Indirect Imaging Research Articles

Chosen Plaintext Attack on Single Pixel Imaging Encryption via Neural Differential Cryptanalysis

AbstractSingle pixel imaging (SPI) shows great potential in encryption by its indirect imaging mechanism. However, there appears to be room for further exploration in the corresponding cryptanalysis. Current studies primarily rely on straightforward end‐to‐end cryptanalysis of plain‐ciphertext pairs, ignoring the fundamental SPI optical path. As a result, the effectiveness of most attacks depends on the training data and the design of network, triggering low certainty and confidence. In this study, an alternative model is proposed to attack multiple SPI encrypting methods based on chosen plaintext attack framework, where arbitrary plaintexts can be encrypted as ciphertexts for cryptanalysis. In terms of the basic SPI setup, it is found that no matter how complicated the patterns are encrypted, the linear relationship between encrypted patterns and intensity always maintain. Thus, specifically, the ciphertext is first differentialized to derive encrypted patterns. By further reconstructing the pixel correlation of these derived patterns, deep learning is employed to correct them. Ultimately, the cracked patterns are used to decrypt plaintexts by conventional correlation. The experiments demonstrate that this method possesses a certain degree of reusability in the SPI encryption with linear propagating characteristic, like pattern‐encrypting class, demonstrating potential for the indirect optical encryption.

A comparative study of the application of three digital imaging techniques to assess the thickness of the palatal mucosa of the maxillary anterior teeth

BackgroundThis study highlights the need for precise and efficient methods to measure palatal mucosal thickness in the maxillary anterior teeth, particularly for soft tissue augmentation in the aesthetic zone. The research evaluates three digital imaging techniques, suggesting that Cone Beam Computed Tomography (CBCT) combined with intraoral scanners (IOS) is a promising approach for reliable clinical assessment.MethodsTen volunteers with healthy periodontium were selected, and three methods were employed: CBCT-based indirect gingival imaging, modified soft tissue CBCT (ST-CBCT), and CBCT combined with IOS. Measurements of palatal mucosal thickness were taken at multiple points along the palatal gingival margin. Statistical analysis included Bland-Altman plots for method agreement and intraclass Correlation Coefficient (ICC) analysis for reliability. All measurements were standardized, repeated for consistency, and accurate to 0.01 mm to ensure reliability.ResultsThe Bland-Altman plots showed that less than 5% of the points for palatal mucosal thickness differences measured by the gingival indirect radiographic method, modified ST-CBCT, and CBCT combined with IOS were located outside the 95% limits of agreement (LoA). The mean value of the differences was within 0.2 mm, indicating good clinical agreement among the three methods. The inter- and intra-study ICC values for palatal mucosal thickness measurements of the maxillary anterior teeth using the three CBCT methods were greater than 0.75 (P < 0.001), demonstrating reproducibility.ConclusionsBased on the evaluation of three digital imaging techniques, this study indicates that the combination of CBCT with IOS is a feasible method for measuring palatal mucosal thickness in the maxillary anterior teeth and demonstrates good reproducibility.

Dark field photon scattering state measurements from bumps on a gold nanofilm

Abstract A dark and bright field (BF) imaging technique explored plasmonic phenomena arising from bumps on a gold nanofilm coated on a silica substrate. The study employs dark field (DF) polarization indirect microscopic imaging to investigate the scattering photon state and reveal the spatial distribution characteristics with distinct multipolar features, contrasting with those observed in the BF imaging configuration. Computational simulations utilizing the finite-difference time-domain method were conducted to understand this behaviour further and consider the experimental setup’s impact. The observations of varying multipolar scattering features with changes in the incident angle of the DF illumination suggest that the excitation of plasmonic effects differs for light beams incident at different angles.

Impact of different parametric Patlak imaging approaches and comparison with a 2-tissue compartment pharmacokinetic model with a long axial field-of-view (LAFOV) PET/CT in oncological patients.

