Browsing by Subject "Computed tomography"

Now showing 1 - 10 of 15
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    A review of deep learning and radiomics approaches for pancreatic cancer diagnosis from medical imaging
    (Wolters Kluwer, 2023) Yao, Lanhong; Zhang, Zheyuan; Keles, Elif; Yazici, Cemal; Tirkes, Temel; Bagco, Ulas; Radiology and Imaging Sciences, School of Medicine
    Purpose of review: Early and accurate diagnosis of pancreatic cancer is crucial for improving patient outcomes, and artificial intelligence (AI) algorithms have the potential to play a vital role in computer-aided diagnosis of pancreatic cancer. In this review, we aim to provide the latest and relevant advances in AI, specifically deep learning (DL) and radiomics approaches, for pancreatic cancer diagnosis using cross-sectional imaging examinations such as computed tomography (CT) and magnetic resonance imaging (MRI). Recent findings: This review highlights the recent developments in DL techniques applied to medical imaging, including convolutional neural networks (CNNs), transformer-based models, and novel deep learning architectures that focus on multitype pancreatic lesions, multiorgan and multitumor segmentation, as well as incorporating auxiliary information. We also discuss advancements in radiomics, such as improved imaging feature extraction, optimized machine learning classifiers and integration with clinical data. Furthermore, we explore implementing AI-based clinical decision support systems for pancreatic cancer diagnosis using medical imaging in practical settings. Summary: Deep learning and radiomics with medical imaging have demonstrated strong potential to improve diagnostic accuracy of pancreatic cancer, facilitate personalized treatment planning, and identify prognostic and predictive biomarkers. However, challenges remain in translating research findings into clinical practice. More studies are required focusing on refining these methods, addressing significant limitations, and developing integrative approaches for data analysis to further advance the field of pancreatic cancer diagnosis.
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    Comparison of hepatic MDCT, MRI, and DSA to explant pathology for the detection and treatment planning of hepatocellular carcinoma
    (The Korean Association for the Study of the Liver, 2016-12) Ladd, Lauren M.; Tirkes, Temel; Tann, Mark; Agarwal, David M.; Johnson, Matthew S.; Tahir, Bilal; Sandrasegaran, Kumaresan; Department of Radiology and Imaging Sciences, IU School of Medicine
    BACKGROUND/AIMS: The diagnosis and treatment plan for hepatocellular carcinoma (HCC) can be made from radiologic imaging. However, lesion detection may vary depending on the imaging modality. This study aims to evaluate the sensitivities of hepatic multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) in the detection of HCC and the consequent management impact on potential liver transplant patients. METHODS: One hundred and sixteen HCC lesions were analyzed in 41 patients who received an orthotopic liver transplant (OLT). All of the patients underwent pretransplantation hepatic DSA, MDCT, and/or MRI. The imaging results were independently reviewed retrospectively in a blinded fashion by two interventional and two abdominal radiologists. The liver explant pathology was used as the gold standard for assessing each imaging modality. RESULTS: The sensitivity for overall HCC detection was higher for cross-sectional imaging using MRI (51.5%, 95% confidence interval [CI]=36.2-58.4%) and MDCT (49.8%, 95% CI=43.7-55.9%) than for DSA (41.7%, 95% CI=36.2-47.3%) (P=0.05). The difference in false-positive rate was not statistically significant between MRI (22%), MDCT (29%), and DSA (29%) (P=0.67). The sensitivity was significantly higher for detecting right lobe lesions than left lobe lesions for all modalities (MRI: 56.1% vs. 43.1%, MDCT: 55.0% vs. 42.0%, and DSA: 46.9% vs. 33.9%; all P<0.01). The sensitivities of the three imaging modalities were also higher for lesions ≥2 cm vs. <2 cm (MRI: 73.4% vs. 32.7%, MDCT: 66.9% vs. 33.8%, and DSA: 62.2% vs. 24.1%; all P<0.01). The interobserver correlation was rated as very good to excellent. CONCLUSION: The sensitivity for detecting HCC is higher for MRI and MDCT than for DSA, and so cross-sectional imaging modalities should be used to evaluate OLT candidacy.
