title: Functional evaluation of cystic duct patency with Gd-EOB-DTPA MR imaging: an alternative to hepatobiliary scintigraphy for diagnosis of acute cholecystitis?
abstract: OBJECTIVE
  To determine if MR cholangiography with Gd-EOB-DTPA can be used to assess cystic duct patency and to establish normal time range for reflux of contrast material into the cystic duct/gallbladder.
  
  
  METHODS
  This retrospective study is HIPAA-compliant and IRB-approved with waiver for informed consent granted. From September 2008 to June 2009, 300 patients who underwent Gd-EOB-DTPA-enhanced MR imaging for various clinical indications, not specifically limited to evaluation for acute cholecystitis, were identified. 112 patients were excluded: prior cholecystectomy (n = 93), severe technical limitations (n = 9), or absence of appropriate clinical follow-up (n = 10). 188 total patients (82 male, 106 female, mean age 51.0 years) were included in the final dataset. Time between contrast administration and contrast reflux into the cystic duct/gallbladder on delayed phase imaging was measured.
  
  
  RESULTS
  Reflux of contrast into the gallbladder was identified in 130/188 patients (69.1%) on delayed phase imaging. Average time to gallbladder reflux was 15:24 ± 5:51 minutes (range: 6:01-41:05 min). 58/188 patients (30.9%) demonstrated no reflux of contrast into the gallbladder at time of final delayed phase images. Of 58 patients who demonstrated no reflux into cystic duct/gallbladder, 15 patients demonstrated no extrahepatic biliary excretion, limiting evaluation of cystic duct patency. A total of 173 patients demonstrated biliary excretion of contrast with 76% overall sensitivity of detection of cystic duct patency.
  
  
  CONCLUSIONS
  MR cholangiography with hepatobiliary MR contrast agents such as Gd-EOB-DTPA can demonstrate cystic duct patency with high sensitivity. MR protocols can be designed within a clinically feasible timeframe to optimize diagnosis of acute cholecystitis.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Pranay
authors.initials: P
authors.lastname: Krishnan
authors.forename: Rajan T
authors.initials: RT
authors.lastname: Gupta
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Boll
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Brady
authors.forename: Daniela B
authors.initials: DB
authors.lastname: Husarik
authors.forename: Elmar M
authors.initials: EM
authors.lastname: Merkle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D041881:Cholecystitis, Acute / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA