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Carbonate formations constitute the primary source of hydrocarbon reservoirs worldwide, highlighting the importance of gaining a deeper understanding of matrix acidizing phenomena to enhance well productivity in these formations. Microstructural analysis of acidified cores is a key method to assess acidizing systems in carbonate rock samples. X-ray computed microtomography (Micro-CT) has significantly contributed to this field, primarily focusing on the qualitative and quantitative characterization of the profiles of carbonate mineral dissolution, also known as wormholes, created during matrix acidizing. This non-destructive evaluation technique allows the internal analysis of a sample without altering its internal structure or chemical composition. This work focuses on a comprehensive review of the research studies and the main applications of micro-CT for evaluating and characterizing matrix acidizing in carbonates. First, an overview of the fundamentals of micro-CT and acid stimulation in carbonates is provided. Next, the applications of micro-CT are discussed and grouped into microstructural characteristics of wormholes, dynamic in-situ experiments, and pore-scale modeling topics. A case study is presented with a methodology based on micro-CT analysis for matrix acidizing. Finally, future work and current challenges, such as 4D CT and CT-based acidizing models, are discussed.

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INTRODUCTION: Circulating tumor DNA (ctDNA) can be obtained from cell-free DNA (cfDNA) andis a new technique for genotyping, response assessment and prognosis in lymphoma. METHODS: Eighteen patients with samples at diagnosis (ctDNA1), after treatment (ctDNA2) and extracted from diagnostic tissue (FFPE) were evaluated. RESULTS: In all patients, at least one mutation in cfDNA was detected at diagnosis. CREBBP was the most frequent mutated gene (67 %). In 12 of the 15 patients with complete remission, the mutation attributed to the disease found at diagnosis cleared with treatment. A reduction in the ctDNA was observed after treatment in 14 patients, 12 of whom achieved complete remission. Correlations were found between the ctDNA at diagnosis and total metabolic tumor volume (r = 0.51; p-value = 0.014) and total lesion glycolysis 2.5 (r = 0.47; p-value = 0.024) by PET at diagnosis and between ctDNA at diagnosis and radiomic features of the lesions with the largest standardized uptake value. There was a strong inverse correlation between ΔctDNA1 and ΔSUVmax by PET/CT (r = -0.8788; p-value = 0.002). CONCLUSION: Analysis of ctDNA and PET/CT in large B-cell lymphoma are complementary data for evaluating tumor burden and tumor clearance after treatment. Analysis of radiomic data might help to identify tumor characteristics and their changes after treatment.

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PURPOSE: This retrospective study was undertaken to assess the predictive efficacy of 18F-FDG PET/CT -derived radiomic features concerning the co-mutation status of epidermal growth factor receptor (EGFR) and TP53 in LUAD. METHODS: A cohort of 150 LUAD patients underwent pretreatment 18F-FDG PET/CT scans with known mutation status of EGFR and TP53 were collected. The feature extraction based on their PET/CT images utilized the Pyradiomics package based on the 3D Slicer. The optimal radiomic features were selected through correlation analysis and the Gradient Boosting Decision Tree (GBDT) algorithm, followed by the construction of the radiomic model. The clinical model incorporated meaningful clinical variables, whereas the complex model integrated both the radiomic and clinical models. The area under the receiver operating characteristic curve (AUC) facilitated the comparison of prediction performance across the three models. The DCA gauged the clinical utility of these models. RESULTS: The patient cohort was randomly allocated into a training set (n = 105) and a validation set (n = 45) in a 7:3 ratio. Eleven PET and eleven CT optimal radiomic features were selected to construct the radiomic model. The model showed a good ability to discriminate the co-occurrence of EGFR and TP53, with AUC equal to 0.850 in the training set, and 0.748 in the validation set, compared with 0.750 and 0.626 for the clinical model. The complex model exhibited the highest AUC values, with 0.880 and 0.794 in both sets, but there were no significant differences compared to the radiomic model. The DCA revealed favorable clinical value.

