title: Magnetic resonance imaging of lipoma and atypical lipomatous tumour/well-differentiated liposarcoma: observer performance using T1-weighted and fluid-sensitive MRI.
abstract: The aim of this study was to evaluate observer performance using T1-weighted spin-echo and fluid-sensitive MRI sequences in distinguishing between lipoma and atypical lipomatous tumour/well-differentiated liposarcoma (ALT/WDL). Magnetic resonance images of 51 patients with benign lipoma and ALT/WDL of the musculoskeletal system were reviewed. There were 33 benign lipomas and 18 ALT/WDL. The character of septa and nodularity of the fatty tumours on T1-weighted spin-echo sequences and the presence of high signal on fluid-sensitive sequences were assessed. Two independent observers took part. Observer agreement was measured. The two observers achieved sensitivities of 100 and 94% for T1-weighted images and 100% each for fluid-sensitive sequences. Specificities were 76 and 64% for T1-weighted and 70 and 73% for fluid-sensitive images. Observer agreement was very good (kappa 0.87 for T1-weighted and 0.88 for fluid-sensitive images). In distinguishing lipoma from ALT/WDL, observer performance was comparable using T1-weighted and fluid-sensitive MR sequences. High sensitivity and moderately high specificity were attained.
authors: Department of Radiology, Auckland City Hospital and University of Auckland, Auskland, New Zealand. adoyle@adhb.govt.nz
authors: A J
authors: AJ
authors: Doyle
authors: A K
authors: AK
authors: Pang
authors: M V
authors: MV
authors: Miller
authors: J G
authors: JG
authors: French
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008067:Lipoma / Q000175:diagnosis*; D008080:Liposarcoma / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity; D012983:Soft Tissue Neoplasms / Q000175:diagnosis*