Advanced Imaging Research Articles

A comprehensive review on role of magnetic resonance imaging in the precise measurement of corpus callosum

Magnetic Resonance Imaging (MRI) has emerged as a powerful and non-invasive imaging technique, playing a pivotal role in neuroimaging research and clinical diagnosis. This comprehensive review explores the significance of MRI in the precise measurement of the corpus callosum, a key structure connecting the two hemispheres of the brain. The corpus callosum plays a crucial role in inter hemispheric communication and is implicated in various neurological and psychiatric disorders. The review begins by elucidating the anatomy and functions of the corpus callosum, emphasizing its importance in facilitating seamless communication between the cerebral hemispheres. Subsequently, the paper delves into the historical evolution of MRI techniques and how advancements have enhanced the visualization and measurement capabilities of the corpus callosum. A detailed examination of various MRI modalities, including structural MRI, diffusion tensor imaging (DTI), and functional MRI, is presented in the context of corpus callosum analysis. Structural MRI provides high-resolution images for accurate morphological assessments, while DTI offers insights into white matter microstructure and fiber tractography, allowing for a more comprehensive understanding of the corpus callosum's integrity. The review also highlights the role of MRI in investigating alterations in the corpus callosum associated with neurological disorders such as multiple sclerosis, epilepsy, and neurodevelopmental disorders. Additionally, the paper explores how functional MRI contributes to understanding the functional connectivity and inter hemispheric interactions mediated by the corpus callosum. Challenges and limitations in the measurement of the corpus callosum using MRI are discussed, including methodological considerations, image artifacts, and potential sources of variability. The review concludes by outlining future directions in corpus callosum imaging research, including the integration of advanced imaging techniques, artificial intelligence, and large-scale multi-center studies to enhance the precision and reliability of measurements.In summary, this comprehensive review underscores the pivotal role of MRI in advancing our understanding of the corpus callosum, providing valuable insights into both normal brain function and pathological conditions. The continual evolution of MRI techniques holds promise for further refining the assessment of the corpus callosum, ultimately contributing to improved diagnostic accuracy and therapeutic interventions in neurological and psychiatric disorders.

Unveiling a foreign body masquerading as periarticular calcification: a case report

IntroductionEvaluating isolated extremity discomfort can be challenging when initial imaging and exams provide limited information. Though subtle patient history hints often underlie occult pathologies, benign symptoms are frequently miscategorized as idiopathic.Case presentationWe present a case of retained glass obscuring as acute calcific periarthritis on imaging. A 48-year-old White male with vague fifth metacarpophalangeal joint pain had unrevealing exams, but radiographs showed periarticular calcification concerning inflammation. Surgical exploration unexpectedly revealed an encapsulated glass fragment eroding bone. Further history uncovered a forgotten glass laceration decade prior. The foreign body was removed, resolving symptoms.DiscussionThis case reveals two imperative diagnostic principles for nonspecific extremity pain: (1) advanced imaging lacks specificity to differentiate inflammatory arthropathies from alternate intra-articular processes such as foreign bodies, and (2) obscure patient history questions unearth causal subtleties that direct accurate diagnosis. Though initial scans suggested acute calcific periarthritis, exhaustive revisiting of the patient’s subtle decade-old glass cut proved pivotal in illuminating the underlying driver of symptoms.ConclusionOur findings underscore the critical limitations of imaging and the vital role that meticulous history-taking plays in clarifying ambiguous chronic limb presentations. They spotlight the imperative of probing even distant trauma when symptoms seem disconnected from causative events. This case reinforces the comprehensive evaluation of all subtle patient clues as key in illuminating elusive extremity pain etiologies.

