title: Clinical application of diffusion-weighted imaging for preoperative differentiation between uterine leiomyoma and leiomyosarcoma.
abstract: OBJECTIVE
  This study investigated the clinical usefulness of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) value for preoperative differentiation between uterine leiomyoma and leiomyosarcoma.
  
  
  METHODS
  This study included 10 lesions from 5 patients with pelvic leiomyosarcoma and 83 leiomyoma nodules from 76 patients, as identified by postoperative pathological examination (1 autopsy). All magnetic resonance examinations were performed with a 1.5-T superconductive magnetic resonance unit.
  
  
  RESULTS
  The leiomyosarcoma lesions were readily apparent via DWI, presenting as an intermediate- to high-intensity area in the uterine wall. All low-intensity areas presented as leiomyoma nodules. The mean ADC value for the 10 leiomyosarcoma lesions was 0.791 ± 0.145 (×10(-3) mm(2)/s), significantly lower than that of the leiomyoma nodules that presented with intermediate-intensity areas, 1.472 ± 0.285 (×10(-3) mm(2)/s) (n = 41) (P < .001), and high-intensity areas (1.100 ± 0.343) (n = 9) (P = .03). Additionally, in this study, the highest ADC value for a leiomyosarcoma was 1.095, with an intermediate DWI intensity. Based on these results, we classified the patients into 2 groups: low-risk group (barely any leiomyosarcoma risk) and high-risk group. Analyses comparing the 2 groups yielded the following: sensitivity, 100%; specificity, 94.0%; positive predictive value, 66.7%; negative predictive value, 100%; and accuracy, 94.6%.
  
  
  CONCLUSIONS
  We suggest that this modality using a combination of signal intensity on DWI and ADC value is very effective, simple, and easy to apply clinically for differential diagnosis of leiomyosarcoma and myoma.
authors.affiliation: Department of Obstetrics and Gynecology, Kyoaikai Hospital, Hakodate, Japan. Electronic address: tomotakusyu@yahoo.co.jp.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Radiology, Steel Memorial Muroran Hospital, Muroran, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Yuasa
authors.affiliation: Department of Pathology, Steel Memorial Muroran Hospital, Muroran, Japan.
authors.forename: Miri
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Department of Obstetrics and Gynecology, Kyoaikai Hospital, Hakodate, Japan.
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Fukushima
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007889:Leiomyoma / Q000473:pathology* / Q000601:surgery; D007890:Leiomyosarcoma / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014594:Uterine Neoplasms / Q000473:pathology* / Q000601:surgery
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: apparent diffusion coefficient value; diffusion-weighted imaging; leiomyosarcoma; preoperative diagnosis; uterus