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Background/Objectives: The accurate quantification of ground-glass opacities (GGOs) and consolidation volumes has prognostic value in COVID-19 patients. Nevertheless, the accurate manual quantification of the corresponding volumes remains a time-consuming task. Deep learning (DL) has demonstrated good performance in the segmentation of normal lung parenchyma and COVID-19 pneumonia. We introduce a Human-in-the-Loop (HITL) strategy for the segmentation of normal lung parenchyma and COVID-19 pneumonia that is both time efficient and quality effective. Furthermore, we propose a Gaussian Mixture Model (GMM) to classify GGO and consolidation based on a probabilistic characterization and case-sensitive thresholds. Methods: A total of 65 Computed Tomography (CT) scans from 64 patients, acquired between March 2020 and June 2021, were randomly selected. We pretrained a 3D-UNet with an international dataset and implemented a HITL strategy to refine the local dataset with delineations by teams of medical interns, radiology residents, and radiologists. Following each HITL cycle, 3D-UNet was re-trained until the Dice Similarity Coefficients (DSCs) reached the quality criteria set by radiologists (DSC = 0.95/0.8 for the normal lung parenchyma/COVID-19 pneumonia). For the probabilistic characterization, a Gaussian Mixture Model (GMM) was fitted to the Hounsfield Units (HUs) of voxels from the CT scans of patients with COVID-19 pneumonia on the assumption that two distinct populations were superimposed: one for GGO and one for consolidation. Results: Manual delineation of the normal lung parenchyma and COVID-19 pneumonia was performed by seven teams on 65 CT scans from 64 patients (56 ± 16 years old (µ ± σ), 46 males, 62 with reported symptoms). Automated lung/COVID-19 pneumonia segmentation with a DSC > 0.96/0.81 was achieved after three HITL cycles. The HITL strategy improved the DSC by 0.2 and 0.5 for the normal lung parenchyma and COVID-19 pneumonia segmentation, respectively. The distribution of the patient-specific thresholds derived from the GMM yielded a mean of -528.4 ± 99.5 HU (µ ± σ), which is below most of the reported fixed HU thresholds. Conclusions: The HITL strategy allowed for fast and effective annotations, thereby enhancing the quality of segmentation for a local CT dataset. Probabilistic characterization of COVID-19 pneumonia by the GMM enabled patient-specific segmentation of GGO and consolidation. The combination of both approaches is essential to gain confidence in DL approaches in our local environment. The patient-specific probabilistic approach, when combined with the automatic quantification of COVID-19 imaging findings, enhances the understanding of GGO and consolidation during the course of the disease, with the potential to improve the accuracy of clinical predictions.

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Parkinsonian syndromes are considered clinicopathological conditions that are challenging to diagnose. Molecular imaging with [18F]-FDOPA and [18F]-FDG contributes to a more accurate clinical diagnosis by evaluating presynaptic dopaminergic pathways and glucose metabolism, respectively. The aim of this study was to correlate diagnoses made from dual PET/CT with the initial clinical diagnoses, as well as during follow-ups in patients with Parkinsonian syndromes. A secondary objective was to describe the imaging findings. Methods: A total of 150 patients with a clinical diagnosis of neurodegenerative Parkinsonism were evaluated using dual PET/CT. Clinically, 82% were diagnosed with PD, while the remaining 18% had an atypical Parkinsonism. Results: Using dual PET/CT, the most frequent diagnosis was PD in 67% of the patients, with the rest being diagnosed with an atypical Parkinsonism. In an agreement analysis between the initial clinical diagnosis and the imaging diagnosis by dual PET/CT, a concordance of 94.1% (n = 95) was observed for PD. In the remaining patients, the clinical diagnosis differed from that suggested by dual PET/CT, with atypical Parkinsonian syndromes being diagnosed as DLB in 40% (n = 4), PSP in 46.7% (n = 7), MSA-C in 75% (n = 6), MSA-P in 70% (n = 7), and CBD in 66.7% (n = 4). A total of 38.66% (n = 58) of patients were followed up (median follow-up of 27 months), with a Kappa coefficient of 0.591 (p < 0.001), suggesting substantial agreement. Conclusions: Dual FDOPA-FDG PET/CT demonstrated moderate agreement with the initial clinical diagnosis of Parkinsonism and moderate to substantial agreement during follow-up. This dual technique, therefore, stands out in differentiating between types of Parkinsonisms.