Intersecting Paths: Unraveling the Complex Journey of Cancer to Bone Metastasis

The phenomenon of bone metastases presents a significant challenge within the context of advanced cancer treatments, particularly pertaining to breast, prostate, and lung cancers. These metastatic occurrences stem from the dissemination of cancerous cells into the bone, thereby interrupting the equilibrium between osteoblasts and osteoclasts. Such disruption results in skeletal complications, adversely affecting patient morbidity and quality of life. This review discusses the intricate interplay between cancer cells and the bone microenvironment, positing the bone not merely as a passive recipient of metastatic cells but as an active contributor to cancer progression through its distinctive biochemical and cellular makeup. A thorough examination of bone structure and the dynamics of bone remodeling is undertaken, elucidating how metastatic cancer cells exploit these processes. This review explores the genetic and molecular pathways that underpin the onset and development of bone metastases. Particular emphasis is placed on the roles of cytokines and growth factors in facilitating osteoclastogenesis and influencing osteoblast activity. Additionally, this paper offers a meticulous critique of current diagnostic methodologies, ranging from conventional radiography to advanced molecular imaging techniques, and discusses the implications of a nuanced understanding of bone metastasis biology for therapeutic intervention. This includes the development of targeted therapies and strategies for managing bone pain and other skeletal-related events. Moreover, this review underscores the imperative of ongoing research efforts aimed at identifying novel therapeutic targets and refining management approaches for bone metastases. It advocates for a multidisciplinary strategy that integrates advancements in medical oncology and radiology with insights derived from molecular biology and genetics, to enhance prognostic outcomes and the quality of life for patients afflicted by this debilitating condition. In summary, bone metastases constitute a complex issue that demands a comprehensive and informed approach to treatment. This article contributes to the ongoing discourse by consolidating existing knowledge and identifying avenues for future investigation, with the overarching objective of ameliorating patient care in the domain of oncology.

Wavy grain in sycamore maple (Acer pseudoplatanus) — a structural analysis of xylem and phloem

Summary Wavy grain (fiddle back) in trees has attracted the interest of both science and industry due to its aesthetic and economic importance. As the underlying causes of this particular structural feature in trees remain uncertain, this study investigates the possibility of non-invasively detecting wavy grain patterns within tree bark tissue of sycamore maple (Acer pseudoplatanus). Wavy grain, characterized by alternating light and dark stripes on the wood surface, is highly valued in the production of musical instruments. This research explores the potential of employing transmission light microscopy and microcomputer tomography (μCT) to examine the internal structure of phloem tissue to inspect whether the wavy grain structure found in the xylem continues in the bark. The investigation of phloem tissue proved challenging due to its irregular cellular arrangement. Nonetheless, slight phloem fibre deviations were observed in individual trees. However, no definite connection was found between the periodic oscillations of the xylem fibre tissue and the structure of the phloem in a given area. Variability in wavy grain expression among the xylem of the trees posed an additional challenge, with amplitudes and wavelengths differing across specimens. The application of μCT offered advantages over traditional sample preparation, enabling the study of the anatomical structure across larger areas and multiple depths without altering the specimen. This study sheds light on the potential of employing advanced imaging techniques to detect wavy grain patterns, providing insights that could benefit industries reliant on high-quality wood, such as musical instrument crafting and forestry.

Morphology characterization of unsaturated soils under drying-wetting cycles: crack opening and closure

AbstractThe volumetric and hydrological responses of clayey soils subjected to drying-wetting (D-W) cycles are of paramount importance for the integrity of geoenvironmental infrastructures. The study aimed to investigate the cracking behavior of clayey soils under D-W cycles by using advanced 2D imaging and 3D scanning techniques to capture the initiation and propagation of desiccation cracks within a soil specimen. The temporal variation in the soil water content and the corresponding 2D digital photography and 3D morphology of cracks were simultaneously monitored, and the cracking characteristics were interpreted. It was found that the time-dependent evaporation process was independent of the D-W cycles. Both 2D and 3D characterization showed the cracking hysteresis phenomenon in the unsaturated soil, which indicates the dependency of the crack opening and closure on the degree of saturation. D-W cycles led to the formation of subcracks and the increase in the total crack length, reflecting the soil degradation. Additionally, it was demonstrated that the 3D characterization exhibited the advantage of capturing the volumetric change and the subtle change in the macroporosity of the cracked soil over the 2D visualization. The current study provides a perspective of combining 2D and 3D characterization for interpreting the volumetric change of cracked soils and enhancing the understanding of the hydromechanical responses and the soil-atmosphere interactions.

