Comparison Of Images Research Articles

Systematic comparison of fluorescence imaging in the near-infrared and shortwave-infrared spectral range using clinical tumor samples containing cetuximab-IRDye800CW

Systematic comparison of fluorescence imaging in the near-infrared and shortwave-infrared spectral range using clinical tumor samples containing cetuximab-IRDye800CW

Characterization of glomalin proteins in soil: A potential indicator of erosion intensity

Abstract In this study, in a pioneering effort, glomalin proteins were extracted and geochemically characterized from soil in Serbia. Standard chemical (dry combustion, Walkley-Black) and spectroscopic methods (fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), scanning electron microscope (SEM)) were used to gain insight into the glomalin proteins. Samples from the City of Novi Sad (Serbia) were used for characterization and comparison. The soil contained an average of 17 mg/g of glomalin, representing ≈21% of the soil organic matter. DLS zeta potential analysis and the FTIR spectra reveal two significant differences before and after glomalin extraction, indicating a relationship between sand fractions and organic matter that affects particle aggregation and erosion potential. A comparison of SEM images and DLS results reveals that the glomalin extract consists of two particle size groups (0.08–1 and 6 µm), suggesting that the extraction process isolates only a smaller fraction of proteins and less tightly bound particles, indicating that soil aggregation is influenced by both mineralogy and the characteristics of organic matter. Hence, our research raises important questions about the role of glomalin in mitigating soil degradation processes, particularly soil erosion. Our study will enhance the overall understanding of glomalin, inspire future research, and prove beneficial for the sustainable restoration of degraded lands.

Comparison of contrast-enhanced ultrasound imaging (CEUS) and super-resolution ultrasound (SRU) for the quantification of ischaemia flow redistribution: A theoretical study.

The study of microcirculation can reveal important information related to pathology. Focusing on alterations that are
represented by an obstruction of blood flow in microcirculatory regions may provide an insight into vascular biomarkers.
The current in silico study assesses the capability of CEUS and SRU flow-quantification to study occlusive actions in a
microvascular bed, particularly the ability to characterise known and model induced flow behaviours. The aim is to in-
vestigate theoretical limits with the use of CEUS and the upcoming particle-tracking in SRU in order to propose realistic
biomarker targets relevant for clinical diagnosis. Results from CEUS flow parameters display limitations congruent with
prior investigations. Conventional resolution limits lead to signals dominated by large vessels, making discrimination
of microvasculature specific signals difficult. Additionally, some occlusions lead to weakened parametric correlation
against flow rate in the remainder of the network. Loss of correlation is dependent on the degree to which flow is redis-
tributed, with comparatively minor redistribution correlating in accordance with ground truth measurements for change
in mean transit time, dM T T (CEUS, R = 0.85; GT, R = 0.82) and change in peak intensity, dIp (CEUS, R = 0.87;
GT, R = 0.96). Major redistributions, however, result in a loss of correlation, demonstrating that TIC-related parame-
ters have efficacy dependent on the location of occlusion. Conversely, results from SRU processing provides accurate
depiction of the anatomy and dynamics present in the vascular bed, that extends to individual microvessels. Correspon-
dence between model vessel structure displayed in SRU maps with the ground truth was > 91% for cases of minor and
major flow redistributions. In conclusion, SRU appears to be a highly promising technology in the quantification of
subtle flow phenomena due ischaemia induced vascular flow redistribution.

Forest Fire Severity and Koala Habitat Recovery Assessment Using Pre- and Post-Burn Multitemporal Sentinel-2 Msi Data

