree-like in 5 eyes, glomerular in 1 and fragmented in 4. A fibrovascular capsule surrounding the CNV net was found in 4 eyes and a feeder trunk was noticed in 6. No changes were observed at t1. Loss of peripheral capillaries, vessel fragmentation and decreased vessel density were evident in 8 eyes at t2. The CNV capillary density and the peripheral anastomosis increased in all of these at t3. Two eyes remained unchanged through the whole length of follow-up. CONCLUSIONS: Significant changes in the CNV net can be observable in OCTA at least 1 week after intravitreal anti-VEGF. The safety of frequent examinations may provide a method of gauging treatment effects.

Registration-by-regression of coronary CTA and X-ray angiography

We evaluate the integration of 3D preoperative computed tomography angiography of the coronary arteries with intraoperative 2D X-ray angiographies by a recently proposed novel registration-by-regression method. The method relates image features of 2D projection images to the transformation parameters of the 3D image. We compared different sets of features and studied the influence of preprocessing the training set. For the registration evaluation, a gold standard was developed from eight X-ray angiography sequences from six different patients. The alignment quality was measured using the 3D mean target registration error (mTRE). The registration-by-regression method achieved moderate accuracy (median mTRE of 15 mm) on real images. It does therefore not provide yet a complete solution to the 3D–2D registration problem but it could be used as an initialisation method to eliminate the need for manual initialisation.

Sequential Morphological Changes in the CNV Net after Intravitreal Anti-VEGF Evaluated with OCT Angiography

PURPOSE: To assess and describe sequential morphological changes in the choroidal neovascularization (CNV) net using optical coherence tomography angiography (OCTA) in patients undergoing treatment with intravitreal antivascular endothelial growth factor (VEGF). METHODS: Prospective cohort study. OCTA was performed sequentially: before (t0), 1 h (t1), 1 week (t2) and 1 month after the injection (t3), using Avanti RTVue XR equipped with the AngioVue® software (Optovue, Calif., USA). All images were classified by two independent graders. RESULTS: Ten eyes of 10 patients, with a mean age of 72.4 ± 10.5 years, were included. CNV morphology was described as tree-like in 5 eyes, glomerular in 1 and fragmented in 4. A fibrovascular capsule surrounding the CNV net was found in 4 eyes and a feeder trunk was noticed in 6. No changes were observed at t1. Loss of peripheral capillaries, vessel fragmentation and decreased vessel density were evident in 8 eyes at t2. The CNV capillary density and the peripheral anastomosis increased in all of these at t3. Two eyes remained unchanged through the whole length of follow-up. CONCLUSIONS: Significant changes in the CNV net can be observable in OCTA at least 1 week after intravitreal anti-VEGF. The safety of frequent examinations may provide a method of gauging treatment effects.

Impact of Routine Fractional Flow Reserve Evaluation During Coronary Angiography on Management Strategy and Clinical Outcome: One-Year Results of the POST-IT.

Penetration of fractional flow reserve (FFR) in clinical practice varies extensively, and the applicability of results from randomized trials is understudied. We describe the extent to which the information gained from routine FFR affects patient management strategy and clinical outcome. METHODS AND RESULTS: Nonselected patients undergoing coronary angiography, in which at least 1 lesion was interrogated by FFR, were prospectively enrolled in a multicenter registry. FFR-driven change in management strategy (medical therapy, revascularization, or additional stress imaging) was assessed per-lesion and per-patient, and the agreement between final and initial strategies was recorded. Cardiovascular death, myocardial infarction, or unplanned revascularization (MACE) at 1 year was recorded. A total of 1293 lesions were evaluated in 918 patients (mean FFR, 0.81±0.1). Management plan changed in 406 patients (44.2%) and 584 lesions (45.2%). One-year MACE was 6.9%; patients in whom all lesions were deferred had a lower MACE rate (5.3%) than those with at least 1 lesion revascularized (7.3%) or left untreated despite FFR≤0.80 (13.6%; log-rank P=0.014). At the lesion level, deferral of those with an FFR≤0.80 was associated with a 3.1-fold increase in the hazard of cardiovascular death/myocardial infarction/target lesion revascularization (P=0.012). Independent predictors of target lesion revascularization in the deferred lesions were proximal location of the lesion, B2/C type and FFR. CONCLUSIONS: Routine FFR assessment of coronary lesions safely changes management strategy in almost half of the cases. Also, it accurately identifies patients and lesions with a low likelihood of events, in which revascularization can be safely deferred, as opposed to those at high risk when ischemic lesions are left untreated, thus confirming results from randomized trials.

CO2-EVAR: An innovative approach to Automated Carbon Dioxide Angiography during Endovascular Abdominal Aortic Aneurysm repair

Objectives CO2-EVAR was proposed for treatment of AAA especially in patients with CKD. Issues regarding standardization, such as visualization of lowest renal artery (LoRA) and quality image in angiographies performed from pigtail or introducer-sheath, are still unsolved. Aim of the study was to analyze different steps of CO2-EVAR to create an operative protocol to standardize the procedure. Methods Patients undergoing CO2-EVAR were prospectively enrolled in 5 European centers (2018-2021). CO2-EVAR was performed using an automated injector. LoRA visualization and image quality (1-4) were analyzed and compared at different procedure steps: preoperative CO2-angiography from Pigtail/Introducer-sheath (1st Step), angiographies from Pigtail at 0%,50%,100% main body (MB) deployment (2nd Step), contralateral hypogastric artery (CHA) visualization with CO2 injection from femoral Introducer-sheath (3rd Step) and completion angiogram from Pigtail/Introducer-sheath (4th Step). Intra-/postoperative adverse events were evaluated. Results Sixty-five patients undergoing CO2-EVAR were enrolled, 55/65(84.5%) male, median age 75(11.5) years. Median ICM was 20(54)cc; 19/65(29.2%) procedures were performed with 0-iodine. 1st Step: median image quality was significantly higher with CO2 injected from femoral introducer [Pigtail2(3)vs.3(3)Introducer,p=.008]. 2nd Step: LoRA was more frequently detected at 50% (93%vs.73.2%, p=.002) and 100% (94.1%vs.78.4%, p=.01) of MB deployment compared with first angiography from Pigtail; image quality was significantly higher at 50% [3(3)vs.2(3),p=<.001] and 100% [4(3) vs.2(3),p=.001] of MB deployment. CHA was detected in 93% cases (3rd Step). Mean image quality was significantly higher when final angiogram (4th Step) was performed from introducer (Pigtail2.6±1.1vs.3.1±0.9Introducer,p=<.001). Rates of intra-/postoperative adverse events (pain,vomit,diarrhea) were 7.7% and 12.5%. Conclusions Preimplant CO2-angiography should be performed from Introducer-sheath. MB steric bulk during its deployment should be used to improve image quality and LoRA visualization with CO2. CHA can be satisfactorily visualized with CO2. Completion CO2-angiogram should be performed from femoral Introducer-sheath. This operative protocol allows to perform CO2-EVAR with minimal ICM and low rate of mild complications.