P914 Changes of echocardiographic parameters in primary mitral regurgitation and determinants of symptom: an assessment from the Asian valve registry data

[Background]Clinicians often have a difficulty in determining the presence of mitral regurgitation (MR)-relatedsymptoms because of subjectivity.However, there are few actual measurement data for echocardiographic left ventricular (LV) and left atrial (LA) size related to the severity of MR and the relationship between MR-related symptoms and these echocardiographic parameters.

[Purpose] The purpose of this study was to clarify actual values for echocardiographic parameters related to severity of MR and determinant factors of MR-related symptoms.

[Methods] Among patients enrolled in the Asian Valve Registry, we investigated 778 consecutive patients with primary MR showing sinus rhythm. Symptoms were determined by NYHA (≤ II or ≥ III).

[Results]MR severity was mild in 106, moderate in 285, and severe in 387 patients. LA volume index, LV end-diastolic diameter, and LV mass index increased with increasing MR grade [LA volume index: 47.9 (mild), 56.2 (moderate), and 64.9 ml/m2(severe) (p < 0.001), LV end-diastolic diameter: 51.2, 54.5, 58.1 mm (p < 0.001), and LV mass index: 101, 109, 123 g/m2(p < 0.001)]. Regarding moderate and severe MR, 70 patients (10.4%) were symptomatic. Table shows multivariable analysis for being symptomatic in moderate and severe MR patients. LV mass index (p = 0.040), ejection fraction (p < 0.001), female gender (p = 0.004), and heart rate (p = 0.007) were independent factors for MR-related symptoms.

[Conclusions] LV and LA parameters on echocardiography worsened as MR severity progressed. Larger LV mass index and lower ejection fraction were independent determinant factors for MR-related symptoms. We should also pay attention to LV hypertrophy in patients with primary MR.

Determinant factors for mitral regurgita Model 1 Model 2 OR (95% CI) P-value OR (95% CI) P-value Age, per 1-y increment 1.03 (1.00-1.05) 0.035 1.02 (0.99-1.05) 0.053 Sex (female) 2.23 (1.20-4.16) 0.011 2.28 (1.31-3.98) 0.004 Hear rate, per 1 bpm increment 1.03 (1.00-1.05) 0.025 1.03 (1.01-1.05) 0.007 LVDs index, per 1 mm increment 0.99 (0.90-1.09) 0.90 EF, per 1% increment 0.95 (0.92-0.99) 0.019 0.96 (0.93-0.98) <0.001 LV mass index, per 10 g/m2increment 1.12 (1.01-1.25) 0.033 1.09 (1.005-1.18) 0.040 LA volume index, per 10 mL/m2increment 0.96 (0.90-1.03) 0.23 E wave, per 1cm/s increment 1.81 (0.70-4.66) 0.23 TR pressure gradient >40 mmHg 2.11 (0.97-4.57) 0.057 Hypertention 1.40 (0.75-2.63) 0.29

P1368 Effect of angiotensin receptor blocker in patients with moderate or severe aortic stenosis: a randomized controlled trial

Funding Acknowledgements

This study was supported by grants from Boryung Pharmacy Research Fund.

Background/Introduction: Pathophysiology of aortic stenosis (AS) and several previous studies suggested the potential role of angiotensin receptor blocker (ARB) in patients with AS.

Purpose

We aimed to investigate the effects of Fimasartan, an ARB, on exercise capacity and progression of AS in patients with moderate to severe AS.

Methods

We conducted a prospective, randomized, double-blind, placebo-controlled trial in 32 normotensive or controlled-hypertensive patients with moderate or severe AS. Study participants were randomized to Fimasartan 30 mg to 60 mg daily (n = 14) or placebo (n = 18) for 1 year, and underwent cardiopulmonary exercise test, 6-minute walk test, and echocardiography at 0, 6, and 12 months, with follow-up data available in 29 subjects.

