title: Intra-abdominal fibromatosis: differentiation from gastrointestinal stromal tumour based on biphasic contrast-enhanced CT findings.
abstract: OBJECTIVE
  To identify the computed tomography (CT) criteria that differentiate intra-abdominal fibromatosis (IAF) from gastrointestinal stromal tumour (GIST).
  
  
  METHODS
  CT images of 34 pathologically proven cases of IAF (n = 15) and GIST (n = 19) were retrospectively reviewed. Location, contour, border, enhancement pattern, presence of necrosis, vessels, and air within the lesion were analysed. Long diameter (LD), short diameter (SD), LD/SD ratio, degree of enhancement, and lesion/aorta (L/A) CT attenuation ratio were measured and calculated. Significant CT criteria were identified using Fisher's exact test, grouped t-test, and receiver operating characteristic (ROC) curve. Sensitivity and specificity values were calculated when single or multiple CT criteria were used.
  
  
  RESULTS
  Extra-gastrointestinal location, ovoid or irregular contour, homogeneous enhancement, absence of intra-lesional necrosis, lower degree of enhancement, and L/A CT attenuation ratio differentiated IAF from GIST (p < 0.05). When any three of these eight criteria were combined, the sensitivity and specificity for diagnosing IAF were 100% (15 of 15) and 89.5% (17 of 19), respectively.
  
  
  CONCLUSIONS
  The following eight CT criteria are helpful to differentiate IAF from GIST: extra-gastrointestinal location, ovoid or irregular contour, homogeneous enhancement, absence of intra-lesional necrosis, a degree of enhancement of less than 40.5 HU in the arterial phase versus 46.5 HU in the portal venous phase, and an L/A CT attenuation ratio <0.315 in the arterial phase versus 0.525 in the portal phase.
authors: Department of Radiology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, China.
authors: H
authors: H
authors: Zhu
authors: H
authors: H
authors: Chen
authors: S
authors: S
authors: Zhang
authors: W
authors: W
authors: Peng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D018221:Fibromatosis, Abdominal / Q000000981:diagnostic imaging*; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging*; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007472:Iohexol; D007479:Iopamidol; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D011856:Radiographic Image Enhancement / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D007472:Iohexol; D007479:Iopamidol