The recently introduced Long-Axial-Field-of-View (LAFOV) PET-CT scanners allow for the first-time whole-body dynamic- and parametric imaging. Primary aim of this study was the comparison of direct and indirect Patlak imaging as well as the comparison of different time frames for Patlak calculation with the LAFOV PET-CT in oncological patients. Secondary aims of the study were lesion detectability and comparison of Patlak analysis with a two-tissue-compartment model (2TCM). 50 oncological patients with 346 tumor lesions were enrolled in the study. All patients underwent [18F]FDG PET/CT (skull to upper thigh). Here, the Image-Derived-Input-Function) (IDIF) from the descending aorta was used as the exclusive input function. Four sets of images have been reviewed visually and evaluated quantitatively using the target-to-background (TBR) and contrast-to-noise ratio (CNR): short-time (30min)-direct (STD) Patlak Ki, short-time (30min)-indirect (STI) Patlak Ki, long-time (59.25min)-indirect (LTI) Patlak Ki, and 50-60min SUV (sumSUV). VOI-based 2TCM was used for the evaluation of tumor lesions and normal tissues and compared with the results of Patlak model. No significant differences were observed between the four approaches regarding the number of tumor lesions. However, we found three discordant results: a true positive liver lesion in all Patlak Ki images, a false positive liver lesion delineated only in LTI Ki which was a hemangioma according to MRI and a true negative example in a patient with an atelectasis next to a lung tumor. STD, STI and LTI Ki images had superior TBR in comparison with sumSUV images (2.9-, 3.3- and 4.3-fold higher respectively). TBR of LTI Ki were significantly higher than STD Ki. VOI-based k3 showed a 21-fold higher TBR than sumSUV. Parameters of different models vary in their differential capability between tumor lesions and normal tissue like Patlak Ki which was better in normal lung and 2TCM k3 which was better in normal liver. 2TCM Ki revealed the highest correlation (r = 0.95) with the LTI Patlak Ki in tumor lesions group and demonstrated the highest correlation with the STD Patlak Ki in all tissues group and normal tissues group (r = 0.93 and r = 0.74 respectively). Dynamic [18F]-FDG with the new LAFOV PET/CT scanner produces Patlak Ki images with better lesion contrast than SUV images, but does not increase the lesion detection rate. The time window used for Patlak imaging plays a more important role than the direct or indirect method. A combination of different models, like Patlak and 2TCM may be helpful in parametric imaging to obtain the best TBR in the whole body in future.

Indirect detector for ultra-high-speed X-ray micro-imaging with increased sensitivity to near-ultraviolet scintillator emission.

Ultra-high-speed synchrotron-based hard X-ray (i.e. above 10 keV) imaging is gaining a growing interest in a number of scientific domains for tracking non-repeatable dynamic phenomena at spatio-temporal microscales. This work describes an optimized indirect X-ray imaging microscope designed to achieve high performance at micrometre pixel size and megahertz acquisition speed. The entire detector optical arrangement has an improved sensitivity within the near-ultraviolet (NUV) part of the emitted spectrum (i.e. 310-430 nm wavelength). When combined with a single-crystal fast-decay scintillator, such as LYSO:Ce (Lu2-xYxSiO5:Ce), it exploits the potential of the NUV light-emitting scintillators. The indirect arrangement of the detector makes it suitable for high-dose applications that require high-energy illumination. This allows for synchrotron single-bunch hard X-ray imaging to be performed with improved true spatial resolution, as herein exemplified through pulsed wire explosion and superheated near-nozzle gasoline injection experiments at a pixel size of 3.2 µm, acquisition rates up to 1.4 MHz and effective exposure time down to 60 ps.