Results

Significant reductions in blood pressures were observed in the Fimasartan group but not in the placebo group. Two of the 14 patients in the Fimasartan group withdrew the study due to mild symptoms probably related with the decreased blood pressure, and one patient decline the study protocol. After the 12-month treatment, the peak oxygen consumption (VO2; the primary outcome) in the Fimasartan group was significantly decreased (from 28.3 ± 5.9 to 25.4 ± 3.8 mL/min/kg, P = 0.021) but not in the placebo group (P for interaction = 0.046) (Figure 1A). The severity of AS showed a gradual progression in both groups, without inter-group differences (mean transaortic pressure; Fimasartan group, +4.0 ± 3.8 mmHg/year; placebo group, +5.3 ± 6.2 mmHg/year; P for interaction = 0.429) (Figure 1B). Parameters of left ventricular systolic and diastolic function did not change in both groups.

Conclusions

The use of ARB impaired exercise capacity in patients with moderate or severe AS, and did not prevent the progression of AS. However, due to the small number of participants, further studies are required to confirm these findings.

Abstract P1368 Figure.

Identifying different types of microorganisms with terahertz spectroscopy

Most microbial detection techniques require pretreatment, such as fluorescent labeling and cultivation processes. Here, we propose novel tools for classifying and identifying microorganisms such as molds, yeasts, and bacteria based on their intrinsic dielectric constants in the THz frequency range. We first measured the dielectric constant of films that consisted of a wide range of microbial species, and extracted the values for the individual microbes using the effective medium theory. The dielectric constant of the molds was 1.24-1.85, which was lower than that of bacteria ranging from 2.75-4.11. The yeasts exhibited particularly high dielectric constants reaching 5.63-5.97, which were even higher than that of water. These values were consistent with the results of low-density measurements in an aqueous environment using microfluidic metamaterials. In particular, a blue shift in the metamaterial resonance occurred for molds and bacteria, whereas the molds have higher contrast relative to bacteria in the aqueous environment. By contrast, the deposition of the yeasts induced a red shift because their dielectric constant was higher than that of water. Finally, we measured the dielectric constants of peptidoglycan and polysaccharides such as chitin, α-glucan, and β-glucans (with short and long branches), and confirmed that cell wall composition was the main cause of the observed differences in dielectric constants for different types of microorganisms.

Tunable broadband terahertz polarizer using graphene-metal hybrid metasurface

We demonstrate an electrically tunable polarizer for terahertz (THz) frequency electromagnetic waves formed from a hybrid graphene-metal metasurface. Broadband (>3 THz) polarization-dependent modulation of THz transmission is demonstrated as a function of the graphene conductivity for various wire grid geometries, each tuned by gating using an overlaid ion gel. We show a strong enhancement of modulation (up to ∼17 times) compared to graphene wire grids in the frequency range of 0.2-2.5 THz upon introduction of the metallic elements. Theoretical calculations, considering both plasmonic coupling and Drude absorption, are in good agreement with our experimental findings.

P5279Pericardial inflammation basced on cardiac magnetic resonance imaging in patients with tuberculous pericarditis

Background

While constrictive pericarditis has been traditionally considered a disabling disease, reversible constrictive pericarditis has been described in previous studies. But there are limited studies on cardiac imaging of tuberculous pericarditis. In particular, no studies on cardiac magnetic resonance imaging (CMR) have been reported. We aimed to investigate CMR findings including pericardial late gadolinium enhancement (LGE) and T2 fat suppression and black blood sequences in patients with tuberculous pericarditis.

Methods

We retrospectively analyzed medical records of patients with tuberculous pericarditis between January 2010 and January 2017 in Samsung Medical Center. Definite diagnosis of tuberculous pericarditis is based on the identification of Mycobacterium tuberculosis in pericardial fluid or tissue; probable diagnosis was made when there was other evidence of tuberculosis elsewhere in patients with unexplained pericarditis. We performed CMR at initial diagnosis. Treatment consists of the standard 4-drug antituberculosis regimen for 6 months with or without steroids. Echocardiography was also conducted at initial diagnosis and 6 months later.

