Consecutive Scans Research Articles

A facile fabrication of zinc oxide‐doped carbon aerogel by cellulose extracted from coconut peat and sodium alginate for energy storage application

AbstractIn this study, ZnO‐doped carbon aerogel is synthesized from cellulose in coconut peat with sodium alginate as a binder via both freeze‐drying and pyrolysis processes. Of those, zinc nitrate is used as not only a crosslinking agent to form gel but also a precursor source to dope ZnO in the carbon aerogel matrix. The effect of precursor ratios on the characterization and energy storage capacity of composite aerogel is investigated. As a result, it is indicated that the formed ZnO‐doped carbon aerogel possesses a highly porous structure which is typical for aerogel structure shown by SEM images, density, and porosity. Besides, via the XRD patterns, the confirmation of the ZnO crystal structure is found within the carbon aerogel lattice. In terms of energy storage, based on the specific capacitance results, the ZCA‐4 sample with a sodium alginate and cellulose weight ratio of 1:20 shows the best energy storage with a specific capacitance of 105 F/g in the voltage range of 0–0.5 V and scan‐rate speed of 0.005 V. Therewithal, the ZCA‐4 also performs high durability, high scanning speed tolerance, and stable storage performance with efficiency reaching more than 99% after 500 consecutive scan cycles. These results demonstrate that the ZnO‐doped carbon aerogel has potential applications as electrode materials in supercapacitors.

Comparing Direct Measurements and Three-Dimensional (3D) Scans for Evaluating Facial Soft Tissue

The inspection of patients' soft tissues and the effects of various dental procedures on their facial physiognomy are quite challenging. To minimise discomfort and simplify the process of manual measuring, we performed facial scanning and computer measurement of experimentally determined demarcation lines. Images were acquired using a low-cost 3D scanner. Two consecutive scans were obtained from 39 participants, to test the scanner repeatability. An additional ten persons were scanned before and after forward movement of the mandible (predicted treatment outcome). Sensor technology that combines red, green, and blue (RGB) data with depth information (RGBD) integration was used for merging frames into a 3D object. For proper comparison, the resulting images were registered together, which was performed with ICP (Iterative Closest Point)-based techniques. Measurements on 3D images were performed using the exact distance algorithm. One operator measured the same demarcation lines directly on participants; repeatability was tested (intra-class correlations). The results showed that the 3D face scans were reproducible with high accuracy (mean difference between repeated scans <1%); the actual measurements were repeatable to some extent (excellent only for the tragus-pogonion demarcation line); computational measurements were accurate, repeatable, and comparable to the actual measurements. Three dimensional (3D) facial scans can be used as a faster, more comfortable for patients, and more accurate technique to detect and quantify changes in facial soft tissue resulting from various dental procedures.

68GaPSMA-11 PET/CT to monitor treatment response in patients with metastatic prostate cancer: The concordance between biochemical response and PSMA response.

49 Background: The aim of this study was to assess whether PSMA PET is associated with flares, with discordant results in regard to biochemical response, and with positivity rates at low PSA values while monitoring metastatic prostate cancer (mPCa) receiving systemic treatment. Methods: A total of 96 patients with PSMA PET-detected mPCa who underwent at least one follow-up scan after receiving systemic treatment were included in the study. PSA levels at baseline PSMA PET-CT (bPSMA) and follow-up PSMA PET scans (fPSMA) were recorded. Any significant PSMA uptake at prostate and/or metastatic lesions were considered PSMA positivity. PSMA response were decided according to PSMA PET Progression (PPP) criteria . Biochemical progression was defined as ≥25% increase in PSA (1 ng/dL was the minimal starting value). PSMA PET and PSA response were dichotomized into progressive disease (PD) vs non-PD. Discordant responses among different metastases and prostate were defined as the condition when some metastatic lesions (or prostate) are responding (CR or PR) to systemic treatment while others had progressed. Results: A total of 346 serial PSMA PET/CT (96 bPSMA and 249 fPSMA) scans were evaluated. The median time between consecutive PSMA PET scans was 6.3 months (IQR: 4.7 – 10.6) Overall PSMA PET positivity rate of fPSMA scans was 88.4% (220/249). PSMA positivity rates according PSA levels were summarized. PPP was detected in 93 cases (37.8%) and biochemical progression was observed in 73 cases (30.2%). PSA and PSMA responses were highly concordant (Cohen’s K=0.623, p&lt;0.001). PSA-PSMA discordant responses were detected in 39 scans (17%). The possible causes could be identified in 34 of 39 scans (87%) while no obvious reason for discordance could be shown in the remaining 5. Conclusions: PSMA PET/CT showed very high detection rates of malignant lesions even in very low PSA values when monitoring treatment response in patients receiving systemic treatment for mPCa. PSA and PSMA responses were highly concordant. In cases with discordance, the reason seems to be the discordant behaviour of intraprostatic and metastatic lesions and not necessarily PSMA flares. PSMA PET is a promising biomarker to assess treatment response in patients with mPCa. [Table: see text]

