Perfusion imaging of parotid gland tumours: usefulness of arterial spin labeling for differentiating Warthin's tumours.
OBJECTIVE
To assess prospectively the efficacy of arterial spin labelling (ASL) against conventional and diffusion-weighted (DW) MR imaging for differentiating parotid gland tumours.


METHODS
We included 10 pleomorphic adenomas, 12 Warthin's tumours, and nine malignant tumours of the parotid glands. Only tumours larger than 10 mm were included in this study. All parotid gland tumours underwent T1-weighted, T2-weighted, DW, and ASL imaging. Tumour-to-parotid gland signal intensity ratios (SIRs) and apparent diffusion coefficients (ADCs) of solid components were correlated with these pathologies.


RESULTS
SIRs on T2-weighted images and ADCs were higher in pleomorphic adenomas than in Warthin's tumours (p < .01) and malignant tumours (p < .01). SIRs on ASL were higher in Warthin's tumours than in pleomorphic adenomas (p < .01) and malignant tumours (p < .05). Az value of SIRs on ASL for differentiating Warthin's tumours from the other pathologies was 0.982. The sensitivity, specificity, and accuracy of SIRs on ASL for the diagnosis of Warthin's tumours at an optimal SIR threshold of over 8.70 were 91.7%, 94.7%, and 93.5%, respectively.


CONCLUSIONS
ASL with SIR measurements could non-invasively evaluate tumour blood flow of parotid gland tumours and differentiate Warthin's tumours from pleomorphic adenomas and malignant tumours.


CONCLUSIONS
• ASL non-invasively evaluates tumour blood flow of parotid gland tumours • ASL differentiates Warthin's tumours from pleomorphic adenomas and malignant tumours • ASL cannot differentiate between pleomorphic adenomas and malignant tumours.
Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan. hkato@gifu-u.ac.jp.
Hiroki
H
Kato
Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.|High-level Imaging Diagnosis Center, Gifu University Hospital, 1-1 Yanagido, Gifu, 501-1194, Japan.
Masayuki
M
Kanematsu
Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
Haruo
H
Watanabe
High-level Imaging Diagnosis Center, Gifu University Hospital, 1-1 Yanagido, Gifu, 501-1194, Japan.
Kimihiro
K
Kajita
Department of Otolaryngology, Gifu University School of Medicine, Gifu, Japan.
Keisuke
K
Mizuta
Department of Otolaryngology, Gifu University School of Medicine, Gifu, Japan.
Mitsuhiro
M
Aoki
Philips Healthcare, 2-13-37 Kohnan, Minato-ku, Tokyo, 108-8507, Japan.
Tomoyuki
T
Okuaki
D000235:Adenolymphoma / Q000473:pathology*; D008949:Adenoma, Pleomorphic / Q000473:pathology*; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D064847:Multimodal Imaging / Q000379:methods; D010306:Parotid Gland / Q000473:pathology; D010307:Parotid Neoplasms / Q000473:pathology*; D055420:Perfusion Imaging / Q000379:methods; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013113:Spin Labels
D013113:Spin Labels
Arterial spin labelling; Diffusion-weighted imaging; Parotid gland; Salivary gland tumour; Warthin’s tumour