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Breast cancer (BC) is the leading cause of death from tumors in women worldwide, influenced by various factors, including genetics. The T allele of the single nucleotide variant (SNV) rs3025039 at position +936 of the VEGFA gene has been reported to affect the mRNA regulatory mechanisms, potentially altering VEGFA expression and increasing BC risk. This study aimed to investigate the association between rs3025039 and BC in Mexican women residing in Jalisco, Mexico. The study included 231 women with a confirmed diagnosis of BC and 201 healthy subjects as a reference group (RG). PCR-RFLP was employed for the genotyping of rs3025039, with the visualization of amplified products using polyacrylamide gel electrophoresis. Significant differences were observed in rs3025039 alleles and genotypes between BC cases and the RG (p = 0.0038). The frequency of the T allele and the CT genotype was higher in the BC group compared to the RG, with a significant difference (p = 0.0006). In conclusion, this research suggests that the SNV rs3025039 is associated with a higher risk of BC in Mexican women. These findings enhance our understanding of the genetic underpinnings of BC in this population, offering potential insights for future studies and interventions.

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Infective Endocarditis (IE) is a complex, life-threatening disease. The aim of the present study was to evaluate the impact of the Endocarditis-Team on management of IE. This observational study conducted at a university hospital (2015‒22), included adult patients with IE. The study period was divided in two periods: before (pre-Endocarditis-Team; pre-ET) and after the establishment of the Endocarditis-Team (post-Endocarditis-Team; post-ET) on January 2018. Among 505 IE episodes (187 in pre-Endocarditis-Team, 318 in post-ET period), 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography was more commonly used in post-ET period (14 % vs. 28 %; p < 0.001). Overall, thirty-day and one-year mortality were 14 % and 27 %, respectively; no difference was observed between the two periods. In post-ET period, the administration of 4-weeks, rather than 6-weeks, of intravenous antimicrobial treatment was higher than in the post-ET period (15 % vs. 45 %; p < 0.001). Indication for surgery was present in 115 (61 %) patients in pre-ET and in 153 (48 %) in the post-ET period. In post-ET period, among patients with indication, valve surgery was more frequently performed (66 % vs. 78 %; p = 0.038). Such difference was due to a higher acceptance of operative indication by the cardiac surgeon (69 % vs. 94 %; p = 0.013). The observed increase in number of patients benefiting from cardiac surgery in the post-ET period led to a decrease of subsequent embolic events, since among patients with operative indication (n = 268), new embolic events after the establishment of the indication were more common in the pre-ET period compared to post-ET (23 % vs. 12 %; p = 0.033). After the implementation of the multidisciplinary Endocarditis-Team we observed several improvements in the general management of IE patients.

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The differential diagnosis between malignant and benign adrenal cortical tumors is challenging, and concurrent androgen and cortisol production should raise  suspicion of a malignant tumor. We present the case of a 36-year-old woman who exhibited pronounced hirsutism, clitoromegaly, and secondary amenorrhea. A contrast-enhanced computed tomography (CT) scan revealed a 35 × 27 mm right adrenal mass with unenhanced CT attenuation of 40 Hounsfield units (HUs). The mass exhibited absolute and relative washout rates of 50% and 28%, respectively, and was accompanied by a 25 × 20 mm adenopathy located in the hepatogastric space. Total testosterone was elevated by 247 ng/dL (8.56 nmol/L) (normal reference range, 10-75 ng/dL; 0.34-2.6 nmol/L). A 1-mg dexamethasone suppression test revealed an elevated serum morning cortisol concentration of 10.57 µg/dL (291.58 nmol/L) (reference range, <1.8 µg/dL; < 49.66 nmol/L). A fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan revealed increased uptake in both the adrenal mass and the adenopathy. Subsequently, the patient underwent an open right adrenalectomy and lymphadenectomy. Histological examination revealed the presence of an adrenal adenoma with myelolipomatous metaplasia, as well as a positive polymerase chain reaction (PCR) for Mycobacterium tuberculosis in the adenopathy.

