Plasma dynamics, instabilities and OH generation in a pulsed atmospheric pressure plasma with liquid cathode: a diagnostic study

While plasma-liquid interactions have been an important focus in the plasma research community, the impact of the strong coupling between plasma and liquid on plasma properties and processes remains not fully understood. In this work, we report on the impact of the applied voltage, pulse width and liquid conductivity on the plasma morphology and the OH generation for a positive pulsed DC atmospheric pressure plasma jet with He-0.1% H2O mixture interacting with a liquid cathode. We adopted diagnostic techniques of fast imaging, 2D laser induced fluorescence (LIF) of OH and Thomson scattering spectroscopy. We show that plasma instabilities and enhanced evaporation occur and have a significant impact on the OH generation. At elevated plasma energies, it is found that the plasma contracts due to a thermal instability through Ohmic heating and the contraction coincides with a depletion in the OH density in the core due to electron impact dissociation. For lower plasma energies, the instability is suppressed/delayed by the equivalent series resistor of the liquid electrode. An estimation of the energy flux from the plasma to the liquid shows that the energy flux of the ions released into the liquid by positive ion hydration is dominant, and significantly larger than the energy needed to evaporate sufficient amount of water to account for the measured H2O concentration increase near the plasma-liquid interface.

Compressed Lateral and anteroposterior Anatomical Systematic Sequences «CLASS»: compressed MRI sequences with assessed anatomical femoral and tibial ACL's footprints, a feasibility study

Purpose This study's main objective is to assess the feasibility of processing the MRI information with identified ACL-footprints into 2D-images similar to a conventional anteroposterior and lateral X-Ray image of the knee. The secondary aim is to conduct specific measurements to assess the reliability and reproducibility. This study is a proof of concept of this technique. Methods Five anonymised MRIs of a right knee were analysed. A orthopaedic knee surgeon performed the footprints identification. An ad-hoc software allowed a volumetric 3D image projection on a 2D anteroposterior and lateral view. The previously defined anatomical femoral and tibial footprints were precisely identified on these views. Several parameters were measured (e.g. coronal and sagittal ratio of tibial footprint, sagittal ratio of femoral footprint, femoral intercondylar notch roof angle, proximal tibial slope and others). The intraclass correlation coefficient (ICCs), including 95% confidence intervals (CIs), has been calculated to assess intraobserver reproducibility and interobserver reliability. Results Five MRI scans of a right knee have been assessed (three females, two males, mean age of 30.8 years old). Five 2D-"CLASS" have been created. The measured parameters showed a "substantial" to "almost perfect" reproducibility and an "almost perfect" reliability. Conclusion This study confirmed the possibility of generating "CLASS" with the localised centroid of the femoral and tibial ACL footprints from a 3D volumetric model. "CLASS" also showed that these footprints were easily identified on standard anteroposterior and lateral X-Ray views of the same patient, thus allowing an individual identification of the anatomical femoral and tibial ACL's footprints. Level of evidence Level IV diagnostic study

Intraoperative hyperspectral imaging (HSI) as a new diagnostic tool for the detection of cartilage degeneration

To investigate, whether hyperspectral imaging (HSI) is able to reliably differentiate between healthy and damaged cartilage tissue. A prospective diagnostic study was performed including 21 patients undergoing open knee surgery. HSI data were acquired during surgery, and the joint surface’s cartilage was assessed according to the ICRS cartilage injury score. The HSI system records light spectra from 500 to 1000 nm and generates several parameters including tissue water index (TWI) and the absorbance at 960 nm and 540 nm. Receiver operating characteristic curves were calculated to assess test parameters for threshold values of HSI. Areas with a cartilage defect ICRS grade ≥ 3 showed a significantly lower TWI (p = 0.026) and higher values for 540 nm (p < 0.001). No difference was seen for 960 nm (p = 0.244). For a threshold of 540 nm > 0.74, a cartilage defect ICRS grade ≥ 3 could be detected with a sensitivity of 0.81 and a specificity of 0.81. TWI was not suitable for cartilage defect detection. HSI can provide reliable parameters to differentiate healthy and damaged cartilage. Our data clearly suggest that the difference in absorbance at 540 nm would be the best parameter to achieve accurate identification of damaged cartilage.