Diffusion-weighted MR imaging and utility of ADC measurements in characterizing nerve and muscle changes in diabetic patients on ankle DWI studies: a cross-sectional study.

To evaluate the utility of apparent diffusion coefficient (ADC) measurements from ankle MRI diffusion-weighted imaging (DWI) studies in identifying neuropathic changes in diabetic patients. In total, 109 consecutive ankle MRI scans (n = 101 patients) at a single tertiary care county hospital from November 1, 2019, to July 11, 2021, who met the inclusion criteria were identified. Patients were divided into 2 cohorts: diabetic (n = 62) and non-diabetic (n = 39). Demographics, HgbA1c, neuropathy diagnosis, and image quality data were collected. Abductor hallucis (AH) ADC mean and minimum (min) values and posterior tibial nerve (PTN) ADC mean and minimum values were measured. Student t-test and Pearson's correlation coefficient analysis were performed using R. Diabetic patients had significantly higher mean and min ADC values (× 10-3 mm2/s) of the AH muscle (mean: 1.77 vs 1.39, p < 0.001; min: 1.51 vs 1.06, p < 0.001) and PTN (mean: 1.65 vs 1.18, p < 0.001; min: 1.33 vs 0.95, p < 0.001) compared to non-diabetic patients. HgbA1c positively correlated with AH and PTN ADC mean values (AH: p = 0.036; PTN: p = 0.004). Our data suggests that an increasing diffusivity of water as quantified by ADC across neuronal and muscular membranes is a consequence of the pathophysiology of the disease. Thus, ankle MRI-DWI studies are useful in identifying neuropathic changes in diabetic patients and quantifying the severity noninvasively. • Diabetic patients had significantly higher mean and minimum ADC values of the abductor hallucis muscle and posterior tibial nerve compared to non-diabetic patients. • HgbA1c positively correlated with ADC mean values (AH: p = 0.036; PTN: p = 0.004) suggesting that an increasing diffusivity of water across neuronal and muscular membranes is a consequence of the pathophysiology of diabetic neuropathy. • Ankle MRI DWI can be used clinically to non-invasively identify neuropathic changes due to diabetes mellitus.

Using computed tomography to evaluate proper chest compression depth for cardiopulmonary resuscitation in Thai population: A retrospective cross-sectional study.

The effectiveness of cardiopulmonary resuscitation is determined by appropriate chest compression depth and rate. The American Heart Association recommended CC depth at 5-6 cm to indicate proper cardiac output during cardiac arrest. However, many studies showed the differences in the body builds between Caucasians and Asians. Therefore, this study aimed to determine heart compression fraction (HCF) in the Thai population by using contrast-enhanced computed tomography (CT) scan of the chest and a mathematical model. Consecutive contrast-enhanced CT scans of the chest performed at Ramathibodi Hospital were retrospectively reviewed from January to March 2018 by two independent radiologists. Patients' characteristics, including gender, age, weight, height, and pre-existing diseases, were recorded, and the chest parameters were measured from a CT scan. The heart compression fraction (HCF) was subsequently calculated. Of 306 subjects, there were 139 (45.4%) males, 148 (47.4%) lung diseases and 10 (3.3%) heart diseases. Mean age and BMI were 60.4 years old and 23.8 kg/m2, respectively. Chest diameter, heart diameter, and non-cardiac soft tissue were significantly smaller in females compared to males. Mean (SD) HCF proportional with 50 mm and 60 mm depth were 38.3% (13.3%) and 50% (14.3%), respectively. There were significant differences of HCF proportional by 50 mm and 60 mm depth between men and women (33.2% vs 42.6% and 44% vs 54.9%, respectively (P<0.001)). In addition, a decrease in HCF was significantly observed among higher BMI groups. The CT scan and mathematical model showed that 38% and 50% HCF proportions were generated by 50 mm and 60 mm CC depth. HCF proportions were significantly different between genders and among BMI groups. The recommended depth of 5-6 cm is likely to provide sufficient CC depth in the population of Thailand.

