Transcranial Doppler ultrasonography predicts cardiovascular events after TIA
Katrin Holzer, Suwad Sadikovic, Lorena Esposito, Angelina Bockelbrink et al
BMC Medical Imaging 2009, 9:13 (30 July 2009)
Provisional PDF http://www.biomedcentral.com/content/pdf/1471-2342-9-13.pdf
Test-Retest variability of High Resolution Positron Emission Tomography (PET) imaging of Cortical Serotonin (5HT2A) receptors in older, healthy adults
Tiffany W Chow, David C Mamo, Hiroyuki Uchida, Sylvain Houle et al
BMC Medical Imaging 2009, 9:12 (6 July 2009)
Provisional PDF http://www.biomedcentral.com/content/pdf/1471-2342-9-12.pdf
Showing posts with label PET. Show all posts
Showing posts with label PET. Show all posts
Thursday, 3 September 2009
Friday, 2 January 2009
Articles from Stroke
Link to journal online
Toth, Gabor ; Albers, Gregory W.
Use of MRI to Estimate the Therapeutic Window in Acute Stroke: Is Perfusion-Weighted Imaging/Diffusion-Weighted Imaging Mismatch an EPITHET for Salvageable Ischemic Brain Tissue?
Source
Stroke. 40(1):333-335, January 2009.
Cai, Weibo ; Guzman, Raphael ; Hsu, Andrew R. ; Wang, Hui ; Chen, Kai et al
Positron Emission Tomography Imaging of Poststroke Angiogenesis
Stroke. 40(1):270-277, January 2009.
Abstract
Background and Purpose-: Vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) play important roles during neurovascular repair after stroke. In this study, we imaged VEGFR expression with positron emission tomography (PET) to noninvasively analyze poststroke angiogenesis.Methods-: Female Sprague-Dawley rats after distal middle cerebral artery occlusion surgery were subjected to weekly MRI, 18F-FDG PET, and 64Cu-DOTA-VEGF121 PET scans. Several control experiments were performed to confirm the VEGFR specificity of 64Cu-DOTA-VEGF121 uptake in the stroke border zone. VEGFR, BrdU, lectin staining, and 125I-VEGF165 autoradiography on stroke brain tissue slices were performed to validate the in vivo findings.Results-: T2-weighed MRI correlated with the "cold spot" on 18F-FDG PET for rats undergoing distal middle cerebral artery occlusion surgery. The 64Cu-DOTA-VEGF121 uptake in the stroke border zone peaked at [almost equal to]10 days after surgery, indicating neovascularization as confirmed by histology (VEGFR-2, BrdU, and lectin staining). VEGFR specificity of 64Cu-DOTA-VEGF121 uptake was confirmed by significantly lower uptake of 64Cu-DOTA-VEGFmutant in vivo and intense 125I-VEGF165 uptake ex vivo in the stroke border zone. No appreciable uptake of 64Cu-DOTA-VEGF121 was observed in the brain of sham-operated rats.Conclusions-: For the first time to our knowledge, we successfully evaluated the VEGFR expression kinetics noninvasively in a rat stroke model. In vivo imaging of VEGFR expression could become a significant clinical tool to plan and monitor therapies aimed at improving poststroke angiogenesis.
Izquierdo-Garcia, David ; Davies, John R. ; Graves, Martin J. et al
Comparison of Methods for Magnetic Resonance-Guided [18-F]Fluorodeoxyglucose Positron Emission Tomography in Human Carotid Arteries: Reproducibility, Partial Volume Correction, and Correlation Between Methods.
Stroke. 40(1):86-93, January 2009.
