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Improved quantification of small hearts for gated myocardial perfusion imaging

Nakajima, Kenichi; Okuda, Koichi; Nystrom, Karin; Richter, Jens; Minarik, David LU ; Wakabayashi, Hiroshi; Matsuo, Shinro; Kinuya, Seigo and Edenbrandt, Lars LU (2013) In European Journal of Nuclear Medicine and Molecular Imaging 40(8). p.1163-1170
Abstract
In patients with a small heart, defined as an end-systolic volume (ESV) of a parts per thousand currency sign20 mL calculated using the Quantitative Gated SPECT (QGS) program, underestimation of ESV and overestimation of ejection fraction (EF) using gated myocardial perfusion imaging are considered errors caused by inappropriate delineation of the left ventricle (LV). The aim of this study was to develop a new method for delineation of the LV and to evaluate it in studies using a digital phantom, normal subjects and patients. The active shape-based method for LV delineation, EXINI heart (ExH), was adjusted to more accurately process small hearts. In small hearts, due to the partial volume effect and the short distance to the opposite... (More)
In patients with a small heart, defined as an end-systolic volume (ESV) of a parts per thousand currency sign20 mL calculated using the Quantitative Gated SPECT (QGS) program, underestimation of ESV and overestimation of ejection fraction (EF) using gated myocardial perfusion imaging are considered errors caused by inappropriate delineation of the left ventricle (LV). The aim of this study was to develop a new method for delineation of the LV and to evaluate it in studies using a digital phantom, normal subjects and patients. The active shape-based method for LV delineation, EXINI heart (ExH), was adjusted to more accurately process small hearts. In small hearts, due to the partial volume effect and the short distance to the opposite ventricular wall, the endocardial and the epicardial surfaces are shifted in the epicardial direction depending on the midventricular volume. The adjusted method was evaluated using digital XCAT phantoms with Monte Carlo simulation (8 virtual patients), a Japanese multicentre normal database (69 patients) and consecutive Japanese patients (116 patients). The LV volumes, EF and diastolic parameters derived from ExH and QGS were compared. The digital phantom studies showed a mean ESV of 87 % +/- 9 % of the true volume calculated using ExH and 22 % +/- 18 % calculated using QGS. In the normal database, QGS gave higher EFs in women than in men (71.4 +/- 6.0 % vs. 67.2 +/- 6.0 %, p = 0.0058), but ExH gave comparable EFs (70.7 +/- 4.9 % and 71.4 +/- 5 % in men and women, respectively, p = ns). QGS gave higher EFs in subjects with a small heart than in those with a normal-sized heart (74.5 +/- 5.1 % vs. 66.1 +/- 4.9 %), but ExH gave comparable values (70.0 +/- 5.9 % vs. 71.6 +/- 4.2 %, respectively, p = ns). In consecutive patients, the average EFs with QGS in patients with ESV > 20 mL, 11-20 mL and a parts per thousand currency sign10 mL were 57.9 %, 71.9 % and 83.2 %, but with ExH the differences among these groups were smaller (65.2 %, 67.8 % and 71.5 %, respectively). The volume-dependent edge correction algorithm was able to effectively reduce the effects on ESV and EF of a small heart. The uniform normal values might be applicable to both men and women and to both small and normal-sized hearts. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Myocardial perfusion imaging, Small heart, Left ventricular function, Software algorithm, Normal values
in
European Journal of Nuclear Medicine and Molecular Imaging
volume
40
issue
8
pages
1163 - 1170
publisher
Springer
external identifiers
  • wos:000321521000006
  • scopus:84879910594
ISSN
1619-7070
DOI
10.1007/s00259-013-2431-x
language
English
LU publication?
yes
id
ce7373c6-3c8c-4d99-a3cb-3877b785a3fe (old id 3975517)
date added to LUP
2013-09-02 07:36:00
date last changed
2019-05-21 01:35:24
@article{ce7373c6-3c8c-4d99-a3cb-3877b785a3fe,
  abstract     = {In patients with a small heart, defined as an end-systolic volume (ESV) of a parts per thousand currency sign20 mL calculated using the Quantitative Gated SPECT (QGS) program, underestimation of ESV and overestimation of ejection fraction (EF) using gated myocardial perfusion imaging are considered errors caused by inappropriate delineation of the left ventricle (LV). The aim of this study was to develop a new method for delineation of the LV and to evaluate it in studies using a digital phantom, normal subjects and patients. The active shape-based method for LV delineation, EXINI heart (ExH), was adjusted to more accurately process small hearts. In small hearts, due to the partial volume effect and the short distance to the opposite ventricular wall, the endocardial and the epicardial surfaces are shifted in the epicardial direction depending on the midventricular volume. The adjusted method was evaluated using digital XCAT phantoms with Monte Carlo simulation (8 virtual patients), a Japanese multicentre normal database (69 patients) and consecutive Japanese patients (116 patients). The LV volumes, EF and diastolic parameters derived from ExH and QGS were compared. The digital phantom studies showed a mean ESV of 87 % +/- 9 % of the true volume calculated using ExH and 22 % +/- 18 % calculated using QGS. In the normal database, QGS gave higher EFs in women than in men (71.4 +/- 6.0 % vs. 67.2 +/- 6.0 %, p = 0.0058), but ExH gave comparable EFs (70.7 +/- 4.9 % and 71.4 +/- 5 % in men and women, respectively, p = ns). QGS gave higher EFs in subjects with a small heart than in those with a normal-sized heart (74.5 +/- 5.1 % vs. 66.1 +/- 4.9 %), but ExH gave comparable values (70.0 +/- 5.9 % vs. 71.6 +/- 4.2 %, respectively, p = ns). In consecutive patients, the average EFs with QGS in patients with ESV > 20 mL, 11-20 mL and a parts per thousand currency sign10 mL were 57.9 %, 71.9 % and 83.2 %, but with ExH the differences among these groups were smaller (65.2 %, 67.8 % and 71.5 %, respectively). The volume-dependent edge correction algorithm was able to effectively reduce the effects on ESV and EF of a small heart. The uniform normal values might be applicable to both men and women and to both small and normal-sized hearts.},
  author       = {Nakajima, Kenichi and Okuda, Koichi and Nystrom, Karin and Richter, Jens and Minarik, David and Wakabayashi, Hiroshi and Matsuo, Shinro and Kinuya, Seigo and Edenbrandt, Lars},
  issn         = {1619-7070},
  keyword      = {Myocardial perfusion imaging,Small heart,Left ventricular function,Software algorithm,Normal values},
  language     = {eng},
  number       = {8},
  pages        = {1163--1170},
  publisher    = {Springer},
  series       = {European Journal of Nuclear Medicine and Molecular Imaging},
  title        = {Improved quantification of small hearts for gated myocardial perfusion imaging},
  url          = {http://dx.doi.org/10.1007/s00259-013-2431-x},
  volume       = {40},
  year         = {2013},
}