Evaluation of the Normal Craniocervical Junction Craniometry in 137 Asymptomatic Patients

To our best knowledge, most of the craniometric studies on the normal craniocervical junction (CCJ), are still poorly studied and based on measurements taken from plain radiographs. In this study, the authors conducted a craniometric evaluation of the CCJ in a population without known CCJ abnormalities. The purpose of the study was to assess the normal CCJ craniometry based on measures obtained from CT scans. The authors examined 137 consecutive CCJ CT scans obtained in patients evaluated at their hospital for treatment of non-CCJ conditions between 2018 and 2019. Twelve craniometrical dimensions were conducted, including the relation of the odontoid with the cranial base, the atlantodental interval (ADI), the clivus length, and the clivus-canal angle (CCA).

Standardized Reporting on the Preoperative CT Assessment of Potential Living Renal Transplant Donors: Can We Create a Universal Report Standard to Meet the Needs of Transplant Urologists?

Purpose: Determine whether standardized template reporting for the preoperative assessment of potential living renal transplant donors improves the comprehensiveness of radiology reports to meet the needs of urologists performing renal transplants. Methods: Urologist and radiologist stakeholders from renal transplant centres in our province ratified a standardized reporting template for evaluation of potential renal donors. Three centres (A, B, and C) were designated "intervention" groups. Centre D was the control group, given employment of a site-specific standardized template prior to study commencement. Up to 100 consecutive CT scan reports per centre, pre- and post-implementation of standardized reporting, were evaluated for reporting specific outcome measures. Results: At baseline, all intervention groups demonstrated poor reporting of urologist-desired outcome measures. Centre A discussed 5/13 variables (38%), Centre B discussed 6/13 variables (46%), and Centre C only discussed 1/13 variables (8%) with ≥90% reliability. The control group exhibited consistent reporting, with 11/13 variables (85%) reported at ≥90% reliability. All institutions in the intervention group exhibited excellent compliance to structured reporting post-template implementation (Centres A = 95%, B = 100%, and C = 77%, respectively). Additionally, all intervention centres demonstrated a significant improvement in the comprehensiveness of reports post-template implementation, with statistically significant increases in the reporting of all variables under-reported at baseline (P > .01). Conclusion: Standardized templates across our province for CT scans of potential renal donors promote completeness of reports. Radiologists can reliably provide our surgical colleagues with needed preoperative anatomy and incidental findings, helping to determine suitable transplant donors and reduce potential complications associated with organ retrieval.

A New Algorithm for Automatically Calculating Noise, Spatial Resolution, and Contrast Image Quality Metrics: Proof-of-Concept and Agreement With Subjective Scores in Phantom and Clinical Abdominal CT.