Abstract
Background and Purpose-: Inflammation is a major risk factor for atherosclerotic plaque rupture and clinical events. Previous studies have shown that plaque [18F]fluorodeoxyglucose (FDG) uptake correlates with macrophage content. In this study we examined the reproducibility of 3 methods of quantifying plaque FDG uptake in the carotid arteries using positron emission tomography (PET). The correlation between 2 simplified uptake parameters (standardized uptake value [SUV], vessel wall-to-blood ratio [VBR]) and a gold standard technique (influx rate [Ki]) was also determined. We used MRI to correct carotid plaque FDG uptake for partial volume error.Methods-: Seven patients with a recent carotid territory transient ischemic attack underwent imaging twice within 8 days using MR and FDG-PET. MR coregistered to PET was used to delineate regions of interest, and to facilitate partial volume correction (PVC).Results-: SUV was the most reproducible parameter irrespective of whether it was normalized by body surface area (BSA), lean body mass, or weight (intraclass correlation coefficient=0.85, 0.88, and 0.90, respectively). VBR correlated better to Ki than SUV (r=0.58 VBR, r=0.46 SUVBSA). PVC improved these correlations to r=0.81 VBR and r=0.76 SUVBSA, and only slightly degraded the reproducibility of SUV (intraclass correlation coefficient=0.83-0.85).Conclusions-: MR-guided FDG-PET is a highly reproducible technique in the carotid artery and the excellent anatomic detail provided by MR facilitates PVC. Of the methods examined, SUVBSAPVC appears to represent the best compromise between reproducible and accurate determination of FDG metabolism in carotid artery vessel wall.
Toth, Gabor ; Albers, Gregory W.
Use of MRI to Estimate the Therapeutic Window in Acute Stroke: Is Perfusion-Weighted Imaging/Diffusion-Weighted Imaging Mismatch an EPITHET for Salvageable Ischemic Brain Tissue?
Source
Stroke. 40(1):333-335, January 2009.
Cai, Weibo ; Guzman, Raphael ; Hsu, Andrew R. ; Wang, Hui ; Chen, Kai et al
Positron Emission Tomography Imaging of Poststroke Angiogenesis
Stroke. 40(1):270-277, January 2009.
Abstract
Background and Purpose-: Vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) play important roles during neurovascular repair after stroke. In this study, we imaged VEGFR expression with positron emission tomography (PET) to noninvasively analyze poststroke angiogenesis.Methods-: Female Sprague-Dawley rats after distal middle cerebral artery occlusion surgery were subjected to weekly MRI, 18F-FDG PET, and 64Cu-DOTA-VEGF121 PET scans. Several control experiments were performed to confirm the VEGFR specificity of 64Cu-DOTA-VEGF121 uptake in the stroke border zone. VEGFR, BrdU, lectin staining, and 125I-VEGF165 autoradiography on stroke brain tissue slices were performed to validate the in vivo findings.Results-: T2-weighed MRI correlated with the "cold spot" on 18F-FDG PET for rats undergoing distal middle cerebral artery occlusion surgery. The 64Cu-DOTA-VEGF121 uptake in the stroke border zone peaked at [almost equal to]10 days after surgery, indicating neovascularization as confirmed by histology (VEGFR-2, BrdU, and lectin staining). VEGFR specificity of 64Cu-DOTA-VEGF121 uptake was confirmed by significantly lower uptake of 64Cu-DOTA-VEGFmutant in vivo and intense 125I-VEGF165 uptake ex vivo in the stroke border zone. No appreciable uptake of 64Cu-DOTA-VEGF121 was observed in the brain of sham-operated rats.Conclusions-: For the first time to our knowledge, we successfully evaluated the VEGFR expression kinetics noninvasively in a rat stroke model. In vivo imaging of VEGFR expression could become a significant clinical tool to plan and monitor therapies aimed at improving poststroke angiogenesis.
Izquierdo-Garcia, David ; Davies, John R. ; Graves, Martin J. et al
Comparison of Methods for Magnetic Resonance-Guided [18-F]Fluorodeoxyglucose Positron Emission Tomography in Human Carotid Arteries: Reproducibility, Partial Volume Correction, and Correlation Between Methods.
Stroke. 40(1):86-93, January 2009.
