scholarly journals Differential Spatial Distribution of TSPO or Amino Acid PET Signal and MRI Contrast Enhancement in Gliomas

Cancers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 53
Author(s):  
Lena Kaiser ◽  
Adrien Holzgreve ◽  
Stefanie Quach ◽  
Michael Ingrisch ◽  
Marcus Unterrainer ◽  
...  
Keyword(s):  
Amino Acid ◽  
Contrast Enhancement ◽  
Specific Binding ◽  
Differential Information ◽  
Moderate Correlation ◽  
Mri Contrast ◽  
Contrast Enhanced ◽  
Amino Acid Pet ◽  
Small Overlap ◽  
Contrast Enhanced Mri

In this study, dual PET and contrast enhanced MRI were combined to investigate their correlation per voxel in patients at initial diagnosis with suspected glioblastoma. Correlation with contrast enhancement (CE) as an indicator of BBB leakage was further used to evaluate whether PET signal is likely caused by BBB disruption alone, or rather attributable to specific binding after BBB passage. PET images with [18F]GE180 and the amino acid [18F]FET were acquired and normalized to healthy background (tumor-to-background ratio, TBR). Contrast enhanced images were normalized voxel by voxel with the pre-contrast T1-weighted MRI to generate relative CE values (rCE). Voxel-wise analysis revealed a high PET signal even within the sub-volumes without detectable CE. No to moderate correlation of rCE with TBR voxel-values and a small overlap as well as a larger distance of the hotspots delineated in rCE and TBR-PET images were detected. In contrast, voxel-wise correlation between both PET modalities was strong for most patients and hotspots showed a moderate overlap and distance. The high PET signal in tumor sub-volumes without CE observed in voxel-wise analysis as well as the discordant hotspots emphasize the specificity of the PET signals and the relevance of combined differential information from dual PET and MRI images.

scholarly journals Differential Spatial Distribution of TSPO or Amino Acid PET Signal and MRI Contrast Enhancement in Gliomas

2021 ◽  
Author(s):  
Lena Kaiser ◽  
Adrien Holzgreve ◽  
Stefanie Quach ◽  
Michael Ingrisch ◽  
Marcus Unterrainer ◽  
...  
Keyword(s):  
Amino Acid ◽  
Contrast Enhancement ◽  
Specific Binding ◽  
Differential Information ◽  
Moderate Correlation ◽  
Mri Contrast ◽  
Contrast Enhanced ◽  
Amino Acid Pet ◽  
Small Overlap ◽  
Contrast Enhanced Mri

In this study dual PET and contrast enhanced MRI were combined to investigate their correlation per voxel in patients at initial diagnosis with suspected glioblastoma. Correlation with contrast enhancement (CE) as an indicator of BBB leakage was further used to evaluate whether PET signal is likely caused by BBB disruption alone, or rather attributable to specific binding after BBB passage. PET images with [18F]GE180 and the amino acid [18F]FET were acquired and normalized to healthy background (TBR). Contrast enhanced images were normalized voxel by voxel with the pre-contrast T1-weighted MRI to generate relative CE values (rCE). Voxel-wise analysis revealed a high PET signal even within the sub-volumes without detectable CE. No to moderate correlation of rCE with TBR voxel-values and a small overlap as well as a larger distance of the hotspots delineated in rCE and TBR-PET images were detected. In contrast, voxel-wise correlation between both PET modalities was strong for most patients and hotspots showed a moderate overlap and distance. The high PET signal in tumor sub-volumes without CE observed in voxel-wise analysis as well as the discordant hotspots emphasize the specificity of the PET signals and the relevance of combined differential information from dual PET and MRI images.

scholarly journals Immobilized contrast-enhanced MRI: Gadolinium-based long-term MR contrast enhancement of the vein graft vessel wall

2010 ◽  
Vol 65 (1) ◽  
pp. 176-183 ◽  
Author(s):  
Dimitris Mitsouras ◽  
Praveen Kumar Vemula ◽  
Peng Yu ◽  
Ming Tao ◽  
Binh T. Nguyen ◽  
...  
Keyword(s):  
Contrast Enhancement ◽  
Vein Graft ◽  
Vessel Wall ◽  
Enhanced Mri ◽  
Contrast Enhanced ◽  
Contrast Enhanced Mri