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This study aimed to evaluate the effects of the estrogen depression during orthodontic tooth movement on alveolar bone microarchitecture and periodontal ligament. Female Wistar rats were divided into two groups, one consisting of non-ovariectomized animals subjected to orthodontic tooth movement, and one comprising ovariectomized animals subjected to orthodontic tooth movement. Micro-CT assessment of bone volume to total volume (BV/TV), total porosity, trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp) in the alveolar bone of the orthodontically moved tooth was performed. Histomorphometric analyses were made in the periodontal ligament, and immunoexpression of RANK, RANKL, OPG, and TUNEL were quantified. Orthodontic tooth movement in the group of ovariectomized rats was faster than in non-ovariectomized animals. The alveolar bone area showed lower values of BV/TV and trabecular thickness, and higher bone porosity and trabeculae numbers in the ovariectomized rats. Histological analyses in the ovariectomized group revealed an increase in collagen fibers in the periodontal ligament. The apoptotic cell counts in the periodontal ligament were higher in the group of ovariectomized rats than in the sham-operated rats. Ovariectomy resulted in an increase in tooth movement and alteration of the alveolar bone microstructure in the first 7 day of orthodontic tooth movement, and in the presence of apoptotic cells in the periodontal ligament.

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OBJECTIVE: To develop a CT-based scoring system for assessment of hip arthropathy in AS. METHODS: All AS patients were prospectively recruited, consented, and underwent whole-body stereoradiographs and pelvis CT, which were assessed by two independent radiologists. Stereoradiographs were assessed according to Kellgreen-Lawrence and BASRI-h. For the Hip arthropathy CT score in AS (HACTSAS), joints were divided into 7 segments and scored for joint space, osteophytes, subchondral cysts/erosions. Patients were clinically assessed for range of motion (ROM), pain, and clinical scores (BASMI, BASFI, ASQol, BASDAI and ASDAS). Radiological scores correlations with clinical parameters were compared. ROM sensitivity and specificity for hip arthropathy (BASRI-h ≥ 2) were calculated. RESULTS: Sample included 112 patients, with 36/112 females and 76/112 males. Average age was 51.0 ± 11.2 years and mean duration of AS was 20.9 ± 9.6 years. ICC for HACTSAS, Kellgreen-Lawrence and BASRI-h were 0.89, 0.89 and 0.82 respectively. HACTSAS showed moderate absolute correlation with ROM (ρ=-0.41) and BASMI (ρ = 0.45), and weak with pain (ρ = 0.18) and BASFI (ρ = 0.25). BASRI-h and Kellgreen-Lawrence exhibited moderate correlation with ROM (ρ=-0.44 and ρ=-0.40, respectively), weak with pain (ρ=-.27and ρ=-0.23, respectively) and BASFI (ρ=-0.16 and ρ=-0.18, respectively), but only weak with BASMI (ρ=-0.34 and ρ=-0.36, respectively). Internal rotation <15°, abduction <31°, and intermalleolar distance <75cm were, respectively, 73%, 70% and 73% sensitivity and 81%, 65% and 68% specific for hip arthropathy. CONCLUSION: HACTSAS exhibited higher correlation with BASMI and BASFI when compared with BASRI-h, but less correlation with pain and ROM. Internal rotation was the best clinical discriminator for hip arthropathy.

