title: Proton, diffusion-weighted imaging, and sodium (23Na) MRI of uterine leiomyomata after MR-guided high-intensity focused ultrasound: a preliminary study.
abstract: OBJECTIVE
  To determine the feasibility of using combined proton (1H), diffusion-weighted imaging (DWI), and sodium (23Na) magnetic resonance imaging (MRI) to monitor the treatment of uterine leiomyomata (fibroids).
  
  
  METHODS
  Eight patients with uterine leiomyomata were enrolled and treated using MRI-guided high-intensity frequency ultrasound surgery (MRg-HIFUS). MRI scans collected at baseline and posttreatment consisted of T2-, T1-, and 1H DWI, as well as posttreatment 23Na MRI. The 23Na and 1H MRi were coregistered using a replacement phantom method. Regions of interest in treated and untreated uterine leiomyoma tissue were drawn on 1H MRI and DWI, wherein the tissue apparent diffusion coefficient of water (ADC) and absolute sodium concentrations were measured.
  
  
  RESULTS
  Regions of treated uterine tissue were clearly identified on both DWI and 23Na images. The sodium concentrations in normal myometrium tissue were 35.8+/-2.1 mmol (mM), in the fundus; 43.4+/-3.8 mM, and in the bladder; 65.3+/-0.8 mM with ADC in normal myometrium of 2.2+/-0.3x10(-3) mm2/sec. Sodium concentration in untreated leiomyomata were 28+/-5 mM, and were significantly elevated (41.6+/-7.6 mM, P<0.05) after treatment. Apparent diffusion coefficient values in the treated leiomyomata (1.30+/-0.38x10(-3) mm2/sec) were decreased compared to areas of untreated leiomyomata (1.75+/--4048micro-4050micro36x10(-3) mm2/sec; P=0.04).
  
  
  CONCLUSIONS
  Multiparametric imaging permits identification of uterine leiomyomata, revealing altered 23Na MRI and DWI levels following noninvasive treatment that provides a mechanism to explore the molecular and metabolic pathways after treatment.
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205, USA. mikej@mri.jhu.edu
authors.forename: Michael A
authors.initials: MA
authors.lastname: Jacobs
authors.forename: Ronald
authors.initials: R
authors.lastname: Ouwerkerk
authors.forename: Ihab
authors.initials: I
authors.lastname: Kamel
authors.forename: Paul A
authors.initials: PA
authors.lastname: Bottomley
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: Hyun S
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007889:Leiomyoma / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D008875:Middle Aged; D019047:Phantoms, Imaging; D011446:Prospective Studies; D011522:Protons; D012975:Sodium Isotopes; D016896:Treatment Outcome; D014464:Ultrasonic Therapy; D014594:Uterine Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*
chemical_list: D015415:Biomarkers; D011522:Protons; D012975:Sodium Isotopes