Contrast Enhanced MRI of Stunned Myocardium Using Mn-Based MRI Contrast Media

2002 ◽  
Vol 9 (2) ◽  
pp. S341-S342 ◽  
Author(s):  
Michael F Wendland ◽  
Gabriele A Krombach ◽  
Charles B Higgins ◽  
Viktor Novikov ◽  
Maythem Saeed
Keyword(s):  
Contrast Media ◽  
Stunned Myocardium ◽  
Mri Contrast ◽  
Enhanced Mri ◽  
Contrast Enhanced ◽  
Contrast Enhanced Mri

scholarly journals Meningeal blood–brain barrier disruption in acute traumatic brain injury

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Lisa Christine Turtzo ◽  
Neekita Jikaria ◽  
Martin R Cota ◽  
Joshua P Williford ◽  
Victoria Uche ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Contrast Enhancement ◽  
Mild Traumatic Brain Injury ◽  
Subarachnoid Space ◽  
Meningeal Enhancement ◽  
Contrast Enhanced ◽  
Acute Traumatic Brain Injury ◽  
The Brain ◽  
Contrast Enhanced Mri

Abstract The meninges serve as a functional barrier surrounding the brain, critical to the immune response, and can be compromised following head trauma. Meningeal enhancement can be detected on contrast-enhanced MRI in patients presenting with acute traumatic brain injury, even when head CT is negative. Following head trauma, gadolinium-based contrast appears to extravasate from the vasculature, enhancing the dura within minutes, and later permeates the subarachnoid space. The aims of this study were to characterize the initial kinetics of the uptake of contrast agent after injury and the delayed redistribution of contrast enhancement in the subarachnoid space in hyperacute patients. Neuroimaging was obtained prospectively in two large ongoing observational studies of patients aged 18 years or older presenting to the emergency department with suspected acute head injury. Dynamic contrast-enhanced MRI studies in a cohort of consecutively enrolling patients with mild traumatic brain injury (n = 36) determined that the kinetic half-life of dural-related meningeal enhancement was 1.3 ± 0.6 min (95% enhancement within 6 min). The extravasation of contrast into the subarachnoid space was investigated in a cohort of CT negative mild traumatic brain injury patients initially imaged within 6 h of injury (hyperacute) who subsequently underwent a delayed MRI, with no additional contrast administration, several hours after the initial MRI. Of the 32 patients with delayed post-contrast imaging, 18 (56%) had conspicuous expansion of the contrast enhancement into the subarachnoid space, predominantly along the falx and superior sagittal sinus. Patients negative for traumatic meningeal enhancement on initial hyperacute MRI continued to have no evidence of meningeal enhancement on the delayed MRI. These studies demonstrate that (i) the initial enhancement of the traumatically injured meninges occurs within minutes of contrast injection, suggesting highly permeable meningeal vasculature, and that (ii) contrast in the meninges redistributes within the subarachnoid space over the period of hours, suggesting a compromise in the blood–brain and/or blood-cerebrospinal barriers. Data from the parent study indicate that up to one in two patients with mild traumatic brain injury have traumatic brain injury on acute (<48 h) MRI, with a higher prevalence seen in patients with moderate or severe traumatic brain injury. The current study’s findings of traumatic meningeal enhancement and the subsequent delayed extravasation of contrast into the subarachnoid spaces indicate that a substantial percentage of patients with even mild traumatic brain injury may have a transient disruption in barriers separating the vasculature from the brain.