The Large Imaging Spectrometer for Solar Accelerated Nuclei (LISSAN): A next-generation solar gamma-ray spectroscopic imaging instrument concept

We present the Large Imaging Spectrometer for Solar Accelerated Nuclei (LISSAN), a new solar dedicated satellite instrument concept. LISSAN relies on an indirect Fourier imaging technique valid over an energy range from 40 keV up to 100 MeV. Spatial information is encoded into 15 moiré patterns by 15 pairs of slightly offset grids (bigrids) separated by a fixed distance enabling a predicted spatial resolution of 10”. The time, location, and energy of each incoming photon is recorded via a pixelated gadolinium aluminium gallium garnet (GAGG) crystal scintillator detector placed in alignment with each bigrid, therefore providing simultaneous imaging and spectroscopy from the same imaging system. X-ray and gamma-ray emission are key diagnostics of electron and ion acceleration, respectively. However, despite being a fundamental process that occurs throughout the Universe, particularly in the solar atmosphere, only one resolved gamma-ray image of ion acceleration in a solar flare has ever been achieved. LISSAN will shed new light on this process by providing spectral resolution better than 1.5% FWHM at 6.1 MeV, an imaging effective area at 2.2 MeV of 100 cm2 (more than 25 times greater than past missions such as RHESSI) and a 10 s cadence. Thanks to these significant advances over the previous satellite-based solar detectors, LISSAN will provide reliable imaging and the spectral characterization of both electron and ion acceleration in solar eruptive events simultaneously for the first time, enabling to it to answer several important open questions regarding solar particle acceleration and the initiation of space weather events.

Pulse Wave Velocity: Methodology, Clinical Applications, and Interplay with Heart Rate Variability.

Pulse wave velocity (PWV) has been established as a promising biomarker in cardiovascular diagnostics, providing deep insights into vascular health and cardiovascular risk. Defined as the velocity at which the mechanical wave propagates along the arterial wall, PWV represents a useful surrogate marker for arterial vessel stiffness. PWV has garnered clinical attention, particularly in monitoring patients suffering from vascular diseases such as hypertension and diabetes mellitus. Its utility extends to preventive cardiology, aiding in identifying and stratifying cardiovascular risk. Despite the development of various measurement techniques, direct or indirect tonometry, Doppler ultrasound, oscillometric analysis, and magnetic resonance imaging (MRI), methodological variability and lack of standardization lead to inconsistencies in PWV assessment. In addition, PWV can be estimated through surrogate parameters, such as pulse arrival or pulse transit times, although this heterogeneity limits standardization and, therefore, its clinical use. Furthermore, confounding factors, such as variations in sympathetic tone, strongly influence PWV readings, thereby necessitating careful control during assessments. The bidirectional relationship between heart rate variability (HRV) and PWV underscores the interplay between cardiac autonomic function and vascular health, suggesting that alterations in one could directly influence the other. Future research should prioritize the standardization and increase comparability of PWV measurement techniques and explore the complex physiological variables influencing PWV. Integrating multiple physiological parameters such as PWV and HRV into algorithms based on artificial intelligence holds immense promise for advancing personalized vascular health assessments and cardiovascular care.

Cell atlas of the regenerating human liver after portal vein embolization

The liver has the remarkable capacity to regenerate. In the clinic, regeneration is induced by portal vein embolization, which redirects portal blood flow, resulting in liver hypertrophy in locations with increased blood supply, and atrophy of embolized segments. Here, we apply single-cell and single-nucleus transcriptomics on healthy, hypertrophied, and atrophied patient-derived liver samples to explore cell states in the regenerating liver. Our data unveils pervasive upregulation of genes associated with developmental processes, cellular adhesion, and inflammation in post-portal vein embolization liver, disrupted portal-central hepatocyte zonation, and altered cell subtype composition of endothelial and immune cells. Interlineage crosstalk analysis reveals mesenchymal cells as an interaction hub between immune and endothelial cells, and highlights the importance of extracellular matrix proteins in liver regeneration. Moreover, we establish tissue-scale iterative indirect immunofluorescence imaging for high-dimensional spatial analysis of perivascular microenvironments, uncovering changes to tissue architecture in regenerating liver lobules. Altogether, our data is a rich resource revealing cellular and histological changes in human liver regeneration.

