TY - JOUR
T1 - Qualitative evaluation of MRI features of lipoma and atypical lipomatous tumor
T2 - results from a multicenter study
AU - Nardo, Lorenzo
AU - Abdelhafez, Yasser G.
AU - Acquafredda, Francesco
AU - Schirò, Silvia
AU - Wong, Andrew L.
AU - Sarohia, Dani
AU - Maroldi, Roberto
AU - Darrow, Morgan A.
AU - Guindani, Michele
AU - Lee, Sonia
AU - Zhang, Michelle
AU - Moawad, Ahmed W.
AU - Elsayes, Khaled M.
AU - Badawi, Ramsey D.
AU - Link, Thomas M.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - Objectives: The objectives of the study are (1) to distinguish lipoma (L) from atypical lipomatous tumor (ALT) using MRI qualitative features, (2) to assess the value of contrast enhancement, and (3) to evaluate the reproducibility and confidence level of radiological readings. Materials and methods: Patients with pathologically proven L or ALT, who underwent MRI within 3 months from surgical excision were included in this retrospective multicenter international study. Two radiologists independently reviewed MRI centrally. Impressions were recorded as L or ALT. A third radiologist was consulted for discordant readings. The two radiologists re-read all non-contrast sequences; impression was recorded; then post-contrast images were reviewed and any changes were recorded. Results: A total of 246 patients (135 females; median age, 59 years) were included. ALT was histopathologically confirmed in 70/246 patients. In multivariable analysis, in addition to the lesion size, deep location, proximal lower limb lesions, demonstrating incomplete fat suppression, or increased architectural complexity were the independent predictive features of ALT; but not the contrast enhancement. Post-contrast MRI changed the impression in a total of 5 studies (3 for R1 and 4 for R2; 2 studies are common); all of them were incorrectly changed from Ls to ALTs. Overall, inter-reader kappa agreement was 0.42 (95% CI 0.39–0.56). Discordance between the two readers was statistically significant for both pathologically proven L (p < 0.001) and ALT (p = 0.003). Conclusion: Most qualitative MR imaging features can help distinguish ALTs from BLs. However, contrast enhancement may be limited and occasionally misleading. Substantial discordance on MRI readings exists between radiologists with a relatively high false positive and negative rates.
AB - Objectives: The objectives of the study are (1) to distinguish lipoma (L) from atypical lipomatous tumor (ALT) using MRI qualitative features, (2) to assess the value of contrast enhancement, and (3) to evaluate the reproducibility and confidence level of radiological readings. Materials and methods: Patients with pathologically proven L or ALT, who underwent MRI within 3 months from surgical excision were included in this retrospective multicenter international study. Two radiologists independently reviewed MRI centrally. Impressions were recorded as L or ALT. A third radiologist was consulted for discordant readings. The two radiologists re-read all non-contrast sequences; impression was recorded; then post-contrast images were reviewed and any changes were recorded. Results: A total of 246 patients (135 females; median age, 59 years) were included. ALT was histopathologically confirmed in 70/246 patients. In multivariable analysis, in addition to the lesion size, deep location, proximal lower limb lesions, demonstrating incomplete fat suppression, or increased architectural complexity were the independent predictive features of ALT; but not the contrast enhancement. Post-contrast MRI changed the impression in a total of 5 studies (3 for R1 and 4 for R2; 2 studies are common); all of them were incorrectly changed from Ls to ALTs. Overall, inter-reader kappa agreement was 0.42 (95% CI 0.39–0.56). Discordance between the two readers was statistically significant for both pathologically proven L (p < 0.001) and ALT (p = 0.003). Conclusion: Most qualitative MR imaging features can help distinguish ALTs from BLs. However, contrast enhancement may be limited and occasionally misleading. Substantial discordance on MRI readings exists between radiologists with a relatively high false positive and negative rates.
KW - Adipose tissue neoplasms
KW - Atypical lipomatous tumor
KW - Lipoma
KW - MRI
KW - Well differentiated liposarcoma
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U2 - 10.1007/s00256-020-03372-5
DO - 10.1007/s00256-020-03372-5
M3 - Article
C2 - 31965239
AN - SCOPUS:85078110618
JO - Skeletal Radiology
JF - Skeletal Radiology
SN - 0364-2348
ER -