Longest Axis Research Articles

Evaluating patient-specific neoadjuvant regimens for breast cancer via a mathematical model constrained by quantitative magnetic resonance imaging data

The ability to accurately predict response and then rigorously optimize a therapeutic regimen on a patient-specific basis, would transform oncology. Toward this end, we have developed an experimental-mathematical framework that integrates quantitative magnetic resonance imaging (MRI) data into a biophysical model to predict patient-specific treatment response of locally advanced breast cancer to neoadjuvant therapy. Diffusion-weighted and dynamic contrast-enhanced MRI data is collected prior to therapy, after 1 cycle of therapy, and at the completion of the first therapeutic regimen. The model is initialized and calibrated with the first 2 patient-specific MRI data sets to predict response at the third, which is then compared to patient outcomes (N = 18). The model's predictions for total cellularity, total volume, and the longest axis at the completion of the regimen are significant within expected measurement precision (P< 0.05) and strongly correlated with measured response (P < 0.01). Further, we use the model to investigate, in silico, a range of (practical) alternative treatment plans to achieve the greatest possible tumor control for each individual in a subgroup of patients (N = 13). The model identifies alternative dosing strategies predicted to achieve greater tumor control compared to the standard of care for 12 of 13 patients (P < 0.01). In summary, a predictive, mechanism-based mathematical model has demonstrated the ability to identify alternative treatment regimens that are forecasted to outperform the therapeutic regimens the patients clinically. This has important implications for clinical trial design with the opportunity to alter oncology care in the future.

Prenatal assessment of congenital diaphragmatic hernia at north american fetal therapy network centers: A continued plea for standardization.

Prenatal work-up for congenital diaphragmatic hernia (CDH) is important for risk stratification, standardization, counseling, and optimal therapeutic choice. To determine current practice patterns regarding prenatal CDH work-up, including prenatal ultrasound and magnetic resonance imaging (MRI) use, and to identify areas for standardization of such evaluation between fetal centers. A survey regarding prenatal CDH work-up was sent to each member center of the North American Fetal Therapy Network (NAFTNet) (n = 36). All responded. Sonographic measurement of lung-to-head ratio (LHR) was determined by all, 89% (32/36) of which routinely calculate observed-to-expected LHR. The method for measuring LHR varied: 58% (21/36) used a "trace" method, 25% (9/36) used "longest axis," and 17% (6/36) used an "antero-posterior" method. Fetal MRI was routinely used in 78% (28/36) of centers, but there was significant variability in fetal lung volume measurement. Whereas all generated a total fetal lung volume, the planes, methodology and references values varied significantly. All evaluated liver position, 71% (20/28) evaluated stomach position and 54% (15/28) quantified the degree of liver herniation. More consistency in workup was seen between centers offering fetal intervention. Prenatal CDH work-up and management differs considerably among North American fetal diagnostic centers, highlighting a need for its standardization.

PEMERIKSAAN MRI PELVIS WANITA DENGAN KLINIS ENDOMETRIOSIS

Introduction: The pelvic anatomy is an ideal part of using Magnetic Resonance Imaging (MRI) as it is particularly suitable for detecting abnormalities in soft tissues. Endometriosis is a disease that is 10% suffered by women in the premenopausal or reproductive period, in which a tissue that resembles endometrium outside the uterus is purely a chronic inflammatory action.&#x0D; Materials and Methods: This research is descriptive qualitative with case study approach. MRI Pelvic Women Examination with clinical Endometriosis using protocol sequences: T2 TSE and T1 SPAIR sagittal planes; T2 TSE long axis (LAX) and short axis (SAX); T1 TSE; T1 FLAIR, T1 TSE FS, EP2D Diffusion axial planes; as well as the T2 Haste FS of coronal planes thick slice and T2 Spc3D sequences.&#x0D; Results and Discussion: In the outcome of the images seen cyst endometriosis in the right-left ovarium, hypointense on T2 and hyperintense on T1 and T1 FS. Enlarged uterine size. Seen multiple cysts of hypointense posterior uterine lesions in sequence T2 and hyperintens in sequence T1 SPAIR.Conclusions: MRI Pelvic Women Examination have a good role to diagnose the pathologies of female genetic organs and the anatomy between organs can be clearly distinguished by the giving of vaginal and rectum ultrasound jelly, and full bladder.

