title: Triple-phase dynamic MRI of intratumoral vessel density and hyalinization grade in uterine leiomyomas.
abstract: OBJECTIVE
  Our purpose was to clarify the relationship between the tissue vascularity shown on triple-phase dynamic MRI and the number of intratumoral vessels and degree of hyalinization, which are two histopathologic changes in leiomyoma. SUBJECTS AND METHODS. The subjects were 10 premenopausal patients with 20 leiomyomas who had undergone surgery without preoperative gonadotropin-releasing hormone analogue treatment. Intratumoral vessel density was determined by the mean number of intratumoral vessels with at least one smooth-muscle layer in the optic fields magnified 100 times. Hyalinization grade was determined by the severity of hyalinization, histopathologically classified in three grades. The enhancement index (EI) of the leiomyoma was calculated using the formula EI(t) = [S(t) - S(0)] / S(0), where S(0) is the signal intensity on pre-enhanced T1-weighted images and S(t) is the signal intensity on each dynamic phase image (t = 20, 60, and 180 sec) [corrected]. The histopathologic parameters of intratumoral vessel density and hyalinization grade were compared with the enhancement indexes obtained from the triple-phase dynamic MRI.
  
  
  RESULTS
  We found positive correlations between intratumoral vessel density and EI(60) and between intratumoral vessel density and EI(180) (in both cases, p = 0.0028 and r = 0.69). We found significant differences among the mean enhancement indexes for each hyalinization grade at all dynamic phases (p < 0.01). The leiomyomas with lower intratumoral vessel densities tended to show greater hyalinization.
  
  
  CONCLUSIONS
  Our results showed that leiomyomas with only slight hyalinization or with abundant vessels were well enhanced, but the leiomyomas with severe hyalinization enhanced poorly.
authors.affiliation: Department of Radiology, Toride Kyodo General Hospital, 2-1-1 Hongo, Toride-shi, Ibaraki 302-0022, Japan. ken-shimada@mse.biglobe.ne.jp
authors.forename: Ken
authors.initials: K
authors.lastname: Shimada
authors.forename: Isamu
authors.initials: I
authors.lastname: Ohashi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kasahara
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Miyasaka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shibuya
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D006818:Hyalin / Q000502:physiology*; D007089:Image Enhancement; D007889:Leiomyoma / Q000098:blood supply* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014594:Uterine Neoplasms / Q000098:blood supply* / Q000473:pathology*
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA