Application of Cardiac Gating to Improve the Reproducibility of Intravoxel Incoherent Motion Measurements in the Head and Neck.
OBJECTIVE
To prospectively evaluate whether cardiac gating can improve the reproducibility of intravoxel incoherent motion (IVIM) parameters in the head and neck, we performed IVIM diffusion-weighted imaging (DWI) using 4 b values (4b), 4 b values with cardiac gating (4b gating) and 17 b values (17b).


METHODS
We performed IVIM DWI twice per person on nine healthy volunteers using 4b, 4b gating and 17b and five patients with head and neck masses using 4b gating and 17b. The ADC, perfusion fraction (f), diffusion coefficient (D) and perfusion-related diffusion coefficient (D*) were calculated in the brain, masticator muscle, parotid gland, submandibular gland, tonsil and masses. Intraclass coefficient (ICC), Bland-Altman analysis (BAA) and coefficient of variation (CV) were used to assess short-term test-retest reproducibility. Kruskal-Wallis test and Mann-Whitney test were used to investigate whether 4b, 4b gating or 17b had significant influences on the parameters.


RESULTS
For normal tissues and masses, ICC was excellent for all maps except the D* map. All parameters showed the lowest CV in the 4b gating. BAA also revealed the narrowest 95% limits of agreement using 4b gating for all parameters. In the subgroup analysis, almost all parameters in brain, muscle, parotid gland and submandibular gland showed the best reproducibility using 4b gating. In the muscle, parotid gland and submandibular gland, the values of ADC, f and D were not significantly different between among the three methods.


CONCLUSIONS
4b gating was more reproducible with respect to measurements of IVIM parameters in comparison with 4b or 17b.
Department of Radiology, Seoul National University Hospital.|Department of Radiology, Seoul National University College of Medicine.
Koung Mi
KM
Kang
Department of Radiology, Seoul National University Hospital.|School of Chemical and Biological Engineering, Seoul National University.
Seung Hong
SH
Choi
General Electronics (GE) Healthcare Korea.
Dong Eun
DE
Kim
Department of Radiology, Seoul National University Hospital.|Department of Radiology, Seoul National University College of Medicine.
Tae Jin
TJ
Yun
Department of Radiology, Seoul National University Hospital.|Department of Radiology, Seoul National University College of Medicine.
Ji-Hoon
JH
Kim
Department of Radiology, Seoul National University Hospital.|Center for Nanoparticle Research, Institute for Basic Science (IBS).
Chul-Ho
CH
Sohn
Department of Radiology, Seoul National University Boramae Hospital.
Sun-Won
SW
Park
D000328:Adult; D057791:Cardiac Imaging Techniques / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging*; D006338:Heart Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009038:Motion; D015203:Reproducibility of Results
cardiac gating; diffusion weighted imaging; head and neck; intravoxel incoherent motion; reproducibility