scholarly journals Cross-Modality Imaging of Murine Tumor Vasculature—a Feasibility Study

2021 ◽  
Author(s):  
Lydia M. Zopf ◽  
Patrick Heimel ◽  
Stefan H. Geyer ◽  
Anoop Kavirayani ◽  
Susanne Reier ◽  
...  
Keyword(s):  
Cancer Biology ◽  
Tumor Vasculature ◽  
Vascular Imaging ◽  
Melanoma Cancer ◽  
Positron Emission ◽  
Vessel Network ◽  
Research Questions ◽  
Magnetic Resonance Imaging Mri ◽  
Single Tumor ◽  
Penetration Depths

AbstractTumor vasculature and angiogenesis play a crucial role in tumor progression. Their visualization is therefore of utmost importance to the community. In this proof-of-principle study, we have established a novel cross-modality imaging (CMI) pipeline to characterize exactly the same murine tumors across scales and penetration depths, using orthotopic models of melanoma cancer. This allowed the acquisition of a comprehensive set of vascular parameters for a single tumor. The workflow visualizes capillaries at different length scales, puts them into the context of the overall tumor vessel network and allows quantification and comparison of vessel densities and morphologies by different modalities. The workflow adds information about hypoxia and blood flow rates. The CMI approach includes well-established technologies such as magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), and ultrasound (US), and modalities that are recent entrants into preclinical discovery such as optical coherence tomography (OCT) and high-resolution episcopic microscopy (HREM). This novel CMI platform establishes the feasibility of combining these technologies using an extensive image processing pipeline. Despite the challenges pertaining to the integration of microscopic and macroscopic data across spatial resolutions, we also established an open-source pipeline for the semi-automated co-registration of the diverse multiscale datasets, which enables truly correlative vascular imaging. Although focused on tumor vasculature, our CMI platform can be used to tackle a multitude of research questions in cancer biology.

A Novel Secure and Robust encryption scheme for medical images

2020 ◽  
Vol 16 ◽  
Author(s):  
Siyamol Chirakkarottu ◽  
Sheena Mathew
Keyword(s):  
Medical Images ◽  
Technological Development ◽  
Imaging Techniques ◽  
Chaotic Map ◽  
Two Phase ◽  
Positron Emission ◽  
Medical Diagnostic ◽  
Wireless Medium ◽  
Health Care Applications ◽  
Magnetic Resonance Imaging Mri

Background: Medical imaging encloses different imaging techniques and processes to image the human body for medical diagnostic and treatment purposes. Hence it plays an important role to improve public health. The technological development in biomedical imaging specifically in X-ray, Computed Tomography (CT), nuclear ultrasound including Positron Emission Tomography (PET), optical and Magnetic Resonance Imaging (MRI) can provide valuable information unique to a person. Objective: In health care applications, the images are needed to be exchanged mostly over wireless medium. The diagnostic images with confidential information of a patient need to be protected from unauthorized access during transmission. In this paper, a novel encryption method is proposed to improve the security and integrity of medical images. Methods: Chaotic map along with DNA cryptography is used for encryption. The proposed method describes a two phase encryption of medical images. Results: Performance of the proposed method is also tested by various analysis metrics. Robustness of the method against different noises and attacks is analyzed. Conclusion: The results show that the method is efficient and well suitable to medical images.

Comparison Between 18F-Dopa and 18F-Fet PET/CT in Patients with Suspicious Recurrent High Grade Glioma: A Literature Review and Our Experience

2019 ◽  
Vol 12 (3) ◽  
pp. 220-228 ◽  
Author(s):  
Laura Evangelista ◽  
Lea Cuppari ◽  
Luisa Bellu ◽  
Daniele Bertin ◽  
Mario Caccese ◽  
...  
Keyword(s):  
Case Series ◽  
High Grade Glioma ◽  
High Grade ◽  
True Negative ◽  
Fet Pet ◽  
Positron Emission ◽  
Pet Ct ◽  
Magnetic Resonance Imaging Mri ◽  
Definition Of ◽  
Sensitivity Specificity