The aims of this study were to develop a proof-of-concept computer algorithm to automatically determine noise, spatial resolution, and contrast-related image quality (IQ) metrics in abdominal portal venous phase computed tomography (CT) imaging and to assess agreement between resulting objective IQ metrics and subjective radiologist IQ ratings. An algorithm was developed to calculate noise, spatial resolution, and contrast IQ parameters. The algorithm was subsequently used on 2 datasets of anthropomorphic phantom CT scans, acquired on 2 different scanners (n = 57 each), and on 1 dataset of patient abdominal CT scans (n = 510). These datasets include a range of high to low IQ: in the phantom dataset, this was achieved through varying scanner settings (tube voltage, tube current, reconstruction algorithm); in the patient dataset, lower IQ images were obtained by reconstructing 30 consecutive portal venous phase scans as if they had been acquired at lower mAs. Five noise, 1 spatial, and 13 contrast parameters were computed for the phantom datasets; for the patient dataset, 5 noise, 1 spatial, and 18 contrast parameters were computed. Subjective IQ rating was done using a 5-point Likert scale: 2 radiologists rated a single phantom dataset each, and another 2 radiologists rated the patient dataset in consensus. General agreement between IQ metrics and subjective IQ scores was assessed using Pearson correlation analysis. Likert scores were grouped into 2 categories, "insufficient" (scores 1-2) and "sufficient" (scores 3-5), and differences in computed IQ metrics between these categories were assessed using the Mann-Whitney U test. The algorithm was able to automatically calculate all IQ metrics for 100% of the included scans. Significant correlations with subjective radiologist ratings were found for 4 of 5 noise ( R2 range = 0.55-0.70), 1 of 1 spatial resolution ( R2 = 0.21 and 0.26), and 10 of 13 contrast ( R2 range = 0.11-0.73) parameters in the phantom datasets and for 4 of 5 noise ( R2 range = 0.019-0.096), 1 of 1 spatial resolution ( R2 = 0.11), and 16 of 18 contrast ( R2 range = 0.008-0.116) parameters in the patient dataset. Computed metrics that significantly differed between "insufficient" and "sufficient" categories were 4 of 5 noise, 1 of 1 spatial resolution, 9 and 10 of 13 contrast parameters for phantom the datasets and 3 of 5 noise, 1 of 1 spatial resolution, and 10 of 18 contrast parameters for the patient dataset. The developed algorithm was able to successfully calculate objective noise, spatial resolution, and contrast IQ metrics of both phantom and clinical abdominal CT scans. Furthermore, multiple calculated IQ metrics of all 3 categories were in agreement with subjective radiologist IQ ratings and significantly differed between "insufficient" and "sufficient" IQ scans. These results demonstrate the feasibility and potential of algorithm-determined objective IQ. Such an algorithm should be applicable to any scan and may help in optimization and quality control through automatic IQ assessment in daily clinical practice.

Appendiceal wall thickness and Alvarado score are predictive of acute appendicitis in the patients with equivocal computed tomography findings

Around 8–13% of the patients who underwent CT scan for diagnosis of appendicitis had equivocal CT results. About one-third of these patients had acute appendicitis and this caused diagnostic challenge to the clinicians. This study was conducted to identify clinical and imaging features that were predictive of acute appendicitis in patients who had equivocal CT findings. During January 2015 to June 2021, we retrospectively included 103 consecutive CT scans of adult patients (22 men and 81 women; mean age, 39.1 ± 17.5 years) who had equivocal CT findings of acute appendicitis. Two readers, blinded to the clinical data, independently assessed CT images for the relevant CT findings of appendicitis. Any disagreement between the readers was solved by consensus. The clinical parameters and CT findings were analyzed and compared between the patients who had appendicitis and patients who did not have appendicitis. Thirty-one (30.1%) patients had appendicitis, all of which were non-complicated. The appendiceal wall thickness of ≥ 2 mm and the Alvarado score of ≥ 7 were independent predictors of appendicitis with adjusted odds ratios (ORs) of 2.76 (95% CI, 1.09–7.02) and 1.47 (95% CI, 1.12–1.94), respectively. The maximal appendiceal diameter was higher in the appendicitis group (7.2 ± 1.2 mm vs. 6.5 ± 1.0 mm), but not predictive of appendicitis. The rest of the clinical parameters and CT findings, including mucosal hyperenhancement, periappendiceal fat reticulation, thickening of peritoneal reflection, appendicolith, focal cecal thickening, and content in appendiceal lumen showed no significant difference between two groups. The appendiceal wall thickness and the Alvarado score were able to predict appendicitis in patients who had equivocal CT findings.

