scholarly journals Use of population input functions for reduced scan duration whole-body Patlak 18F-FDG PET imaging

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Joyce van Sluis ◽  
Maqsood Yaqub ◽  
Adrienne H. Brouwers ◽  
Rudi A. J. O. Dierckx ◽  
Walter Noordzij ◽  
...  
Keyword(s):  
Rate Constants ◽  
Arterial Input Function ◽  
Input Function ◽  
Dynamic Imaging ◽  
Whole Body ◽  
Time Interval ◽  
Time Activity ◽  
Dynamic Scan ◽  
Patlak Analysis ◽  
Body Dynamic

Abstract Whole-body Patlak images can be obtained from an acquisition of first 6 min of dynamic imaging over the heart to obtain the arterial input function (IF), followed by multiple whole-body sweeps up to 60 min pi. The use of a population-averaged IF (PIF) could exclude the first dynamic scan and minimize whole-body sweeps to 30–60 min pi. Here, the effects of (incorrect) PIFs on the accuracy of the proposed Patlak method were assessed. In addition, the extent of mitigating these biases through rescaling of the PIF to image-derived IF values at 30–60 min pi was evaluated. Methods Using a representative IF and rate constants from the literature, various tumour time-activity curves (TACs) were simulated. Variations included multiplication of the IF with a positive and negative gradual linear bias over 60 min of 5, 10, 15, 20, and 25% (generating TACs using an IF different from the PIF); use of rate constants (K1, k3, and both K1 and k2) multiplied by 2, 1.5, and 0.75; and addition of noise (μ = 0 and σ = 5, 10 and 15%). Subsequent Patlak analysis using the original IF (representing the PIF) was used to obtain the influx constant (Ki) for the differently simulated TACs. Next, the PIF was scaled towards the (simulated) IF value using the 30–60-min pi time interval, simulating scaling of the PIF to image-derived values. Influence of variabilities in IF and rate constants, and rescaling the PIF on bias in Ki was evaluated. Results Percentage bias in Ki observed using simulated modified IFs varied from − 16 to 16% depending on the simulated amplitude and direction of the IF modifications. Subsequent scaling of the PIF reduced these Ki biases in most cases (287 out of 290) to < 5%. Conclusions Simulations suggest that scaling of a (possibly incorrect) PIF to IF values seen in whole-body dynamic imaging from 30 to 60 min pi can provide accurate Ki estimates. Consequently, dynamic Patlak imaging protocols may be performed for 30–60 min pi making whole-body Patlak imaging clinically feasible.

scholarly journals A Short Dynamic Scan Method of Measuring Bone Metabolic Flux Using [18F]NaF PET

Tomography ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 623-635
Author(s):  
Tanuj Puri ◽  
Musib M. Siddique ◽  
Michelle L. Frost ◽  
Amelia E. B. Moore ◽  
Glen M. Blake
Keyword(s):  
Rate Constants ◽  
Statistical Power ◽  
Metabolic Flux ◽  
Arterial Input Function ◽  
Input Function ◽  
Ct Scans ◽  
Fixed Rate ◽  
Time Activity ◽  
Pet Ct ◽  
Dynamic Scan

[18F]NaF PET measurements of bone metabolic flux (Ki) are conventionally obtained with 60-min dynamic scans analysed using the Hawkins model. However, long scan times make this method expensive and uncomfortable for subjects. Therefore, we evaluated and compared measurements of Ki with shorter scan times analysed with fixed values of the Hawkins model rate constants. The scans were acquired in a trial in 30 postmenopausal women, half treated with teriparatide (TPT) and half untreated. Sixty-minute PET-CT scans of both hips were acquired at baseline and week 12 after injection with 180 MBq [18F]NaF. Scans were analysed using the Hawkins model by fitting bone time–activity curves at seven volumes of interest (VOIs) with a semi-population arterial input function. The model was re-run with fixed rate-constants for dynamic scan times from 0–12 min increasing in 4-min steps up to 0–60 min. Using the Hawkins model with fixed rate-constants, Ki measurements with statistical power equivalent or superior to conventionally analysed 60-min dynamic scans were obtained with scan times as short as 12 min.

scholarly journals Influence of O-Methylated Metabolite Penetrating the Blood–Brain Barrier to Estimation of Dopamine Synthesis Capacity in Human L-[β-11C]DOPA PET

