scholarly journals Anatomical-Functional Correlation Using an Adjustable MRI-Based Region of Interest Atlas with Positron Emission Tomography

1988 ◽  
Vol 8 (4) ◽  
pp. 513-530 ◽  
Author(s):  
A. C. Evans ◽  
C. Beil ◽  
S. Marrett ◽  
C. J. Thompson ◽  
A. Hakim
Keyword(s):  
Positron Emission Tomography ◽  
Region Of Interest ◽  
Brain Structures ◽  
Regions Of Interest ◽  
Emission Tomography ◽  
Utilization Rate ◽  
Positron Emission ◽  
Reproducible Analysis ◽  
Magnetic Resonance Imaging Mri ◽  
Trained Observers

A procedure is described for combining anatomical information from magnetic resonance imaging (MRI) or computerized tomography (CT) and functional information from positron emission tomography (PET) in a rapid fashion. MRI data are combined with a procedure for the definition, storage, and recall of anatomically based regions of interest. An atlas of standard regions of interest, defined for a set of 18 parallel planes spaced at 6-mm intervals, provides an initial region of interest template for each patient slice. Global adjustments to scale, orientation, and position are applied to obtain an initial match. Individual regions of interest may then be moved, deleted, or redrawn as needed. The ability to store region of interest templates ensures reproducibility of analysis over long periods and introduces a standardization of analysis technique. In 25 brain structures, the mean coefficient of variation in cerebral glucose utilization rate (CMRGlc) measurements among five neuroanatomically trained observers was reduced from 8.1% for manual region of interest definition to 4.0% using the template approach with MRI. Template analysis for space-occupying lesions such as tumors or infarcts is illustrated with PET data from a stroke study, emphasizing the facility for rapid, reproducible analysis of multifunctional studies. MRI-PET matching for a structurally intact caudate nucleus having reduced CMRGlc in Huntington's disease emphasizes the accuracy of anatomical localization required to quantify small structures.

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.

Tracer kinetic model of regional pulmonary function using positron emission tomography

2002 ◽  
Vol 93 (3) ◽  
pp. 1104-1114 ◽  
Author(s):  
Gaetano G. Galletti ◽  
José G. Venegas
Keyword(s):  
Positron Emission Tomography ◽  
Pulmonary Function ◽  
Goodness Of Fit ◽  
Molecular Nitrogen ◽  
Region Of Interest ◽  
Emission Tomography ◽  
Gas Content ◽  
Pulmonary Vasculature ◽  
Model Parameters ◽  
Positron Emission

To determine the spatial distributions of pulmonary perfusion, shunt, and ventilation, we developed a compartmental model of regional 13N-labeled molecular nitrogen (13NN) kinetics measured from positron emission tomography (PET) images. The model features a compartment for right heart and pulmonary vasculature and two compartments for each region of interest: 1) aerated alveolar units and 2) alveolar units with no gas content (shunting). The model was tested on PET data from normal animals (dogs and sheep) and from animals with experimentally injured lungs simulating acute respiratory distress syndrome. The analysis yielded estimates of regional perfusion, shunt fraction, and specific ventilation with excellent goodness-of-fit to the data ( R 2 > 0.99). Model parameters were estimated to within 10% accuracy in the presence of exaggerated levels of experimental noise by using a Monte Carlo sensitivity analysis. Main advantages of the present model are that 1) it separates intraregional blood flow to aerated alveolar units from that shunting across nonaerated units and 2) it accounts and corrects for intraregional tracer removal by shunting blood when estimating ventilation from subsequent washout of tracer. The model was thus found to provide estimates of regional parameters of pulmonary function in sizes of lung regions that could potentially approach the intrinsic resolution for PET images of 13NN in lung (∼7.0 mm for a multiring PET camera).

scholarly journals Positron Emission Tomography as a Surrogate Marker for Evaluation of Treatment Response in Patients with Desmoid Tumors under Therapy with Imatinib

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bernd Kasper ◽  
Antonia Dimitrakopoulou-Strauss ◽  
Lothar R. Pilz ◽  
Ludwig G. Strauss ◽  
Christos Sachpekidis ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Progressive Disease ◽  
Surrogate Marker ◽  
Standardized Uptake Value ◽  
Response Prediction ◽  
Emission Tomography ◽  
Desmoid Tumors ◽  
Positron Emission ◽  
The Mean ◽  
Magnetic Resonance Imaging Mri

We used 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography (PET) to evaluate patients with desmoid tumors undergoing therapy with imatinib. The study included 22 patients with progressive disease (PD) of a biopsy proven desmoid tumor treated orally with imatinib 800 mg daily. Patients were examined using PET prior to onset of therapy and during treatment. Restaging was performed in parallel using computed tomography (CT) and/or magnetic resonance imaging (MRI). Outcome of 22 evaluable patients was as follows: five patients with partial response (PR); twelve patients with stable disease (SD) accounting for 77% with non-progressive disease; five patients showed PD. A 30% decrease of the mean average standardized uptake value (SUV) of sequential PET examinations could be demonstrated; no patient demonstrated a substantial increase in SUV. Patients with PR/SD were matched to a group of nonprogressive disease and tested versus PD. The initial average SUV and seem to be candidates for a response prediction with an approximate -value of0.06553and0.07785, respectively. This is the first larger series of desmoid patients monitored using PET showing that early SUV changes may help to discriminate responders from nonresponders and, thus, to decide whether imatinib therapy should be continued.

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