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The article addresses the diagnostic value of the combined use of computed tomography (CT) perfusion and dual-energy CT (DECT) in patients with neuroendocrine tumors. It emphasizes the heterogeneity and complexity of these neoplasms, primarily affecting the gastrointestinal tract, bronchopulmonary system, and pancreas. While conventional CT is widely employed in their diagnosis, the combination of CT perfusion and dual-energy CT offers greater precision, particularly in detecting synchronous tumors and characterizing their vascularization. A clinical case of a patient with chronic abdominal symptoms, whose diagnosis was facilitated using both combined techniques, is presented. The discussion explores how CT perfusion assesses tumor vascularization and how dual-energy CT improves soft tissue differentiation, resulting in increased diagnostic accuracy. It is highlighted that this approach not only enhances detection rates but also positively impacts clinical management and healthcare costs. Therefore, the importance of considering these advanced tools in the diagnosis of neuroendocrine tumors to improve diagnostic precision and efficiency in patient care is underscored.

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Mycotic aneurysms and pseudoaneurysms, though rare, present significant diagnostic and therapeutic challenges. The case follows a 74-year-old male with a history of bladder cancer who developed multifocal mycotic aneurysms and pseudoaneurysms following sepsis. Initially misdiagnosed as a Pancoast tumor, imaging revealed an extensive disease involving the right subclavian artery, proximal descending thoracic aorta, infrarenal abdominal aorta, and right common iliac artery. This case highlights the importance of considering mycotic aneurysms in the differential diagnosis of patients with a history of infection and highlights the role of Computed Tomography Angiography in early diagnosis.

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PURPOSE: This study aimed to develop a tumor radiomics quality and quantity model (RQQM) based on preoperative enhanced CT to predict early recurrence after radical surgery for colorectal liver metastases (CRLM). METHODS: A retrospective analysis was conducted on 282 cases from 3 centers. Clinical risk factors were examined using univariate and multivariate logistic regression (LR) to construct the clinical model. Radiomics features were extracted using the least absolute shrinkage and selection operator (LASSO) for dimensionality reduction. The LR learning algorithm was employed to construct the radiomics model, RQQM (radiomics-TBS), combined model (radiomics-clinical), clinical risk score (CRS) model and tumor burden score (TBS) model. Inter-model comparisons were made using area under the curve (AUC), decision curve analysis (DCA) and calibration curve. Log-rank tests assessed differences in disease-free survival (DFS) and overall survival (OS). RESULTS: Clinical features screening identified CRS, KRAS/NRAS/BRAF and liver lobe distribution as risk factors. Radiomics model, RQQM, combined model demonstrated higher AUC values compared to CRS and TBS model in training, internal and external validation cohorts (Delong-test P < 0.05). RQQM outperformed the radiomics model, but was slightly inferior to the combined model. Survival curves revealed statistically significant differences in 1-year DFS and 3-year OS for the RQQM (P < 0.001). CONCLUSIONS: RQQM integrates both "quality" (radiomics) and "quantity" (TBS). The radiomics model is superior to the TBS model and has a greater impact on patient prognosis. In the absence of clinical data, RQQM, relying solely on imaging data, shows an advantage in predicting early recurrence after radical surgery for CRLM.

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Introduction: This study aimed to compare the effectiveness of two endodontic cleaning techniques, passive ultrasonic irrigation (PUI) and the XP-endo Finisher R (XPR) system, in removing residual filling material during endodontic retreatment procedures. Materials and Methods: Forty mandibular premolars with oval canals were divided into four groups based on the sealer used (AH-Plus or Bio-C Sealer) and the cleaning technique employed (PUI or XPR). To ensure uniformity of canal volume among groups, initial micro-CT scans were conducted. The canals were instrumented, filled, and then re-instrumented before undergoing either PUI or XPR cleaning techniques. Residual filling material volumes were assessed through micro-CT scans, and statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests. Results: Following instrumentation, there was no significant difference in residual filling material volumes between AH-Plus and Bio-C Sealer groups (1.35 mm3and 1.02 mm3, respectively; P>0.05). However, after supplementary cleaning techniques, XPR-cleaned specimens exhibited significantly less residual material compared to PUI-cleaned specimens (0.01 mm3 and 0.29 mm3 for Bio-C Sealer, and 0.07 mm3 and. 0.30 mm3 for AH-Plus, P<0.05). Conclusion: The XPR system was found to be more effective than PUI in removing residual filling material from Bio-C Sealer-filled root canals. This highlights its potential as a useful supplementary cleaning technique in endodontic retreatment procedures.