Results

Total 39 cases with tuberculous pericarditis in immunocompetent patients were enrolled. Ten patients were diagnosed as definite tuberculous pericarditis. CMR finding at initial diagnosis divided into five groups: 1) pericardial effusion only (n=20, 51.3%), 2) effusive constrictive pericarditis (n=5, 12.8%), 3) constrictive pericarditis (n=11, 28.2%), 4) pericardial abscess formation (n=4, 10.3%) and 5) absence of pericardial effusion and constrictive physiology (n=1, 2.6%). One of the 4 patients with pericardial abscess formation was together with pericardial effusion and the other was accompanied by effusive constrictive pericarditis. Pericardial thickness increased to more than 4mm in 25 patients (64.1%) and the mean pericardial thickness was 10.0±6.9mm. Delayed enhancement of pericardium was noticed in 29 patients (74.4%). In T2 fat suppression and black blood sequences, 30 patients showed increased T2 signal intensity indicating inflammation with extensive edema. Pericardial thickening (>4mm) with constriction (n=15) was not statistically significant in the delayed enhancement and increased T2 signal intensity compared with pericardial thickening without constrictive pericarditis (n=10) (delayed enhancement 93.8% vs. 77.8% p=0.287; increased T2 signal intensity 88.9% vs. 87.5%, p=0.713). After 6 months, only 3 patients still had constrictive pericarditis in echocardiography.

Effusive constrictive pericarditis

Conclusions

Pericardial thickening is associated with delayed enhancement and increased T2 signal intensity in patients with tuberculous pericarditis regardless of constrictive pericarditis. Even though there were hemodynamic feature of constrictive pericarditis and pericardial inflammation with extensive edema in CMR at initial diagnosis, 80% of the patients were improved from constrictive pericarditis.

Acknowledgement/Funding

None

Time series analysis of delta neutrophil index as the predictor of sepsis in patients with acute poisoning

Delta neutrophil index (DNI), which reflects the fraction of immature granulocytes, is used to detect infection and sepsis from noninfectious conditions, but few studies have evaluated in the early stage of acute poisoning. This retrospective observational study was performed on acute poisoning patients who visited to the emergency department (ED) and were consecutively admitted in intensive care units over 18-month period. The serial DNI, conventional inflammatory biomarkers, and culture results were obtained in the ED and after admission. The outcomes were the identification of sepsis, bacteremia, and 30-day mortality. Of 166 patients (mean age, 56.0 years) in this cohort, 59 (35.5%) had sepsis and 29 (17.5%) had bacteremia. Initial and peak DNI fractions 24 h after ED admission were strong independent predictors of sepsis development. Analysis of the area under the curve according to multiple receiver operating characteristics showed that DNI had a higher capability to predict sepsis than other parameters (0.815 for DNI, 0.700 for procalcitonin, 0.681 for C-reactive protein, and 0.741 for white blood cell). Using multivariable logistic regression analysis, it was found that DNI was an independent predictor of sepsis (95% confidence interval (CI) of odds: 1.03-1.18) and bacteremia (95% CI: 1.01-1.14). Therefore, initial and serial measurement of DNI may serve as useful risk predictor for development of sepsis or bacteremia in acute poisoning.

Increasing the sensitivity of terahertz split ring resonator metamaterials for dielectric sensing by localized substrate etching

We demonstrate a significant enhancement in the sensitivity of split ring resonator terahertz metamaterial dielectric sensors by the introduction of etched trenches into their inductive-capacitive gap area, both through finite element simulations and in experiments performed using terahertz time-domain spectroscopy. The enhanced sensitivity is demonstrated by observation of an increased frequency shift in response to overlaid dielectric material of thicknesses up to 18 µm deposited on to the sensor surface. We show that sensitivity to the dielectric is enhanced by a factor of up to ∼2.7 times by the incorporation of locally etched trenches with a depth of ∼3.4 µm, for example, and discuss the effect of the etching on the electrical properties of the sensors. Our experimental findings are in good agreement with simulations of the sensors obtained using finite element methods.

