Evaluation of Splenic Involvement in Lymphomas Using Extracellular Volume Fraction Computed Tomography.

Objective: To evaluate whether the extracellular volume (ECV) fraction can be used to identify splenic involvement in lymphoma patients and whether it can be used to improve the diagnostic performance of conventional computed tomography (CT) in the diagnosis of splenic diffuse involvement.

Methods: Consecutive patients with newly diagnosed lymphoma who underwent abdomen contrast-enhanced CT and 18F-fluorodeoxyglucose positron emission tomography/CT for diagnosis or staging were retrospectively enrolled. Patients were divided into the splenic involvement (diffuse or focal) and noninvolvement groups. The ECV fraction was obtained in all patients. In the splenic diffuse involvement and noninvolvement groups, spleen vertical length (SVL) >13 cm and obliteration of normal heterogeneous enhancement of the spleen in arterial phase were recorded. Receiver operating characteristic curve was used to analyze the diagnostic performance, and area under the curve (AUC) comparison was performed using the Delong test.

Results: A total of 135 patients were included, 56 patients with splenic involvement (36 diffuse and 20 focal) and 79 patients with noninvolvement. Splenic involvement can be identified via the ECV fraction (AUC = 0.839). In distinguishing splenic diffuse involvement, the AUC of the ECV fraction was superior to the SVL >13 cm (0.788 vs 0.627, P = 0.007) and obliteration of normal heterogeneous enhancement of the spleen (0.788 vs 0.596, P = 0.001). The combination of ECV fraction and SVL >13 cm demonstrated superior diagnostic performance, with an AUC of 0.830, surpassing all other parameters.

Conclusion: The ECV fraction can be used to identify splenic involvement. The ECV fraction combined with SVL >13 cm is recommended for the prediction of splenic diffuse involvement.