2013 ◽  
Vol 34 (2) ◽  
pp. 268-274 ◽  
Author(s):  
Keisuke Matsubara ◽  
Yoko Ikoma ◽  
Maki Okada ◽  
Masanobu Ibaraki ◽  
Tetsuya Suhara ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Arterial Input Function ◽  
Input Function ◽  
Brain Barrier ◽  
Dopamine Synthesis ◽  
Synthesis Rate ◽  
Time Activity ◽  
Blood Brain ◽  
The Impact ◽  
Patlak Analysis

O-methyl metabolite (L-[ β-11C]OMD) of 11C-labeled L-3,4-dihydroxyphenylalanine (L-[ β-11C]DOPA) can penetrate into brain tissue through the blood–brain barrier, and can complicate the estimation of dopamine synthesis capacity by positron emission tomography (PET) study with L-[ β-11C]DOPA. We evaluated the impact of L-[ β-11C]OMD on the estimation of the dopamine synthesis capacity in a human L-[ β-11C]DOPA PET study. The metabolite correction with mathematical modeling of L-[ β-11C]OMD kinetics in a reference region without decarboxylation and further metabolism, proposed by a previous [18F]FDOPA PET study, were implemented to estimate radioactivity of tissue L-[ β-11C]OMD in 10 normal volunteers. The component of L-[ β-11C]OMD in tissue time-activity curves (TACs) in 10 regions were subtracted by the estimated radioactivity of L-[ β-11C]OMD. To evaluate the influence of omitting blood sampling and metabolite correction, relative dopamine synthesis rate ( kref) was estimated by Gjedde–Patlak analysis with reference tissue input function, as well as the net dopamine synthesis rate ( Ki) by Gjedde–Patlak analysis with the arterial input function and TAC without and with metabolite correction. Overestimation of Ki was observed without metabolite correction. However, the kref and Ki with metabolite correction were significantly correlated. These data suggest that the influence of L-[ β-11C]OMD is minimal for the estimation of kref as dopamine synthesis capacity.

1F14 Biodistribution of [^I]oxLDL in the mouse determined using whole body dynamic imaging

2013 ◽  
Vol 2013.25 (0) ◽  
pp. 205-206
Author(s):  
Atushi Nakano ◽  
Hidekazu Kawashima ◽  
Yosinori Miyake ◽  
Tatsuya Sawamura ◽  
Hidehiro Iid
Keyword(s):  
Dynamic Imaging ◽  
Whole Body ◽  
Body Dynamic

scholarly journals Arterial Input Function Derived from Pairwise Correlations Between PET-image Voxels

2013 ◽  
Vol 33 (7) ◽  
pp. 1058-1065 ◽  
Author(s):  
Martin Schain ◽  
Simon Benjaminsson ◽  
Katarina Varnäs ◽  
Anton Forsberg ◽  
Christer Halldin ◽  
...  
Keyword(s):  
Arterial Input Function ◽  
Pearson Correlation ◽  
Invasive Procedure ◽  
Compartmental Analysis ◽  
Input Function ◽  
Time Activity ◽  
Pairwise Correlation ◽  
Positron Emission ◽  
Using Data ◽  
Suitable Reference

A metabolite corrected arterial input function is a prerequisite for quantification of positron emission tomography (PET) data by compartmental analysis. This quantitative approach is also necessary for radioligands without suitable reference regions in brain. The measurement is laborious and requires cannulation of a peripheral artery, a procedure that can be associated with patient discomfort and potential adverse events. A non invasive procedure for obtaining the arterial input function is thus preferable. In this study, we present a novel method to obtain image-derived input functions (IDIFs). The method is based on calculation of the Pearson correlation coefficient between the time-activity curves of voxel pairs in the PET image to localize voxels displaying blood-like behavior. The method was evaluated using data obtained in human studies with the radioligands [ 11 C]flumazenil and [ 11 C]AZ10419369, and its performance was compared with three previously published methods. The distribution volumes ( VT) obtained using IDIFs were compared with those obtained using traditional arterial measurements. Overall, the agreement in VT was good (~3% difference) for input functions obtained using the pairwise correlation approach. This approach performed similarly or even better than the other methods, and could be considered in applied clinical studies. Applications to other radioligands are needed for further verification.