Association of blood n-3 fatty acid with bone mass and bone marrow TRAP-5b in the elderly with and without hip fracture

The plasma n-3 fatty acid level was 26.2% lower in patients with osteoporotic hip fracture than in those with osteoarthritis. In all patients, n-3 fatty acid was positively associated with bone mineral density and inversely associated with tartrate-resistant acid phosphatase-5b level in bone marrow aspirates, reflecting the bone microenvironment.

INTRODUCTION

Despite the potential beneficial role of n-3 fatty acid (FA) on bone metabolism, the specific mechanisms underlying these effects in humans remain unclear. Here, we assessed whether the plasma n-3 level, as an objective indicator of its status, is associated with osteoporosis-related phenotypes and bone-related markers in human bone marrow (BM) samples.

METHODS

This was a case-control and cross-sectional study conducted in a clinical unit. n-3 FA in the blood and bone biochemical markers in the BM aspirates were measured by gas chromatography/mass spectrometry and immunoassay, respectively. BM fluids were collected from 72 patients who underwent hip surgery because of either osteoporotic hip fracture (HF; n = 28) or osteoarthritis (n = 44).

RESULTS

After adjusting for confounders, patients with HF had 26.2% lower plasma n-3 levels than those with osteoarthritis (P = 0.006), and each standard deviation increment in plasma n-3 was associated with a multivariate-adjusted odds ratio of 0.40 for osteoporotic HF (P = 0.010). In multivariate analyses including all patients, a higher plasma n-3 level was associated with higher bone mass at the lumbar spine (β = 0.615, P = 0.002) and total femur (β = 0.244, P = 0.045). Interestingly, the plasma n-3 level was inversely associated with the tartrate-resistant acid phosphatase-5b level (β = - 0.633, P = 0.023), but not with the bone-specific alkaline phosphatase level, in BM aspirates.

CONCLUSIONS

These findings provide clinical evidence that n-3 FA is a potential inhibitor of osteoclastogenesis that favors human bone health.

Abstract P3-03-05: Not presented

This abstract was not presented at the conference.

Citation Format: Jung S-Y, Han JH, Park SJ, Lee E-G, Lee MH, Lee ES, Kang H-S, Lee KS, Park IH, Sim SH, Jeong HJ, Kwon Y, Lee D-E, Joo J, Kim S-K, Lee S. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-05.

Living-donor Liver Retransplantation Using the Vessels of the Previous Allograft by Means of Intragraft Dissection

Retransplantation with the use of a living-donor graft can be the only therapeutic option for patients with irreversible graft failure, especially in regions with limited access to deceased donors, but it can be technically demanding because of severe adhesion around the hepatic hilum and inferior vena cava. We introduce an effective and safe technique to overcome this challenge for right-lobe living-donor liver retransplantation by using the vessels of the previous right liver allograft with the use of intragraft dissection. The technique was used in 2 critically ill patients undergoing the graft failure. The operative times were 360 and 410 minutes. The recipients were discharged on days 18 and 25 with normal liver function. One postoperative complication occurred 3 months after retransplantation: biliary leakage, corrected with the use of percutaneous transhepatic biliary drainage. Both patients were alive with a functioning allograft at last follow-up of >3 years. Intragraft dissection to use the vessels of the previous right-liver allograft can be a useful technique and should be considered for right-lobe living-donor liver retransplantation.

Abstract P4-06-12: Different patterns of risk reducing decisions in affected or unaffected BRCA mutation carriers

BACKGROUND

Risk-reducing (RR) management decreases the risk of breast cancer and BRCA related gynecologic cancer. However, there are fewer reports on the RR management in Asia compared to Western countries.The aim of this study is to identify risk reducing management patterns with BRCA1 or BRCA2 mutation carriers.

METHODS

The study group consisted of all consecutive 1104 breast cancer, ovarian patients and their families of high-risk patients who underwent BRCA gene testing in National Cancer Center, Korea from 2008 to 2016. A total 220 BRCA mutations (19.9%) were detected with 125(11.3%) of BRCA1 gene and 95 (8.6%) of BRCA2 gene.