MRI-based adrenal gland volume is associated with cardiovascular alterations in individuals without prior cardiovascular disease

Aim of this study was to analyse the associations of cardiovascular health and adrenal gland volume as a rather new imaging biomarker of chronic hypothalamic–pituitary–adrenal (HPA) axis activation. The study population originates from the KORA population-based cross-sectional prospective cohort. 400 participants without known cardiovascular disease underwent a whole-body MRI. Manual segmentation of adrenal glands was performed on VIBE-Dixon gradient-echo sequence. MRI based evaluation of cardiac parameters was achieved semi-automatically. Cardiometabolic risk factors were obtained through standardized interviews and medical examination. Univariate and multivariate associations were derived. Bi-directional causal mediation analysis was performed. 351 participants were eligible for analysis (56 ± 9.1 years, male 58.7%). In multivariate analysis, significant associations were observed between adrenal gland volume and hypertension (outcome hypertension: Odds Ratio = 1.11, 95% CI [1.01, 1.21], p = 0.028), left ventricular remodelling index (LVRI) (outcome LVRI: β = 0.01, 95% CI [0.00, 0.02], p = 0.011), and left ventricular (LV) wall thickness (outcome LV wall thickness: β = 0.06, 95% CI [0.02, 0.09], p = 0.005). In bi-directional causal mediation analysis adrenal gland volume had a borderline significant mediating effect on the association between hypertension and LVRI (p = 0.052) as well as wall thickness (p = 0.054). MRI-based assessment of adrenal gland enlargement is associated with hypertension and LV remodelling. Adrenal gland volume may serve as an indirect cardiovascular imaging biomarker.

Early detection of pancreatic cancer

The diagnosis of pancreatic cancer associates an appalling significance. Detection of preinvasive stage of pancreatic cancer will ameliorate the survival of this deadly disease. Premalignant lesions such as Intraductal Papillary Mucinous Neoplasms or Mucinous Cystic Neoplasms of the pancreas are detectable on imaging exams and this permits their management prior their invasive development. Pancreatic intraepithelial neoplasms (PanIN) are the most frequent precursors of pancreatic adenocarcinoma (PDAC), and its particular type PanIN high-grade represents the malignant non-invasive form of PDAC. Unfortunately, PanINs are not detectable on radiologic exams. Nevertheless, they can associate indirect imaging signs which would rise the diagnostic suspicion. When this suspicion is established, the patient will be enrolled in a follow-up strategy that includes performing of blood test and serial imaging test such as computed tomography or magnetic resonance imaging, which will cost in the best-case scenario a burden of healthcare systems, and potential mortality in the worst-case scenario when the patient underwent resection surgery, worthless when there is no moderate or high grade dysplasia in the final histopathology. This issue will be avoid having at its disposal a diagnostic technique capable of detecting high-grade PanIN lesions, such is the cytology of pancreatic juice obtained by nasopancreatic intubation. Herein, we review the possibility of detection of early malignant lesions before they become invasive PADC.

Pancreatic juice cytology for diagnosing invasive pancreatic carcinoma/high-grade pancreatic intraepithelial neoplasia without visible tumors on endoscopic ultrasound