Purpose: The aims of the present study were to: 1- critically assess the utility of L-3,4- dihydroxy-6-18Ffluoro-phenyl-alanine (18F-DOPA) and O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) Positron Emission Tomography (PET)/Computed Tomography (CT) in patients with high grade glioma (HGG) and 2- describe the results of 18F-DOPA and 18F-FET PET/CT in a case series of patients with recurrent HGG. Methods: We searched for studies using the following databases: PubMed, Web of Science and Scopus. The search terms were: glioma OR brain neoplasm and DOPA OR DOPA PET OR DOPA PET/CT and FET OR FET PET OR FET PET/CT. From a mono-institutional database, we retrospectively analyzed the 18F-DOPA and 18F-FET PET/CT of 29 patients (age: 56 ± 12 years) with suspicious for recurrent HGG. All patients underwent 18F-DOPA or 18F-FET PET/CT for a multidisciplinary decision. The final definition of recurrence was made by magnetic resonance imaging (MRI) and/or multidisciplinary decision, mainly based on the clinical data. Results: Fifty-one articles were found, of which 49 were discarded, therefore 2 studies were finally selected. In both the studies, 18F-DOPA and 18F-FET as exchangeable in clinical practice particularly for HGG patients. From our institutional experience, in 29 patients, we found that sensitivity, specificity and accuracy of 18F-DOPA PET/CT in HGG were 100% (95% confidence interval- 95%CI - 81-100%), 63% (95%CI: 39-82%) and 62% (95%CI: 39-81%), respectively. 18F-FET PET/CT was true positive in 4 and true negative in 4 patients. Sensitivity, specificity and accuracy for 18F-FET PET/CT in HGG were 100%. Conclusion: 18F-DOPA and 18F-FET PET/CT have a similar diagnostic accuracy in patients with recurrent HGG. However, 18F-DOPA PET/CT could be affected by inflammation conditions (false positive) that can alter the final results. Large comparative trials are warranted in order to better understand the utility of 18F-DOPA or 18F-FET PET/CT in patients with HGG.

scholarly journals A Review on the Value of Imaging in Differentiating between Large Vessel Vasculitis and Atherosclerosis

2021 ◽  
Vol 11 (3) ◽  
pp. 236
Author(s):  
Pieter H. Nienhuis ◽  
Gijs D. van Praagh ◽  
Andor W. J. M. Glaudemans ◽  
Elisabeth Brouwer ◽  
Riemer H. J. A. Slart
Keyword(s):  
Fdg Pet ◽  
Large Vessel Vasculitis ◽  
Large Vessel ◽  
Current Evidence ◽  
Future Directions ◽  
Inflammatory Conditions ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Review Reports ◽  
Ct Studies

Imaging is becoming increasingly important for the diagnosis of large vessel vasculitis (LVV). Atherosclerosis may be difficult to distinguish from LVV on imaging as both are inflammatory conditions of the arterial wall. Differentiating atherosclerosis from LVV is important to enable optimal diagnosis, risk assessment, and tailored treatment at a patient level. This paper reviews the current evidence of ultrasound (US), 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET), computed tomography (CT), and magnetic resonance imaging (MRI) to distinguish LVV from atherosclerosis. In this review, we identified a total of eight studies comparing LVV patients to atherosclerosis patients using imaging—four US studies, two FDG-PET studies, and two CT studies. The included studies mostly applied different methodologies and outcome parameters to investigate vessel wall inflammation. This review reports the currently available evidence and provides recommendations on further methodological standardization methods and future directions for research.

Clinicopathological correlation of pre-biopsy quantitative PSMA uptake in patients with persistently raised serum PSA: initial experience in 74 patients with simultaneous 68-Ga PSMA PET/MRI

2020 ◽  
pp. 205141582095640
Author(s):  
Malik A Rouf ◽  
Rajesh Taneja ◽  
Venkatesh Kumar
Keyword(s):  
Specific Antigen ◽  
Digital Rectal Examination ◽  
Whole Body ◽  
Characteristic Analysis ◽  
Positron Emission ◽  
Psma Pet ◽  
Significant Difference ◽  
Magnetic Resonance Imaging Mri ◽  
Normal Urine ◽  
Delayed Phase

Objective: To analyze 68-Ga prostate-specific membrane antigen (PSMA) uptake pattern of the prostate and its correlation with prostate-specific antigen (PSA), digital rectal examination (DRE), and Gleason’s score in the diagnosis of carcinoma of the prostate (CaP). Methods: This was a retrospective study conducted between June 2015 and August 2017. Patients who had undergone whole body 68-Ga PSMA HBED-CC simultaneous positron emission tomography (PET) or magnetic resonance imaging (MRI) for the diagnosis or staging of CaP were eligible. Patients who presented with persistently raised serum PSA (>4 ng/mL) and normal urine routine and negative culture were included in the study. Results: A total of 74 patients were included in the study. Significant positive correlation was observed between PSMA delayed uptake with the Prostate Imaging Reporting and Data System (PI-RADS) score ( p<0.001, ρ=0.750), PSA level ( p<0.001, ρ=0.414), DRE ( p<0.002, ρ=0.400), and Gleason’s score ( p<0.300, ρ=0.02). There was a significant difference between early and delayed phase of PSMA uptake in malignant prostatic lesions ( p<0.001). Delayed phase of PSMA uptake was able to characterize prostate lesions with an area under curve (AUC) of 0.91. Combined receiver operating characteristic analysis of PI-RADS score derived from multiparametric MRI and differential PSMA uptake to characterize prostatic lesions improved AUC to 0.94. Conclusion: Results demonstrated that the correlation with clinicopathological features (PSA, DRE, and Gleason’s score) could be used in prognostication of prostatic lesion along with PSMA PET/MRI.