scholarly journals NIMG-27. EVALUATING THE POTENTIAL OF 18F-FLUCICLOVINE POSITRON EMISSION TOMOGRAPHY TO DETECT WHOLE BRAIN TUMOR BURDEN: A PRECLINICAL STUDY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi167-vi167
Author(s):  
Matthew Scarpelli ◽  
Debbie Healey ◽  
Ernesto Luna Melendez ◽  
Shwetal Mehta ◽  
Chad Quarles
Keyword(s):  
Amino Acid ◽  
Tumor Volume ◽  
Brain Slices ◽  
Mean Value ◽  
Tumor Burden ◽  
Fluorescent Imaging ◽  
Conventional Mri ◽  
Contrast Enhanced ◽  
The Mean ◽  
Contrast Enhanced Mri

Abstract BACKGROUND Accurately identifying the boundary of invasive brain tumors is critical for planning effective treatment. Conventional imaging includes T1-weighted contrast-enhanced MRI to identify regions where tumor angiogenesis has broken down the blood-brain barrier. However, conventional MRI has limited sensitivity for identifying invading tumor cells. Amino acid PET with 18F-fluciclovine may offer improved sensitivity. We investigate whether 18F-fluciclovine PET provides a superior measure of tumor burden than MRI. METHODS Rats were implanted with patient-derived glioblastoma xenografts that had been transduced to enable fluorescent imaging of the TdTomato protein. When the tumors grew to a sufficient size, the rats were scanned with 18F-fluciclovine PET followed immediately by contrast-enhanced MRI. Rats were sacrificed and whole brains were removed. Western blots were performed to measure amino acid transporter levels. Fluorescent imaging of optically cleared brain slices enabled visualization of the labelled tumor and determination of whole tumor burden. A methodology for registering in vivo PET/MRI slices to ex vivo fluorescent images of optically cleared brain slices (1-mm thickness) has been developed. Tumor volumes are manually segmented on all images. RESULTS The ratio of tumor to normal brain uptake (TNB) of 18F-fluciclovine peaked ten minutes post-injection (mean value 7.1) and was followed by a continual decrease in the TNB ratio (mean value 4.6 at fifty minutes post-injection). The mean percentage of MRI segmented tumor volume that was inside the PET segmented tumor volume was 95%. The mean percentage of PET segmented tumor volume that was inside the MRI segmented tumor volume was 40%. Tumors with the highest level of amino acid transporters had the highest 18F-fluciclovine uptake. CONCLUSIONS The majority of 18F-fluciclovine PET identified tumor regions were not identified using conventional MRI, indicating the potential of this approach to detect invasive tumor cells and provide a more robust assessment of whole tumor burden.

scholarly journals The Emerging Role of Amino Acid PET in Neuro-Oncology

2018 ◽  
Vol 5 (4) ◽  
pp. 104 ◽  
Author(s):  
Amer Najjar ◽  
Jason Johnson ◽  
Dawid Schellingerhout
Keyword(s):  
Amino Acid ◽  
Treatment Planning ◽  
Radiation Treatment ◽  
Critical Role ◽  
Therapy Response ◽  
Response Assessment ◽  
Early Therapy ◽  
Contrast Enhanced ◽  
Amino Acid Pet ◽  
Cns Malignancies

Imaging plays a critical role in the management of the highly complex and widely diverse central nervous system (CNS) malignancies in providing an accurate diagnosis, treatment planning, response assessment, prognosis, and surveillance. Contrast-enhanced magnetic resonance imaging (MRI) is the primary modality for CNS disease management due to its high contrast resolution, reasonable spatial resolution, and relatively low cost and risk. However, defining tumor response to radiation treatment and chemotherapy by contrast-enhanced MRI is often difficult due to various factors that can influence contrast agent distribution and perfusion, such as edema, necrosis, vascular alterations, and inflammation, leading to pseudoprogression and pseudoresponse assessments. Amino acid positron emission tomography (PET) is emerging as the method of resolving such equivocal lesion interpretations. Amino acid radiotracers can more specifically differentiate true tumor boundaries from equivocal lesions based on their specific and active uptake by the highly metabolic cellular component of CNS tumors. These therapy-induced metabolic changes detected by amino acid PET facilitate early treatment response assessments. Integrating amino acid PET in the management of CNS malignancies to complement MRI will significantly improve early therapy response assessment, treatment planning, and clinical trial design.

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