title: Sensitivity of magnetic resonance imaging in the detection of colorectal liver metastases.
abstract: BACKGROUND
  The aim of this study was to evaluate the sensitivity of magnetic resonance imaging (MRI) in the detection of colorectal liver metastases.
  
  
  METHODS
  Pre-operative MRI scanning of the liver was performed by a single radiologist and the size and number of definite liver metastases were recorded. Patients then underwent hepatectomy with routine intra-operative ultrasonography (IOUS) and resected specimens were sent for histopathology. Pathology findings were compared with those of MRI scans to determine the sensitivity of this imaging modality. Exclusions were patients undergoing hepatic resection more than 4 weeks after the MRI scan, those undergoing chemotherapy at the time of the scan, and those with conglomerate unilobar metastases.
  
  
  RESULTS
  Complete data were available for 84 patients. There was total agreement between MRI, IOUS and histology in 79 patients (101 metastases). MRI missed 5 metastases in 5 patients that were found on IOUS (or palpation of superficial lesions) and subsequently confirmed by histological examination. These measured 5 mm or less (4 patients) and 7 mm (one patient). The sensitivity of MRI in the detection of colorectal liver metastases was thus 94% for all lesions and 100% for lesions 1 cm or larger in diameter.
  
  
  CONCLUSIONS
  MRI of the liver is a non-invasive technique with an extremely high degree of sensitivity in the detection of colorectal liver metastases and should be considered as the 'gold standard' in the pre-operative imaging of these patients.
authors.affiliation: Department of Surgery, Royal Hallamshire Hospital, Sheffield, UK.
authors.forename: S
authors.initials: S
authors.lastname: Blyth
authors.forename: A
authors.initials: A
authors.lastname: Blakeborough
authors.forename: M
authors.initials: M
authors.lastname: Peterson
authors.forename: I C
authors.initials: IC
authors.lastname: Cameron
authors.forename: A W
authors.initials: AW
authors.lastname: Majeed
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms; D005260:Female; D006498:Hepatectomy / Q000379:methods; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000556:secondary; D008279:Magnetic Resonance Imaging / Q000592:standards*; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D012680:Sensitivity and Specificity; D014463:Ultrasonography