title: Texture analysis of preoperative CT images for prediction of postoperative hepatic insufficiency: a preliminary study.
abstract: BACKGROUND
  Texture analysis is a promising method of analyzing imaging data to potentially enhance diagnostic capability. This approach involves automated measurement of pixel intensity variation that may offer further insight into disease progression than do standard imaging techniques alone. We postulated that postoperative liver insufficiency, a major source of morbidity and mortality, correlates with preoperative heterogeneous parenchymal enhancement that can be quantified with texture analysis of cross-sectional imaging.
  
  
  METHODS
  A retrospective case-matched study (waiver of informed consent and HIPAA authorization, approved by the Institutional Review Board) was performed comparing patients who underwent major hepatic resection and developed liver insufficiency (n = 12) with a matched group of patients with no postoperative liver insufficiency (n = 24) by procedure, remnant volume, and year of procedure. Texture analysis (with gray-level co-occurrence matrices) was used to quantify the heterogeneity of liver parenchyma on preoperative CT scans. Statistical significance was evaluated using Wilcoxon's signed rank and Pearson's chi-square tests.
  
  
  RESULTS
  No statistically significant differences were found between study groups for preoperative patient demographics and clinical characteristics, with the exception of sex (p < 0.05). Two texture features differed significantly between the groups: correlation (linear dependency of gray levels on neighboring pixels) and entropy (randomness of brightness variation) (p < 0.05).
  
  
  CONCLUSIONS
  In this preliminary study, the texture of liver parenchyma on preoperative CT was significantly more varied, less symmetric, and less homogeneous in patients with postoperative liver insufficiency. Therefore, texture analysis has the potential to provide an additional means of preoperative risk stratification.
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN.
authors.forename: Amber L
authors.initials: AL
authors.lastname: Simpson
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Lauryn B
authors.initials: LB
authors.lastname: Adams
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Allen
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Michael I
authors.initials: MI
authors.lastname: D'Angelica
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Ronald P
authors.initials: RP
authors.lastname: DeMatteo
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Yuman
authors.initials: Y
authors.lastname: Fong
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: T Peter
authors.initials: TP
authors.lastname: Kingham
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Universe
authors.initials: U
authors.lastname: Leung
authors.affiliation: Department of Biomedical Engineering, Vanderbilt University, Nashville, TN.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Miga
authors.affiliation: Pathfinder Technologies Inc, Nashville, TN.
authors.forename: E Patricia
authors.initials: EP
authors.lastname: Parada
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY. Electronic address: jarnagiw@mskcc.org.
authors.forename: William R
authors.initials: WR
authors.lastname: Jarnagin
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Richard K G
authors.initials: RK
authors.lastname: Do
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003661:Decision Support Techniques; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy; D048550:Hepatic Insufficiency / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D063868:Patient Outcome Assessment; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology; D011300:Preoperative Care / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*