Contrast enhanced spectral mammography (CESM) guided breast biopsy as an alternative to MRI guided biopsy

Objective: Contrast Enhanced Spectral Mammography (CESM) breast biopsy has been recently introduced into clinical practice. This short communication describes the technique and potential as an alternative to MRI guided biopsy. Methods and materials: An additional abnormality was detected on a breast MRI examination in a patient with lobular carcinoma. The lesion was occult on conventional mammography, tomosynthesis and ultrasound and required histological diagnosis. Traditionally this would have necessitated a MRI guided breast biopsy, but was performed under CESM guidance. Results: A diagnostic CESM study was performed to ensure the lesion visibility with CESM and then targeted under CESM guidance. A limited diagnostic study, CESM scout and paired images for stereotactic targeting were obtained within a 10 min window following a single injection of iodinated contrast agent. The time from positioning in the biopsy device to releasing compression after biopsy and marker clip placement was 15 min. The biopsy confirmed the presence of multifocal breast cancer. Conclusion: CESM guided breast biopsy is a new technique that can be successfully used as an alternative to MRI guided breast biopsy. Advances in knowledge: CESM guided biopsy can be used to sample breast lesions which remain occult on standard mammography and ultrasound.

The Performance of Artificial Intelligence in Cervical Colposcopy: A Retrospective Data Analysis

Objective. We aimed to evaluate the performance of artificial intelligence (AI) system in detecting high-grade precancerous lesions. Methods. A retrospective and diagnostic study was conducted in Chongqing Cancer Hospital. Anonymized medical records with cytology, HPV testing, colposcopy findings with images, and the histopathological results were selected. The sensitivity, specificity, and areas under the curve (AUC) in detecting CIN2+ and CIN3+ were evaluated for the AI system, the AI-assisted colposcopy, and the human colposcopists, respectively. Results. Anonymized medical records from 346 women were obtained. The images captured under colposcopy of 194 women were found positive by the AI system; 245 women were found positive either by human colposcopists or the AI system. In detecting CIN2+, the AI-assisted colposcopy significantly increased the sensitivity (96.6% vs. 88.8%, p = 0.016 ). The specificity was significantly lower for AI-assisted colposcopy (38.1%), compared with human colposcopists (59.5%, p < 0.001 ) or the AI system (57.6%, p < 0.001 ). The AUCs for the human colposcopists, AI system, and AI-assisted colposcopy were 0.741, 0.765, and 0.674, respectively. In detecting CIN3+, the sensitivities of the AI system and AI-assisted colposcopy were not significantly higher than human colposcopists (97.5% vs. 92.6%, p = 0.13 ). The specificity was significantly lower for AI-assisted colposcopy (37.4%) compared with human colposcopists (59.2%, p < 0.001 ) or compared with the AI system (56.6%, p < 0.001 ). The AUCs for the human colposcopists, AI system, and AI-assisted colposcopy were 0.759, 0.674, and 0.771, respectively. Conclusions. The AI system provided equally matched sensitivity to human colposcopists in detecting CIN2+ and CIN3+. The AI-assisted colposcopy significantly improved the sensitivity in detecting CIN2+.

Momentum budget of low level westerly jet during monsoon onset

In this paper a diagnostic study is carried Out to the source and sink terms for the formation and acceleration/deceleration of low level westerly Jet during monsoon onset. For this purpose momentum budget technique is used. The budget equation is derived in the (x.y.p.t) system. The area is confined to a small box the boundaries over the central Arabian Sea the westerly flow prominent during the onset of monsoon. Each tem in the budget equation is calculated separately. FGG E III b. 1200 UTC data set is used for the analysis. The Coriolis force term is found to be sink term rather than a source tern Tram. Transient north-south term is prominent source terms when time averaged momentum budget is considered. When the time averaged momentum budget for each pressure slab is considered. it is concluded that, north-south force terms are prominent source terms of momentum for all slabs and large .cumulus type convection may contribute to frictional dissipation of momentum for the upper pressure slabs. Frictional force is the main sink term when one examines the momentum budget for each day and the source term are varying day-by-day. On the average, the jet is accelerated during the period. It is also found that the net momentum tendency is small and oscillatory in nature. it is also found that at Minicoy. rainfall is inversely related to momentum tendency and whenever westerly jet is strong (weak) the rainfall is less (more). Distribution of U-momentum is also found to be oscillatory ill nature.

