title: Combined use of T2-weighted and diffusion-weighted 3-T MR imaging for differentiating uterine sarcomas from benign leiomyomas.
abstract: The objective of our study was to compare diffusion-weighted imaging (DWI) alone and DWI combined with T2-weighted MRI for the differentiation of uterine sarcomas from benign leiomyomas. T2-weighted imaging and DWI were performed in 103 patients with 103 myometrial tumours, including 8 uterine sarcomas and 95 benign leiomyomas on 3-T MR imaging. The signal intensity (SI) of the tumour on T2-weighted images was quantified as the tumour-myometrium contrast ratio (TCR) by using the following formula: (SI(tumour)-SI(myometrium))/SI(myometrium). The TCR or apparent diffusion coefficient (ADC) value alone and then the ADC value combined with T2-weighted imaging were evaluated for differentiation between sarcomas and leiomyomas. The mean ADC value of sarcomas was 0.86 +/- 0.11 x 10(-3) m(2)/s, which was significantly lower than that of leiomyomas 1.18 +/- 0.24 x 10(-3) m(2)/s; however, there was a substantial overlap. The mean TCR of sarcomas was 0.66 +/- 0.71, which was significantly higher than that of the leiomyomas, -0.37 +/- 0.34; however, again, there was a considerable overlap. When ADC was less than 1.05 x 10(-3) mm(2)/s and TCR was greater than 0 this condition was considered to confirm a sarcoma; a combination of ADC and TCR achieved a significant improvement without any overlap between sarcomas and leiomyomas (sensitivity 100%, specificity 100%). Our preliminary results indicate that combined DWI and T2-weighted MR imaging is better than DWI alone in the differentiation of uterine sarcomas from benign leiomyomas.
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University 1-1-1, Honjo, Kumamoto 860-8556, Japan. namimottoo@yahoo.co.jp
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Namimoto
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakaura
authors.forename: Yumi
authors.initials: Y
authors.lastname: Yanaga
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Saito
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Katabuchi
mesh_terms: D000328:Adult; D000368:Aged; D003952:Diagnostic Imaging / Q000379:methods; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007889:Leiomyoma / Q000175:diagnosis / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008495:Medical Oncology / Q000379:methods; D008875:Middle Aged; D015203:Reproducibility of Results; D012509:Sarcoma / Q000175:diagnosis / Q000473:pathology*; D012680:Sensitivity and Specificity; D014594:Uterine Neoplasms / Q000175:diagnosis / Q000473:pathology*