Comparison of Eight Methods for the Estimation of the Image-Derived Input Function in Dynamic [¹⁸F]-FDG PET Human Brain Studies

Abstract

The aim of this study was to compare eight methods for the estimation of the image-derived input function (IDIF) in [ 18 F]-FDG positron emission tomography (PET) dynamic brain studies. The methods were tested on two digital phantoms and on four healthy volunteers. Image-derived input functions obtained with each method were compared with the reference input functions, that is, the activity in the carotid labels of the phantoms and arterial blood samples for the volunteers, in terms of visual inspection, areas under the curve, cerebral metabolic rates of glucose (CMRglc), and individual rate constants. Blood-sample-free methods provided less reliable results as compared with those obtained using the methods that require the use of blood samples. For some of the bloodsample-free methods, CMRglc estimations considerably improved when the IDIF was calibrated with a single blood sample. Only one of the methods tested in this study, and only in phantom studies, allowed a reliable calculation of the individual rate constants. For the estimation of CMRglc values using an IDIF in [ 18 F]-FDG PET brain studies, a reliable absolute blood-sample-free procedure is not available yet.

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

“…However, when considering that Mourik's approach is based on very small ROIs, it is likely that the number of iterations could affect the signal recovery, depending on the radioligand. In the present study, Mourik's approach showed good performance for [ 11 15,33,34 have shown better agreement between MIF and IDIF than the one we found for [ 11 C]flumazenil. Thus, the performance of Mourik's approach may be radioligand dependent and, for some radioligands, the approach may require specific settings for the image reconstruction.…”

“…16 Several methods without the need of blood samples have been proposed, 14,[37][38][39] but their accuracy in the estimates of V T and cerebral metabolic rate of glucose has been shown to be significantly lower when compared with methods including arterial blood sampling. 15,33 Furthermore, even if a non invasive method was able to provide high accuracy in the blood curve estimate, multiple blood samples would still be needed to correct for plasma-to-blood ratio and radioactive metabolites, and to provide accurate estimates of binding parameters.…”

Searching for Alternatives to Full Kinetic Analysis in 18F-FDG PET: An Extension of the Simplified Kinetic Analysis Method

“…Other groups used image-derived input functions without scaling (14,15), an approach limited by the PET image partial-volume effect and radiolabel uptake in tissue surrounding the region of interest.…”

Back to the future: the absolute quantification of cerebral metabolic rate of glucose

“…These IDIF methods still suffer from errors ultimately leading to less reliable CMRGlc measurements [32]. Blood sample-free methods provide rather biased estimation of CMRGlc, with variations [±10 % as compared to the CMRGlc values obtained with the gold-standard IF method (with arterial sampling).…”

“…One of its advantages is the presence of carotid arteries in the brain volume acquired with the dynamic PET, which means that both the arterial and the brain uptake can be measured from their very start. However, the inner diameter of the carotid arteries is similar to the PET spatial resolution; therefore, IDIF measured in this way will suffer from the partial volume effect in the initial phase and spill-in from adjacent brain tissue later on, making it necessary to apply laborious correction methods [24,31,32].…”