scholarly journals Simultaneous PET/Mri in Stroke: A Case Series

2015 ◽  
Vol 35 (9) ◽  
pp. 1421-1425 ◽  
Author(s):  
Peter Werner ◽  
Dorothee Saur ◽  
Vilia Zeisig ◽  
Barbara Ettrich ◽  
Marianne Patt ◽  
...  
Keyword(s):  
Case Series ◽  
Patient Stratification ◽  
Resonance Imaging ◽  
Ovine Model ◽  
Stroke Patients ◽  
Complementary Information ◽  
Systemic Thrombolysis ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Post Hoc

Prospective studies on magnetic resonance imaging (MRI)-guided systemic thrombolysis 44.5 hours after stroke onset did not reach their primary end points. It was discussed and observed in post hoc data re-assessment that this was partly because of limited MRI accuracy to measure critical hypoperfusion. We report the first cases of simultaneous [15O]H2O-positron emission tomography (PET)/MRI in stroke patients and an ovine model. Discrepancies between simultaneously obtained PET and MRI readouts were observed that might explain the above current limitations of stroke MRI. By offering highly complementary information, [15O]H2O-PET/MRI might help to identify critically hypoperfused tissue resulting in an improved patient stratification in thrombolysis trials.

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.

Epilepsy in Propionic Acidemia: Case Series of 14 Saudi Patients

2018 ◽  
Vol 33 (11) ◽  
pp. 713-717 ◽  
Author(s):  
Afnan AlGhamdi ◽  
Muhammad Talal Alrifai ◽  
Abdullah I. Al Hammad ◽  
Fuad Al Mutairi ◽  
Abdulrahman Alswaid ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Case Series ◽  
Brain Magnetic Resonance Imaging ◽  
Propionic Acidemia ◽  
Resonance Imaging ◽  
Mri Findings ◽  
Epileptiform Discharges ◽  
Magnetic Resonance Imaging Mri ◽  
Autosomal Recessive Manner ◽  
Delayed Myelination

Propionic acidemia is an inborn error of metabolism that is inherited in an autosomal recessive manner. It is characterized by a deficient propionyl-CoA carboxylase due to mutations in either of its beta or alpha subunits. In the literature, there is a clear association between propionic acidemia and epilepsy. In this cohort, we retrospectively reviewed the data of 14 propionic acidemia patients in Saudi Arabia and compared the findings to those of former studies. Six of the 14 (43%) patients developed epileptic seizure, mainly focal seizures. All patients were responsive to conventional antiepileptic drugs as their seizures are controlled. The predominant electroencephalographic (EEG) findings were diffuse slowing in 43% and multifocal epileptiform discharges in 14% of the patients. In 1 patient, burst suppression pattern was detected, a pattern never before reported in patients with propionic acidemia. Brain magnetic resonance imaging (MRI) findings mainly consisted of signal changes of the basal ganglia (36%), generalized brain atrophy (43%), and delayed myelination (43%).The most common genotype in our series is the homozygous missense mutation in the PCCA gene (c.425G>A; p. Gly142Asp). However, there is no clear genotype–seizure correlation. We conclude that seizure is not an uncommon finding in patients with propionic acidemia and not difficult to control. Additional studies are needed to further elaborate on genotype–seizure correlation.

scholarly journals Deep learning based MRI contrast synthesis using full volume prediction

2021 ◽  
Author(s):  
Jose V Manjon ◽  
Jose E Romero ◽  
Pierrick Coupé
Keyword(s):  
Three Dimensional ◽  
Patient Comfort ◽  
Segmentation Method ◽  
Resonance Imaging ◽  
Complementary Information ◽  
Mri Contrast ◽  
Ambiguity Reduction ◽  
Magnetic Resonance Imaging Mri ◽  
Time Limitations ◽  
Full Volume

Abstract In Magnetic Resonance Imaging (MRI), depending on the image acquisition settings, a large number of image types or contrasts can be generated showing complementary information of the same imaged subject. This multi-spectral information is highly beneficial since can improve MRI analysis tasks such as segmentation and registration, thanks to pattern ambiguity reduction. However, the acquisition of several contrasts is not always possible due to time limitations and patient comfort constraints. Contrast synthesis has emerged recently as an approximate solution to generate other image types different from those acquired originally. Most of the previously proposed methods for contrast synthesis are slice-based which result in intensity inconsistencies between neighbor slices when applied in 3D. We propose the use of a 3D convolutional neural network (CNN) capable of generating T2 and FLAIR images from a single anatomical T1 source volume. The proposed network is a 3D variant of the UNet that processes the whole volume at once breaking with the inconsistency in the resulting output volumes related to 2D slice or patch-based methods. Since working with a full volume at once has a huge memory demand we have introduced a spatial-to-depth and a reconstruction layer that allows working with the full volume but maintain the required network complexity to solve the problem. Our approach enhances the coherence in the synthesized volume while improving the accuracy thanks to the integrated three-dimensional context-awareness. Finally, the proposed method has been validated with a segmentation method, thus demonstrating its usefulness in a direct and relevant application.

scholarly journals Metal-Based Complexes as Pharmaceuticals for Molecular Imaging of the Liver

2019 ◽  
Vol 12 (3) ◽  
pp. 137 ◽  
Author(s):  
Julia Greiser ◽  
Wolfgang Weigand ◽  
Martin Freesmeyer
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Metal Complexes ◽  
Imaging Technique ◽  
Imaging Modality ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Uptake Mechanisms

This article reviews the use of metal complexes as contrast agents (CA) and radiopharmaceuticals for the anatomical and functional imaging of the liver. The main focus was on two established imaging modalities: magnetic resonance imaging (MRI) and nuclear medicine, the latter including scintigraphy and positron emission tomography (PET). The review provides an overview on approved pharmaceuticals like Gd-based CA and 99mTc-based radiometal complexes, and also on novel agents such as 68Ga-based PET tracers. Metal complexes are presented by their imaging modality, with subsections focusing on their structure and mode of action. Uptake mechanisms, metabolism, and specificity are presented, in context with advantages and limitations of the diagnostic application and taking into account the respective imaging technique.

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