ObjectivesPancreatic ductal adenocarcinoma (PDAC) with a diameter ≤10 mm and high-grade pancreatic intraepithelial neoplasia (HG-PanIN) require pre-operative diagnosis. Most cases present only indirect imaging findings without visible tumors on endoscopic ultrasound (EUS). Therefore, EUS-guided fine-needle aspiration/biopsy is not applicable. An alternative diagnostic method is pancreatic juice cytology (PJC) via endoscopic naso-pancreatic drainage (ENPD-PJC), which is not the standard practice. This study aimed to investigate ENPD-PJC for diagnosing suspected PDAC/HG-PanIN cases without visible tumors on EUS. MethodsData of patients with suspected PDAC/HG-PanIN without visible tumors who underwent PJC were retrospectively evaluated. One PJC sample was collected during endoscopic retrograde pancreatography (ERP-PJC), and 12 samples were collected during ENPD-PJC, 3-hourly for cytological analysis. ERP-PJC, ERP/ENPD-PJC, and ENPD-PJC positivity indicated cytologically positive samples. Patients with positive/negative PJC with follow-up for <4-years were excluded as undiagnosed cases. A non-malignant diagnosis was based on histopathological absence/stable imaging findings for ≥4-years. The primary endpoint was to demonstrate that ERP/ENPD-PJC has a higher diagnostic ability than ERP-PJC. ResultsTwenty-two patients with histopathologically diagnosed PDAC/HG-PanIN and 31 with a non-malignant diagnosis were enrolled. ERP-PJC, ERP/ENPD-PJC, and ENPD-PJC showed sensitivities of 36.4 %, 86.4 %, and 77.3 %, specificities of 93.5 %, 87.1 %, and 93.5 %, and accuracies of 69.8 %, 86.7 %, and 86.7 %, respectively. ERP/ENPD-PJC and ENPD-PJC demonstrated superior sensitivity and accuracy compared to ERP-PJC. A greater occurrence of positive outcomes markedly distinguished true positives from false positives. ConclusionsERP/ENPD-PJC and ENPD-PJC had higher diagnostic accuracies for PDAC/HG-PanIN without visible tumors on EUS. ENPD-PJC is recommended for the diagnosis of these lesions.

The Effect of Battery Configuration on Dendritic Growth: A Magnetic Resonance Microscopy Study on Symmetric Lithium Cells

The potential of metallic lithium to become the anode material for next-generation batteries is hampered by significant challenges, chief among which is dendrite growth during battery charging. These dendritic structures not only impair battery performance but also pose safety risks. Among the non-destructive analytical techniques in battery research, Magnetic Resonance Imaging (MRI) stands out as a promising tool. However, the direct imaging of lithium by 7Li MRI is limited by its low sensitivity and spatial resolution, making it a less effective way of imaging dendrite growth. Instead, a recently introduced indirect imaging approach which is based on 1H MRI of the electrolyte was used in this study. This method was used to sequentially 3D image and thus monitor the charging process of lithium metal symmetric cells in three different electrical circuits, namely those composed of a single cell, four cells in parallel, and four cells in series. The measured sequential images allowed for the measurement of dendrite growth in each cell using volumetric analysis. The growth results confirmed the theoretical prediction that the growth across cells is uneven in a parallel circuit, and even in a series circuit. The methods presented in this study can also be applied to analyze many other dendrite-related issues in batteries.

In-situ growth of Cs5Cu3Cl6I2 nanocrystals within AAO arrays for X-ray imaging

Lead-free halide perovskites have shown promising application for indirect X-ray detection as fascinating scintillator. The fabrication of pixelated scintillator films leveraging directional confinement allows high-resolution imaging, yet process complexity and the potential crystal structure damage pose challenges that compromises the corresponding scintillator performance. In this work, a facile in-situ strategy for growing scintillation perovskite of Cs5Cu3Cl6I2 within anodic aluminum oxide (AAO) membrane is developed as scintillator Cs5Cu3Cl6I2@AAO film. The as-fabricated pixelated scintillator array with an enhanced light directional confinement for high-resolution X-ray imaging is demonstrated. The corresponding film achieves a spatial resolution of approximately 20 lp mm−1 and a detection limit of 0.152 Gy·s−1. Moreover, the Cs5Cu3Cl6I2@AAO film performs excellent stability under long-term X-ray irradiation, making it a reliable option for cost-effective pixelated indirect X-ray imaging.

Phase reconstruction and singularity recovery of submicron particles in far-field phase space data using deep learning networks

Phase images often contain more comprehensive information compared to amplitude images. The precise visualization of phase images generated from light scattering by submicron particles is paramount for investigating the underlying scattering mechanisms and exploring applications centered around these submicron particles. This study showcases the efficacy of neural networks in acquiring the capacity to conduct phase reconstruction and recover singularities through appropriate training. Our deep learning-based approach introduces an entirely novel framework for phase recovery, accomplished by learning the distribution of scattered light fields from submicron particles, as obtained through a polarized indirect microscopic imaging (PIMI) system, within a custom Poincaré sphere (phase space). We validate this method by successfully reconstructing phase images of polystyrene (PS) balls with varying radii, and comparing diverse network structures and data flows in the process. Furthermore, we substantiate our experimental results by corroborating them with finite difference time domain (FDTD) simulations. These findings underscore the remarkable regularity within the distribution of phase space data, opening up new avenues for advancing the study of nanostructures.