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    Computed tomography angiography-derived extracellular volume fraction predicts early recovery of left ventricular systolic function after transcatheter aortic valve replacement
    (Oxford University Press, 2021) Han, Donghee; Tamarappoo, Balaji; Klein, Eyal; Tyler, Jeffrey; Chakravarty, Tarun; Otaki, Yuka; Miller, Robert; Eisenberg, Evann; Park, Rebekah; Singh, Siddharth; Shiota, Takahiro; Siegel, Robert; Stegic, Jasminka; Salseth, Tracy; Cheng, Wen; Dey, Damini; Thomson, Louise; Berman, Daniel; Makkar, Raj; Friedman, John; Radiation Oncology, School of Medicine
    Aims: Recovery of left ventricular ejection fraction (LVEF) after aortic valve replacement has prognostic importance in patients with aortic stenosis (AS). The mechanism by which myocardial fibrosis impacts LVEF recovery in AS is not well characterized. We sought to evaluate the predictive value of extracellular volume fraction (ECV) quantified by cardiac CT angiography (CTA) for LVEF recovery in patients with AS after transcatheter aortic valve replacement (TAVR). Methods and results: In 109 pre-TAVR patients with LVEF <50% at baseline echocardiography, CTA-derived ECV was calculated as the ratio of change in CT attenuation of the myocardium and the left ventricular (LV) blood pool before and after contrast administration. Early LVEF recovery was defined as an absolute increase of ≥10% in LVEF measured by post-TAVR follow-up echocardiography within 6 months of the procedure. Early LVEF recovery was observed in 39 (36%) patients. The absolute increase in LVEF was 17.6 ± 8.8% in the LVEF recovery group and 0.9 ± 5.9% in the no LVEF recovery group (P < 0.001). ECV was significantly lower in patients with LVEF recovery compared with those without LVEF recovery (29.4 ± 6.1% vs. 33.2 ± 7.7%, respectively, P = 0.009). In multivariable analysis, mean pressure gradient across the aortic valve [odds ratio (OR): 1.07, 95% confidence interval (CI): 1.03-1.11, P: 0.001], LV end-diastolic volume (OR: 0.99, 95% CI: 0.98-0.99, P: 0.035), and ECV (OR: 0.92, 95% CI: 0.86-0.99, P: 0.018) were independent predictors of early LVEF recovery. Conclusion: Increased myocardial ECV on CTA is associated with impaired LVEF recovery post-TAVR in severe AS patients with impaired LV systolic function.
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    Connexin Mutants Cause Cataracts Through Deposition of Apatite
    (Frontiers Media, 2022-07-22) Minogue, Peter J.; Sommer, Andre J.; Williams, James C., Jr.; Bledsoe, Sharon B.; Beyer, Eric C.; Berthoud, Viviana M.; Anatomy, Cell Biology and Physiology, School of Medicine
    Cataracts are lens opacities that are among the most common causes of blindness. It is commonly believed that cataracts develop through the accumulation of damage to lens proteins. However, recent evidence suggests that cataracts can result from calcium ion accumulation and the precipitation of calcium-containing salts. To test for the presence of precipitates and to identify their components, we studied the lenses of mice that develop cataracts due to mutations of connexin46 and connexin50. Micro-computed tomography showed the presence of radio-dense mineral in the mutant lenses, but not in wild-type lenses. Three-dimensional reconstructions of the scans showed that the distribution of the radio-dense mineral closely paralleled the location and morphology of the cataracts. The mutant lens homogenates also contained insoluble particles that stained with Alizarin red (a dye that stains Ca2+ deposits). Using attenuated total internal reflection micro–Fourier transform infrared spectroscopy, we identified the mineral as calcium phosphate in the form of apatite. Taken together, these data support the novel paradigm that cataracts are formed through pathological mineralization within the lens.
