Multiscale Modeling of the Blood Circulation in the Human Liver Using Vascular Corrosion Casting and Micro-CT Imaging Techniques

2011 ◽  
Author(s):  
Charlotte Debbaut ◽  
Diethard Monbaliu ◽  
Christophe Casteleyn ◽  
Pieter Cornillie ◽  
Denis Van Loo ◽  
...  
Keyword(s):  
Blood Circulation ◽  
Numerical Models ◽  
Imaging Techniques ◽  
Organ Transplant ◽  
Diagnostic Techniques ◽  
Corrosion Casting ◽  
Micro Ct ◽  
Contrast Enhanced ◽  
Branching Patterns ◽  
Vascular Trees

Numerical models to analyze blood flow may be important for a better understanding of organ hemodynamics and (dys)function (e.g. in organ transplant research), and diagnostic techniques (e.g. contrast-enhanced MRI to characterize tumors). Existing models of (liver) vascular trees are predominantly based on idealized models using fractional calculus to describe bifurcating branching patterns. In contrast, we previously developed an electrical analog model of the human hepatic circulation, based on measured data of the macrocirculation and extrapolated data of the microcirculation [1]. Furthermore, the microcirculation is usually modeled as a porous medium [2].

scholarly journals Modelling the skeletal muscle injury recovery using in vivo contrast-enhanced micro-CT: a proof-of-concept study in a rat model

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Bruno Paun ◽  
Daniel García Leon ◽  
Alex Claveria Cabello ◽  
Roso Mares Pages ◽  
Elena de la Calle Vargas ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Rat Model ◽  
Muscle Injury ◽  
Micro Ct ◽  
Skeletal Muscle Injury ◽  
Monitoring Time ◽  
Contrast Enhanced Ct ◽  
Contrast Enhanced ◽  
Injury Recovery

Abstract Background Skeletal muscle injury characterisation during healing supports trauma prognosis. Given the potential interest of computed tomography (CT) in muscle diseases and lack of in vivo CT methodology to image skeletal muscle wound healing, we tracked skeletal muscle injury recovery using in vivo micro-CT in a rat model to obtain a predictive model. Methods Skeletal muscle injury was performed in 23 rats. Twenty animals were sorted into five groups to image lesion recovery at 2, 4, 7, 10, or 14 days after injury using contrast-enhanced micro-CT. Injury volumes were quantified using a semiautomatic image processing, and these values were used to build a prediction model. The remaining 3 rats were imaged at all monitoring time points as validation. Predictions were compared with Bland-Altman analysis. Results Optimal contrast agent dose was found to be 20 mL/kg injected at 400 μL/min. Injury volumes showed a decreasing tendency from day 0 (32.3 ± 12.0mm3, mean ± standard deviation) to day 2, 4, 7, 10, and 14 after injury (19.6 ± 12.6, 11.0 ± 6.7, 8.2 ± 7.7, 5.7 ± 3.9, and 4.5 ± 4.8 mm3, respectively). Groups with single monitoring time point did not yield significant differences with the validation group lesions. Further exponential model training with single follow-up data (R2 = 0.968) to predict injury recovery in the validation cohort gave a predictions root mean squared error of 6.8 ± 5.4 mm3. Further prediction analysis yielded a bias of 2.327. Conclusion Contrast-enhanced CT allowed in vivo tracking of skeletal muscle injury recovery in rat.

scholarly journals BIMG-04. MAPPING HETEROGENEITY OF HIGH-GRADE GLIOMA METABOLISM USING HIGH RESOLUTION 7T MRSI

2021 ◽  
Vol 3 (Supplement_1) ◽  
pp. i1-i1
Author(s):  
Gilbert Hangel ◽  
Cornelius Cadrien ◽  
Philipp Lazen ◽  
Sukrit Sharma ◽  
Julia Furtner ◽  
...  
Keyword(s):  
High Resolution ◽  
Imaging Techniques ◽  
Basis Set ◽  
Metabolic Imaging ◽  
Tumor Segmentation ◽  
Low Grade ◽  
High Grade ◽  
Isotropic Resolution ◽  
Contrast Enhanced ◽  
Definition Of

