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- Incidence and fate of the abnormal septal motion after open heart surgeries. [Journal Article]
- J Cardiovasc Ultrasound 2014 Mar; 22(1):6-7.
- Exercise Echocardiography in Asymptomatic Patients with Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction. [REVIEW]
- J Cardiovasc Ultrasound 2014 Mar; 22(1):1-5.
The management of asymptomatic patients with severe aortic stenosis (AS) remains controversial. Recent series reported that early aortic valve replacement might be associated with improved clinical outcomes. However, the risk-benefit ratio should be carefully evaluated and early surgery only be proposed to a subset of asymptomatic patients considered at higher risk. Exercise echocardiography can help unmask symptomatic patients combined with assessment of the hemodynamic consequences of AS. Recent studies have demonstrated that exercise echocardiography can provide incremental prognostic value to identify patients who may benefit most from early surgery. In "truly" asymptomatic patients, an increase in mean aortic gradient ≥ 18-20 mmHg, a limited left ventricular contractile reserve or a pulmonary hypertension during exercise are predictive parameters of adverse cardiac events. Exercise echocardiography is low-cost, safe and available in many referral centers, and does not expose patients to radiation. The purpose of this article is to describe the role of exercise testing and echocardiography in the management of asymptomatic patients with severe AS and preserved left ventricular ejection fraction.
- Comparison of transvaginal ultrasonography and hysteroscopy in the diagnosis of uterine pathologies. [Journal Article]
- Int J Clin Exp Med 2014; 7(3):764-9.
A thorough evaluation of the uterine cavity is frequently required in gynecology practice. The aim of this study was to compare the diagnostic values of transvaginal ultrasound examination and hysteroscopy in detecting uterine abnormalities in a group of patients within a range of menopausal status and symptomatology. This study included 285 patients admitted with complaints of abnormal uterine bleeding, postmenopausal bleeding, lower abdominal pain, abnormal vaginal discharge or for a routine gynecological examination. All patients had available transvaginal ultrasonography and hysteroscopy data for evaluation. A biopsy was obtained from all patients during the hysteroscopy session. Sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratio were calculated for both methods and compared, considering the histopathological diagnosis as the gold standard. The mean age of the patients was 49.5±12.9 years (range, 24-89 y). Majority of the patients admitted for abnormal uterine bleeding (n=198, 69.4%). For the diagnosis of polyps of any size, hysteroscopy had better sensitivity (p<0.001), however, specificities did not differ (p=1.0). On the other hand, hysteroscopy did not have a sensitivity advantage over TVU in diagnosing polyps greater than 1 cm (p=0.077), although this time hysteroscopy had better specificity (p<0.001). Combined approach did not offer diagnostic advantage for any of the specific pathologies. Although TVU represents a practical approach for the initial evaluation of uterine pathologies, hysteroscopy seems to offer better diagnostic value for uterine pathologies in general, and uterine polyps in particular.
- Contrast-enhanced ultrasonography of skeletal muscles for type 2 diabetes mellitus patients with microvascular complications. [Journal Article]
- Int J Clin Exp Med 2014; 7(3):573-9.
To explore the applicability of contrast-enhanced ultrasound (CEUS) as a new method to detect impaired microcirculation in type 2 diabetes mellitus patients with microvascular complications (DM+MC).Ultrasound contrast agent was injected into peripheral vein of 28 patients with DM+MC, 30 uncomplicated type 2 diabetes mellitus (DM) patients, and 30 control subjects. Its appearance in the calf muscle was detected by contrast-enhanced ultrasound. Time-intensity curves were established based on mathematical modeling, particularly in small artery, muscular tissue and small vein. Times to peak intensity (TTPs), arrival times (ATs) and contrast transit times (CTTs) were analyzed. CTTs were calculated as the differences between arrival times. With patients under fasting conditions, plasma glucose and rheologic parameters of erythrocyte deformability and plasma viscosity were measured.DM and DM+MC groups tended to have longer TTPs than the control group, but without significant differences between DM group and DM+MC group. The median artery-vein and muscle-vein CTTs were statistically significantly highest in the DM+MC group (P < 0.05). Blood viscosity in the DM+MC group was higher than two other groups (P < 0.05). Blood viscosity correlated positively with both blood glucose and C-reactive peptide (P < 0.01).CEUS is potentially reliable to detect changes in the microvascular bed. Abnormalities in capillary recruitment may be related to abnormal hemorheology.
- Nonlinear contrast enhancement in photoacoustic molecular imaging with gold nanosphere encapsulated nanoemulsions. [JOURNAL ARTICLE]
- Appl Phys Lett 2014 Jan 20; 104(3):033701.
A composite contrast agent, a nanoemulsion bead with assembled gold nanospheres at the interface, is proposed to improve the specific contrast of photoacoustic molecular imaging. A phase transition in the bead's core is induced by absorption of a nanosecond laser pulse with a fairly low laser fluence (∼3.5 mJ/cm(2)), creating a transient microbubble through dramatically enhanced thermal expansion. This generates nonlinear photoacoustic signals with more than 10 times larger amplitude compared to that of a linear agent with the same optical absorption. By applying a differential scheme similar to ultrasound pulse inversion, more than 40 dB contrast enhancement is demonstrated with suppression of background signals.
