title: Dynamic contrast-enhanced MRI coupled with a subtraction technique is useful for treatment response evaluation of malignant melanoma hepatic metastasis.
abstract: OBJECTIVE
  To determine whether contrast-enhanced MRI including subtraction sequences can predict the treatment response of melanoma liver metastasis.
  
  
  RESULTS
  High precontrast T1 signal intensity (SI) of melanoma lesions obscured detection of enhancement after contrast injection. It was impossible to determine whether or not enhancement occurred in the majority of lesions (85.4%, n = 35/41) without including the subtraction technique. Positive enhancement was identified in 14.6% (n = 6/41) of patients without subtraction images, but increased to 68.3% (n = 28/41) by including subtraction images. Follow-up studies determined lesion progression in 34.1% (n = 14/41) of patients. Positive enhancement on the subtraction image (odds ratio = 12.1, P = 0.048) and intermediate high T2 SI (odds ratio = 8.16, P = 0.040) were significantly associated with higher risk of lesion progression.
  
  
  METHODS
  Patients who underwent MRI for melanoma liver metastases between January 2007 and February 2015 were enrolled. The study analyzed 41 liver metastases in 15 patients [11 male and four female; median age 56 years (range 21-81)] for size, lesion enhancement with and without subtraction images, and T2 SI. Follow-up imaging studies were used to determine treatment response. Data were analyzed with generalized estimating equations.
  
  
  CONCLUSIONS
  MRI including the subtraction technique is useful for determining the treatment response of melanoma liver metastases. Lesion contrast enhancement and intermediate high T2 SI increased the risk of lesion progression.
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.|Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Minsu
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.|Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Song-Ee
authors.initials: SE
authors.lastname: Baek
authors.affiliation: Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jieun
authors.initials: J
authors.lastname: Moon
authors.affiliation: Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yun Ho
authors.initials: YH
authors.lastname: Roh
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.|Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Joon Seok
authors.initials: JS
authors.lastname: Lim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.|Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Mi-Suk
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.|Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.|Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Honsoul
authors.initials: H
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D009362:Neoplasm Metastasis; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: mRECIST; magnetic resonance imaging; melanoma liver metastasis; subtraction technique; treatment response