Abstract OBJECTIVES Neurosurgical resection in gliomas depends on the precise preoperative definition of the tumor and its margins to realize a safe maximum resection that translates into a better patient outcome. New metabolic imaging techniques could improve this delineation as well as designate targets for biopsies. We validated the performance of our fast high-resolution whole-brain 3D-magnetic resonance spectroscopic imaging (MRSI) method at 7T in high-grade gliomas (HGGs) as first step to this regard. METHODS We measured 23 patients with HGGs at 7T with MRSI covering the whole cerebrum with 3.4mm isotropic resolution in 15 min. Quantification used a basis-set of 17 neurochemical components. They were evaluated for their reliability/quality and compared to neuroradiologically segmented tumor regions-of-interest (necrosis, contrast-enhanced, non-contrast-enhanced+edema, peritumoral) and histopathology (e.g., grade, IDH-status). RESULTS We found 18/23 measurements to be usable and ten neurochemicals quantified with acceptable quality. The most common denominators were increases of glutamine, glycine, and total choline as well as decreases of N-acetyl-aspartate and total creatine over most tumor regions. Other metabolites like taurine and serine showed mixed behavior. We further found that heterogeneity in the metabolic images often continued into the peritumoral region. While 2-hydroxy-glutarate could not be satisfyingly quantified, we found a tendency for a decrease of glutamate in IDH1-mutant HGGs. DISCUSSION Our findings corresponded well to clinical tumor segmentation but were more heterogeneous and often extended into the peritumoral region. Our results corresponded to previous knowledge, but with previously not feasible resolution. Apart from glycine/glutamine and their role in glioma progression, more research on the connection of glutamate and others to specific mutations is necessary. The addition of low-grade gliomas and statistical ROI analysis in a larger cohort will be the next important steps to define the benefits of our 7T MRSI approach for the definition of spatial metabolic tumor profiles.

scholarly journals Evaluation of Peritoneal Deposits in Undiagnosed Ascites by Advanced Endoscopic Ultrasound Imaging Techniques

2021 ◽  
Vol 12 (01) ◽  
pp. 049-050
Author(s):  
Surinder Singh Rana ◽  
Ravi Sharma ◽  
Rajesh Gupta
Keyword(s):  
Ascitic Fluid ◽  
Endoscopic Ultrasound ◽  
Imaging Techniques ◽  
Needle Aspiration ◽  
Enhancement Pattern ◽  
Etiological Diagnosis ◽  
Fine Needle ◽  
Contrast Enhanced ◽  
Biochemical Evaluation ◽  
Repeat Sampling

AbstractEtiology of ascites can be usually determined with ascitic fluid cytological and biochemical evaluation. Occasionally, the cause of ascites cannot be determined despite repeated ascitic fluid evaluations. These patients with undiagnosed ascites usually undergo diagnostic laparotomy/laparoscopy for etiological diagnosis. Endoscopic ultrasound (EUS) can help in resolving the diagnostic conundrum of undiagnosed ascites by visualizing as well as sampling peritoneal and omental deposits/thickening. However, rarely fine-needle aspiration from deposits may be falsely negative and patient may need repeat sampling. Newer EUS imaging techniques such as elastography and contrast-enhanced harmonic EUS by providing additive information on stiffness and enhancement pattern of the lesion can help in differential diagnosis.

scholarly journals Optical Detection and Eradication of Dysplastic Barrett's Esophagus

2003 ◽  
Vol 2 (4) ◽  
pp. 289-302 ◽  
Author(s):  
Louis-Michel Wong Kee Song ◽  
Kenneth K. Wang
Keyword(s):  
Barrett’S Esophagus ◽  
Barrett's Esophagus ◽  
Sampling Error ◽  
Imaging Techniques ◽  
Standard Of Care ◽  
Diagnostic Techniques ◽  
Endoscopic Surveillance ◽  
Current Status ◽  
Delay In Diagnosis ◽  
Multiple Biopsies

Dysplastic Barrett's esophagus is a condition that offers multiple diagnostic and therapeutic challenges. The diagnosis of dysplasia within Barrett's esophagus currently relies on periodic endoscopic surveillance with multiple biopsies, a methodology limited by random sampling error, inconsistent histopathologic interpretation and delay in diagnosis. Optical spectroscopic and imaging techniques have the potential to identify dysplastic or early neoplastic lesions in real-time. These diagnostic modalities are needed to enhance the endoscopic surveillance of Barrett's esophagus in the future as well as help to define lesions for endoscopic therapy. Esophagectomy has been the standard of care for Barrett's esophagus with high-grade dysplasia although it is a procedure associated with significant morbidity and mortality. Minimally invasive endoscopic ablative therapies are attractive and less morbid alternatives to esophagectomy, with promising results obtained from the use of light-activated drugs (i.e., photodynamic therapy). The combination of novel optical diagnostic techniques and therapies will provide the endoscopist with much needed tools that can considerably enhance the management of patients with Barrett's esophagus. This article reviews the current status and future prospects of optical-based modalities for diagnosis and therapy of dysplastic Barrett's esophagus.