Computational ghost imaging with adaptive intensity illumination for scenes featuring specular surfaces

Imaging a target scene with specular surfaces is a daunting challenge for both direct imaging and indirect computational imaging techniques. The intense specular reflection component during the measurement severely degrades the quality of the reconstructed image, resulting in a substantial loss of scene information. To address this issue, we propose a computational ghost imaging (CGI) method with adaptive intensity illumination. Capitalizing on the encoded imaging feature of CGI, this method enables effective imaging of target scenes with specular surfaces through two series of measurements, eliminating the necessity for additional optical components. Based on the position and intensity information of pixels in the specular regions from the first series of measurements, our method modulates the illumination patterns to weaken the intensity of the specular region in the second series of measurements. Simulation and experimental results demonstrate that the utilization of these modulated illumination patterns for target scene measurement effectively mitigates interference from the specular surface during imaging. Consequently, the reconstructed image is capable of presenting more detailed information about the target scene other than the specular regions. Our work introduces a novel approach for imaging target scenes with specular surfaces and broadens the scope of applications for CGI in reality.

Computational Imaging Encryption with a Steganographic and Holographic Authentication Strategy

AbstractRobust data security is of paramount importance, particularly for highly classified information. To achieve this, advanced encryption and decryption methods, along with stringent access control and physical security measures, are essential to mitigate the risk of unauthorized access and data exposure. Ghost imaging (GI), a computational imaging technique that operates indirectly, offers a distinct approach compared to traditional spatially resolved imaging techniques. By utilizing computational algorithms, GI enables indirect image reconstruction, making it well‐suited for encryption applications. This proposal introduces a new computational imaging encryption scheme that combines Fourier ghost imaging (FGI) and computational holography. The scheme utilizes an untrained‐tree‐network to generate two camouflaged computer‐generated holograms (CGHs). Integration of CGH‐based steganography and holographic authentication enhances the encoding and decoding processes of FGI encryption. The effectiveness and security of the proposed scheme are rigorously validated through numerical simulations and optical experiments. The results demonstrate promising potential for effectively merging direct and indirect imaging methods in security applications.

Direct and Indirect Chimeric Antigen Receptor T-Cell Imaging with PET/MRI in a Tumor Xenograft Model.

Background Chimeric antigen receptor (CAR) T cells are a promising cancer therapy; however, reliable and repeatable methods for tracking and monitoring CAR T cells in vivo remain underexplored. Purpose To investigate direct and indirect imaging strategies for tracking the biodistribution of CAR T cells and monitoring their therapeutic effect in target tumors. Materials and Methods CAR T cells co-expressing a tumor-targeting gene (anti-CD19 CAR) and a human somatostatin receptor subtype 2 (hSSTr2) reporter gene were generated from human peripheral blood mononuclear cells. After direct labeling with zirconium 89 (89Zr)-p-isothiocyanatobenzyl-desferrioxamine (DFO), CAR T cells were intravenously injected into immunodeficient mice with a CD19-positive and CD19-negative human tumor xenograft on the left and right flank, respectively. PET/MRI was used for direct in vivo imaging of 89Zr-DFO-labeled CAR T cells on days 0, 1, 3, and 7 and for indirect cell imaging with the radiolabeled somatostatin receptor-targeted ligand gallium 68 (68Ga)-DOTA-Tyr3-octreotide (DOTATOC) on days 6, 9, and 13. On day 13, mice were euthanized, and tissues and tumors were excised. Results The 89Zr-DFO-labeled CAR T cells were observed on PET/MRI scans in the liver and lungs of mice (n = 4) at all time points assessed. However, they were not visualized in CD19-positive or CD19-negative tumors, even on day 7. Serial 68Ga-DOTATOC PET/MRI showed CAR T cell accumulation in CD19-positive tumors but not in CD19-negative tumors from days 6 to 13. Notably, 68Ga-DOTATOC accumulation in CD19-positive tumors was highest on day 9 (mean percentage injected dose [%ID], 3.7% ± 1.0 [SD]) and decreased on day 13 (mean %ID, 2.6% ± 0.7) in parallel with a decrease in tumor volume (day 9: mean, 195 mm3 ± 27; day 13: mean, 127 mm3 ± 43) in the group with tumor growth inhibition. Enhanced immunohistochemistry staining of cluster of differentiation 3 (CD3) and hSSTr2 was also observed in excised CD19-positive tumor tissues. Conclusion Direct and indirect cell imaging with PET/MRI enabled in vivo tracking and monitoring of CAR T cells in an animal model. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Bulte in this issue.