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BACKGROUND: The prevalence of lung cancer among individuals afflicted with interstitial pneumonia (IP) stands at approximately 20%. The early detection of lung cancer via chest computed tomography (CT) surveillance proves challenging in IP patients. Our investigation sought to identify a potential biomarker capable of providing early indications of the presence of lung tumors in such patients. MATERIALS AND METHODS: We examined the attributes of serum tumor markers, imaging characteristics, and histological findings in individuals diagnosed with IP, both with and without concurrent lung cancer. RESULTS: 106 patients diagnosed with IP were included in the study, comprising 36 individuals with concurrent lung cancer and 70 patients solely diagnosed with IP. Serum concentrations of CEA and CA12-5 were notably elevated in IP patients with lung cancer, compared to those with IP alone. Logistic regression analyses revealed that, in comparison to IP patients within the first quartile of CEA levels, the relative risk of developing lung cancer associated with IP escalated by 4.0-fold, 3.1-fold, 11.0-fold, and 13.3-fold in the second, third, fourth, and fifth quartiles, respectively. Upon controlling for gender and age, statistical significance in risk was observed solely for the fourth and fifth quartiles. Receiver operating characteristic (ROC) curve analysis conducted in patients diagnosed with ILD-CA identified a CEA cutoff point of 6.9 ng/mL, demonstrating sensitivities of 61.1% and specificities of 78.5%. The area under the curve was calculated as 0.7(95% CI: 0.63-0.81). CONCLUSION: The serum levels of CEA were notably elevated in IP patients with concurrent lung cancer in contrast to those who were just suffering from IP. The heightened serum CEA levels correlate with an escalated risk of cancer occurrence among IP patients, suggesting that serum CEA levels could potentially serve as an indicative marker for the presence of cancer in IP patients.

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AIM: CT images can identify structural and opacity alterations of the lungs while nuclear medicine's lung perfusion studies show the homogeneity (or lack of) of blood perfusion on the organ. Therefore, the use of SPECT/CT in lung perfusion scintigraphies can help physicians to assess anatomical and functional alterations of the lungs and to differentiate between acute and chronic disease. OBJECTIVE: To develop a computer-aided methodology to quantify the total global perfusion of the lungs via SPECT/CT images and to compare these results with parenchymal alterations obtained in CT images. METHODS: 39 perfusion SPECT/CT images collected retrospectively from the Nuclear Medicine Facility of Botucatu Medical School's Clinics Hospital in São Paulo, Brazil, were analyzed. Anatomical lung impairments (emphysema, collapsed and infiltrated tissue) and the functional percentage of the lungs (blood perfusion) were quantified from CT and SPECT images, with the aid of the free, open-source software 3D Slicer. The results obtained with 3D Slicer (3D-TGP) were also compared to the total global perfusion of each patient's found on their medical report, obtained from visual inspection of planar images (2D-TGP). RESULTS: This research developed a novel and practical methodology for obtaining lungs' total global perfusion from SPECT/CT images in a semiautomatic manner. 3D-TGP versus 2D-TGP showed a bias of 7% with a variation up to 67% between the two methods. Perfusion percentage showed a weak positive correlation with infiltration (p = 0.0070 and ρ = 0.43) and collapsed parenchyma (p = 0.040 and ρ = 0.33). CONCLUSIONS: This research brings meaningful contributions to the scientific community because it used a free open-source software to quantify the lungs blood perfusion via SPECT/CT images and pointed that the relationship between parenchyma alterations and the organ's perfusion capability might not be so direct, given compensatory mechanisms.