scholarly journals Quiescent-Interval Single-Shot Magnetic Resonance Angiography

Diagnostics ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 84
Author(s):  
Aman Saini ◽  
Alex Wallace ◽  
Hassan Albadawi ◽  
Sailendra Naidu ◽  
Sadeer Alzubaidi ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Quality ◽  
Magnetic Resonance Angiography ◽  
Diagnostic Imaging ◽  
Imaging Techniques ◽  
Feasibility Studies ◽  
Subsequent Treatment ◽  
Single Shot ◽  
Contrast Enhanced ◽  
Diagnostic Imaging Techniques

Lower extremity peripheral arterial disease (PAD) is a chronic, debilitating disease with a significant global burden. A number of diagnostic imaging techniques exist, including computed tomography angiography (CTA) and contrast-enhanced magnetic resonance angiography (CEMRA), to aid in PAD diagnosis and subsequent treatment planning. Due to concerns of renal toxicity or nephrogenic systemic fibrosis (NSF) for iodinated and gadolinium-based contrasts, respectively, a number of non-enhanced MRA (NEMRA) protocols are being increasingly used in PAD diagnosis. These techniques, including time of flight and phase contrast MRA, have previously demonstrated poor image quality, long acquisition times, and/or susceptibility to artifacts when compared to existing contrast-enhanced techniques. In recent years, Quiescent-Interval Single-Shot (QISS) MRA has been developed to overcome these limitations in NEMRA methods, with promising results. Here, we review the various screening and diagnostic tests currently used for PAD. The various NEMRA protocols are discussed, followed by a comprehensive review of the literature on QISS MRA to date. A particular emphasis is placed on QISS MRA feasibility studies and studies comparing the diagnostic accuracy and image quality of QISS MRA versus other diagnostic imaging techniques in PAD.

scholarly journals 3D-histopathological grading of articular cartilage using contrast-enhanced high-resolution micro-CT

2016 ◽  
Vol 24 ◽  
pp. S277-S278
Author(s):  
H. Gahunia ◽  
S. Karhula ◽  
T. Ylitalo ◽  
E. Hæggström ◽  
K.P. Pritzker ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
High Resolution ◽  
Micro Ct ◽  
Contrast Enhanced ◽  
Histopathological Grading

scholarly journals ON THE ROLE OF HISTOMORPHOMETRIC (STEREOLOGICAL) MICROSTRUCTURE PARAMETERS IN THE PREDICTION OF VERTEBRAE COMPRESSION STRENGTH

2019 ◽  
Vol 38 (1) ◽  
pp. 63 ◽  
Author(s):  
Leszek Karol Wojnar ◽  
Aneta Gądek-Moszczak ◽  
Jacek Pietraszek
Keyword(s):  
Compression Strength ◽  
Correlation Coefficients ◽  
Diagnostic Techniques ◽  
Micro Ct ◽  
Compression Tests ◽  
Mineral Density ◽  
3D Images ◽  
Microstructure Parameters

The well-documented relation between bone mineral density (BMD) and bone compression strength constitutes the basis for osteoporosis diagnostics and the assessment of fracture risk. Simultaneously, this relation demonstrates a considerable scatter of results as bones of identical mineral density may have significantly different properties. The experimentally confirmed theorem that two materials or tissues of identical microstructure have identical properties leads to the evaluation of various quantitative stereological parameters (also referred to in biomedicine as histomorphology). These parameters, obtained from analysis of 2D or 3D images, have been used in numerous attempts to explain changes in bone strength. Although numerous correlation dependencies, often with high correlation coefficients, were evaluated, we do not know which parameters are worth evaluating, and there is no physical interpretation of these relations. An extended statistical analysis was accomplished on the basis of analysis of 3D images from 23 lumbar (L3) vertebrae scanned with micro-CT and the results of subsequent compression tests. A new parameter called SDF (structure destruction factor) was proposed in order to characterise the quality of 3D trabecular structures, and its significance was demonstrated. The final correlation function, which uses only three stereological parameters, made it possible to predict compression strength with considerable precision. The estimated values correlated very well with the apparent values (correlation coefficient r=0.96). Finally, the stereological parameters most suitable for characterisation of bone compression strength were chosen and a mechanism responsible for the changes in mechanical properties was proposed. The results obtained defined the necessary improvements in diagnostic techniques that would allow for more efficient quantitative microstructure evaluation and guidelines on how to improve treatment of patients with weakened bones.

scholarly journals Cutting-edge microangio-CT: new dimensions in vascular imaging and kidney morphometry

2018 ◽  
Vol 314 (3) ◽  
pp. F493-F499 ◽  
Author(s):  
Ruslan Hlushchuk ◽  
Cédric Zubler ◽  
Sébastien Barré ◽  
Carlos Correa Shokiche ◽  
Laura Schaad ◽  
...  
Keyword(s):  
Data Sets ◽  
Micro Ct ◽  
Quantitative Methodology ◽  
Micro Computed Tomography ◽  
Qualitative And Quantitative ◽  
Correlative Imaging ◽  
Contrast Enhanced ◽  
Consistent Assessment ◽  
Definition Of ◽  
X Ray Absorption

In the last decades, the contrast-enhanced micro-computed tomography (micro-CT) imaging of a whole animal kidney became increasingly important. The visualization was mainly limited to middle-sized vessels. Since modern desktop micro-CT scanners provide the necessary detail resolution, we developed an approach for rapid visualization and consistent assessment of kidney vasculature and glomeruli number. This method is based on μAngiofil, a new polymerizing contrast agent with homogenous X-ray absorption, which provides continuous filling of the complete vasculature and enables correlative imaging approaches. For rapid and reliable kidney morphometry, the microangio-CT (µaCT) data sets from glial cell line-derived neurotrophic factor (GDNF)+/− mice and their wild-type littermates were used. The results were obtained much faster compared with the current gold standard, histology-based stereology, and without processing artifacts. The histology-based morphometry was done afterward on the same kidneys. Both approaches revealed that the GDNF+/− male mice had about 40% fewer glomeruli. Furthermore, our approach allows for the definition of sites of interest for further histological investigation, i.e., correlative morphology. The polymerized μAngiofil stays in perfused vessels and is autofluorescent, which is what greatly facilitates the matching of histological sections with µaCT data. The presented approach is a time-efficient, reliable, qualitative, and quantitative methodology. Besides glomerular morphometry, the µaCT data can be used for qualitative and quantitative analysis of the kidney vasculature and correlative morphology.

Imaging Modalities

Chest Imaging ◽  
2019 ◽  
pp. 7-11
Author(s):  
Melissa L. Rosado-de-Christenson
Keyword(s):  
Chest Radiography ◽  
Pulmonary Thromboembolism ◽  
Imaging Techniques ◽  
Imaging Study ◽  
Chest Ct ◽  
Imaging Modalities ◽  
Vascular Abnormalities ◽  
Contrast Enhanced ◽  
Lateral Chest ◽  
Fdg Pet Ct

The chapter titled imaging modalities describes various methods of imaging the thorax. Imaging of patients presenting with thoracic complaints typically begins with chest radiography. Ambulatory patients should undergo posteroanterior (PA) and lateral chest radiographs. Anteroposterior (AP) chest radiography should be reserved for debilitated, critically ill and traumatized patients. Special chest radiographic projections such as decubitus chest radiography may be employed for specific indications. Chest CT is the imaging study of choice for evaluating most abnormalities found on radiography. Contrast-enhanced chest CT is optimal for evaluation of vascular abnormalities, the hila and some mediastinal lesions. CT angiography is routinely employed in patients with suspected pulmonary thromboembolism or acute aortic syndromes. High-resolution chest CT is reserved for the evaluation of diffuse infiltrative lung disease and often includes expiratory and prone imaging. FDG PET/CT is increasingly employed in the assessment of patients with malignancy for the purposes of initial staging and post therapy re-staging of affected patients. Ventilation/perfusion scintigraphy is used in the assessment of pulmonary thromboembolism. Additional thoracic imaging techniques include: Fluoroscopy for evaluation of the diaphragm, and ultrasound for evaluation of the thyroid and the pleural space.

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