Quantitative Analysis of Epicardial Adipose Tissue: 120K Shades of Heart

Background: Epicardial adipose tissue (EAT) is the fat deposited between the myocardium and epicardium. Due to its unique anatomical position, EAT has both protective and harmful effects on the heart, influencing conditions such as coronary artery disease, atrial fibrillation, and heart failure. This study aimed to quantify the amount of EAT by analyzing the color shades of the heart's anterior surface during coronary artery bypass grafting (CABG) procedures. Objective: To assess the number of color shades in different sub-regions of the heart and quantify EAT using real-time 2D images captured during CABG procedures, and to correlate these findings with clinical conditions and risk factors. Methods: The study was conducted at Rehman Medical Institute, Peshawar, from October 2023 to April 2024. Images were captured using an iPhone 11 with a 12-megapixel camera during CABG procedures, specifically before cannulation, after opening the pericardium, and tucking the pericardium to the skin on a beating heart. Photographs were taken at a 90-degree angle and one-foot distance during systole, including surrounding tissues and a self-retaining retractor with a ruler for measurement reference. The images from three patients were processed to form the "HEART ANTERIOR VIEW THROUGH STERNOTOMY (HATS)" dataset. The data were cleaned and standardized for consistency. The surgical team annotated and labeled the images using the LabelMe tool, identifying the full heart region and its sub-regions: Aorta, Right Ventricle (RV) Myocardium, RV and Pulmonary Artery (PA) Epicardial Fat, and Right Atrium (RA) Appendage. Image segmentation techniques isolated the heart region and identified fat deposits. The total area of fat on the anterior surface of RV, PA, and RA was quantified using appropriate algorithms. Pixel analysis was conducted to determine the color shades, with each pixel having three color channels (Red, Green, Blue) and 256 intensity values per channel. Results: The total pixel count for the full image (heart and surrounding region) was 1600x1200 for Patient 1, 480x624 for Patient 2, and 480x848 for Patient 3. The heart regions contained 218,864 pixels (Patient 1), 44,020 pixels (Patient 2), and 77,919 pixels (Patient 3). The EAT areas were found to be 158,213 pixels (Patient 1), 35,608 pixels (Patient 2), and 52,723 pixels (Patient 3). The percentage areas of the sub-regions varied, with RV and PA Epicardial Fat comprising 72.3%, 80.9%, and 67.7% of the heart regions for Patients 1, 2, and 3, respectively. The top 100 color shades were identified, with unique colors in the Aorta (23,323), Appendage (7,030), Epicardial Fat (80,257), and Myocardium (10,131). Conclusion: The study demonstrated that EAT and the color shades of heart sub-regions could be accurately quantified using advanced imaging and computational techniques. These findings provide valuable insights into the correlation between EAT and cardiac risk factors, enhancing the ability to predict postoperative morbidity and mortality and enabling early interventions to improve patient outcomes.

Noninvasive Atherosclerotic Phenotyping: The Next Frontier into Understanding the Pathobiology of Coronary Artery Disease.

Despite recent advances, coronary artery disease remains one of the leading causes of mortality worldwide. Noninvasive imaging allows atherosclerotic phenotyping by measurement of plaque burden, morphology, activity and inflammation, which has the potential to refine patient risk stratification and guide personalized therapy. This review describes the current and emerging roles of advanced noninvasive cardiovascular imaging methods for the assessment of coronary artery disease. Cardiac computed tomography enables comprehensive, noninvasive imaging of the coronary vasculature, and is used to assess luminal stenoses, coronary calcifications, and distinct adverse plaque characteristics, helping to identify patients prone to future events. Novel software tools, implementing artificial intelligence solutions, can automatically quantify and characterize atherosclerotic plaque from standard computed tomography datasets. These quantitative imaging biomarkers have been shown to improve patient risk stratification beyond clinical risk scores and current clinical interpretation of cardiac computed tomography. In addition, noninvasive molecular imaging in higher risk patients can be used to assess plaque activity and plaque thrombosis. Noninvasive imaging allows unique insight into the burden, morphology and activity of atherosclerotic coronary plaques. Such phenotyping of atherosclerosis can potentially improve individual patient risk prediction, and in the near future has the potential for clinical implementation.

Virtual reality modelling in a child after multiple interventions for hypoplastic aortic arch and coarctation.