Abstract
Background and Purpose-: Inflammation is a major risk factor for atherosclerotic plaque rupture and clinical events. Previous studies have shown that plaque [18F]fluorodeoxyglucose (FDG) uptake correlates with macrophage content. In this study we examined the reproducibility of 3 methods of quantifying plaque FDG uptake in the carotid arteries using positron emission tomography (PET). The correlation between 2 simplified uptake parameters (standardized uptake value [SUV], vessel wall-to-blood ratio [VBR]) and a gold standard technique (influx rate [Ki]) was also determined. We used MRI to correct carotid plaque FDG uptake for partial volume error.Methods-: Seven patients with a recent carotid territory transient ischemic attack underwent imaging twice within 8 days using MR and FDG-PET. MR coregistered to PET was used to delineate regions of interest, and to facilitate partial volume correction (PVC).Results-: SUV was the most reproducible parameter irrespective of whether it was normalized by body surface area (BSA), lean body mass, or weight (intraclass correlation coefficient=0.85, 0.88, and 0.90, respectively). VBR correlated better to Ki than SUV (r=0.58 VBR, r=0.46 SUVBSA). PVC improved these correlations to r=0.81 VBR and r=0.76 SUVBSA, and only slightly degraded the reproducibility of SUV (intraclass correlation coefficient=0.83-0.85).Conclusions-: MR-guided FDG-PET is a highly reproducible technique in the carotid artery and the excellent anatomic detail provided by MR facilitates PVC. Of the methods examined, SUVBSAPVC appears to represent the best compromise between reproducible and accurate determination of FDG metabolism in carotid artery vessel wall.
Wednesday, 3 December 2008
Aunt Minnie - Performing PET/CT for breast imaging at two points in time
Performing PET/CT for breast imaging at two points in time improves the technique's accuracy compared to studies done at just one time point. But even with this improvement, dual-time-point PET/CT may not be as good as breast MRI for small lesions.
MRI remains the preferred modality for characterizing those lesions, according to an article by staff writer Kate Madden Yee that we're featuring this week in our Women's Imaging Digital Community. Italian researchers compared FDG-PET/CT taken three hours apart to contrast-enhanced breast MRI, which has been winning favor as a method for analyzing suspicious lesions found on mammography.
The researchers found that the time difference between PET/CT studies improved the technique's sensitivity and specificity by over 10 percentage points. But the modality still fell short of the accuracy produced by breast MRI. Get the rest of the story by clicking here.
MRI remains the preferred modality for characterizing those lesions, according to an article by staff writer Kate Madden Yee that we're featuring this week in our Women's Imaging Digital Community. Italian researchers compared FDG-PET/CT taken three hours apart to contrast-enhanced breast MRI, which has been winning favor as a method for analyzing suspicious lesions found on mammography.
The researchers found that the time difference between PET/CT studies improved the technique's sensitivity and specificity by over 10 percentage points. But the modality still fell short of the accuracy produced by breast MRI. Get the rest of the story by clicking here.
Monday, 27 October 2008
Myocardial Metastases of Carcinoid Visualized by 18F-Dihydroxy-Phenyl-Alanine PET
Link to journal
Fiebrich, Helle-Brit ; Brouwers, Adrienne H. ; Links, Thera P. ; de Vries, Elisabeth G.E.
Myocardial Metastases of Carcinoid Visualized by 18F-Dihydroxy-Phenyl-Alanine Positron Emission Tomography.
Circulation. 118(15):1602-1604, October 7, 2008.
Fiebrich, Helle-Brit ; Brouwers, Adrienne H. ; Links, Thera P. ; de Vries, Elisabeth G.E.
Myocardial Metastases of Carcinoid Visualized by 18F-Dihydroxy-Phenyl-Alanine Positron Emission Tomography.
Circulation. 118(15):1602-1604, October 7, 2008.