Inconsistencies in mapping current distribution in transcranial direct current stimulation.

tDCS is a non-invasive neuromodulation technique that has been widely studied both as a therapy for neuropsychiatric diseases and for cognitive enhancement. However, recent meta-analyses have reported significant inconsistencies amongst tDCS studies. Enhancing empirical understanding of current flow in the brain may help elucidate some of these inconsistencies. We investigated tDCS-induced current distribution by injecting a low frequency current waveform in a phantom and in vivo. MR phase images were collected during the stimulation and a time-series analysis was used to reconstruct the magnetic field. A current distribution map was derived from the field map using Ampere's law. The current distribution map in the phantom showed a clear path of current flow between the two electrodes, with more than 75% of the injected current accounted for. However, in brain, the results did evidence a current path between the two target electrodes but only some portion ( 25%) of injected current reached the cortex demonstrating that a significant fraction of the current is bypassing the brain and traveling from one electrode to the other external to the brain, probably due to conductivity differences in brain tissue types. Substantial inter-subject and intra-subject (across consecutive scans) variability in current distribution maps were also observed in human but not in phantom scans. An in-vivo current mapping technique proposed in this study demonstrated that much of the injected current in tDCS was not accounted for in human brain and deviated to the edge of the brain. These findings would have ramifications in the use of tDCS as a neuromodulator and may help explain some of the inconsistencies reported in other studies.

Development and External Validation of a Deep Learning Algorithm to Identify and Localize Subarachnoid Hemorrhage on CT Scans.

In medical imaging, a limited number of trained deep learning algorithms have been externally validated and released publicly. We hypothesized that a deep learning algorithm can be trained to identify and localize subarachnoid hemorrhage (SAH) on head computed tomography (CT) scans and that the trained model performs satisfactorily when tested using external and real-world data. We used noncontrast head CT images of patients admitted to Helsinki University Hospital between 2012 and 2017. We manually segmented (i.e., delineated) SAH on 90 head CT scans and used the segmented CT scans together with 22 negative (no SAH) control CT scans in training an open-source convolutional neural network (U-Net) to identify and localize SAH. We then tested the performance of the trained algorithm by using external data sets (137 SAH and 1,242 control cases) collected in 2 foreign countries and also by creating a data set of consecutive emergency head CT scans (8 SAH and 511 control cases) performed during on-call hours in 5 different domestic hospitals in September 2021. We assessed the algorithm's capability to identify SAH by calculating patient- and slice-level performance metrics, such as sensitivity and specificity. In the external validation set of 1,379 cases, the algorithm identified 136 of 137 SAH cases correctly (sensitivity 99.3% and specificity 63.2%). Of the 49,064 axial head CT slices, the algorithm identified and localized SAH in 1845 of 2,110 slices with SAH (sensitivity 87.4% and specificity 95.3%). Of 519 consecutive emergency head CT scans imaged in September 2021, the algorithm identified all 8 SAH cases correctly (sensitivity 100.0% and specificity 75.3%). The slice-level (27,167 axial slices in total) sensitivity and specificity were 87.3% and 98.8%, respectively, as the algorithm identified and localized SAH in 58 of 77 slices with SAH. The performance of the algorithm can be tested on through a web service. We show that the shared algorithm identifies SAH cases with a high sensitivity and that the slice-level specificity is high. In addition to openly sharing a high-performing deep learning algorithm, our work presents infrequently used approaches in designing, training, testing, and reporting deep learning algorithms developed for medical imaging diagnostics. This study provides Class III evidence that a deep learning algorithm correctly identifies the presence of subarachnoid hemorrhage on CT scan.

Impact of 24-Hr Diet and Physical Activity Control on Short-Term Precision Error of Dual-Energy X-Ray Absorptiometry Physique Assessment.

Dual-energy X-ray absorptiometry (DXA) is a popular technique used to quantify physique in athletic populations. Due to biological variation, DXA precision error (PE) may be higher than desired. Adherence to standardized presentation for testing has shown improvement in consecutive-day PE. However, the impact of short-term diet and physical activity standardization prior to testing has not been explored. This warrants investigation, given the process may reduce variance in total body water and muscle solute, both of which can have high daily flux amongst athletes. Twenty (n = 10 males, n = 10 females) recreationally active individuals (age: 30.7 ± 7.5years; stature: 176.4 ± 9.1cm; mass: 74.6 ± 14.3kg) underwent three DXA scans; two consecutive scans on 1day, and a third either the day before or after. In addition to adhering to standardized presentation for testing, subjects recorded all food/fluid intake plus activity undertaken in the 24hr prior to the first DXA scan and replicated this the following 24hr. International Society of Clinical Densitometry recommended techniques were used to calculate same- and consecutive-day PE. There was no significant difference in PE of whole-body fat mass (479g vs. 626g) and lean mass (634g vs. 734g) between same- and consecutive-day assessments. Same- and consecutive-day PE of whole-body fat mass and lean mass were less than the smallest effect size of interest. Inclusion of 24-hr standardization of diet and physical activity has the potential to reduce biological error further, but this needs to be verified with follow-up investigation.