We present the benefits of advanced multimodality imaging and virtual reality modelling in the diagnosis and treatment planning of a child with aneurysms after numerous interventions for treatment of a hypoplastic aortic arch and coarctation.

Intrasphenoidal cephalocoeles: Knowing the less known

Intrasphenoidal encephalocoeles are acquired or congenital herniations of meninges and brain parenchyma through a structural sphenoid bone defect. Acquired causes are most common, either iatrogenic, post-traumatic, or spontaneous. However, defects in the lateral wall of the sphenoid sinus are uncommon and cephalocoeles through them relatively underexplored in current literature, warranting dedicated attention to unravel their complexities. Congenital causes such as persistence of Sternberg’s canal, which can lead to lateral cephalocoeles, is a rare entity, seen in two of the presented cases, based on the location of the defect with respect to the line connecting the foramen rotundum and the vidian canal (VR line). Three cases of intrasphenoidal cephalocoeles are presented; two patients presented with watery nasal discharge without prior trauma or surgery and the third case was incidentally detected in an elderly patient with intraparenchymal haemorrhage. Imaging with CT cisternography and brain MR were performed to ascertain the exact location of the leak and confirm the presence of herniated brain tissue via the defects. Patients were evaluated by otolaryngology for transnasal endoscopic repair, which was deemed unfeasible, and referred to neurosurgery for transcranial duroplasty.Contribution: These cases provide crucial insights into the aetiology of lateral intrasphenoidal cephalocoeles, offering a practical system to classify cerebrospinal fluid (CSF) leaks based on the bony defect location. The three illustrative cases and emphasis on advanced imaging modalities refine the knowledge of their aetiology, clinical presentation and management, which hold direct clinical relevance for accurate diagnosis and tailored management of these rare anomalies.

Brain structure comparison among Parkinson disease, essential tremor, and healthy controls using 7T MRI.

Both Parkinson disease (PD) and Essential tremor (ET) are movement disorders causing tremors in elderly individuals. Although PD and ET are different disease, they often present with similar initial symptoms, making their differentiation challenging with magnetic resonance imaging (MRI) techniques. This study aimed to identify structural brain differences among PD, ET, and health controls (HCs) using 7-Tesla (T) MRI. We assessed the whole-brain parcellation in gray matter volume, thickness, subcortical volume, and small regions of basal ganglia in PD (n = 18), ET (n = 15), and HCs (n = 18), who were matched for age and sex. Brain structure analysis was performed automatic segmentation through Freesurfer software. Small regions of basal ganglia were manually segmented by ITK-SNAP. Additionally, we examined the associations between clinical indicators (symptom duration, unified Parkinson diseases rating scale (UPDRS), and clinical rating scale for tremor (CRST)) and brain structure. PD showed a significant reduction in gray matter volume in the postcentral region compared to ET. ET showed a significant reduction in cerebellum volume compared to HCs. There was a negative correlation between CRST scores (B and C) and gray matter thickness in right superior frontal in ET. This study demonstrated potential of 7T MRI in differentiating brain structure differences among PD, ET, and HCs. Specific findings, such as parietal lobe atrophy in PD compared to ET and cerebellum atrophy in ET compared to HCs, the importance of advanced imaging techniques in accurately diagnosing and distinguishing between movement disorders that present with similar initial symptoms.