Flexible ureteroscopy and laser lithotripsy for renal stones 2 cm or greater: A single institutional experience.

With improvements in endoscopy and laser technology, flexible ureteroscopy (FURS) has been a viable treatment option for large renal stones. Here, we share our experience of the FURS treatment for renal stones 2 cm or greater.We evaluated 251 consecutive patients who underwent FURS and holmium laser lithotripsy for renal stones 2 cm or greater between January 2015 and April 2019. Stone size was defined as the longest axis on non-contrast computed tomography. Data were retrospectively collected from electronic medical records. Patient demographics, stone clearance rates and perioperative complications were evaluated.There were 165 male patients and 86 female patients with an average age of 46.9 years (range 22–80 years). Mean stone size was 2.7 cm and the average number of procedures was 1.4 (range 1–5). The stone-free rate at the end of the first, second and third procedure was 61.9%, 82.9%, and 89.5%, respectively. The final stone-free rate decreased as stone size grows, and it was only 58.3% for kidney stones larger than 4 cm after an average of 2.3 procedures. The lowest clearance rates were observed in lower calyx calculi (87.2%) and multiple calyx calculi (83.5%). The overall complication rate was 15.1%, and the most common complication was postoperative fever (9.6%). One patient required blood transfusion, owing to postoperative coagulation disorders induced by urosepsis.Single or staged FURS is a practical treatment option for the renal stones sized 2 to 4 cm with acceptable efficacy and safety. Stone clearance rate of FURS treatment is mainly affected by stone size and location.

Abstract 5485: Patient-specific neoadjuvant regimens for breast cancer identified via image-driven mathematical modeling

Abstract Introduction: We show that the combination of quantitative magnetic resonance imaging (MRI) and mathematical modeling can accurately predict tumor response for individual patients, and we demonstrate the selection of personalized therapeutic regimens using our mathematical model to vary, in silico, a range of clinically feasible treatment plans to achieve the greatest tumor control. Methods: Breast cancer patients (N = 18) were scanned by MRI at three time points during neoadjuvant therapy (NAT): 1) prior to NAT, 2) after one cycle of their initial NAT regimen, and 3) after the completion of their initial NAT regimen. Specifically, diffusion-weighted MRI data characterizing tumor cellularity was collected to estimate tumor cell burden, and dynamic contrast-enhanced MRI data was collected to estimate the local drug delivery using pharmacokinetic analysis and population-derived plasma curves of the administered chemotherapies. To predict tumor response, we calibrated our tissue scale, 3D, biophysical mathematical model to each patient's MRI data set using their first two scans. Using the calibrated, patient-specific parameters, the model was projected forward to the third scan time. The predicted total tumor cellularity, volume, and longest axis were compared to the actual values measured from the patient's third scan. Following evaluation of the model's predictive ability, we then employed the model to identify potentially superior, clinically relevant, alternative dosing regimens for each patient. The alternative regimens were defined using the same total amount of drug each patient received during their standard regimen, while varying dosages and frequency between their second and third scans. Statistical analysis was completed with Pearson correlation and Wilcoxon signed rank test. Results: The model's predictions of tumor response are significantly correlated to the measured tumor burden at the time of scan 3 (r2 &amp;gt; 0.88, p &amp;lt; 0.01) for total cellularity, total volume, and longest axis. For the alternative dosing regimens assessed, the model predicted that individual patients could have achieved, on average, an additional 21% (0-46%) reduction in total cellularity. The optimal dosing regimens chosen by the model were predicted to significantly outperform standard regimens for tumor control (p &amp;lt; 0.001). Conclusions: These results suggest that the mathematical model can be predictive of tumor response by MRI in the clinical setting using data at the earliest times of therapy. With in silico studies, we illustrate how therapeutic regimens can be selected for individual patients for better tumor control, revealing that standard regimens may not be the most effective for every patient. These results represent a first step towards mathematically-based, personalized patient regimens. Future work aims to optimize therapy regimens via established optimal control theory methods. Citation Format: Angela M. Jarrett, Ernesto A. Lima, David A. Hormuth, Chengyue Wu, John Virostko, Anna G. Sorace, Julie C. DiCarlo, Debra Patt, Boone Goodgame, Sarah Avery, Thomas E. Yankeelov. Patient-specific neoadjuvant regimens for breast cancer identified via image-driven mathematical modeling [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5485.

