title: MRI of colorectal cancer liver metastases: comparison of orally administered manganese with intravenously administered gadobenate dimeglumine.
abstract: OBJECTIVE
  To compare the sensitivity of MRI to detect colorectal cancer liver metastases (CRLM) after ingestion of manganese-based contrast agent (CMC-001) with that of a comprehensive intravenous gadobenate dimeglumine protocol, and to assess the safety and acceptability of oral manganese.
  
  
  METHODS
  20 patients suspected of having 1-6 CRLM were included prospectively in this randomised cross-over study. Liver MRI was performed with a one-week interval at 1.5 T and included T1-w VIBE and T2-HASTE, before and after administration of 1.6 g CMC-001 or 0.1 mmol/kg gadobenate dimeglumine. The metastasis-to-liver signal intensity (SI) ratio was calculated. Standard of reference was histopathology after surgery, or combination of other imaging studies and/or follow up. Adverse events (AE) and clinicolaboratory tests were monitored.
  
  
  RESULTS
  Of 44 metastases, 41 were detected after CMC-001 (93%) and 42 after gadobenate dimeglumine (95%). Fifteen false-positive lesions were found after CMC-001 and 2 after gadobenate dimeglumine. The metastasis-to-liver SI ratio was significantly higher after CMC-001 than after gadobenate dimeglumine (0.51 and 0.21 respectively, P < 0.0001). More AE occurred after manganese compared to gadobenate dimeglumine.
  
  
  CONCLUSIONS
  CMC-001 is as sensitive as an extensive intravenous gadobenate dimeglumine protocol in detecting CRLM. It was relatively well tolerated but had higher rates of gastrointestinal AE.
  
  
  CONCLUSIONS
  • Liver MRI after ingestion of manganese is highly sensitive for detecting metastases • High false-positive rate necessitates further evaluation, in some cases • The MR examination time is short • Oral ingestion of manganese seems safe and relatively well tolerated by patients • Manganese compounds may be useful for liver metastasis surveillance after colorectal cancer.
authors.affiliation: Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm, Sweden. torkel.brismar@karolinska.se
authors.forename: Torkel B
authors.initials: TB
authors.lastname: Brismar
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kartalis
authors.forename: Christian
authors.initials: C
authors.lastname: Kylander
authors.forename: Nils
authors.initials: N
authors.lastname: Albiin
mesh_terms: D000284:Administration, Oral; D000368:Aged; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008345:Manganese / Q000008:administration & dosage*; D008536:Meglumine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage*; D010743:Phospholipids / Q000008:administration & dosage; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013459:Sulfur Hexafluoride / Q000008:administration & dosage; D014463:Ultrasonography
chemical_list: C504368:CMC-001; D003287:Contrast Media; D009942:Organometallic Compounds; D010743:Phospholipids; C420843:contrast agent BR1; C064572:gadobenic acid; D008345:Manganese; D008536:Meglumine; D013459:Sulfur Hexafluoride