scholarly journals Whole-body dynamic imaging with continuous bed motion PET/CT

2016 ◽  
Vol 37 (4) ◽  
pp. 428-431 ◽  
Author(s):  
Dustin R. Osborne ◽  
Shelley Acuff
Keyword(s):  
Dynamic Imaging ◽  
Whole Body ◽  
Pet Ct ◽  
Body Dynamic

scholarly journals Semi-quantitative cerebral blood flow parameters derived from non-invasive [15O]H2O PET studies

2017 ◽  
Vol 39 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Thomas Koopman ◽  
Maqsood Yaqub ◽  
Dennis FR Heijtel ◽  
Aart J Nederveen ◽  
Bart NM van Berckel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Input Function ◽  
Input Function ◽  
Time Activity ◽  
Non Invasive ◽  
Flow Parameters ◽  
Positron Emission ◽  
Arterial Sampling ◽  
Activity Curve

Quantification of regional cerebral blood flow (CBF) using [15O]H2O positron emission tomography (PET) requires the use of an arterial input function. Arterial sampling, however, is not always possible, for example in ill-conditioned or paediatric patients. Therefore, it is of interest to explore the use of non-invasive methods for the quantification of CBF. For validation of non-invasive methods, test–retest normal and hypercapnia data from 15 healthy volunteers were used. For each subject, the data consisted of up to five dynamic [15O]H2O brain PET studies of 10 min and including arterial sampling. A measure of CBF was estimated using several non-invasive methods earlier reported in literature. In addition, various parameters were derived from the time-activity curve (TAC). Performance of these methods was assessed by comparison with full kinetic analysis using correlation and agreement analysis. The analysis was repeated with normalization to the whole brain grey matter value, providing relative CBF distributions. A reliable, absolute quantitative estimate of CBF could not be obtained with the reported non-invasive methods. Relative (normalized) CBF was best estimated using the double integration method.

scholarly journals Early differences in dynamic uptake of 68Ga-PSMA-11 in primary prostate cancer: A test-retest study

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246394
Author(s):  
J. olde Heuvel ◽  
B. J. de Wit-van der Veen ◽  
M. Sinaasappel ◽  
C. H. Slump ◽  
M. P. M. Stokkel
Keyword(s):  
Prostate Cancer ◽  
Iliac Artery ◽  
Prostate Tumor ◽  
Whole Body ◽  
Time Interval ◽  
Tumor Uptake ◽  
Gluteal Muscle ◽  
Time Activity ◽  
Primary Prostate Cancer ◽  
Pet Ct

Introduction Dynamic PET/CT allows visualization of pharmacokinetics over the time, in contrast to static whole body PET/CT. The objective of this study was to assess 68Ga-PSMA-11 uptake in pathological lesions and benign tissue, within 30 minutes after injection in primary prostate cancer (PCa) patients in test-retest setting. Materials and methods Five patients, with biopsy proven PCa, were scanned dynamically in list mode for 30 minutes on a digital PET/CT-scanner directly after an intravenous bolus injection of 100 MBq 68Ga-PSMA-11. Approximately 45 minutes after injection a static whole body scan was acquired, followed by a one bed position scan of the pelvic region. The scans were repeated approximately four weeks later, without any intervention in between. Semi-quantitative assessment was performed using regions-of-interest in the prostate tumor, bladder, gluteal muscle and iliac artery. Time-activity curves were extracted from the counts in these regions and the intra-patient variability between both scans was assessed. Results The uptake of the iliac artery and gluteal muscle reached a plateau after 5 and 3 minutes, respectively. The population fell apart in two groups with respect to tumor uptake: in some patients the tumor uptake reached a plateau after 5 minutes, whereas in other patients the uptake kept increasing, which correlated with larger tumor volumes on PET/CT scan. Median intra-patient variation between both scans was 12.2% for artery, 9.7% for tumor, 32.7% for the bladder and 14.1% for the gluteal muscle. Conclusion Dynamic 68Ga-PSMA-11 PET/CT scans, with a time interval of four weeks, are reproducible with a 10% variation in uptake in the primary prostate tumor. An uptake plateau was reached for the iliac artery and gluteal muscle within 5 minutes post-injection. A larger tumor volume seems to be related to continued tumor uptake. This information might be relevant for both response monitoring and PSMA-based radionuclide therapies.

scholarly journals FDG-PET Quantification of Lung Inflammation with Image-Derived Blood Input Function in Mice