Can the law of maximum entropy production describe the field-induced orientation of ellipsoids of rotation?

Electrostatic approaches are successful in explaining the experimentally observed field-induced orientations of the axis with the highest Clausius-Mossotti factor. For conductive or nonconductive, prolate or oblate spheroids, this is always the longest axis when different frequency-dependent dispersions of their effective conductivity along the three principal axes are neglected. Here, it is shown that these orientations correspond to the ‘law of maximum entropy production’ (LMEP) by comparing the axes-ratio dependencies of the torques calculated with the electrostatic approach with the effective conductivity differences between a suspension with field-oriented and randomly oriented objects. At low volume fraction, the obtained conductivity differences, which enter the LMEP, predict almost exactly the torque curves when plotted over axis ratio of the objects. Since the field-induced orientation at constant field strength increases the effective conductivity, the suspension system obviously does not behave according to the Prigogine principle, which would demand the minimization of energy dissipation and entropy production through object orientation. However, the Prigogine principle requires the suspension system to be close to equilibrium in its linear range. These conditions must be rejected if the LMEP is to be applied. Apparently the LMEP provides a phenomenological criterion for axis orientation, even though it is not yet clear whether and how increased conductivity, power dissipation and entropy production can also be introduced as driving forces at the single object level. However, the results also indicate that the disregard of energy dissipation may not be a problem in the electrostatic description of field-induced object orientation.

Spin Filtering Along Chiral Polymers.

Spin‐dependent conduction and polarization in chiral polymers were studied for polymers organized as self‐assembled monolayers with conduction along the polymer backbone, namely, along its longer axis. Large spin polarization and magnetoresistance effects were observed, showing a clear dependence on the secondary structure of the polymer. The results indicate that the spin polarization process does not include spin flipping and hence it results from backscattering probabilities for the two spin states.

Spin Filtering Along Chiral Polymers

AbstractSpin‐dependent conduction and polarization in chiral polymers were studied for polymers organized as self‐assembled monolayers with conduction along the polymer backbone, namely, along its longer axis. Large spin polarization and magnetoresistance effects were observed, showing a clear dependence on the secondary structure of the polymer. The results indicate that the spin polarization process does not include spin flipping and hence it results from backscattering probabilities for the two spin states.

Automated Multi-Chamber Segmentation And Imaging Plane Re-slicing Of Cardiac CT Images Via Deep Learning

Introduction: Cardiac function assessment requires accurate segmentation of chamber volumes, and multiple long-axis (LAX) planes and the short-axis (SAX) stack are the standards for visualization of cardiac anatomy. However, cardiac CT currently requires manual segmentation and re-slicing of planes after acquisition. We developed a deep learning (DL) system to simultaneously segment multiple chambers and identify cardiac imaging planes to enable routine evaluation.

Cross-stream migration of non-spherical particles in a second-order fluid – theories of particle dynamics in arbitrary quadratic flows