RESULTS

Out of 220 BRCA mutations carriers, they were consisted of 83 breast cancers, 10 ovarian cancers, 7 both cancers, and 120 unaffected carriers. Among them, 42 were men and 178 were women. About 90 % (198/ 220) had the familial history of breast, ovarian or both malignancies (113 in BRCA1 and 85 in BRCA2 mutation (p=0.821)).

All 42 men chose surveillance. Among 178 female BRCA mutation carriers, 98(55.1%) underwent risk reducing management including 18(10.1%) of chemoprevention, and 80(49.9%) had risk-reducing surgeries (RRSs) (1 case of risk-reducing mastectomy, 76 of risk reducing bilateral salphingo-oophorectomy (RRSO), and 3 of both) and 80 (54.9%) chose only intensive surveillance for both of breast and ovary cancer.

In affected carriers with breast cancer, 59 (71.1%) underwent RR management (1 case of risk reducing mastectomy, 53 of RRSO, 3 of both surgery, and 2 of chemoprevention). There was no risk reducing management in affected carrier with ovarian cancer patients. In 78 unaffected women carriers, 39(50.0%) women received RR management (23(29.5%) cases of RRSO and 16(20.5%) cases of chemoprevention). The rates of RRSs have increased annually since the 2013 year, (prior to 2013 vs. since 2013, RRSs 28.6% (6 cases/21 carriers) vs. 37.2% (74/199), p<0.01).

CONCLUSION

This study was conducted on the largest numbers of BRCA mutation carriers in Asian countries. RRSO is the more preferred management for affected carriers with breast cancer or unaffected carriers. The results might be explained by the severity of the illness and that RRSO was only reimbursed RR strategy from the Korean Government Insurance. Tailored genetic counseling and insurance policy may enhance overall levels of RR management.

Citation Format: Lee EG, Kang H, Park SJ, Han JH, Jung S-Y, Lee S, Kang H-S, Park B, Kong S-Y, Lim MC, Park S-Y, Lee ES. Different patterns of risk reducing decisions in affected or unaffected BRCA mutation carriers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-06-12.

Faucial Pillar Perforation by Glidescope Intubation with Incorrectly Placed Stylet

Glidescope GVL® is frequently used in intubation of difficult airway. We report a case of right side of faucial pillar perforation during intubation with Glidescope®. A rigid stylet can facilitate placing of endotracheal tube quickly but it may also penetrate the soft tissue to cause injuries.

TRIENNIAL GROWTH AND DEVELOPMENT SYMPOSIUM: Molecular mechanisms related to bovine intramuscular fat deposition in the longissimus muscle

The intramuscular fat (IMF) content of the LM, also known as marbling, is particularly important in determining the price of beef in Korea, Japan, and the United States. Deposition of IMF is influenced by both genetic (e.g., breed, gender, and genotype) and nongenetic factors (e.g., castration, nutrition, stressors, animal weight, and age). Castration of bulls markedly increases deposition of IMF, resulting in improved beef quality. Here, we present a comparative gene expression approach between bulls and steers. Transcriptomic and proteomic studies have demonstrated that the combined effects of increases in lipogenesis, fatty acid uptake, and fatty acid esterification and decreased lipolysis are associated with increased IMF deposition in the LM. Several peripheral tissues (LM, adipose tissues, and the liver) are involved in lipid metabolism. Therefore, understanding the significance of the tissue network in lipid metabolism is important. Here, we demonstrate that lipid metabolism in LM tissues is crucial for IMF deposition, whereas lipid metabolism in the liver plays only a minor role. Metabolism of body fat and IMF deposition in bovine species has similarities with these processes in metabolic diseases, such as obesity in humans and rodents. Extensive studies on metabolic diseases using epigenome modification (DNA methylation, histone modification, and microRNA), microbial metagenomics, and metabolomics have been performed in humans and rodents, and new findings have been reported using these technologies. The importance of applying "omics" fields (epigenomics, metagenomics, and metabolomics) to the study of IMF deposition in cattle is described. New information on the molecular mechanisms of IMF deposition may be used to design nutritional or genetic methods to manipulate IMF deposition and to modify fatty acid composition in beef cattle. Applying nutrigenomics could maximize the expression of genetic potential of economically important traits (e.g., marbling) in animals.