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Los salmónidos, durante su desarrollo, pueden experimentar ocasionalmente deformaciones esqueléticas. Para su diagnóstico se emplean diversas metodologías, entre las que se incluyen radiografías, técnicas histológicas, diafanización con tinciones de alizarina y azul de alcián, así como el uso del microscopio electrónico de barrido (SEM), cada una con sus inherentes ventajas y desventajas. Este estudio tuvo como finalidad evaluar y comparar la eficacia de la tomografía microcomputarizada (Micro-CT) para el análisis anatómico, reconstruyendo tridimensionalmente las imágenes y contrastándolas con los resultados obtenidos mediante la técnica de diafanización. Se analizaron las aletas caudales de cinco ejemplares de salmón Oncorhynchus kisutch: dos sujetos a diafanización y tres procesados para análisis mediante Micro-CT utilizando el equipo BRUKER SkyScan 1272. La técnica de Micro-CT demostró superioridad en la resolución de las estructuras óseas, facilitando una exploración detallada de las variaciones morfológicas y la distribución de la densidad mineral. Este enfoque permitió identificar anomalías en la morfología y crecimiento de las últimas vértebras y lepidotriquias dorsales, así como una densidad incrementada en lepidotriquias dorsales malformadas. La mayor resolución proporcionada por la Micro-CT no solo potencia nuestra comprensión de la ontogenia piscícola y su adaptación a ambientes diversos, sino que además inaugura perspectivas innovadoras para el estudio de la evolución de las estrategias locomotoras y las respuestas adaptativas frente a cambios ambientales a través del tiempo.

SUMMARY: During their development, some species of salmonids may occasionally experience skeletal deformations. Several methodologies are currently being used for the diagnosis of such malformations, among which X-rays, histological techniques, diaphanization coupled either with Alizarin Red or Alcian Blue stains, as well as Scanning Electron Microscopy (SEM) can be mentioned. Each one of those methods presents inherent advantages and disadvantages. The purpose of this study was twofold: Firstly, to evaluate and compare the effectiveness of microcomputed tomography (Micro-CT) technology for anatomical analysis, three-dimensionally reconstructing the obtained images; and secondly, to contrast those images with the results obtained through the diaphanization technique. The caudal fins of five specimens of the Oncorhynchus kisutch salmon were analyzed: Two specimens were subjected to diaphanization and three were processed for Micro-CT analysis, using the BRUKER SkyScan 1272 equipment. The Micro-CT technology demonstrated superiority in the resolution of bone structures, facilitating a detailed exploration of morphological variations, as well as the distribution of mineral density. This experimental approach allowed us to identify anomalies in the morphology and growth of the last vertebrae and dorsal lepidotrichiae, as well as an increased mineral density in the malformed dorsal lepidotrichiae. The higher resolution provided by Micro-CT not only enhances our understanding of the fish ontogeny and its adaptation to diverse environments, but also opens innovative perspectives for the study of the evolution of locomotor strategies and adaptive responses to environmental changes.

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Introduction Diseases of the paranasal sinuses, nasal cavities, and those related to the skull base can be treated with nasal endoscopic surgery. Anatomical references are essential to safely perform these surgeries. Objective To measure and compare the distance from the posterior wall of the maxillary sinus to the anterior skull base in cadavers and on computed tomography (CT) scans to determine a measurement as an anatomical reference in imaging exams for sinus and anterior skull base surgery. Methods In dissections and CT scans, we took measurements from the most upper and medial point of the posterior wall of the maxillary sinus (point A) to the point where the skull base deflects and the anterior sphenoid wall is formed (Δ 90°; point B), in the right and left nasal cavities. We used 51 cadavers aged ≥ 18 years in the present research. Results The measurements obtained from CT scans and dissections were greater than 1.5 cm in all cadavers, and they were positively correlated. The 1-cm increase in the AB-tomography measurement corresponded to the 1.08-cm increase to the right and 1.07-cm to the left in the AB-dissection measurement. Conclusion The CT measurements may be considered a reliable tool to promote safe and effective access to the paranasal sinuses, matching the distance that should be dissected until the anterior base of the skull.