Particle migration in viscoelastic suspensions is vital in many applications in the biomedical community and the chemical/oil industries. Previous studies have provided insight into the motion of spherical particles in simple viscoelastic flows, yet the combined effect of more complex flow profiles and particle shapes is under-explored. Here, we develop approximate analytical expressions for the polymeric force and torque on an arbitrarily shaped particle in a second-order fluid, subject to a general quadratic flow field. This model is exact for the case when the first and second normal stress coefficients satisfy . Under this assumption, we examine how particle shape alters cross-stream particle migration (i.e. lift) and particle orientation in both shear- and pressure-driven flows. In shear-driven flows, we observe that spheroidal particles adjust their orientation to align their longer axis along the vorticity direction, although significant deviations from slender-body theories occur for finite aspect ratios. In a slit-like pressure-driven flow, we identify scaling theories to quantify how the particle lift depends on shape for a wide variety of shapes. We find that prolate particles slowly transition to a log-rolling state as they approach the flow centre, with the lift initially being larger than that of an equal-volume sphere, but then becoming smaller as log-rolling emerges. The net effect is a smaller average migration speed for particles with larger aspect ratio. Lastly, we discuss future directions for experimental studies on particle dynamics as well as directions to extend the current work towards more complicated systems.

Initial experience of irreversible electroporation for locally advanced pancreatic cancer in a Korean population.

Locally advanced pancreatic cancer (LAPC) is one of the most aggressive malignancies. Irreversible electroporation (IRE) is a novel technique that uses a non-thermal ablation to avoid vessel or duct injury. To investigate the safety and efficacy of IRE for the management of LAPC in a Korean population. Twelve patients (median age 64 years; age range 46-73 years) treated between December 2015 and March 2017 underwent intraoperative IRE for LAPC. Technical success and clinical outcomes, including complications, serum pancreatic enzyme levels, overall survival (OS), and progression-free survival (PFS), were evaluated. Tumors were located in the pancreas head in 7 (58.3%) patients and in the body/tail in 5 (41.7%) patients. The median tumor diameter in the longest axis was 3.1 cm. Vascular invasion was observed in all patients and bowel abutment in 3 (25%) patients. Technical success was achieved in all patients. The median serum levels of amylase and lipase were 55 U/L and 31 U/L, respectively, at baseline, increased to 141.5 U/L (P = 0.008) and 53 U/L (P = 0.505), respectively, one day after IRE, and normalized after one week. The rate of 30-day mortality of unknown relation was 8.3% (one individual experienced massive hematemesis 12 days after IRE). The median OS from diagnosis and IRE was 24.5 months and 13.5 months, respectively. The median PFS from diagnosis and IRE was 19.2 months and 8.6 months, respectively. For patients with LAPC, IRE appears to be a promising treatment modality with an acceptable safety profile.

Short-axis versus long-axis approach in ultrasound-guided central venous cannulation: an updated systematic review and meta-analysis

To compare the success rate and safety of the short-axis (SAX) approach and long- axis (LAX) approach to ultrasound-guided central venous cannulation. Electronic bibliographic databases including PubMed, Cochrane Library, Science Direct, and Web of Science were searched for randomized controlled trials comparing ultrasound-guided central venous cannulation via the LAX and SAX approaches published during the period from January, 2011 to October, 2017. We extracted the data from the eligible studies and assessed the first-attempt success rate, overall puncture success rate and complication rate of the two approaches. The relative risk (RR) with the 95% CI was calculated using a fixed or random effects model. Seven randomized controlled trials were included for meta-analysis. The results showed that the first-attempt success rate was significantly higher in the SAX group than in the LAX group (RR=1.27, 95%CI: 1.11-1.46; P=0.0005, I2=49%), but the overall puncture success rate did not differ significantly between the two approaches (RR=1.04, 95%CI: 0.97-1.10; P=0.27, I2=84%). The incidence of accidental arterial puncture with the SAX approach was significantly lower than that with the LAX approach (RR=1.04; 95%CI: 1.01-1.08; P=0.01, I2=30%). Ultrasound-guided central venous cannulation via the SAX approach, as compared with the LAX approach, can increase first-attempt success rate and reduce the incidence of accidental arterial puncture.