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    Delayed focal seizures following gunshot wound to the head in a child with minimal initial sequelae
    (Elsevier, 2024-10-31) Singhal, Saurabh; Miller, Derryl; Croxton, Amanda; Walsh, Laurence; Neurology, School of Medicine
    A 6 year old girl accidentally discovered a gun in her home and shot herself in her mouth. A bullet lodged in her right frontal lobe, but she remained neurologically intact with minimal symptoms. Her diagnosis was delayed due to the family leaving the emergency room for long wait times and later noticed over 72 hours from the injury at a dentist appointment. She was sent back to the emergency department, where head imaging revealed the injury to be inoperable. Six months later, the patient developed focal impaired awareness seizures. This was treated with oxcarbazepine, and patient responded well with no further spells. The case was highly unusual as the neurological symptoms were mild compared to the severity and the risk of initial intracranial injury. It emphasizes the frequently overlooked risk of leaving guns unsecured in households with children.
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    Effects of Raloxifene and tibial loading on bone mass and mechanics in male and female mice
    (Taylor & Francis, 2022) Berman, Alycia G.; Damrath, John G.; Hatch, Jennifer; Pulliam, Alexis N.; Powell, Katherine M.; Hinton, Madicyn; Wallace, Joseph M.; Biomedical Engineering, School of Engineering and Technology
    Raloxifene (RAL) is a selective estrogen receptor modulator (SERM) that has previously been shown to cause acellular benefits to bone tissue. Due to these improvements, RAL was combined with targeted tibial loading to assess if RAL treatment during periods of active bone formation would allow for further mechanical enhancements. To do so, structural, mechanical, and microstructural effects were assessed in bone from C57BL/6 mice that were treated with RAL (0.5 mg/kg), tibial loading, or both for 6 weeks, beginning at 10 weeks of age. Ex vivo microcomputed tomography (CT) images indicated RAL and loading work together to improve bone mass and architecture, especially within the cancellous region of males. Increases in cancellous bone volume fraction were heavily driven by increases in trabecular thickness, though there were some effects on trabecular spacing and number. In the cortical regions, RAL and loading both increased cross-sectional area, cortical area, and cortical thickness. Whole-bone mechanical testing primarily indicated effects of loading. Further characterization through Raman spectroscopy and nanoindentation showed load-based changes in mineralization and micromechanics, while both loading and RAL caused changes in the secondary collagen structure. In contrast to males, in females, there were large load-based effects in the cancellous and cortical regions, resulting in increased whole-bone mechanical properties. RAL had less of an effect on cancellous and cortical architecture, though some effects were still present. In conclusion, RAL and loading work together to impact bone architecture and mechanical integrity, leading to greater improvements than either treatment individually.
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    Impact of COPD on clinical and CT characteristics of COVID-19-associated pneumonia: single tertiary center experience
    (Springer, 2022-11-29) Filippenko, Yevgeniya; Zagurovskaya, Marianna; Abdrakhmanova, Aigul; Kassenova, Saule; Zhakenova, Zhanar; Aimakhanova, Aizat; Zholdybay, Zhamilya; Radiology and Imaging Sciences, School of Medicine
    Background The severe acute respiratory syndrome-related coronavirus 2 pandemic continues to this day worldwide. Individuals with COPD are at increased risk of contracting SARS-CoV-2. Most of the conducted studies are based on the clinical assessment of COVID-19 infection with different comorbidities. The specific contribution of COPD to the severity of the disease and outcome still remains the point of investigation. The main goals of our study are to assess COPD’s influence on the severity of clinical and CT characteristics of COVID-19 pneumonia and associated in-hospital mortality. Results This is a retrospective study on 281 patients with RT-PCR-confirmed COVID-19 infection and CT spectrum of COVID-19 pneumonia. Fifty patients have COPD based on CT criteria. No significant difference was observed in the mean hospital length of stay, arterial oxygen saturation on admission or in-hospital mortality between COPD and non-COPD groups. Patients with COPD were two times less likely to have fever less than 37.9 °C (RR = 2.037; 95% CI 1.114–3.724, p = 0.016), but higher absolute neutrophil count (p = 0.033) and median level of neutrophil/lymphocyte ratio (p = 0.029). The COPD group was presented with milder CT severity score (especially CT1, less than 25% of lung involvement) (p = 0.022), less likely to have bilateral (RR = 2.601; 95% CI: 1.341–5.044, p = 0.023) or central (RR = 1.754; 95% CI 1.024–3.003, p = 0.046) distribution of ground-glass opacities, right lower lobe (RR = 2.887; 95% CI 1.574–5.293, p = 0.008) or left lung (RR = 2.627; 95% CI 1.448–4.765, p = 0.009) involvement, and “crazy-paving” pattern (RR = 2.208; 95% CI 1.292–3.774, p = 0.003). Both moderate positive and negative relationship was observed between CT1, CT4, hypoxia and in-hospital mortality in the COPD group (r = − 0.383, p = 0.033; r = 0.486, p = 0.007; r = − 0,354, p = 0,022, respectively). Conclusion The presence of COPD by imaging criteria in the settings of COVID-19-associated pneumonia did not significantly influence the clinical or imaging performance of the patients, nor was it linked to the increased in-hospital mortality.
