title: Complex cystic renal masses: comparison of cyst complexity and Bosniak classification between 1.5 T and 3 T MRI.
abstract: OBJECTIVE
  To retrospectively compare perceived complexity and Bosniak cyst classification of cystic renal lesions between 1.5 T and 3 T MRI.
  
  
  METHODS
  33 cystic renal lesions in 26 patients that underwent contrast-enhanced MRI at both 1.5 T and 3 T within a 12 month span were included. Two radiologists (R1, R2) independently assessed lesions, unaware of field strength, in terms of number of septations, septal thickening, mural thickening, presence of mural nodule, and Bosniak cyst category. Scores were compared between field strengths for each lesion.
  
  
  RESULTS
  R1 observed increases in septal number, septal thickening, mural thickening, and presence of mural nodule at 3T in 8, 7, 4, and 2 lesions, and at 1.5 T in 3, 3, 2, and 0 lesions, respectively; R2 observed increases in septal number, septal thickening, mural thickening, and presence of mural nodule at 3T in 3, 4, 3, and 0 lesions, and at 1.5 T in 2, 0, 0, and 0 lesions, respectively. R1 provided higher Bosniak category at 3T in 9 cases and at 1.5 T in 4 cases; R2 provided higher Bosniak category at 3T in 4 cases and at 1.5 T in 0 cases. Higher scores at 3T than 1.5 T were associated with differences in advised clinical management in 7/9 cases for R1 and 4/4 cases for R2.
  
  
  CONCLUSIONS
  There was an overall tendency for both readers to upgrade cyst complexity and Bosniak cyst category at 3T than 1.5 T, which impacted advised management. Thus, we suggest that serial MRI evaluation of cystic renal lesions be performed at constant field strength.
authors.affiliation: Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016, United States. Electronic address: Andrew.Rosenkrantz@nyumc.org.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Rosenkrantz
authors.affiliation: Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016, United States. Electronic address: Natasha.Wehrli@nyumc.org.
authors.forename: Natasha E
authors.initials: NE
authors.lastname: Wehrli
authors.affiliation: Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016, United States. Electronic address: thaiscaldara@gmail.com.
authors.forename: Thais C
authors.initials: TC
authors.lastname: Mussi
authors.affiliation: Department of Urology, Division of Urologic Oncology, NYU Langone Medical Center, 150 East 32nd Street, Suite 200, New York, NY 10016, United States. Electronic address: Samir.Taneja@nyumc.org.
authors.forename: Samir S
authors.initials: SS
authors.lastname: Taneja
authors.affiliation: Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016, United States. Electronic address: Michael.Triolo@nyumc.org.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Triolo
mesh_terms: D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D052177:Kidney Diseases, Cystic / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016037:Single-Blind Method
keywords: 3.0T; Bosniak classification; MRI; Renal cyst