Habitat loss due to wildfire is an increasing problem internationally for threatened animal species, particularly tree-dependent and arboreal animals. The koala (Phascolartos cinereus) is endangered in most of its range, and large areas of forest were burnt by widespread wildfires in Australia in 2019/2020, mostly areas dominated by eucalypts, which provide koala habitats. We studied the impact of fire and three subsequent years of recovery on a property in South-East Queensland, Australia. A classified Differenced Normalised Burn Ratio (dNBR) calculated from pre- and post-burn Sentinel-2 scenes encompassing the local study area was used to assess regional impact of fire on koala-habitat forest types. The geometrically structured composite burn index (GeoCBI), a field-based assessment, was used to classify fire severity impact. To detect lower levels of forest recovery, a manual classification of the multitemporal dNBR was used, enabling the direct comparison of images between recovery years. In our regional study area, the most suitable koala habitat occupied only about 2%, and about 10% of that was burnt by wildfire. From the five koala habitat forest types studied, one upland type was burnt more severely and extensively than the others but recovered vigorously after the first year, reaching the same extent of recovery as the other forest types. The two alluvial forest types showed a negligible fire impact, likely due to their sheltered locations. In the second year, all the impacted forest types studied showed further, almost equal, recovery. In the third year of recovery, there was almost no detectable change and therefore no more notable vegetative growth. Our field data revealed that the dNBR can probably only measure the general vegetation present and not tree recovery via epicormic shooting and coppicing. Eucalypt foliage growth is a critical resource for the koala, so field verification seems necessary unless more-accurate remote sensing methods such as hyperspectral imagery can be implemented.

Comparison of tibial and femoral physeal diffusion tensor imaging in adolescents.

Distal femoral diffusion tensor imaging (DTI) is a predictor of height gain but it is uncertain whether DTI can demonstrate differences in growth potential between the tibia and femur. To explore the differences in structure and growth potential of the proximal tibia physeal-metaphyseal complex compared to those of the distal femur through DTI tractographic characterization and DTI metric comparison. Prospective cross-sectional study involved 108 healthy children (59 females) aged 8-14years (females) and 10-16years (males) around the growth spurt. We acquired knee DTI once at 3T with b-values of 0s/mm2 and 600s/mm2. Tract parameters including number, length, volume, and fractional anisotropy were measured. Regression analysis with linear and negative binomial models, incorporating bone age-based quadratic fitting, characterized DTI parameter changes in relation to bone age and sex, as well as variations between physes. Femorotibial ratios were calculated based on paired DTI parameter absolute values during peak height gain. The study was approved by the institutional review board of two tertiary pediatric centers in compliance with the Health Insurance Portability and Accountability Act. Proximal tibial tracts were more numerous in the central physis, whereas distal femoral tracts predominated peripherally. Tract volume rose and fell during adolescence and peaked earlier in females (140-160months vs. 160-180months, P=0.02). At maximal height velocity (160months), tibial tract volume (5.43cc) was 37.4% of total knee tract volume (14.53cc). Tibial fractional anisotropy decreased and then increased, both earlier than the femur. Proximal tibial and distal femoral tract distributions differ. The tibia accounts for 37.4% of total knee tract volume during maximal height velocity. Tract volumes rise and fall, earlier in females. Tibiofemoral ratios of DTI metrics resemble known ratios of growth rates between tibia and femur.

Research on Autonomous Navigation of Unmanned Aerial Vehicles Based on Correlation-Based Image Comparison Methods

Relevance. Autonomous navigation of unmanned aerial vehicles (UAVs) is one of the key challenges in the modern aerospace industry. Specifically, for small UAVs, the task of autonomous navigation becomes even more complex due to limitations in computational resources and sensor capabilities. Optimizing navigation methods under such conditions is a pressing issue that requires solutions capable of providing high performance with minimal resource consumption.Objective. Improving the efficiency of autonomous navigation for small UAVs by using correlation methods for image comparison. Achieving this objective is linked to the development and evaluation of algorithms that provide high-speed and accurate navigation with limited computational resources. The work uses methods such as the autocorrelation function, Pearson correlation, the structural similarity index, and a simple neural network for image comparison.Solution. The research showed that the autocorrelation-based approach demonstrates the best performance under low computational resources. It ensures high-speed processing of the entire image and shows optimal detection accuracy. Compared to other methods presented in the study, the autocorrelation approach is capable of working not only with noise in the "reference" map but also of using alternative areas with altered patterns as detected regions.The scientific novelty of the study is determined by the systematic comparison of various methods applied to the task of image comparison for small UAVs with limited computational resources. Unlike well-known works in the field of correlation-extreme systems, this research focuses on the use of a "reference map" and a search area, representing two different images of the same terrain taken from different sources. This is a key difference, as most methods are not highly efficient in processing such images where patterns may differ significantly.The practical significance of the developed algorithm lies in the fact that the proposed autocorrelation-based method can be used by developers of autonomous small UAV control systems to reduce computational load and increase data processing speed.

The Adolescent Mental Health Consequences of Social Media Usage

This paper looks into the impact of social media on an individual’s mental health status in the adolescent population. The scope of the study includes both addiction and recovery, addressing risks such as anxiety, depression, and distorted self-perception associated with the continuous use of social platforms like Instagram, TikTok, Facebook, etc. Besides recognizing the detrimental impacts of bullying, body image comparison, and excessive use of screens, the paper also underlines some advantages of social media, such as connecting people and access to assistance. In the present research, numerical indicators and empirical observations are used, i.e. the nvestigation is conducted on the basis of the mixed research method. It reveals variations in social media effects amongst adolescents based on the moderating variables of individual characteristics and situational context. The paper ends with solutions to alleviate the negative effects, such as digital literacy education, parental guidance, and mental health strategies while fostering the healthy usage of social media regarding mental health. These findings suggest the need for a longitudinal study in order to assess the changes over time in this somewhat new aspect.

Exploring the potential of historical images for the investigation of glacier changes: the case of Belvedere Glacier, Italian Alps

Historical images dispersed in various archives can be instrumental in documenting processes connected to glacier changes in mountains. A series of more than 29 engravings and photographs of the Monte Rosa east face have been found covering the period since 1789. Some images were produced by a combination of photography and engraving, a common approach before practical techniques for printing halftone images were introduced. Using a repeat photography approach, the present study documents the changes in the extent and debris cover of the Belvedere Glacier. Based on visual comparison of images, it appears that the debris cover of the lower part of the glacier developed mainly during the period of the 1860s–1880s. Furthermore, the image series documents the evolution of the terminus both in terms of elevation and shape, as well as a breach in lateral moraine which could be dated back to the end of the 19th century, well before the reported glacier lake outburst flood in 1904.

INFLUÊNCIA DAS MÍDIAS SOCIAIS EM TRANSTORNOS ALIMENTARES NA ADOLESCÊNCIA

This article highlights the influence of social media on the lives of adolescents and its correlation with the development of eating disorders, with the purpose of raising awareness among readers so that they understand the importance of this topic, as well as the forms of prevention and the perspective of adolescents regarding the aesthetic standards imposed by globalization. Therefore, the general objective of this article is to evaluate the influence of social media in adolescence on distorted body perception and dissatisfaction. The research was developed through the use of a literature review method. The results presented showed that social media has become a catalyst for eating disorders in adolescence, influencing image distortion and comparisons made with other media users. However, the study concludes that more research on this relationship is needed to achieve a greater understanding of this association and the mechanism of influence on the mental and nutritional health of adolescents.

Morphology and agents of urban transformation

The study aims to propose a method of analysis that promotes a clearer perception of the spatial transformation resulting from the action of certain social groups to shape the urban space according to their interests. The territorial transformation related to the role of different agents is investigated, through urban morphology, in order to understand the correlation between the Brazilian urban form with public management and the direction of public investments. To analyze how the city is shaping over time, the work was structured from a case study, which mapped the urban transformations of the municipalities of Cuiabá and Várzea Grande, during the 2006-2021 interval. The method adopted by the research proposes as tools for investigating the territory: the conception of thematic cartographies through the comparison of aerial images from Google Earth, the establishment of analysis categories that allow the identification of the different types of building transformations preponderant of the urban blocks and the main interventions on the road system and the impact of important events that occurred in the cities in the period studied. A quantitative analysis is presented, with the approximate values of areas in hectares (ha), which represent the categories of analysis indicated. As a result, it can be seen, through the maps, that the relationship between the different forms of urban land occupation and the road infrastructure implemented ends up reinforcing the process of socio-spatial segregation. It is concluded that the proposed method, combined with historical and socioeconomic studies, manages to reconstitute urbanization processes in order to understand them in order to intervene in the reality of our cities.

Simulation-based optimization and experimental comparison of intracranial T2-weighted DANTE-SPACE vessel wall imaging at 3T and 7T.

T2-weighted DANTE-SPACE (Delay Alternating with Nutation for Tailored Excitation - Sampling Perfection with Application optimized Contrasts using different flip angle Evolution) sequences facilitate non-invasive intracranial vessel wall imaging at 7T through simultaneous suppression of blood and CSF. However, the achieved vessel wall delineation depends closely on the selected sequence parameters, and little information is available about the performance of the sequence using more widely available 3T MRI. Therefore, in this paper a comprehensive DANTE-SPACE simulation framework is used for the optimization and quantitative comparison of T2-weighted DANTE-SPACE at both 7T and 3T. Simulations are used to propose optimized sequence parameters at both 3T and 7T. At 7T, an additional protocol which uses a parallel transmission (pTx) shim during the DANTE preparation for improved suppression of inflowing blood is also proposed. Data at both field strengths using optimized and literature protocols are acquired and quantitatively compared in six healthy volunteers. At 7T, more vessel wall signal can be retained while still achieving sufficient CSF suppression by using fewer DANTE pulses than described in previous implementations. The use of a pTx shim during DANTE at 7T provides a modest further improvement to the inner vessel wall delineation. At 3T, aggressive DANTE preparation is required to achieve CSF suppression, resulting in reduced vessel wall signal. As a result, the achievable vessel wall definition at 3T is around half that of 7T. Simulation-based optimization of DANTE parameters facilitates improved T2-weighted DANTE-SPACE contrasts at 7T. The improved vessel definition of T2-weighted DANTE-SPACE at 7T makes DANTE preparation more suitable for T2-weighted VWI at 7T than at 3T.

Comparison of Imaging and Actual Measurement ​​of Plant Height and Leaf Area of ​​Cucumber Grafted Seedlings using LiDAR and Multispectral Camera

Comparison of Imaging and Actual Measurement ​​of Plant Height and Leaf Area of ​​Cucumber Grafted Seedlings using LiDAR and Multispectral Camera

Exploring the role of packaging in the formation of brand images: a mixed methods investigation of consumer perspectives

Purpose This study aims to explore consumers’ perspectives on how packaging plays a role in their consumption experience and how it contributes to the formation of brand images. By adopting a consumer’s perspective, the authors identify the criteria that consumers apply to evaluate packaging and reveal how packaging relates to consumers’ overall brand associations. Design/methodology/approach Through a sequential exploratory mixed methods design, the authors explore brand packaging of chocolate bars as emotionally laden, well-known fast-moving consumer goods. First, the authors conduct a qualitative focus group study to explore how consumers perceive package design, and how it relates to their brand impressions. Second, the authors test the constructs and attributes with an independent sample through a quantitative survey. Findings The qualitative findings reveal the different roles of packaging and highlight how packaging provides value for consumer experiences not only at the point-of-sale but also during later consumption. More specifically, the authors identify 12 main criteria that consumers use to evaluate packaging. The authors unwrap how packaging is embedded in consumers’ brand image networks by mapping out its connections to other brand associations pertaining to product attributes, the brand itself and personality impressions. The quantitative findings confirm the importance of practical and symbolic packaging criteria and the brand image comparisons. Originality/value Taking a consumer’s perspective, this study contributes to a more holistic understanding of how packaging supports brand building as we reveal the various ways in which packaging relates to consumers’ overall brand image associations. This study further directs attention to the roles that consumers themselves assign to packaging and how they evaluate packaging based on its practical, symbolic and social value.

Ultrasonographic approach to visualize the medial shoulder compartment and diagnose medial glenohumeral ligament and subscapularis lesions in dogs.

To provide a video tutorial on the diagnostic ultrasound approach to the medial compartment of the canine shoulder and provide comparisons of normal and pathological images with corresponding MRI. Dogs undergoing diagnostic ultrasound of the medial shoulder. The medial shoulder was positioned in flexion with external rotation to allow transducer access, clipped, and scrubbed with dilute chlorhexidine. A 2- to 14-MHz linear array probe with a footprint of 50 mm (V8 ultrasound system; Samsung) was used to visualize the medial glenohumeral ligament (MGL), subscapularis, and coracobrachialis with coupling gel, confirmed by cadaveric ultrasound-guided dye injection and dissection. Ultrasound and corresponding MRI were then used to contrast normal anatomy to a live sedated dog with clinical subscapularis tendinopathy and MGL desmopathy. Proton density-weighted MRI sequences (1.5T Vantage Orian; Canon) using a flex coil were able to identify all 3 structures and corresponded to ultrasound findings for normal and pathological anatomy. Diagnostic ultrasound identified normal and abnormal structures of the medial shoulder (coracobrachialis, subscapularis, and MGL). All imaging correlated well to MRI. Medial compartment disease of the shoulder is a well-described cause of canine lameness, but diagnosis has traditionally relied on MRI or arthroscopy. Prior ultrasound approaches did not distinguish MGL components, failed to consistently identify normal or surgically transected ligaments, and have not been studied in vivo. Our approach is different and can play an important role in diagnosing medial compartment lesions, as it possesses greater anatomical visualization than arthroscopy and is noninvasive, accomplished with sedation, and relatively accessible and affordable.

The Impact of Image Comparison on The Self-Identity Formation of Female University Students on Social Media

Nowadays, social media is not only an important way for female college students to express themselves but also the main source and way to receive and obtain information. Different platforms push various ‘perfect images’ to female users through algorithms, and constantly create labels and topics about beauty, such as ‘white, thin and young’, ‘straight shoulders’, and so on. Female college students are in an important stage of self-identity construction, during which they will consciously or unconsciously compare themselves with others, and these comparisons affect their aesthetic concepts views, and understanding of themselves. This thesis employs a qualitative research methodology to examine and elucidate the nexus between image comparison on social media and women’s identity. To this end, it conducts in-depth interviews with 11 female university students representing diverse academic disciplines, institutional affiliations, and geographical locations. The study found that there are differences in personal preferences and purposes when female college students choose comparison objects and that the comparison of images on social media has different positive or negative impacts on psychological aspects, and there are individual differences in the degree of impacts, but the comparison of images does not have a direct impact on individual behavior, and generally stays at the psychological level of the individual: in addition, the social activities in daily life and study and other activities of personal growth nowadays can effectively reduce the impacts of social media.

Smartphone Aided Funduscopy in Albino Rabbits

Aims: The methodology, utility and clinical feasibility of using a smartphone camera to obtain images of ocular fundus of albino rabbits with ocular hypertension and normotension were studied. A comparative analysis of fundus images obtained from two popularly used smartphone models, android and iOS device was performed on 36 adult albino rabbits. Study Design: A cross-sectional study involving two cohorts of ocular hypertensive and normotensive albino rabbits. Place and Duration of Study: Department of Veterinary Surgery and Radiology, College of Veterinary and Animal Sciences, Mannuthy for an eight-week period (2023). Methodology: A total of 36 adult albino rabbits (18 males and 18 females; age range 6- 8 months of age) with ocular normotensive eyes and unilateral ocular hypertension-induced models were used. The conscious animals were gently restrained in an acrylic restrainer. Instillation of topical mydriatic solution (tropicamide 0.8% and phenylephrine 5%) facilitated visual examination and enhanced field of view along with auxiliary condensing lenses of 20 and 40 Diopters. A comparison of fundus images obtained from two popularly used smartphone models, android and iOS devices was performed on 36 adult albino rabbits. Results: Fundus images comprising the optic nerve head and peripapillary retina were obtained with adequate spatial resolution and detail. The variation between optic disc of ocular hypertensive eye revealed mild edema and cupping of optic disc. Normal merangiotic retina and optic disc were clearly obtained in normotensive rabbit eyes. The iOS device used in this case yielded better images in resolution and field of view compared to the android version used in this case. Conclusion: Smart phone funduscopy offered good detail in contrast and resolution even in amelanotic eyes of albino rabbits using inbuilt technology without the need for an external adapter or sophisticated additional software. It is an animal-friendly futuristic solution for digital documentation, telemedicine, teaching and clinical prognosis formulation.