Liver lesion changes analysis in longitudinal CECT scans by simultaneous deep learning voxel classification with SimU-Net.

The identification and quantification of liver lesions changes in longitudinal contrast enhanced CT (CECT) scans is required to evaluate disease status and to determine treatment efficacy in support of clinical decision-making. This paper describes a fully automatic end-to-end pipeline for liver lesion changes analysis in consecutive (prior and current) abdominal CECT scans of oncology patients. The three key novelties are: (1) SimU-Net, a simultaneous multi-channel 3D R2U-Net model trained on pairs of registered scans of each patient that identifies the liver lesions and their changes based on the lesion and healthy tissue appearance differences; (2) a model-based bipartite graph lesions matching method for the analysis of lesion changes at the lesion level; (3) a method for longitudinal analysis of one or more of consecutive scans of a patient based on SimU-Net that handles major liver deformations and incorporates lesion segmentations from previous analysis. To validate our methods, five experimental studies were conducted on a unique dataset of 3491 liver lesions in 735 pairs from 218 clinical abdominal CECT scans of 71 patients with metastatic disease manually delineated by an expert radiologist. The pipeline with the SimU-Net model, trained and validated on 385 pairs and tested on 249 pairs, yields a mean lesion detection recall of 0.86±0.14, a precision of 0.74±0.23 and a lesion segmentation Dice of 0.82±0.14 for lesions > 5mm. This outperforms a reference standalone 3D R2-UNet mdel that analyzes each scan individually by ∼50% in precision with similar recall and Dice score on the same training and test datasets. For lesions matching, the precision is 0.86±0.18 and the recall is 0.90±0.15. For lesion classification, the specificity is 0.97±0.07, the precision is 0.85±0.31, and the recall is 0.86±0.23. Our new methods provide accurate and comprehensive results that may help reduce radiologists' time and effort and improve radiological oncology evaluation.

Repeatability of new optical biometer and agreement with 2 validated optical biometers, all based on SS-OCT.

To evaluate the repeatability of the measurements provided by a new optical biometer (EyeStar 900) based on swept-source optical coherence tomography (SS-OCT) and their agreement with the measurements given by 2 validated biometers based on the same technology, the IOLMaster 700 and Argos. IRCCS G.B. Bietti Foundation, Rome, Italy. Prospective evaluation of diagnostic test. In a series of unoperated eyes, 3 consecutive scans were acquired with the EyeStar 900, and 1 with the IOLMaster 700 and the Argos. The following biometry parameters were analyzed: axial length (AL), keratometry (K), corneal astigmatism, central corneal thickness, corneal diameter (CD), anterior chamber depth (ACD), lens thickness (LT), and lens tilting. Repeatability was assessed using test-retest variability, the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC); agreement was based on the 95% limits of agreement. 56 eyes of 56 patients were analyzed. High repeatability was achieved for all measured parameters, as the CoV was <1% in most cases and ICC was >0.95 for all parameters. Good to high agreement was found among the measurements of the 3 optical biometers, although some statistically significant differences were detected between the EyeStar 900 and Argos (mean K, ACD, LT, and CD were higher with the Argos). The Argos measured a shorter AL in eyes >25 mm. The new generation SS-OCT EyeStar 900 optical biometer produces highly repeatable measurements that are in good agreement with those provided by 2 previously validated instruments.

