MRI-guided region-of-interest delineation is comparable to manual delineation in dopamine transporter SPECT quantification in patients: a reproducibility study

TY - JOUR

T1 - MRI-guided region-of-interest delineation is comparable to manual delineation in dopamine transporter SPECT quantification in patients: a reproducibility study

AU - Ziebell, Morten

AU - Pinborg, Lars H

AU - Thomsen, Gerda

AU - de Nijs, Robin

AU - Svarer, Claus

AU - Wagner, Aase

AU - Knudsen, Gitte M

PY - 2010/6/1

Y1 - 2010/6/1

N2 - A particularly sensitive step in the quantification of SPECT images of the dopamine transporter (DAT) is a correct delineation of the region of interest (ROI). In this study, we primarily compared the reproducibility of the following different approaches for ROI delineation in SPECT images of the DAT: the use of manual delineation (MD) on high-count striatal slides directly on the SPECT image, ROI delineation based on individual MR images (MRD), and oversized striatal ROIs-that is, the striatal volume of interest (SVI), as described previously. We also assessed the ability of the different approaches to identify striatal pathology in patients with parkinsonism. Methods: Eight patients with highly variable reductions in cerebral DAT availability were SPECT-scanned twice with 123I-labeled N-(3-iodoprop-(2E)-enyl)-2β-carboxymethoxy-3β-(4′-methylphenyl) nortropane bolus infusion setup and once with an MRI scanner. For SPECT/MRI coregistration, we used external fiducial markers visible on both MRI and SPECT. With the MD and MRD methods, the outcome parameters for DAT availability were the binding potentials and the ratio at equilibriumof specifically bound radioligand to nondisplaceable radioligand in tissue (BPND). For theSVImethod, the outcome parameterwas the specific binding ratio (SBR). Results: No statistically significant difference in striatal BPND intraobserver reproducibility was seen among any of the 3 methods. The intraobserver reproducibility average ± SD forMDwas 7.0% ± 4.1%; for MRD, 5.7% ± 5.4%; and for SVI, 6.7% ± 6.0%.Mean intrasubject variability, as determined from the test-retest scans, did not differ with the 3 delineationmethods used. The average (±SD) intrasubject variability of striatal BPND was 11.9% ± 10.0% with MD and 14.6% ± 15.3%with MRD. With the SVI method, the intrasubject variability of striatal specific binding ratio was 10.0% ± 10.2%. BPND values obtainedwith the MD and MRD methods were similar (paired t test, P > 0.4). Conclusion: In patients with reduced striatal DAT binding, the reproducibility of the outcome from ROI MD is comparable to both that obtained by delineation of ROI on individual MR images, followed by coregistration to the SPECT image, and that obtained with the SVI-based approach,

AB - A particularly sensitive step in the quantification of SPECT images of the dopamine transporter (DAT) is a correct delineation of the region of interest (ROI). In this study, we primarily compared the reproducibility of the following different approaches for ROI delineation in SPECT images of the DAT: the use of manual delineation (MD) on high-count striatal slides directly on the SPECT image, ROI delineation based on individual MR images (MRD), and oversized striatal ROIs-that is, the striatal volume of interest (SVI), as described previously. We also assessed the ability of the different approaches to identify striatal pathology in patients with parkinsonism. Methods: Eight patients with highly variable reductions in cerebral DAT availability were SPECT-scanned twice with 123I-labeled N-(3-iodoprop-(2E)-enyl)-2β-carboxymethoxy-3β-(4′-methylphenyl) nortropane bolus infusion setup and once with an MRI scanner. For SPECT/MRI coregistration, we used external fiducial markers visible on both MRI and SPECT. With the MD and MRD methods, the outcome parameters for DAT availability were the binding potentials and the ratio at equilibriumof specifically bound radioligand to nondisplaceable radioligand in tissue (BPND). For theSVImethod, the outcome parameterwas the specific binding ratio (SBR). Results: No statistically significant difference in striatal BPND intraobserver reproducibility was seen among any of the 3 methods. The intraobserver reproducibility average ± SD forMDwas 7.0% ± 4.1%; for MRD, 5.7% ± 5.4%; and for SVI, 6.7% ± 6.0%.Mean intrasubject variability, as determined from the test-retest scans, did not differ with the 3 delineationmethods used. The average (±SD) intrasubject variability of striatal BPND was 11.9% ± 10.0% with MD and 14.6% ± 15.3%with MRD. With the SVI method, the intrasubject variability of striatal specific binding ratio was 10.0% ± 10.2%. BPND values obtainedwith the MD and MRD methods were similar (paired t test, P > 0.4). Conclusion: In patients with reduced striatal DAT binding, the reproducibility of the outcome from ROI MD is comparable to both that obtained by delineation of ROI on individual MR images, followed by coregistration to the SPECT image, and that obtained with the SVI-based approach,

U2 - 10.2967/jnmt.109.072801

DO - 10.2967/jnmt.109.072801

M3 - Journal article

SN - 0091-4916

VL - 38

SP - 61

EP - 68

JO - Journal of Nuclear Medicine Technology

JF - Journal of Nuclear Medicine Technology

IS - 2

ER -