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Landon W. Locke ◽  
Mark B. Williams ◽  
Karen D. Fairchild ◽  
Min Zhong ◽  
Bijoy K. Kundu ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Virulent Strain ◽  
Compartment Model ◽  
Input Function ◽  
Time Activity ◽  
Fdg Uptake ◽  
Lung Infiltrate ◽  
Kinetics Of ◽  
Patlak Analysis ◽  
Model Approach

Dynamic FDG-PET imaging was used to study inflammation in lungs of mice following administration of a virulent strain of Klebsiella (K.) pneumoniae. Net whole-lung FDG influx constant (Ki) was determined in a compartment model using an image-derived blood input function. Methods. K. pneumoniae (~3 x 105 CFU) was intratracheally administered to six mice with 6 other mice serving as controls. Dynamic FDG-PET and X-Ray CT scans were acquired 24 hr after K. pneumoniae administration. The experimental lung time activity curves were fitted to a 3-compartment FDG model to obtain Ki. Following imaging, lungs were excised and immunohistochemistry analysis was done to assess the relative presence of neutrophils and macrophages. Results. Mean Ki for control and K. pneumoniae infected mice were (5.1±1.2) ×10-3 versus (11.4±2.0) ×10-3 min−1, respectively, revealing a 2.24 fold significant increase (P=0.0003) in the rate of FDG uptake in the infected lung. Immunohistochemistry revealed that cellular lung infiltrate was almost exclusively neutrophils. Parametric Ki maps by Patlak analysis revealed heterogeneous inflammatory foci within infected lungs. Conclusion. The kinetics of FDG uptake in the lungs of mice can be noninvasively quantified by PET with a 3-compartment model approach based on an image-derived input function.

Accurate Total-Body Ki Parametric Imaging with Shortened Dynamic 18F-FDG PET Scan Durations via Effective Data Processing

2021 ◽  
Author(s):  
Zixiang Chen ◽  
Zhaoping Cheng ◽  
Yanhua Duan ◽  
Fengyun Gu ◽  
Ying Wang ◽  
...  
Keyword(s):  
Data Processing ◽  
Fdg Pet ◽  
Parametric Imaging ◽  
Imaging Data ◽  
Parametric Images ◽  
Tumor Lesion ◽  
Dynamic Scan ◽  
Total Body ◽  
Patlak Analysis ◽  
Body Dynamic

Abstract Background: Total-body dynamic PET (dPET) imaging using 18F-fluorodeoxyglucose (18F-FDG) has received widespread attention in clinical oncology. However, the conventionally required scan duration of approximately one hour seriously limits the application and promotion of this imaging technique. In this study, using Patlak analysis-based Ki parametric imaging as the evaluation standard, we investigated the possibility and feasibility of shortening the total-body dynamic scan duration to 30 mins post-injection (PI) with the help of a novel Patlak data processing algorithm.Methods: Total-body dPET images acquired by uEXPLORER (United Imaging Healthcare Inc.) using 18F-FDG of 15 patients with different types of tumors were analyzed in this study. Dynamic images were reconstructed into 25 frames with a specific temporal dividing protocol for the scan data acquired one hour PI. Patlak analysis-based Ki parametric imaging was carried out based on the imaging data corresponding to the first 30 mins PI, during which a Patlak data processing method based on third-order Hermite interpolation (THI) was applied. The resulting Ki images and standard Ki images were compared in terms of visual imaging effect and Ki estimation accuracy to evaluate the performance of the proposed data processing algorithm for parametric imaging with dPET with a shortened scan duration.Results: With the help of Patlak data processing, acceptable Ki parametric images were obtained from dPET data acquired with a shortened scan duration. Compared to Ki images obtained from unprocessed Patlak data, the resulting images from the proposed method contained less image noise, leading to remarkably improved imaging quality. Moreover, box plot analysis showed that that 30-min Ki images obtained from processed Patlak data have higher accuracy regarding tumor lesion Ki values.Conclusion: Acceptable Ki parametric images can be acquired from dynamic imaging data corresponding to the first 30 mins PI. Patlak data processing can help achieve higher Ki imaging quality and higher accuracy regarding tumor lesion Ki values. Clinically, it is possible to shorten the dynamic scan duration of 18F-FDG PET to 30 mins to facilitate the usage of such imaging techniques on uEXPLORER scanners.

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