Retinal Pigment Epithelium Cell Density and Bruch\u2019s Membrane Thickness in Secondary versus Primary High Myopia and Emmetropia

To assess differences between secondary high myopia (SHM) due to congenital glaucoma and primary high myopia (PHM) and non-highly myopic eyes (NHM) in the relationships between axial length and Bruch’s membrane (BM) thickness and retinal pigment epithelium (RPE) density. The histomorphometric study included human globes enucleated for reasons such as malignant uveal melanoma, end-stage painful secondary angle-closure glaucoma and congenital glaucoma. BM thickness and RPE cell density were measured upon light microscopy. The investigation included 122 eyes (mean axial length: 26.7 ± 3.7 mm; range: 20.0–37.0 mm): 7 eyes with SHM (axial length: 33.7 ± 2.1 mm; range: 31.0–37.0 mm), 56 eyes with PHM (mean axial length: 29.1 ± 2.4 mm; range: 26.0–36.0 mm) and 59 eyes in the NHM-group (axial length: 23.5 ± 1.3 mm; range: 20.0–25.5 mm). In the SHM group, longer axial length was associated with lower RPE cell density at the posterior pole (standardized regression coefficient beta: 0.92; non- standardized regression coefficient B: −2.76; 95% confidence interval (CI): −4.41, −1.10;P = 0.01), at the midpoint posterior pole/equator (beta: −0.87; B: −3.60; 95% CI: −6.48, −0.73;P = 0.03), and at the equator (beta: −0.88; B: −0.95; 95% CI: −1.68, −0.23; P = 0.02), but not at the ora serrata (P = 0.88). In the PHM-group and NHM group, RPE cell density at the posterior pole (P = 0.08) and ora serrata (P = 0.88) was statistically independent of axial length, while at the midpoint posterior pole/equator (P = 0.01) and equator (P < 0.001), RPE cell density decreased with longer axis. BM thickness in the SHM group decreased with longer axial length at the posterior pole (beta: −0.93;B: −0.29; 95% CI: −0.39, −0.14; P = 0.003), midpoint posterior pole/equator (beta: −0.79; B: −0.22; 95% CI: −0.42, −0.02; P = 0.035) and equator (beta: −0.84; B: −0.21; 95% CI: −0.37, −0.06; P = 0.017), while in the PHM-group and NHM-group, BM thickness at any ocular region was not statistically significantly correlated with axial length (all P > 0.05). In the SHM-group, but not in the PHM-group or NHM-group (P = 0.98), lower BM thickness was associated with lower RPE cell density (beta: 0.93; B: 0.09; 95% CI: 0.04, 0.14; P = 0.007), while in the eyes without congenital glaucoma the relationship was not statistically significant. In SHM in contrast to PHM, BM thickness and RPE cell density decrease in a parallel manner with longer axial length. The findings fit with the notion of BM being a primary driver in the process of axial elongation in PHM as compared to SHM.

Resistive and impedimetric properties of elastic composite based on graphene and CNT under uniaxial compressive displacement

In this paper the fabrication of built–in rubber graphene and CNT based elastic composite samples under uniaxial compressive displacements is presented along with the investigation of their resistive and impedimetric properties. Thin layer structure of CNT-graphene-CNT was deposited on one side of a rectangular prism elastic rubber substrate through rubbing-in technology. The requirements of the resistance and impedances along the three orthogonal axis at the frequencies of 100Hz, 1kHz, 10kHz, 100 kHz and 200 kHz respectively were investigated from uniaxial compressive displacements that were applied in the longest axis directions of the sample. The anisotropy for the requirements of the resistance and impedances on the compressive displacements along the longest axis of the sample was also observed. The longitudinal resistance and impedance of the samples were decreased under the effect of both longitudinal compressive displacement and for the displacement in the direction perpendicular to the surface of graphene film. The longitudinal resistance and impedances increased with increase of the transverse displacement along the surface of graphene film. Influence of the uniaxial compressive displacements on the interatomic distances was investigated through XRD. Magnitude of resistance and impedances of the samples were decreased with increase of temperature and humidity.