Unveiling the Effects of Diabetes on Coronary Artery Disease Through Angiography

Background: Coronary artery disease (CAD) remains a leading cause of morbidity and mortality globally, particularly among patients with Type 2 Diabetes Mellitus (T2DM). Diabetic patients are at a higher risk of developing CAD due to factors such as poor glycemic control, lipid metabolism abnormalities, and endothelial dysfunction. Prior studies have demonstrated that diabetic patients tend to present with more extensive coronary artery involvement and worse outcomes following cardiovascular interventions. Objective: This study aimed to assess the impact of T2DM on coronary angiography outcomes, specifically focusing on the incidence of multi-vessel disease and the severity of coronary artery stenosis. Methods: This observational cohort study was conducted at Lady Reding Hospital, a tertiary care center specializing in cardiovascular diseases. Participants were recruited from the outpatient cardiology clinic between January 2020 and January 2022. Inclusion criteria included patients aged 40 to 80 years undergoing coronary angiography for the first time due to suspected CAD. Exclusion criteria were previous coronary artery interventions, congenital heart disease, active infections, and renal insufficiency (creatinine > 2.0 mg/dL). Baseline characteristics such as age, gender, BMI, hypertension status, and smoking history were collected. Diabetes status was confirmed via HbA1c levels (≥6.5%). Coronary angiography was performed using standard techniques, with angiograms analyzed by two blinded cardiologists. Primary outcomes included the presence of multi-vessel disease (≥70% stenosis in two or more major coronary arteries) and the severity of stenosis (>70% blockage). Additional assessments using Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT) evaluated plaque characteristics and vessel sizes in a subset of patients. Statistical analysis was performed using SPSS version 25.0, employing Chi-square tests for categorical variables, independent t-tests for continuous variables, and multivariable logistic regression to adjust for confounders. Results: The study included 300 participants, with 150 diabetic and 150 non-diabetic patients. Diabetic patients had a mean age of 62.3 ± 10.4 years, while non-diabetic patients had a mean age of 58.2 ± 9.8 years. The prevalence of hypertension was higher among diabetic patients (60%) compared to non-diabetic patients (40%). The incidence of multi-vessel disease was significantly higher in diabetic patients (70%) compared to non-diabetic patients (50%) (p < 0.05). Severe stenosis was observed in 65% of diabetic patients versus 45% of non-diabetic patients (p < 0.01). IVUS and OCT analyses showed a higher prevalence of lipid-rich plaques in diabetic patients (55% vs. 30%) and a smaller mean luminal diameter (2.8 ± 0.6 mm vs. 3.4 ± 0.5 mm). Conclusion: Diabetes significantly impacts the severity and extent of coronary artery disease, with diabetic patients exhibiting higher rates of multi-vessel disease and severe stenosis. Advanced imaging techniques highlighted distinct plaque characteristics in diabetic patients, underscoring the need for aggressive and personalized management strategies. These findings emphasize the importance of integrating advanced imaging and comprehensive management to mitigate cardiovascular risks in diabetic patients.

Do Hounsfield Units From Intraoperative CT Scans Correlate With Preoperative Values?

There is increasing interest in forecasting postoperative complications using bone density metrics. Vertebral Hounsfield unit measurements obtained from CT scans performed for surgical planning or other purposes, known as opportunistic CTs, have shown promise for their ease of measurement and the ability to target density measurement to a particular region of interest. Concomitant with the rising interest in prognostic bone density measurement use has been the increasing adoption of intraoperative advanced imaging techniques. Despite the interest in both outcome prognostication and intraoperative advanced imaging, there is little information regarding the use of CT-based intraoperative imaging as a means to measure bone density. (1) Can vertebral Hounsfield units be reliably measured by physician reviewers from CT scans obtained intraoperatively? (2) Do Hounsfield units measured from intraoperative studies correlate with values measured from preoperative CT scans? To be eligible for this retrospective study, patients had to have been treated with the use of an intraoperative CT scan for instrumented spinal fusion for either degenerative conditions or traumatic injuries between January 2015 and December 2022. Importantly, patients without a preoperative CT scan of the fused levels within 180 days before surgery or who were indicated for surgery because of infection, metastatic disease, or who were having revision surgery after prior instrumentation were excluded from the query. Of the 285 patients meeting these inclusion criteria, 53% (151) were initially excluded for the following reasons: 36% (102) had intraoperative CT scans obtained after placement of instrumentation, 16% (47) had undergone intraoperative CT scans but the studies were not accessible for Hounsfield unit measurement, and 0.7% (2) had prior kyphoplasty wherein the cement prevented Hounsfield unit measurement. Finally, an additional 19% (53) of patients were excluded because the preoperative CT and intraoperative CT were obtained at different peak voltages, which can influence Hounsfield unit measurement. This yielded a final population of 81 patients from whom 276 preoperative and 276 intraoperative vertebral Hounsfield unit measurements were taken. Hounsfield unit data were abstracted from the same vertebra(e) from both preoperative and intraoperative studies by two physician reviewers (one PGY3 and one PGY5 orthopaedic surgery resident, both pursuing spine surgery fellowships). For a small, representative subset of patients, measurements were taken by both reviewers. The feasibility and reliability of Hounsfield unit measurement were then assessed with interrater reliability of values measured from the same vertebra by the two different reviewers. To compare Hounsfield unit values from intraoperative CT scans with preoperative CT studies, an intraclass correlation using a two-way random effects, absolute agreement testing technique was employed. Because the data were formatted as multiple measurements from the same vertebra at different times, a repeated measures correlation was used to assess the relationship between preoperative and intraoperative Hounsfield unit values. Finally, a linear mixed model with patients handled as a random effect was used to control for different patient and clinical factors (age, BMI, use of bone density modifying agents, American Society of Anesthesiologists [ASA] classification, smoking status, and total Charlson comorbidity index [CCI] score). We found that Hounsfield units can be reliably measured from intraoperative CT scans by human raters with good concordance. Hounsfield unit measurements of 31 vertebrae from a representative sample of 10 patients, measured by both reviewers, demonstrated a correlation value of 0.82 (95% CI 0.66 to 0.91), indicating good correlation. With regard to the relationship between preoperative and intraoperative measurements of the same vertebra, repeated measures correlation testing demonstrated no correlation between preoperative and intraoperative measurements (r = 0.01 [95% CI -0.13 to 0.15]; p = 0.84). When controlling for patient and clinical factors, we continued to observe no relationship between preoperative and intraoperative Hounsfield unit measurements. As intraoperative CT and measurement of vertebral Hounsfield units both become increasingly popular, it would be a natural extension for spine surgeons to try to extract Hounsfield unit data from intraoperative CTs. However, we found that although it is feasible to measure Hounsfield data from intraoperative CT scans, the obtained values do not have any predictable relationship with values obtained from preoperative studies, and thus, these values should not be used interchangeably. With this knowledge, future studies should explore the prognostic value of intraoperative Hounsfield unit measurements as a distinct entity from preoperative measurements. Level III, diagnostic study.