Monday, 14 April 2008
Identification of Distant Metastases With PET
Gourin, Christine G. MD; Watts, Tammara L. MD, PhD; Williams, Hadyn T. MD; Patel, Vijay S. MD; Bilodeau, Paul A. MD; Coleman, Teresa A.
Identification of Distant Metastases With Positron-Emission Tomography-Computed Tomography in Patients With Previously Untreated Head and Neck Cancer
Laryngoscope. 118(4):671-675, April 2008.
Abstract
Objectives: To investigate the utility of positron-emission tomography-computed tomography (PET-CT) in identifying distant metastatic disease in patients with previously untreated head and neck squamous cell cancer (HNSCC) prior to definitive treatment.Materials and Methods: Retrospective analysis of 27 consecutive patients with previously untreated HNSCC who underwent PET-CT imaging in addition to chest radiography (CXR) as part of their metastatic workup.Results: The majority of patients (89%) had TNM stage III or IV disease. PET-CT was suspicious for pulmonary malignancy in four (15%) patients and indeterminate in one (4%) patient. CXR was suspicious for pulmonary malignancy in two (7%) patients. Pulmonary metastases or a new lung primary was present in 3 (11%) patients: 3 of 4 (75%) patients with positive PET-CT scans and 0 of 23 (0%) patients with negative or indeterminate PET-CT scans compared with 2 of 2 (100%) patients with positive CXR and 1 of 25 (4%) patients with negative CXR. The sensitivity and specificity of PET-CT in predicting pulmonary malignancy was 100% and 96%, respectively, with a positive predictive value of 75% and a negative predictive value of 100%. The sensitivity and specificity of CXR in predicting pulmonary malignancy was 67% and 100%, respectively, with a positive predictive value of 100% and a negative predictive value of 96%. Including nonpulmonary sites, the overall incidence of distant metastatic disease was 19% (5/27) with 11% (3/27) unsuspected prior to PET-CT.Conclusions: PET-CT improves detection of metastatic disease in the high-risk patient and should be performed as part of the routine pretreatment evaluation of patients with advanced stage HNSCC.
Link to journal
Identification of Distant Metastases With Positron-Emission Tomography-Computed Tomography in Patients With Previously Untreated Head and Neck Cancer
Laryngoscope. 118(4):671-675, April 2008.
Abstract
Objectives: To investigate the utility of positron-emission tomography-computed tomography (PET-CT) in identifying distant metastatic disease in patients with previously untreated head and neck squamous cell cancer (HNSCC) prior to definitive treatment.Materials and Methods: Retrospective analysis of 27 consecutive patients with previously untreated HNSCC who underwent PET-CT imaging in addition to chest radiography (CXR) as part of their metastatic workup.Results: The majority of patients (89%) had TNM stage III or IV disease. PET-CT was suspicious for pulmonary malignancy in four (15%) patients and indeterminate in one (4%) patient. CXR was suspicious for pulmonary malignancy in two (7%) patients. Pulmonary metastases or a new lung primary was present in 3 (11%) patients: 3 of 4 (75%) patients with positive PET-CT scans and 0 of 23 (0%) patients with negative or indeterminate PET-CT scans compared with 2 of 2 (100%) patients with positive CXR and 1 of 25 (4%) patients with negative CXR. The sensitivity and specificity of PET-CT in predicting pulmonary malignancy was 100% and 96%, respectively, with a positive predictive value of 75% and a negative predictive value of 100%. The sensitivity and specificity of CXR in predicting pulmonary malignancy was 67% and 100%, respectively, with a positive predictive value of 100% and a negative predictive value of 96%. Including nonpulmonary sites, the overall incidence of distant metastatic disease was 19% (5/27) with 11% (3/27) unsuspected prior to PET-CT.Conclusions: PET-CT improves detection of metastatic disease in the high-risk patient and should be performed as part of the routine pretreatment evaluation of patients with advanced stage HNSCC.
Link to journal
Subscribe to:
Posts (Atom)