Diffusion tensor imaging in unclear intramedullary tumor-suspected lesions allows separating tumors from inflammation

Design Prospective diagnostic study. Objectives Primary imaging-based diagnosis of spinal cord tumor-suspected lesions is often challenging. The identification of the definite entity is crucial for dedicated treatment and therefore reduction of morbidity. The aim of this trial was to investigate specific quantitative signal patterns to differentiate unclear intramedullary tumor-suspected lesions based on diffusion tensor imaging (DTI). Setting Medical Center - University of Freiburg, Germany. Methods Forty patients with an unclear tumor-suspected lesion of the spinal cord prospectively underwent DTI. Primary diagnosis was determined by histological or clinical work-up or remained indeterminate with follow-up. DTI metrics (FA/ADC) were evaluated at the central lesion area, lesion margin, edema, and normal spinal cord and compared between different diagnostic groups (ependymomas, other spinal cord tumors, inflammations). Results Mean DTI metrics for all spinal cord tumors (n = 18) showed significantly reduced FA and increased ADC values compared to inflammatory lesions (n = 8) at the lesion margin (p < 0.001, p = 0.001) and reduced FA at the central lesion area (p < 0.001). There were no significant differences comparing the neoplastic subgroups of ependymomas (n = 10) and other spinal cord tumors (n = 8), but remaining differences for both compared to the inflammation subgroup. We found significant higher ADC (p = 0.040) and a trend to decreased FA (p = 0.081) for ependymomas compared to inflammations at the edema. Conclusion Even if distinct differentiation of ependymomas from other spinal cord neoplasms was not possible based on quantitative DTI metrics, FA and ADC were feasible to separate inflammatory lesions. This may avoid unnecessary surgery in patients with unclear intramedullary tumor-suspected lesions.

The Radial Synergy Test: An Aid to Diagnose de Quervain’s Tenosynovitis

Background: Diagnosis of de Quervain’s tenosynovitis is made clinically. Finkelstein’s and Eichoff’s tests are commonly utilized examination maneuvers. Their specificity has been questioned due to a propensity to provoke pain in asymptomatic patients. Using the principle of synergism, the novel radial synergy test takes advantage of isometric contraction of the first dorsal compartment with resisted abduction of the small finger. Methods: Electromyography was performed on 3 authors and the first dorsal compartment sampled during the maneuver. Sensitivity evaluation was performed via retrospective chart review for patients diagnosed with de Quervain’s from 2013 to 2018. Inclusion criteria were documented radial synergy test, Eichoff’s test, and ≥90% pain relief after lidocaine/corticosteroid injection. We enrolled 222 patients with 254 affected extremities. Specificity evaluation was performed via a prospective cohort of volunteers undergoing radial synergy and Eichoff’s tests. Inclusion criterion was lack of preexisting wrist pain. Score > 0 on Visual Analog Scale was considered positive. We enrolled 48 volunteers with 93 tested extremities. Results: Electromyography revealed positive recruitment of the first dorsal compartment. Sensitivity of the radial synergy test was inferior to Eichoff’s test (97% vs 91%, relative risk [RR] = 0.93 [95% confidence interval [CI] = 0.89-0.97], P < .01). Specificity of the radial synergy test was superior to Eichoff’s test (99% vs 74%, RR = 1.33 [95% CI = 1.18-1.51], P < .001). Conclusions: We describe and evaluate the radial synergy test, a novel examination maneuver to aid the diagnosis of de Quervain’s. This serves as an adjunct for future diagnostic evaluations with its high specificity. Level of Evidence: Level II, diagnostic study.