Epstein-Barr Virus-Associated Smooth-Muscle Tumor of the Brain.

Epstein-Barr virus, a herpesvirus, has been associated with a variety of cancers, including Burkitt, Hodgkin, and non-Hodgkin lymphomas; posttransplant lymphoproliferative disorders; gastric carcinoma; and nasopharyngeal carcinoma, in both immunocompetent and immunocompromised individuals. Previous studies have established a connection between Epstein-Barr virus and the development of smooth-muscle tumors. Smooth-muscle tumors of the brain are very rare and are often misdiagnosed as meningiomas on imaging. To our knowledge, advanced imaging findings such as MR perfusion of smooth-muscle tumors of the brain have never been reported. We describe the radiologic and pathologic features of the Epstein-Barr virus-associated smooth-muscle tumors of the brain in a person with newly diagnosed advanced HIV.

Vectorial adaptive optics for advanced imaging systems

Vectorial adaptive optics (V-AO) is a cutting-edge technique extending conventional AO into the vectorial domain encompassing both polarization and phase feedback correction for optical systems. However, previous V-AO approaches focus on point correction. In this letter, we extend this AO approach into the imaging domain. We show how V-AO can benefit an aberrated imaging system to enhance not only scalar imaging but also the quality of vectorial information. Two important criteria, vectorial precision and uniformity are put forward and used in practice to evaluate the performance of the correction. These experimental validations pave the way for real-world imaging for V-AO technology and its applications.