Self-spreading of the wetting ridge during stick-slip on a viscoelastic surface

Dynamic wetting behaviors on soft solids are important to interpret complex biological processes from cell-substrate interactions. Despite intensive research studies over the past half-century, the underlying mechanisms of spreading behaviors are not clearly understood. The most interesting feature of wetting on soft matter is the formation of a "wetting ridge", a surface deformation by a competition between elasticity and capillarity. Dynamics of the wetting ridge formed at the three-phase contact line underlies the dynamic wetting behaviors, but remains largely unexplored mostly due to limitations in indirect observation. Here, we directly visualize wetting ridge dynamics during continuous- and stick-slip motions on a viscoelastic surface using X-ray microscopy. Strikingly, we discover that the ridge spreads spontaneously during stick and triggers contact line depinning (stick-to-slip transition) by changing the ridge geometry which weakens the contact line pinning. Finally, we clarify 'viscoelastic-braking', 'stick-slipping', and 'stick-breaking' spreading behaviors through the ridge dynamics. In stick-breaking, no ridge-spreading occurs and contact line pinning (hysteresis) is enhanced by cusp-bending while preserving a microscopic equilibrium at the ridge tip. We have furthered the understanding of spreading behaviors on soft solids and demonstrated the value of X-ray microscopy in elucidating various dynamic wetting behaviors on soft solids as well as puzzling biological issues.

Borrelia Species Detected in Ticks Feeding on Wild Korean Water Deer (Hydropotes inermis) Using Molecular and Genotypic Analyses

Lyme borreliosis is a vector-borne disease transmitted through the bite of ticks infected by Borrelia burgdorferi sensu lato group, including B. burgdorferi sensu stricto, B. afzelii, and B. garinii. The goal of the present study was to detect Borrelia species in ticks infesting wild Korean water deer (KWD; Hydropotes inermis Swinhoe), using molecular and genotypic analyses. In total, 48 ticks were collected from KWD, all of which were morphologically identified as Haemaphysalis longicornis Neumann that is dominant in Korea. Nested PCR was performed to detect the Borrelia-specific 5S (rrf)-23S (rrl) intergenic spacer region and the outer surface protein A (ospA) genes in ticks. Both rrf-rrl and ospA were amplified from one of the 48 ticks (2.1%) and were identified as B. afzelii. To our knowledge, this study constitutes the first molecular detection of B. afzelii in Haemaphysalis ticks in Korea. Because B. afzelii is a zoonotic tick-borne pathogen, understanding the molecular characteristics of this bacterium is important for preventing the transmission of Borrelia from ticks to other animals and humans.

Adequate interval for the monitoring of vital signs during endotracheal intubation

Background

In the perioperative period, it may be inappropriate to monitor vital signs during endotracheal intubation using the same interval as during a hemodynamically stable period. The aim of the present study was to determine whether it is appropriate to use the same intervals used during the endotracheal intubation and stable periods to monitor vital signs of patients under general anesthesia.

Methods

The mean arterial pressure (MAP) and heart rate (HR) were continuously measured during endotracheal intubation (15 min after intubation) and hemodynamically stable (15 min before skin incision) periods in 24 general anesthesia patients. Data was considered “unrecognized” when continuously measured values were 30% more or less than the monitored value measured at 5- or 2.5-min intervals. The incidence of unrecognized data during endotracheal intubation was compared to that during the hemodynamically stable period.

Result

There were significantly more unrecognized MAP data measured at 5-min intervals during endotracheal intubation than during the hemodynamically stable period (p value <0.05). However, there was no difference in the incidence of unrecognized MAP data at 2.5 min intervals or HR data at 5 or 2.5 min intervals between during the endotracheal intubation and hemodynamically stable periods.

Conclusion

A 5-min interval throughout the operation period was not appropriate for monitoring vital signs. Therefore, , a 2.5-min interval is recommended for monitoring the MAP during endotracheal intubation.