PO0228: Comparison of Transabdominal Ultrasound Guidance versus Magnetic Resonance Image Guided Brachytherapy for Cervical Cancer

PO0228: Comparison of Transabdominal Ultrasound Guidance versus Magnetic Resonance Image Guided Brachytherapy for Cervical Cancer

360° CZT-SPECT/CT cameras: 99mTc- and 177Lu-phantom-based evaluation under clinical conditions

PurposeFor the first time, three currently available 360° CZT-SPECT/CT cameras were compared under clinical conditions using phantom-based measurements.MethodsA 99mTc- and a 177Lu-customized NEMA IEC body phantom were imaged with three different cameras, StarGuide (GE Healthcare), VERITON-CT versions 200 (V200) and 400 (V400) (Spectrum Dynamics Medical) under the same clinical conditions. Energy resolution and volumetric sensitivity were evaluated from energy spectra. Vendors provided the best reconstruction parameters dedicated to visualization and/or quantification, based on their respective software developments. For both 99mTc- and 177Lu-phantoms, noise level, quantification accuracy, and recovery coefficient (RC) were performed with 3DSlicer. Image quality metrics from an approach called “task-based” were computed with iQMetrix-CT on 99mTc visual reconstructions to assess, through spatial frequencies, noise texture in the background (NPS) and contrast restitution of a hot insert (TTF). Spatial resolution indices were calculated from frequencies corresponding to TTF10% and TTF50%.ResultsDespite the higher sensitivity of VERITON cameras and the enhanced energy resolution of the V400 (3.2% at 140 keV, 5.2% at 113 keV, and 3.6% at 208 keV), StarGuide presents comparable image quality. This highlights the need to differentiate sensitivity from count quality, which is influenced by hardware design (collimator, detector block) and conditions image quality as well as the reconstruction process (algorithms, scatter correction, noise regulation). For 99mTc imaging, the quantitative image optimization approach based on RCmean for StarGuide versus RCmax for V200 and V400 systems (RCmean/RCmax: 0.9/1.8; 0.5/0.9; 0.5/0.9 respectively—Ø37 mm). SRTB10/50 showed nearly equivalent spatial resolution performances across the different reconstructed images. For 177Lu imaging, the 113 keV imaging of the V200 and V400 systems demonstrated strong performances in both image quality and quantification, while StarGuide and V400 systems offer even better potential due to their ability to exploit signals from both the 113 and 208 keV peaks. 177Lu quantification was optimized according to RCmax for all cameras and reconstructions (1.07 ± 0.09—Ø37 mm).ConclusionsThe three cameras have equivalent potential for 99mTc imaging, while StarGuide and V400 have demonstrated higher potential for 177Lu. Dedicated visual or quantitative reconstructions offer better specific performances compared to the unified visual/quantitative reconstruction. The task-based approach appears to be promising for in-depth comparison of images in the context of system characterization/comparison and protocol optimization.

D-[5-11C]-Glutamine Positron Emission Tomography Imaging for Diagnosis and Therapeutic Monitoring of Orthopedic Implant Infections.