Compact pixelated scintillator detector investigation for gamma ray detection

Objective. A scintillator is a luminescent material that converts high-energy photons into visible light and is widely used in medical imaging. Different scintillators are applied to gamma imaging in proton therapy and boron neutron capture therapy (BNCT). A pixelated scintillator is suitable for position measurement. The energy resolution, detection efficiency and position measurement of pixelated scintillators coupled to a SiPM were investigated via two kinds of detectors. The goal of this manuscript was to accurately measure the gamma source position through spectrum analysis in selection of energy windows for characteristic gamma lines. Approach. Scintillators were effectively manufactured and encapsulated before testing, especially for the easily deliquescent LaBr3. The compact front-end electronic prototype modules with 2 × 2 array SiPMs in stacked form and 1 × 10 array SiPMs in parallel form were developed for gamma ray energy resolution and efficiency measurements with a radioactive source of 22Na, which had two energy gamma lines at 511 keV and 1274 keV. Energy calibration was used for accurate energy window selection when measuring the position of the gamma source. Main results. Evident inconsistencies were present between different pixels of the same type of scintillator. Thus, an energy calibration method was needed. LaBr3 was the first candidate scintillator for the gamma ray spectrum measurement since it exhibited the best performance with an energy resolution of ∼5%. The recommended size of LaBr3 was 5 × 5 mm2, which had a higher efficiency than the 3 × 3 mm2 size. The gamma count of the multiple mode of the 2 × 2 array was much higher than that of the single mode, while the energy resolution was poorer. Thus, multiple mode was not suitable for gamma ray detection. The 1 × 10 array detector had the potential to measure the gamma ray source position and could be used for proton therapy and BNCT. A small deviation of 0.22 cm was observed in the measurement of the source center position with Energy Window 1 for 511 keV and Energy Window 2 for 1274 keV before the energy calibration. No deviation was observed after energy calibration. Thus, to achieve a higher accuracy position measurement, automatic energy calibration algorithm was coded into data acquisition software. Significance. The characteristic gamma lines produced by particle therapy are abundant and useful for imaging technology. Our developed compact pixelated scintillator detector coupled with SiPMs could measure the gamma spectrum with high resolution. The energy calibration and window selection method could measure the position of the source with high accuracy. Therefore, an advanced imaging device based on the energy spectrum for particle therapy could be potentially attainable.

Simplified Beam Hardening Correction for Ultrafast X-ray CT Imaging of Binary Granular Mixtures

Ultrafast X-ray computed tomography is an advanced imaging technique for multiphase flows. It has been used with great success for studying gas–liquid as well as gas–solid flows. Here, we apply this technique to analyze density-driven particle segregation in a rotating drum as an exemplary use case for analyzing industrial particle mixing systems. As glass particles are used as the denser of two granular species to be mixed, beam hardening artefacts occur and hamper the data analysis. In the general case of a distribution of arbitrary materials, the inverse problem of image reconstruction with energy-dependent attenuation is often ill-posed. Consequently, commonly known beam hardening correction algorithms are often quite complex. In our case, however, the number of materials is limited. We therefore propose a correction algorithm simplified by taking advantage of the known material properties, and demonstrate its ability to improve image quality and subsequent analyses significantly.

Toward a brighter constellation: multiorgan neuroimaging of neural and vascular dynamics in the spinal cord and brain.

Pain comprises a complex interaction between motor action and somatosensation that is dependent on dynamic interactions between the brain and spinal cord. This makes understanding pain particularly challenging as it involves rich interactions between many circuits (e.g., neural and vascular) and signaling cascades throughout the body. As such, experimentation on a single region may lead to an incomplete and potentially incorrect understanding of crucial underlying mechanisms. We aimed to develop and validate tools to enable detailed and extended observation of neural and vascular activity in the brain and spinal cord. The first key set of innovations was targeted to developing novel imaging hardware that addresses the many challenges of multisite imaging. The second key set of innovations was targeted to enabling bioluminescent (BL) imaging, as this approach can address limitations of fluorescent microscopy including photobleaching, phototoxicity, and decreased resolution due to scattering of excitation signals. We designed 3D-printed brain and spinal cord implants to enable effective surgical implantations and optical access with wearable miniscopes or an open window (e.g., for one- or two-photon microscopy or optogenetic stimulation). We also tested the viability for BL imaging and developed a novel modified miniscope optimized for these signals (BLmini). We describe "universal" implants for acute and chronic simultaneous brain-spinal cord imaging and optical stimulation. We further describe successful imaging of BL signals in both foci and a new miniscope, the "BLmini," which has reduced weight, cost, and form-factor relative to standard wearable miniscopes. The combination of 3D-printed implants, advanced imaging tools, and bioluminescence imaging techniques offers a coalition of methods for understanding spinal cord-brain interactions. Our work has the potential for use in future research into neuropathic pain and other sensory disorders and motor behavior.