The application of an acellular dermal allograft (AlloDerm) for patients with insufficient conjunctiva during evisceration and implantation surgery

PurposeTo describe the use of an acellular dermal allograft (AlloDerm) for patients with insufficient conjunctiva during evisceration and implantation surgery.Patients and methodsThe medical records of six patients with insufficient conjunctiva during evisceration surgery were reviewed. It was not possible to close the Tenon's capsule and conjunctiva without wound tension in these patients, so AlloDerm was placed over the sclera, and the edges were sutured with adjacent conjunctiva without tension. The size of the bare AlloDerm graft was measured in all patients. The clinical outcome was the incidence of complications, and the percentage of patients needing additional surgery was also recorded.ResultsThe cause of evisceration was end stage glaucoma (four patients) and endogenous endophthalmitis (two patients). All six eyes of six patients (100%) had a successful outcome showing no complications. Four cases achieved full conjunctivalisation over the bare AlloDerm graft. Two cases had a bare AlloDerm until the last follow-up, but showed no implant exposure. It took a median of 11 weeks for the slow advance of the conjunctival edge to entirely cover the AlloDerm graft.ConclusionsAlloDerm is a promising material for covering sclera and implants in a tension-free manner after evisceration surgery in patients with insufficient conjunctiva.

Crystallization Kinetics of Lead Halide Perovskite Film Monitored by In Situ Terahertz Spectroscopy

Vibrational modes in the terahertz (THz) frequency range are good indicators of lead halide perovskite's crystallization phase. We performed real-time THz spectroscopy to monitor the crystallization kinetics in the perovskite films. First, THz absorptance was measured while the perovskite film was annealed at different temperatures. By analyzing the Avrami exponent, we observed an abrupt dimensionality switch (from 1D to 2D) with increasing temperature starting at approximately 90 °C. We also monitored the laser-induced crystallinity enhancement of the preannealed perovskite film. The THz absorptance increased initially, then subsequently decayed over a couple of hours, although the enhancement factor varies depending on the film crystallinity. In particular, the Avrami analysis implied that the light-induced crystallization was assisted by the 1D diffusion processes. The activation photon energy was measured at 2.3 eV, which indicated that enhanced crystallization originated from the photoinduced structural change of residual lead iodide at the grain boundary.

3D isotropic T2-weighted fast spin echo (VISTA) versus 2D T2-weighted fast spin echo in evaluation of the calcaneofibular ligament in the oblique coronal plane

AIM

To investigate whether the image quality of three-dimensional (3D) volume isotropic fast spin echo acquisition (VISTA) magnetic resonance imaging (MRI) of the calcaneofibular ligament (CFL) view is comparable to that of 2D fast spin echo T2-weighted images (2D T2 FSE) for the evaluation of the CFL, and whether 3D VISTA can replace 2D T2 FSE for the evaluation of CFL injuries.

MATERIALS AND METHODS

This retrospective study included 76 patients who underwent ankle MRI with CFL views of both 2D T2 FSE MRI and 3D VISTA. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of both techniques were measured. The anatomical identification score and diagnostic performances were evaluated by two readers independently. The diagnostic performances of 3D VISTA and 2D T2 FSE were analysed by sensitivity, specificity, and accuracy for diagnosing CFL injury with reference standards of surgically or clinically confirmed diagnoses. Surgical correlation was performed in 29% of the patients, and clinical examination was used in those who did not have surgery (71%).

RESULTS

The SNRs and CNRs of 3D VISTA were significantly higher than those of 2D T2 FSE. The anatomical identification scores on 3D VISTA were inferior to those on 2D T2 FSE, and the differences were statistically significant (p<0.05). There were no significant differences in diagnostic performance between the two sequences when diagnoses were classified as normal or abnormal.

CONCLUSION

Although the image quality of 3D VISTA MRI of the CFL view is not equal to that of 2D T2 FSE for the anatomical evaluation of CFL, 3D VISTA has a diagnostic performance comparable to that of 2D T2 FSE for the diagnosis of CFL injuries.