Influences of point-spread function and time-of-flight reconstructions on standardized uptake value of lymph node metastases in FDG-PET

Go Akamatsu; Katsuhiko Mitsumoto; Takafumi Taniguchi; Yuji Tsutsui; Shingo Baba; Masayuki Sasaki

doi:10.1016/j.ejrad.2013.09.030

Influences of point-spread function and time-of-flight reconstructions on standardized uptake value of lymph node metastases in FDG-PET

Eur J Radiol. 2014 Jan;83(1):226-30. doi: 10.1016/j.ejrad.2013.09.030. Epub 2013 Oct 6.

Authors

Go Akamatsu¹, Katsuhiko Mitsumoto², Takafumi Taniguchi³, Yuji Tsutsui⁴, Shingo Baba⁵, Masayuki Sasaki⁶

Affiliations

¹ Division of Medical Quantum Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Institute of Biomedical Research and Innovation, 2-2, Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan. Electronic address: golilin5@gmail.com.
² Division of Medical Quantum Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: kamitsumo@gmail.com.
³ Division of Medical Quantum Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: bock.0517.tt@gmail.com.
⁴ Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: yuji1006@med.kyushu-u.ac.jp.
⁵ Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: sbaba127@radiol.med.kyushu-u.ac.jp.
⁶ Division of Medical Quantum Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: msasaki@hs.med.kyushu-u.ac.jp.

PMID: 24144448
DOI: 10.1016/j.ejrad.2013.09.030

Abstract

Purpose: The purpose of this study was to investigate the effects of point-spread function (PSF) and time-of-flight (TOF) on the standardized uptake value (SUV) of lymph node metastasis in FDG-PET/CT.

Materials and methods: This study evaluated 41 lymph node metastases in 15 patients who had undergone (18)F-FDG PET/CT. The lesion diameters were 2.5 cm or less. The mean short-axis diameter of the lymph nodes was 10.5 ± 3.7 mm (range 4.6-22.8mm). The PET data were reconstructed with baseline OSEM algorithm, with OSEM+PSF, with OSEM+TOF and with OSEM+PSF+TOF. A semi-quantitative analysis was performed using the maximum and mean SUV of lymph node metastases (SUVmax and SUVmean) and mean SUV of normal lung tissue (SUVlung). We also evaluated image quality using the signal-to-noise ratio in the liver (SNRliver).

Results: Both PSF and TOF increased the SUV of lymph node metastases. The combination of PSF and TOF increased the SUVmax by 43.3% and the SUVmean by 31.6% compared with conventional OSEM. By contrast, the SUVlung was not influenced by PSF and TOF. TOF significantly improved the SNRliver.

Conclusion: PSF and TOF both increased the SUV of lymph node metastases. Although PSF and TOF are considered to improve small-lesion detectability, it is important to be aware that PSF and TOF influence the accuracy of quantitative measurements.

Keywords: FDG-PET; Lymph node metastasis; Point-spread function; Standardized uptake value; Time-of-flight.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Algorithms
Fluorodeoxyglucose F18 / pharmacokinetics*
Humans
Image Interpretation, Computer-Assisted / methods*
Lymphatic Metastasis / diagnostic imaging*
Lymphatic Metastasis / physiopathology*
Models, Biological
Models, Statistical
Positron-Emission Tomography / methods*
Positron-Emission Tomography / standards
Radiopharmaceuticals / pharmacokinetics
Reference Values
Reproducibility of Results
Sensitivity and Specificity

Substances

Radiopharmaceuticals
Fluorodeoxyglucose F18