ShapeMetrics: A userfriendly pipeline for 3D cell segmentation and spatial tissue analysis

The demand for single-cell level data is constantly increasing within life sciences. In order to meet this demand, robust cell segmentation methods that can tackle challenging in vivo tissues with complex morphology are required. However, currently available cell segmentation and volumetric analysis methods perform poorly on 3D images. Here, we generated ShapeMetrics, a MATLAB-based script that segments cells in 3D and, by performing unbiased clustering using a heatmap, separates the cells into subgroups according to their volumetric and morphological differences. The cells can be accurately segregated according to different biologically meaningful features such as cell ellipticity, longest axis, cell elongation, or the ratio between cell volume and surface area. Our machine learning based script enables dissection of a large amount of novel data from microscope images in addition to the traditional information based on fluorescent biomarkers. Furthermore, the cells in different subgroups can be spatially mapped back to their original locations in the tissue image to help elucidate their roles in their respective morphological contexts. In order to facilitate the transition from bulk analysis to single-cell level accuracy, we emphasize the user-friendliness of our method by providing detailed step-by-step instructions through the pipeline hence aiming to reach users with less experience in computational biology.

Roa haraguchiae, a new species of butterflyfish (Teleostei: Perciformes: Chaetodontidae) from Japan and the Philippines

A new butterflyfish, Roa haraguchiae, is described on the basis of eight specimens (63.2–92.8 mm standard length: SL) collected from Japan and the Philippines. The new species is most similar to Roa rumsfeldi Rocha, Pinheiro, Wandell, Rocha and Shepherd 2017, known only from the holotype from the Philippines. Both species are distinguished from all other congeners by the following combination of characters: long snout (12.6–14.1% of SL), lesser head depth (46.2–54.9%), short postorbital area (12.1–14.1%) and pectoral fin (27.9–32.4%), and second and third bands on the body without blackish edges. The new species is however easily distinguished from R. rumsfeldi (based on the original description and an additional Philippine specimen) in having 5–8 non-pored lateral-line scales (vs. 13 scales in the latter), 11 or 12 scale rows above the lateral line (vs. 8), 22–28 scale rows below the lateral line (vs. 19), 10–12 scale rows under the longer axis of a black blotch on the dorsal-fin soft-rayed portion (vs. 8), the anterior margin of the second body band not reaching anteroventrally to the pelvic-fin spine base, and the pelvic-fin spine and first soft ray white (vs. black).

Geometrical analysis for assessing torsional alignment of humerus

BackgroundCompared to other types of surgeries, minimally invasive surgeries (MISs) of humeral shaft fractures are associated with less radial nerve injury, less soft tissue injury and higher union rate. However, malrotation often occurs in MISs when closed reduction methods are used.This study aims to define specific palpable landmarks to help surgeons determine the correct torsional angle and reduce the incidence of malrotation.MethodsTwenty-eight normal humeral computed tomography scans were retrieved from our image database. One line was drawn through the vertices of the intertubercular sulcus of the humeral head in the coronal view, and another line was drawn through the longest axis between the medial and lateral condyles in the coronal view. The angle between these two lines was measured at least 3 times for each scan.ResultsThe profile of the intertubercular sulcus tangent line of the humeral head and the axis of the distal humerus was identified as the most accurate method for assessing the precision of torsion during MIS for humeral shaft fractures. The transepicondylar axis line is more internally rotated than the intertubercular sulcus tangent line. The mean angle was measured to be 41.1 degrees.ConclusionsThe axis of the distal humeral condyles is internally rotated by approximately 41.1 degrees compared with the intertubercular sulcus tangent line of the humeral head. Minimally invasive surgeries can be performed by using these palpable landmarks. The torsional deformities can be reduced with the proper angle adjustment without the need for fluoroscopy. It can also be used to treat unstable comminuted humeral fractures.Level of evidenceRetrospective Study, Diagnostic study, Level III.