- Effects of alternate day feeding of dried distiller's grain plus solubles to forage-fed beef cows in mid- to late- gestation. [JOURNAL ARTICLE]
- J Anim Sci 2014 Apr 21.
Forty-six non-lactating beef cows were used to examine effects dried distiller's grains plus solubles (DG) supplementation strategies to cows fed grass hay during mid- to late- gestation on BW, ultrasound body composition characteristics, concentrations of serum NEFA and urea, feeding behavior, and calf birth weight. Cows were assigned to dietary treatments in a completely randomized design: 1) control, where hay was fed each day of the week (CON); 2) both hay and DG fed daily during the week (DG7); 3) hay daily but DG fed 3 days of the week (DG3); and 4) hay fed 4 days of the week alternating with DG fed on the remaining 3 days (DGA). Hay was offered ad libitum on days it was fed. The DG was fed at 0.40% of BW when offered daily and 0.93% of BW when offered 3 days per week (Monday, Wednesday, and Friday). Feed intake was monitored continuously over the 84 d feeding period. Hay intake and total DMI were reduced (P < 0.05) in DGA compared with DG7 and DG3. Gain and G:F were decreased (P < 0.05) for CON compared with other treatments. No differences (P > 0.05) were observed among treatments for change in BCS, intramuscular fat, rib fat, or rump fat from d 1 to d 84. On a day when DG7, DG3, and DGA all received DG (Friday), DGA had reduced (P < 0.05) concentrations of urea compared with DG3 and DG7. On a day when only DG7 received DG (Saturday), urea was greater (P < 0.01) for DG3 and DGA compared with DG7, and concentrations of NEFA were greater (P < 0.01) in CON and DGA compared with DG7. On the second consecutive day when only DG7 received DG (Sunday), concentrations of NEFA were less (P < 0.001) for DG7 compared with other treatments. On days when all cows received hay, DGA spent more time eating (P < 0.05) compared with DG7 and DG3. Cows fed DGA had greater (P < 0.05) hay intake per meal and time per meal compared with other treatments. On days when DG7, DG3, and DGA all received DG, cows in the DG3 and DGA treatments had greater (P < 0.05) number of DG meals, time spent eating, intake per meal, and time per meal, but a slower (P < 0.05) rate of DG intake compared with DG7. No differences (P > 0.05) were observed in calf birth weights among treatments. The alternate day feeding strategy reduced hay and total intake, altered concentrations of serum urea and NEFA, and altered feeding behavior compared with other supplementation methods.
- Evaluation of Columbia, USMARC-Composite, Suffolk, and Texel rams as terminal sires in an extensive rangeland production system: VII. Accuracy of ultrasound predictors and their association with carcass weight, yield, and value. [JOURNAL ARTICLE]
- J Anim Sci 2014 Apr 21.
Use of lamb body or chilled carcass weights; live-animal ultrasound or direct carcass measurements of backfat thickness (BF; mm) and LM area (LMA; cm(2)); and carcass body wall thickness (BWall; mm) to predict carcass yield and value was evaluated using 512 crossbred lambs produced over 3 yr by mating Columbia, USMARC Composite, Suffolk, and Texel rams to adult Rambouillet ewes. Lambs were harvested at 3 BW endpoints within each year. The predictive value of 3 to 5 additional linear measurements of live-animal or carcass size and shape was also evaluated. Residual correlations (adjusted for effects of year, breed, and harvest group) between ultrasound and direct measurements were 0.69 for BF and 0.65 for LMA. Increasing ultrasound or carcass LMA had positive effects (P < 0.001) on yield of chilled carcass (i.e., on dressing percentage) and, at comparable chilled carcass weights (CCW), on weights of high-value cuts (rack, loin, leg, and sirloin) before (HVW) and after (TrHVW) trimming, and on carcass value before (CVal) and after (TrCVal) trimming of high-value cuts. By contrast, ultrasound and direct measures of BF had positive effects on yields of CCW and on HVW and CVal, but large negative effects on TrHVW and TrCVal. After adjusting for BW at scanning, increases of 1 mm in ultrasound BF or 1 cm(s) in ultrasound LMA were associated with changes of -$0.32 (P < 0.10) and $1.62 (P < 0.001), respectively, in TrCVal. Carcass BWall was generally superior to carcass BF as a predictor of TrHVW and TrCVal. Carcass LMA was superior to ultrasound LMA but carcass BF was inferior to ultrasound BF for prediction of carcass yield and value. Increasing LMA thus would be expected to improve carcass yield and value. Addition of linear measurements of live-animal or carcass size and shape to the prediction model reduced residual SD (RSD) for TrHVW and TrCVal by 0.4 to 2.2%, but subsequent removal of ultrasound or direct measures of BF and LMA from the prediction model increased RSD by 7.4 to 12.2%. Measurements of CCW, LMA, BF, and BWall would thus be appropriate to support programs for value-based marketing of lamb carcasses and are superior to systems based only on measurements of size and shape in unribbed carcasses.
