title: Evolution of multi-parametric MRI quantitative parameters following transrectal ultrasound-guided biopsy of the prostate.
abstract: BACKGROUND
  To determine the evolution of prostatic multi-parametric magnetic resonance imaging (mp-MRI) signal following transrectal ultrasound (TRUS)-guided biopsy.
  
  
  METHODS
  Local ethical permission and informed written consent was obtained from all the participants (n=14, aged 43-69, mean 64 years). Patients with a clinical suspicion of prostate cancer (PSA range 2.2-11.7, mean 6.2) and a negative (PIRAD 1-2/5) pre-biopsy mp-MRI (pre-contrast T1, T2, diffusion-weighted and dynamic-contrast-enhanced MRI) who underwent 10-core TRUS-guided biopsy were recruited for additional mp-MRI examinations performed at 1, 2 and 6 months post biopsy. We quantified mp-MRI peripheral zone (PZ) and transition zone (TZ) normalized T2 signal intensity (nT2-SI); T1 relaxation time (T10); diffusion-weighted MRI, apparent diffusion coefficient (ADC); dynamic contrast-enhanced MRI, maximum enhancement (ME); slope of enhancement (SoE) and area-under-the-contrast-enhancement-curve at 120 s (AUC120). Significant changes in mp-MRI parameters were identified by analysis of variance with Dunnett's post testing.
  
  
  RESULTS
  Diffuse signal changes were observed post-biopsy throughout the PZ. No significant signal change occurred following biopsy within the TZ. Left and right PZ mean nT2-SI (left PZ: 5.73, 5.16, 4.90 and 5.12; right PZ: 5.80, 5.10, 4.84 and 5.05 at pre-biopsy, 1, 2 and 6 months post biopsy, respectively) and mean T10 (left PZ: 1.02, 0.67, 0.78, 0.85; right PZ: 1.29, 0.64, 0.78, 0.87 at pre-biopsy, 1, 2 and 6 months post biopsy, respectively) were reduced significantly (P<0.05) from pre-biopsy values for up to 6 months post biopsy. Significant changes (P<0.05) of PZ-ME and AUC120 were observed at 1 month but resolved by 2 months post biopsy. PZ ADC did not change significantly following biopsy (P=0.23-1.0). There was no significant change of any TZ mp-MRI parameter at any time point following biopsy (P=0.1-1.0).
  
  
  CONCLUSIONS
  Significant PZ (but not TZ) T2 signal changes persist up to 6 months post biopsy, whereas PZ and TZ ADC is not significantly altered as early as 1 month post biopsy. Caution must be exercised when interpreting T1- and T2-weighted imaging early post biopsy, whereas ADC images are more likely to maintain clinical efficacy.
authors.affiliation: Centre for Medical Imaging, University College London, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Latifoltojar
authors.affiliation: Centre for Medical Imaging, University College London, London, UK.
authors.forename: N
authors.initials: N
authors.lastname: Dikaios
authors.affiliation: Department of Urology, University College London Hospital, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Ridout
authors.affiliation: Department of Urology, University College London Hospital, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Moore
authors.affiliation: Department of Radiology, University College London Hospital, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Illing
authors.affiliation: Department of Radiology, University College London Hospital, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Kirkham
authors.affiliation: Centre for Medical Imaging, University College London, London, UK.|Department of Radiology, University College London Hospital, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Taylor
authors.affiliation: Centre for Medical Imaging, University College London, London, UK.|Department of Radiology, University College London Hospital, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Halligan
authors.affiliation: Centre for Medical Imaging, University College London, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Atkinson
authors.affiliation: Department of Radiology, University College London Hospital, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Allen
authors.affiliation: Department of Urology, University College London Hospital, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Emberton
authors.affiliation: Centre for Medical Imaging, University College London, London, UK.|Department of Radiology, University College London Hospital, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Punwani
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000379:methods; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology
chemical_list: D003287:Contrast Media