title: Magnetic resonance imaging relaxation times of female reproductive organs.
abstract: BACKGROUND
  Relaxation time of female reproductive organs affects the tissue contrast of magnetic resonance image (MRI), and is used for quantitative analysis.
  
  
  OBJECTIVE
  To evaluate the relaxation times of normal female reproductive organs in the luteal phase of the menstrual cycle.
  
  
  METHODS
  On a 1.5-T MRI, relaxation times were measured in pelvic tissues (endometrium, junctional zone, myometrium, follicle, and stroma) of 32 female healthy volunteers (33.5 ± 6.8 years). The Look-Locker sequence was used to measure T1 relaxation times. Furthermore, a multiple spin-echo method with 32 different echo times was used to measure T2 relaxation times. The images were obtained in the luteal phase of each volunteer's menstrual cycle.
  
  
  RESULTS
  The measured relaxation times (means ± standard deviations) were as follows: endometrium (T1, 1703 ± 147 ms; T2, 214 ± 35 ms), junctional zone (T1, 1168 ± 63 ms; T2, 72 ± 12 ms), myometrium (T1, 1314 ± 103 ms; T2, 138 ± 20 ms), follicle (T1, 2267 ± 49 ms; T2, 603 ± 68 ms), and stroma (T1, 1481 ± 129 ms; T2, 126 ± 29 ms).
  
  
  CONCLUSIONS
  Reliable MRI measurements of T1 and T2 relaxation times of normal female reproductive organs in the luteal phase of the menstrual cycle are useful as references to recognize the normal value.
authors.affiliation: Department of Radiology, Osaka Red Cross Hospital, Osaka, Japan Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan pcblue2@yahoo.co.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takatsu
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Okada
authors.affiliation: Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
authors.affiliation: Department of Diagnostic Radiology, Kurashiki Central Hospital, Okayama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
mesh_terms: D000328:Adult; D003198:Computer Simulation; D004553:Electric Conductivity; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods* / Q000592:standards; D007564:Japan; D008183:Luteal Phase / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D008954:Models, Biological; D010053:Ovary / Q000033:anatomy & histology / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014599:Uterus / Q000033:anatomy & histology / Q000502:physiology*
keywords: Reproductive organs; luteal phase; magnetic resonance imaging; pelvis; relaxation time