Imaging analysis for muscle stem cells and regeneration

Composed of a diverse variety of cells, the skeletal muscle is one of the body’s tissues with the remarkable ability to regenerate after injury. One of the key players in the regeneration process is the muscle satellite cell (MuSC), a stem cell population for skeletal muscle, as it is the source of new myofibers. Maintaining MuSC quiescence during homeostasis involves complex interactions between MuSCs and other cells in their corresponding niche in adult skeletal muscle. After the injury, MuSCs are activated to enter the cell cycle for cell proliferation and differentiate into myotubes, followed by mature myofibers to regenerate muscle. Despite decades of research, the exact mechanisms underlying MuSC maintenance and activation remain elusive. Traditional methods of analyzing MuSCs, including cell cultures, animal models, and gene expression analyses, provide some insight into MuSC biology but lack the ability to replicate the 3-dimensional (3-D) in vivo muscle environment and capture dynamic processes comprehensively. Recent advancements in imaging technology, including confocal, intra-vital, and multi-photon microscopies, provide promising avenues for dynamic MuSC morphology and behavior to be observed and characterized. This chapter aims to review 3-D and live-imaging methods that have contributed to uncovering insights into MuSC behavior, morphology changes, interactions within the muscle niche, and internal signaling pathways during the quiescence to activation (Q-A) transition. Integrating advanced imaging modalities and computational tools provides a new avenue for studying complex biological processes in skeletal muscle regeneration and muscle degenerative diseases such as sarcopenia and Duchenne muscular dystrophy (DMD).

Circulating microRNAs May Be Predictive of Degenerative Cervical Myelopathy.

Basic Science. The objective of this study was to identify a unique serum profile of circulating miRNAs and inflammatory markers in patients with degenerative cervical myelopathy (DCM) compared to healthy controls (HC). Currently, DCM is diagnosed with a combination of history, physical examination, and close correlation to advanced imaging. To date, no serum marker has been identified to be diagnostic of this condition. Whole venous blood was collected from patients with DCM as well as healthy age- and sex-matched controls. miRNA was extracted from venous blood and a screening analysis was initially conducted to identify miRNA dysregulation in DCM patients. RT-qPCR was used to analyze the expression of 2 specific miRNAs based on screening analysis and literature review. Bioinformatics analysis was used to identify gene networks and potential targets of the miRNA. In addition, the serum inflammatory profile of DCM and HC groups was differentiated using a pro-inflammatory panel. Thirty-six patients were enrolled in the DCM group (36.1% male, 61.5±9.5y) while 35 patients were enrolled in the HC group (31.4% male, 57.5±8.9y). Of the 15 total miRNAs differentially expressed between DCM and HC groups, two were selected for further analysis: miR-223-3p (upregulated) and miR-451a (downregulated). Functional gene network analysis revealed the highest-ranking gene network was involved in neurological disease, while the most overexpressed miRNA in this network (miR-233-3p) was noted to have over 100 targets including CDKN1B and the insulin receptor. Serum cytokine analysis showed significant upregulation of several pro-inflammatory cytokines in the DCM cohort compared to the HC group. DCM patients demonstrated a set of unique circulating miRNAs in addition to a different serum inflammatory profile compared to HC. These miRNAs may potentially serve as targets for future therapeutic intervention or diagnostic/prognostic testing.

Transforming breast cancer care: harnessing the power of artificial intelligence and imaging for predicting pathological complete response. a narrative review.

This narrative review explores the transformative potential of Artificial Intelligence (AI) and advanced imaging techniques in predicting Pathological Complete Response (pCR) in Breast Cancer (BC) patients undergoing Neo-Adjuvant Chemotherapy (NACT). Summarizing recent research findings underscores the significant strides made in the accurate assessment of pCR using AI, including deep learning and radiomics. Such AI-driven models offer promise in optimizing clinical decisions, personalizing treatment strategies, and potentially reducing the burden of unnecessary treatments, thereby improving patient outcomes. Furthermore, the review acknowledges the potential of AI to address healthcare disparities in Low- and Middle-Income Countries (LMICs), where accessible and scalable AI solutions may enhance BC management. Collaboration and international efforts are essential to fully unlock the potential of AI in BC care, offering hope for a more equitable and effective approach to treatment worldwide.