Orthopedic implant infections (OIIs) present diagnostic and therapeutic challenges, owing to the lack of methods to distinguish between active infection and sterile inflammation. To address this unmet need, d-amino-acid-based radiotracers with unique metabolic profiles in microorganisms have emerged as a novel class of infection-specific imaging agents. Given the pivotal role of d-glutamine in bacterial biofilm formation and virulence, herein, we explored the potential of positron emission tomography (PET) imaging with d-[5-11C]-Glutamine (d-[5-11C]-Gln) for early detection and treatment monitoring of OIIs. In vitro studies confirmed an active uptake of d-[5-11C]-Gln by Staphylococcus aureus (S. aureus) biofilm commonly associated with OIIs. In vivo evaluations included PET imaging comparisons with d-[5-11C]-Gln vs l-[5-11C]-Gln or 2-deoxy-2-[18F]-fluoroglucose ([18F]-FDG) in a rat OII model with tibial implantation of sterile or S. aureus-colonized stainless-steel screws before and after treatment. These studies demonstrated that the uptake of d-[5-11C]-Gln was significantly higher in the infected screws than that in sterile screws (∼3.4-fold, p = 0.008), which displayed significantly higher infection-to-background muscle uptake ratios (∼2-fold, p = 0.011) with d-[5-11C]-Gln as compared to l-[5-11C]-Gln. Following a 3 week vancomycin treatment, imaging with d-[5-11C]-Gln showed a significant reduction in uptake at the infected sites (∼3-fold, p = 0.0008). Further regression analyses revealed a superior correlation of residual infection-associated radiotracer uptake with the postimaging ex vivo bacterial counts for d-[5-11C]-Gln (k = 0.473, R2 = 0.796) vs [18F]-FDG (k = 0.212, R2 = 0.434), suggesting that d-[5-11C]-Gln PET had higher sensitivity for detecting residual bacterial burden than [18F]-FDG PET. Our results demonstrate the translational potential of d-[5-11C]-Gln PET imaging for noninvasive detection and treatment monitoring of OIIs.

Uterine layers hypervascularization in atypical placentation: the comparison of magnetic resonance imaging with vascular pathomorphology

Rationale: One in five women worldwide delivers through cesarean section, which is associated to a high rate of placenta previa and abnormal placenta attachment to the uterine wall. The grade of placenta accreta spectrum (PAS) correlates with blood loss volume, which could be related to vascularization characteristics. Up to now, there have been no studies on the diagnostic value of magnetic resonance criteria for hypervascularization of the uterine wall and their correlation with an assumed grade of PAS according to the International Federation of Gynecology and Obstetrics (FIGO) classification. Also, abnormal vessels location and their wall structure have not been studied with state-of-the-art pathomorphological methods. Aim: To develop a classification for various types of the uterine wall hypervascularization depending on the depth of placental invasion assessed by magnetic resonance imaging (MRI). Methods: We retrospectively analyzed medical files of 66 patients aged 18 to 45 years, who were assumed to have PAS based on their sonography results. To clarify the extent and localization of the placental invasion, all patients had MRI performed at 24 to 32 weeks of gestation. In all patients, the PAS grade was verified pathologically; in 30 of them (45,5%), a detailed pathological examination was additionally performed. The PAS grades were classified according to Morbidly Adherent Placenta Imaging Reporting and Data System (MAPI-RADS). The MRI data were correlated with the PAS (FIGO) grade estimated from intraoperative data and with intraoperative blood loss. At the final study step, the MRI data was correlated with abnormal pathomorphology, with the assessment of the degree of vascularization and the visual picture of abnormal uteroplacental vasculature. Results: We have proposed a classification of MRI signs of hypervascularization in the lower uterine segment correlating with the depth of placenta accreta. Type 1. Single small vessels in the myometrium, medium caliber arteries in the projection of the uterine serosa (normal variation for the 3rd trimester of gestation). Type 2. Numerous small confluent vessels, mainly in the uteroplacental region, and retroplacental hematomas (typical for placenta accreta, or FIGO PAS 1). Type 3. Intrauterine hypervascularization with a deficient myometrium thickness, predominantly vessels of the middle layer (typical for placenta increta, or FIGO PAS 2). Type 4. Thinning of the lower uterine segment due to significant bulging of the placenta in the presence of curved anastomosing vessels of vast caliber over 4 mm (typical for placenta increta – FIGO PAS 2, as well as placenta percreta – FIGO PAS 3a). Type 5. Hypervascularization outside the uterus, over its surface and in the parametrial tissues: at the border with the bladder, uterine isthmus, including signs of fibrosis and growing into the posterior bladder wall (typical for various grades of placenta percreta – FIGO PAS 3b, 3c). Conclusion: The proposed classification of uterine wall hypervascularization in accordance with the grades of placenta accreta spectrum (FIGO PAS) could be useful for its practical implementation by radiologists.