- T1 ρ mapping for the evaluation of high intensity focused ultrasound tumor treatment. [JOURNAL ARTICLE]
- Magn Reson Med 2014 Apr 18.
This study was aimed to assess the effects of High Intensity Focused Ultrasound (HIFU) thermal ablation on tumor T1ρ .In vivo T1ρ measurements of murine tumors at various spin-lock amplitudes (B1 = 0-2000 Hz) were performed before (n = 13), directly after (n = 13) and 3 days (n = 7) after HIFU treatment. T2 maps were obtained from the measurements at B1 = 0 Hz.Average tumor T1ρ distributions at the different experimental time points showed a shift toward lower T1ρ values after HIFU for all spin-lock amplitudes, which became larger with increasing spin-lock amplitude at 3 days after treatment. Statistical analysis confirmed a significant effect of spin-lock amplitude on the average change in T1ρ (ΔT1ρ ) as compared to baseline at 3 days after HIFU. At 3 days after treatment, ΔT1ρ values at B1 above 100 Hz were significantly lower (more negative) than at B1 = 0 Hz (T2 ).Significant changes in tumor T1ρ were observed after HIFU treatment. These T1ρ changes were distinctly more pronounced than HIFU-induced changes in T2 . The results indicate that T1ρ imaging is sensitive to HIFU-induced tissue changes and may thus be a suitable MR method for the evaluation of HIFU treatment. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.
- Pilot study on high-intensity focused ultrasound ablation as a bridging therapy for hepatocellular carcinoma patients waitlisted for liver transplant. [JOURNAL ARTICLE]
- Liver Transpl 2014 Apr 18.
Objective: To investigate the outcomes of high-intensity focused ultrasound (HIFU) ablation as a bridging therapy for patients with hepatocellular carcinoma (HCC) waitlisted for deceased-donor liver transplantation. Patients and Methods: Adult patients with unresectable and unablatable HCCs within the UCSF criteria waitlisted for deceased-donor liver transplantation were screened for suitability for HIFU ablation as a bridging therapy if they were not suitable for transarterial chemoembolization (TACE). Comparison of treatment outcomes was made between patients receiving HIFU ablation, TACE and best medical treatment (BMT). Results: Fifty-one patients were included in the analysis. Before the introduction of HIFU ablation, only 39.2% of patients received bridging therapy (TACE only, n=20). With HIFU ablation in use, the rate increased dramatically to 80.4% (TACE+HIFU, n=20+21). The overall dropout rate was 51% (n=26). Patients in the BMT group had a significantly higher dropout rate (p=0.027) and significantly poorer liver function as reflected by higher Model of End-stage Liver Disease scores and Child-Pugh grading. Clinically relevant ascites was found in 5 patients in the HIFU group and 2 patients in the BMT group but none in the TACE group (p=0.010 and 0.029). The TACE and HIFU groups had comparable percentages of tumor necrosis in livers excised (p=0.353), both significantly higher than that in the BMT group (p=0.010 and 0.020). Conclusions: HIFU ablation was safe even for HCC patients with Child-Pugh C disease. Its adoption increased the percentage of patients receiving bridging therapy from 39.2% to 80.4%. A randomized controlled trial for further validation of its efficacy is warranted Liver Transpl , 2014. © 2014 AASLD.
- Using dynamic contrast-enhanced MRI to quantitatively characterize maternal vascular organization in the primate placenta. [JOURNAL ARTICLE]
- Magn Reson Med 2014 Apr 18.
The maternal microvasculature of the primate placenta is organized into 10-20 perfusion domains that are functionally optimized to facilitate nutrient exchange to support fetal growth. This study describes a dynamic contrast-enhanced magnetic resonance imaging method for identifying vascular domains and quantifying maternal blood flow in them.A rhesus macaque on the 133rd day of pregnancy (G133, term = 165 days) underwent Doppler ultrasound procedures, dynamic contrast-enhanced magnetic resonance imaging and Cesarean-section delivery. Serial T1 -weighted images acquired throughout intravenous injection of a contrast reagent bolus were analyzed to obtain contrast reagent arrival time maps of the placenta.Watershed segmentation of the arrival time map identified 16 perfusion domains. The number and location of these domains corresponded to anatomical cotyledonary units observed following delivery. Analysis of the contrast reagent wave front through each perfusion domain enabled determination of volumetric flow, which ranged from 9.03 to 44.9 mL/s (25.2 ± 10.3 mL/s). These estimates are supported by Doppler ultrasound results.The dynamic contrast-enhanced magnetic resonance imaging analysis described here provides quantitative estimates of the number of maternal perfusion domains in a primate placenta and estimates flow within each domain. Anticipated extensions of this technique are to the study placental function in non-human primate models of obstetric complications. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.