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    Limited Impacts of Thermoneutral Housing on Bone Morphology and Mechanical Properties in Growing Female Mice Exposed to External Loading and Raloxifene Treatment
    (Elsevier, 2021) Tastad, Carli A.; Kohler, Rachel; Wallace, Joseph M.; Biomedical Engineering, School of Engineering and Technology
    Thermoregulation is an important factor that could have physiological consequences on pre-clinical research outcomes. Simply housing mice at thermoneutral temperature has been shown to prevent the well-established loss of cancellous bone that is typical in growing mice. In this study, active tissue formation was induced by non-invasive tibial loading in female mice and combined with raloxifene treatment to assess whether temperature could enhance their combined effects on bone morphology and mechanical properties. It was hypothesized that by removing the cold stress under which normal lab mice are housed, a metabolic boost would allow for further architectural and mechanical improvements in mice exposed to a combination of tibial loading and raloxifene. Ten-week old female C57BL/6J mice were treated with raloxifene, underwent tibial loading to a maximum tensile stress of 2050 με, and were housed in thermoneutral conditions (32 °C) for 6 weeks. We investigated bone morphology through microcomputed tomography (μCT), mechanical properties via four-point bending, and fracture toughness testing. Results confirmed previous work showing a combined effect of external loading and raloxifene which led to greater improvements in most properties than either individual treatment. Counter to the hypothesis, temperature had modest effects on body weight, overall bone size, and trabecular architecture, and most effects were detrimental. Thermoneutrality had no impact on mechanical integrity or fracture toughness. In most cases, the magnitude of temperature-based effects were less robust than either RAL treatment or loading.
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    Micro-CT imaging of Randall's plaques
    (Springer, 2015-01) Williams, James C.; Lingeman, James E.; Coe, Fredric L.; Worcester, Elaine M.; Evan, Andrew P.; Department of Anatomy and Cell Biology, IU School of Medicine
    Micro-computed tomographic imaging (micro-CT) provides unprecedented information on stone structure and mineral composition. High-resolution micro-CT even allows visualization of the lumens of tubule and/or vessels within Randall's plaque, on stones or in papillary biopsies, thus giving a non-destructive way to study these sites of stone adhesion. This paper also shows an example of a stone growing on a different anchoring mechanism: a mineral plug within the lumen of a Bellini duct (BD plug). Micro-CT shows striking structural differences between stones that have grown on Randall's plaque and those that have grown on BD plugs. Thus, Randall's plaque can be distinguished by micro-CT, and this non-destructive method shows great promise in helping to elucidate the different mechanisms by which small stones are retained in the kidney during the development of nephrolithiasis.
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    Objective and patient‐based measures of chronic rhinosinusitis in people with cystic fibrosis treated with highly effective modulator therapy
    (Wiley, 2022) Beswick, Daniel M.; Humphries, Stephen M.; Miller, Jessa E.; Balkissoon, Connor D.; Khatiwada, Aastha; Vladar, Eszter K.; Ramakrishnan, Vijay R.; Lynch, David A.; Taylor-Cousar, Jennifer L.; Otolaryngology -- Head and Neck Surgery, School of Medicine