Normal dimensions of the lacrimal gland on magnetic resonance imaging in Indian adult population: a retrospective study.

the lacrimal gland size is affected by a variety of pathologic conditions like inflammatory, infections, neoplastic, autoimmune and granulomatous disorders. Earlier, the dimensions of the gland were estimated by extracting lacrimal glands from cadavers, later ultrasonography and computed tomography studies were used, but had limited soft tissue differentiation. The aim of this study was to retrospectively evaluate Magnetic Resonance Imaging (MRI) data from normal orbits and determine lacrimal gland dimensions. five hundred and twelve (512) consecutive MRI brain contrast scans (of 240 females, of 272 males; age range 40±20 years) for non-orbital diseases were evaluated retrospectively. The mean axial length (AL), axial width (AW), coronal length (CL), and coronal width (CW) of each lacrimal gland were measured separately. five hundred and twelve (512) MRI brain contrast scans of 272 men and 240 women, with mean age of 40 ± 20 years were included. Right and left LG dimensions were similar, mean AL (13.2±1.35 mm versus 13.11±1.24 mm), mean AW [3.5±0.99 mm versus 3.3±0.82 mm], mean CL [16.3±2.5 mm versus 16.10±2.4 mm], and mean CW (4.15±0.89 mm versus 4.11±0.85 mm). The AL of both lacrimal glands and the CL and CW of right but not left lacrimal glands were significantly lower in women than in men. Age showed significant correlations with the AL and CL of both LGs. in this study, evaluation of normal morphometric parameters of the lacrimal gland in Indian population was established. LG dimensions are smaller in women than men, as well as correlating with side and age.

Austenite Reversion Behavior of Maraging Steel Additive-manufactured by Laser Powder Bed Fusion

This study was set to fundamentally investigate the characteristics of austenite reversion occurring in maraging steels additive-manufactured by laser powder bed fusion (L-PBF). The maraging steel samples manufactured under different L-PBF process conditions (laser power P and scan speed v) were subjected to heat treatments at 550°C for various durations, compared with the results of the austenitized and water-quenched sample with fully martensite structure. The L-PBF manufactured samples exhibited the martensite structure (including localized austenite (γ) phases) containing submicron-sized cellular structures. Enriched alloy elements were detected along the cell boundaries, whereas such cellar structure was not found in the water-quenched sample. The localized alloy elements can be rationalized by the continuous variations in the γ-phase composition in solidification during the L-PBF process. The precipitation of nanoscale intermetallic phases and the following austenitic reversion occurred in all of the experimental samples. The L-PBF manufactured samples exhibited faster kinetics of the precipitation and austenite reversion than the water-quenched sample at elevated temperatures. The kinetics changed depending on the L-PBF process condition. The enriched Ni element (for stabilizing γ phase) localized at cell boundaries would play a role in the nucleation site for the formation of γ phase at 550°C, resulting in the enhanced austenite reversion in the L-PBF manufactured samples. The variation in the reaction kinetics depending on the L-PBF condition would be due to the varied thermal profiles of the manufactured samples by consecutive scanning laser irradiation operated under different P and v values.

Nano-apertures vs. nano-barriers: Surface scanning through obstacles and super-resolution in AFM-NSOM dual-mode

As part of the performance characterization of a combined and enhanced new AFM-NSOM tip-photo-detector, diffraction limitations were studied on two complementary samples: a nano-barrier embedded between two nano-apertures and one nano-aperture embedded between two nano-barriers. These consecutive multiple-obstacle scanning paths are part of this challenging specifications study of a new conical-shaped and drilled tip-photodetector, sharing a subwavelength aperture. A super-resolution algorithm feature was added in order to overcome possible obstacles, while scanning the same object with several small angles. The new multi-mode system includes scanning topography, optical imaging and an obstacle-overcoming algorithm. The present article study emphasizes the complexity of nano-scanning multiple-apertures/barriers. Both complementary analytical (Python) and numerical (Comsol) analyses are presented to forecast the expected scanning behavior and limitations. Moreover, in addition to a new concept of a combined AFM-NSOM drilled photo-sensor tip, several breakthroughs are presented in the algorithm itself: treatment of one unique pixel, angular scanning and reconstruction of sub-wavelength information. The uniqueness of the present study lies in its provision of a comprehensive solution to near field scanning: a paired hardware and software package solution.

Repeatability of choriocapillaris flow voids by optical coherence tomography angiography in central serous chorioretinopathy.