scholarly journals CD36 promotes vasculogenic mimicry in melanoma by mediating adhesion to the extracellular matrix

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Carmela Martini ◽  
Mark DeNichilo ◽  
Danielle P. King ◽  
Michaelia P. Cockshell ◽  
Brenton Ebert ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cancer Cells ◽  
Vasculogenic Mimicry ◽  
Tumor Vasculature ◽  
Melanoma Cells ◽  
Human Melanoma ◽  
Cell Surface Glycoprotein ◽  
Melanoma Cancer ◽  
In Vitro Angiogenesis

Abstract Background The formation of blood vessels within solid tumors directly contributes to cancer growth and metastasis. Until recently, tumor vasculature was thought to occur exclusively via endothelial cell (EC) lined structures (i.e. angiogenesis), but a second source of tumor vasculature arises from the cancer cells themselves, a process known as vasculogenic mimicry (VM). While it is generally understood that the function of VM vessels is the same as that of EC-lined vessels (i.e. to supply oxygen and nutrients to the proliferating cancer cells), the molecular mechanisms underpinning VM are yet to be fully elucidated. Methods Human VM-competent melanoma cell lines were examined for their VM potential using the in vitro angiogenesis assays (Matrigel), together with inhibition studies using small interfering RNA and blocking monoclonal antibodies. Invasion assays and adhesion assays were used to examine cancer cell function. Results Herein we demonstrate that CD36, a cell surface glycoprotein known to promote angiogenesis by ECs, also supports VM formation by human melanoma cancer cells. In silico analysis of CD36 expression within the melanoma cohort of The Cancer Genome Atlas suggests that melanoma patients with high expression of CD36 have a poorer clinical outcome. Using in vitro ‘angiogenesis’ assays and CD36-knockdown approaches, we reveal that CD36 supports VM formation by human melanoma cells as well as adhesion to, and invasion through, a cancer derived extracellular matrix substrate. Interestingly, thrombospondin-1 (TSP-1), a ligand for CD36 on ECs that inhibits angiogenesis, has no effect on VM formation. Further investigation revealed a role for laminin, but not collagen or fibronectin, as ligands for CD36 expressing melanoma cells. Conclusions Taken together, this study suggests that CD36 is a novel regulator of VM by melanoma cancer cells that is facilitated, at least in part, via integrin-α3 and laminin. Unlike angiogenesis, VM is not perturbed by the presence of TSP-1, thus providing new information on differences between these two processes of tumor vascularization which may be exploited to combat cancer progression.

scholarly journals Complete heart block in cardiac sarcoidosis reversed by corticosteroid therapy: time course of resolution

2021 ◽  
Vol 14 (3) ◽  
pp. e240834
Author(s):  
Anna Tomdio ◽  
Huzaefah Syed ◽  
Kenneth Ellenbogen ◽  
Jordana Kron
Keyword(s):  
Heart Block ◽  
Time Course ◽  
Cardiac Sarcoidosis ◽  
Complete Heart Block ◽  
Positron Emission ◽  
Av Conduction ◽  
Magnetic Resonance Imaging Mri ◽  
High Level ◽  
Active Inflammation ◽  
Lateral Walls

A 53-year-old man was admitted for recurrent syncope and found to have complete heart block (CHB). Cardiac magnetic resonance imaging MRI) showed extensive patchy late gadolinium enhancement in the apical and lateral walls, consistent with cardiac sarcoidosis (CS) but no scar in the septum. A fluorodeoxyglucose (FDG)–positron emission tomography showed FDG uptake in the septum and basal lateral walls. Imaging suggested active inflammation in the septum affecting atrioventricular (AV) conduction but no irreversible fibrosis. Diagnosis of isolated CS requires a high level of suspicion and multidisciplinary teamwork involving heart failure specialists, electrophysiologists and rheumatologists. After specialist and patient discussion, treatment of the disease was initiated with prednisone 40 mg daily, 11 months after presenting with CHB. Three weeks later, ECG with pacing inhibited showed second-degree AV block Mobitz type II and 4 weeks later, AV conduction recovery. This highlights the importance of immediate therapy in reversing AV conduction abnormalities in CS.