Abstract A107: MAPK signaling is a conserved mechanism explaining phenotypic heterogeneity across diverse drivers of epithelial-mesenchymal transition in pancreas cancer

Abstract Epithelial-mesenchymal transition (EMT) is a developmental process that is aberrantly activated in cancers such as pancreatic ductal adenocarcinoma (PDAC) to promote disease progression and chemoresistance. EMT occurs heterogeneously among PDAC ductal cells, which frustrates efforts to identify the underlying signaling regulatory mechanisms. We hypothesize that cell-to-cell variation in the activities of specific signaling pathways explains EMT heterogeneity. To test this, we developed a workflow integrating: 1) iterative indirect immunofluorescence imaging (4i) to quantify the activities of up to seven purported EMT-regulating pathways with single-cell resolution and 2) a multivariate mutual information computational model to predict the pathways that are most informative of the EMT phenotype. In cultured PDAC cells, EMT was induced by treating cells with growth factors present in the tumor microenvironment (hepatocyte growth factor, epidermal growth factor, transforming growth factor β1, or two combinations) or with chemotherapeutics (gemcitabine or 5-fluorouracil). EMT phenotypic markers and signaling pathway proxies were assessed daily for up to 96 hr. A mutual information analysis of the aggregated data identified ERK as the most important signaling node explaining EMT heterogeneity across the diverse set of agonists investigated. Kinase inhibition and siRNA studies confirmed the implied role of ERK but also revealed a compensatory, EMT-driving JNK activation in the context of MEK inhibition that explains a cooperative effect of simultaneous MEK and JNK inhibition on EMT antagonism. Importantly, a model based on cell population-level measurements nominated JNK as more informative than ERK for determining EMT state in response to growth factors. We are implementing this approach in vivo using pancreas cancer tissue sections to determine generalizability of these findings in different microenvironmental contexts. Overall, our results demonstrate the pervasive importance of ERK for diverse drivers of EMT and the need to account for the effects of heterogeneous signaling pathway activation in the determination of EMT. Citation Format: Michelle C. Barbeau, Matthew J. Lazzara. MAPK signaling is a conserved mechanism explaining phenotypic heterogeneity across diverse drivers of epithelial-mesenchymal transition in pancreas cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A107.

Multimodality imaging in cerebral venous thrombosis: a synopsis for emergency radiologist.

Cerebral venous thrombosis (CVT) is an uncommon but potentially fatal condition which presents with a wide range of symptoms. Some of these presenting features are vague thus contributing to the delay in diagnosis. A prompt diagnosis and initiation of appropriate therapy are therefore of paramount importance. In this pictorial, we have tried to illustrate the direct and indirect imaging features of CVT in detail on multiple imaging modalities, along with the potential pitfalls of imaging.

Indirect imaging evidence of hematogenous spread of benign metastasizing leiomyomatosis.

Indirect imaging evidence of hematogenous spread of benign metastasizing leiomyomatosis.