To assess the repeatability of flow signal voids (FSV) measurements of the choriocapillaris (CC) and choroid (CH) in central serous chorioretinopathy (CSCR) by Swept-Source optical coherence tomography angiography (SS-OCTA). Cross-sectional study including 104 eyes of 52 patients with unilateral CSCR. Two consecutive macular 6x6 mm SS-OCTA scans (Plex Elite 9000; Zeiss, Dublin, CA) were obtained from the affected eyes with persistent subretinal fluid (SRF) (CSCR group) and the fellow unaffected eyes (control group). FSV area and the number of contours measurements were analyzed using three slabs: inner CC, outer CC and CH. The repeatability of the measurements was assessed with intraclass correlation coefficients (ICC) and coefficients of variation (CV). In the CSCR group, ICCs for the FSV area in the three slabs were all ≥0.859, observing higher values for the outer CC and the CH (0.959 and 0.964) than for the inner CC (0.859). Similar ICC values were obtained for the FSV area in control eyes, observing the highest values for the outer CC (0.949), followed by the CH (0.932) and inner CC (0.844). Regarding the FSV number of contours measurements, ICCs were higher for the outer CC and CH (0.949 and 0.932) than for inner CC (0.844). CV for the FSV area was 4.7%, 3.8% and 8.6% in the CSCR eyes and 4.8%, 3.9% and 9.3% in the control group for the inner CC, outer CC and CH respectively. SS-OCTA offers good repeatability to quantify macular FSV in CSCR eyes and fellow eyes.

Ultra high precision in-vacuum long trace profiler for real time slope determination of optical surface

The development of an in-vacuum long trace profiler (IVLTP) which can provide ultra high precision real time measurements on the surface slope of optical elements is reported. The unique features of this instrument include a specifically designed ultra high repeatability linear slide, a pentamirror composed of two plane mirrors of ultra low slope error, and an ultra high vacuum (UHV) compatible complementary metal oxide semiconductor (CMOS) image sensor. The mechanical system is made of Invar 36 alloy to reduce the room temperature drift effect during data acquisitions. Each IVLTP scan completes in 120 seconds, covering a 168 mm of surface length and generating more than 5000 slope data points. The root mean square (RMS) of the difference between two consecutive scans was found to be 0.0081 μrad on average and 0.0045 μrad RMS at its best. The main application of this IVLTP is to provide the real time feedback signals needed for controlling the 25-actuator surface benders of the active mirrors and active gratings installed in the ultra high resolution soft X-ray beamlines at the Taiwan Photon Source (TPS).

Does Double Reading of Screening Breast MRI Scans Impact Recall Rates and Cancer Detection?

Objective: To investigate the effect of double reads by a second radiologist on cancer detection rate (CDR), positive predictive value of recommendation for tissue diagnosis (PPV2), and the positive predictive value of biopsy performed (PPV3) for biopsy recommendations in high-risk screening breast MRIs. Methods: The policy of second reads on biopsies recommended for MRIs was prospectively implemented in October 2019. This IRB approved retrospective analysis compared consecutive high-risk screening breast MRI scans performed in a single academic institution between 06/01/2018 to 06/01/2019 (pre-intervention) with screening breast MRI scans performed between 10/31/2019 to 10/31/2020 (post-intervention). Pathology results after biopsy were recorded. Testing of association was performed using the Chi-square test. Results/Discussion: A total of 1124 screening breast MRIs in the pre-intervention and 1672 screening breast MRIs were performed in the post-intervention periods. Biopsies were recommended in 8.6% (97/1124) of pre-intervention and 5.5% (92/1672) of post-intervention MRIs (P = .0012). There was a non-significant increase in PPV2 from pre-intervention 10.3% (10/97) to post-intervention 18.4% (17/92) (P = .109) and in PPV3 from 14% (10/71) to 22.9% (17/74), respectively (P = .17). Similar cancer detection rates, 8.9/1000 (10/1124) and 10.2/1000 (17/1672) (P = .736) were diagnosed in pre-intervention and post-intervention periods, respectively. Conclusion: Double reading of screening breast MRI scans significantly reduced the number of unnecessary biopsies without significant impact in the PPVs or cancer detection rate.