scholarly journals Clinical and Pathological Evidence of Anti-GD2 Immunotherapy Induced Differentiation in Relapsed/Refractory High-Risk Neuroblastoma

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1264
Author(s):  
Jaume Mora ◽  
Alicia Castañeda ◽  
Maria Cecilia Colombo ◽  
Maite Gorostegui ◽  
Fernando Gomez ◽  
...  
Keyword(s):  
High Risk ◽  
Fdg Pet ◽  
Current Therapy ◽  
Bone Lesions ◽  
Functional Magnetic Resonance ◽  
Positron Emission ◽  
Apparent Diffusion ◽  
Neuroblastic Tumors ◽  
Direct Cell ◽  
Magnetic Resonance Imaging Mri

Background: Neuroblastic tumors (NBTs) originate from a block in the process of differentiation. Histologically, NBTs are classified in neuroblastoma (NB), ganglioneuroblastoma (GNB), and ganglioneuroma (GN). Current therapy for high-risk (HR) NB includes chemotherapy, surgery, radiotherapy, and anti-GD2 monoclonal antibodies (mAbs). Anti-GD2 mAbs induce immunological cytoxicity but also direct cell death. Methods: We report on patients treated with naxitamab for chemorefractory NB showing lesions with long periods of stable disease. Target lesions with persisting 123I-Metaiodobenzylguanidine (MIBG) uptake after 4 cycles of immunotherapy were further evaluated by functional Magnetic Resonance Imaging (MRI) and/or Fluorodeoxyglucose (FDG)-positron emission tomography (PET). MIBG avid lesions that became non-restrictive on MRI (apparent diffusion coefficient (ADC) > 1) and/or FDG-PET negative (SUV < 2) were biopsied. Results: Twenty-seven relapse/refractory (R/R) HR-NB patients were enrolled on protocol Ymabs 201. Two (7.5%) of the 27 showed persistent bone lesions on MIBG, ADC high, and/or FDG-PET negative. Forty-four R/R HR-NB patients received chemo-immunotherapy. Twelve (27%) of the 44 developed persistent MIBG+ but FDG-PET- and/or high ADC lesions. Twelve (86%) of the 14 cases identified were successfully biopsied producing 16 evaluable samples. Histology showed ganglioneuroma maturing subtype in 6 (37.5%); ganglioneuroma mature subtype with no neuroblastic component in 4 (25%); differentiating NB with no Schwannian stroma in 5 (31%); and undifferentiated NB without Schwannian stroma in one (6%). Overall, 10 (62.5%) of the 16 specimens were histopathologically fully mature NBTs. Conclusions: Our results disclose an undescribed mechanism of action for naxitamab and highlight the limitations of conventional imaging in the evaluation of anti-GD2 immunotherapy clinical efficacy for HR-NB.

scholarly journals PET Scan Perfusion Imaging in the Prader–Willi Syndrome: New Insights into the Psychiatric and Social Disturbances

2010 ◽  
Vol 31 (1) ◽  
pp. 275-282 ◽  
Author(s):  
Carine Mantoulan ◽  
Pierre Payoux ◽  
Gwenaëlle Diene ◽  
Mélanie Glattard ◽  
Bernadette Rogé ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Severe Disabilities ◽  
Brain Regions ◽  
Pet Scan ◽  
Prader Willi Syndrome ◽  
Behavioral Skills ◽  
Positron Emission ◽  
Functional Consequences ◽  
Magnetic Resonance Imaging Mri ◽  
Pet Scans

The Prader–Willi syndrome (PWS), a rare multisystem genetic disease, leads to severe disabilities, such as morbid obesity, endocrine dysfunctions, psychiatric disorders, and social disturbances. We explored the whole brain of patients with PWS to detect abnormalities that might explain the behavioral and social disturbances, as well as the psychiatric disorders of these patients. Nine patients with PWS (six males, three females; mean age 16.4 years) underwent a positron emission tomography (PET) scan with H215O as a tracer to measure regional cerebral blood flow (rCBF). The images were compared with those acquired from nine controls (six males, three females; mean age 21.2 years). A morphologic magnetic resonance imaging (MRI) was also performed in PWS patients, and their cognitive and behavioral skills were assessed with Wechsler Intelligence Scale for Children III and the Child Behavior Check List (CBCL). The MRI images showed no evident anatomic abnormalities, whereas PET scans revealed hypoperfused brain regions in PWS patients compared with controls, particularly in the anterior cingulum and superior temporal regions. We observed a significant relationship ( P<0.05) between rCBF in the hypoperfused regions and CBCL scores. The functional consequences of these perfusion abnormalities in specific brain regions might explain the behavioral and social problems observed in these individuals.

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