On the aspect ratio of ’Oumuamua : less elongated shape for irregular surface properties

ABSTRACT The large brightness variation in the observed light curve of ’Oumuamua is probably related to its shape, i.e. to the ratio between its longest axis and its shortest axis (aspect ratio). Several approaches found the aspect ratio of ’Oumuamua to be unusually elongated. Moreover, the spin axis orientation has to be almost perpendicular to the observer in order to obtain such an extreme light curve, a configuration which is unlikely. However, interstellar ’Oumuamua may have different surface properties than we know in our Solar system. Therefore, in this work we widen the parameter space for surface properties beyond the asteroid-like models and study its effect on ’Oumuamua’s light curve. We calculate reflection from a rotating ellipsoidal object for four models: Lambertian reflection, specular reflection, single scattering diffusive, and backscatter . We then calculate the probability to obtain a light-curve ratio larger than the observed, as a function of the object’s aspect ratio, assuming an isotopic spin orientation distribution. We find the elongation of ’Oumuamua to be less extreme for the Lambertian and specular reflection models. Consequently, the probability to observe the light-curve ratio of ’Oumuamua given its unknown spin axis orientation is larger for those models. We conclude that different surface reflection properties may suggest alternatives to the extreme shape of ’Oumuamua , relieving the need for complicated formation scenario, extreme albedo variation, or unnatural origin. Although the models suggested here are for ideal ellipsoidal shape and ideal reflection method, the results emphasize the importance of surface properties for the derived aspect ratio.

Finite element analysis of Tumor Treating Fields in a patient with posterior fossa glioblastoma

IntroductionTumor Treating Fields (TTFields) are alternating electric fields at 200 kHz that disrupt tumor cells as they undergo mitosis. Patient survival benefit has been demonstrated in randomized clinical trials but much of the data are available only for supratentorial glioblastomas. We investigated a series of alternative array configurations for the posterior fossa to determine the electric field coverage of a cerebellar glioblastoma.MethodsSemi-automated segmentation of neuro-anatomical structures was performed while the gross tumor volume (GTV) was manually delineated. A three-dimensional finite-element mesh was generated and then solved for field distribution.ResultsCompared to the supratentorial array configuration, the alternative array configurations consist of posterior displacement the 2 lateral opposing arrays and inferior displacement of the posteroanterior array, resulting in an average increase of 46.6% electric field coverage of the GTV as measured by the area under the curve of the electric field-volume histogram (EAUC). Hotspots, or regions of interest with the highest 5% of TTFields intensity (E5%), had an average increase of 95.6%. Of the 6 posterior fossa configurations modeled, the PAHorizontal arrangement provided the greatest field coverage at the GTV when the posteroanterior array was placed centrally along the patient’s posterior neck and horizontally parallel, along the longer axis, to the coronal plane of the patient’s head. Varying the arrays also produced hotspots proportional to TTFields coverage.ConclusionsOur finite element modeling showed that the alternative array configurations offer an improved TTFields coverage to the cerebellar tumor compared to the conventional supratentorial configuration.

A prospective, randomised, comparative study to evaluate long axis, short axis and medial oblique axis approach for ultrasound-guided internal jugular vein cannulation

Background and Aims: The Ultrasound (USG)-guided internal jugular vein (IJV) cannulation can be performed using different approaches like short axis (SAX), long axis (LAX), oblique axis (OAX) or medial oblique axis (M-OAX). We aimed to determine which view was optimal for IJV cannulation.Methods: After ethical committee approval and written informed consent, this prospective, randomised, controlled trial was conducted on 108 patients. Patients were allocated into one of the three groups: A (SAX), B (LAX) and C (M-OAX approach) for USG-guided IJV cannulation. The number of needle passes, the success of IJV cannulation and its diameter, venous access time, guidewire time, catheterisation time and complications if any were recorded. Statistical analysis was performed by SPSS version 17.0.Results:First needle pass success rate was highest in M-OAX (97.2%) followed by SAX (88.9%) and then LAX (77.8%) but it was statistically insignificant among the groups. Mean venous access, guidewire insertion and catheterisation time were shortest in M-OAX followed by SAX and then LAX approach. It was statistically significant between LAX and SAX and between LAX and M-OAX group. (P < 0.001). The carotid puncture was noticed in two patients in the LAX group. The overall success rate and the number of needle passes were comparable among the groups.Conclusion: The M-OAX approach is a safe and effective technique for USG-guided IJV cannulation when compared to SAX and LAX approaches.