Enhancement characteristics of lymphomatous lymph nodes of the neck

Abstract

Previous studies of computed tomography (CT) enhancement of lymphomatous lymph nodes suggest that these nodes might have lower post contrast attenuation values than normal lymph nodes. We have previously found that the contrast medium enhancement curves of lymphomatous lymph nodes of the neck had significantly lower enhancement than those of presumably normal lymph nodes. To prospectively compare CT contrast medium enhancement curves of a homogeneous population of 28 patients with lymphomatous lymph nodes of the neck with 20 controls; to compare enhancement curves before and after successful treatment and to compare nodes with Hodgkin lymphoma (HL) and nodes with non-Hodgkin lymphoma (NHL). Twenty-eight consecutive patients (12 with HL) with lymphomatous lymph nodes of the neck and 20 control patients with sarcomas and presumably normal neck nodes underwent dynamic CT examinations. Seventeen of the patients in complete remission after lymphoma treatment were also examined. The lymphomatous lymph nodes had significantly lower mean enhancement values than those of the control group (mean HU value at 90 s 77.9+/-10.5 HU and 93.4+/-15.3 HU, respectively, sensitivity 91% for values <92 HU at 90 s). Late enhancement values in the treated patients were significantly higher than those in the untreated patients. Patients with HL and patients with NHL had similar enhancement curves except that those with NHL had higher values at 7 min. No significant difference in mean percentage loss of enhancement was found between normal nodes and lymph nodes with HL before treatment, but there was a slightly significant difference between normal nodes and lymph nodes with NHL. No significant difference in percentage loss of enhancement was found between normal nodes and lymphomatous lymph nodes after treatment. Dynamic CT examinations showed that lymphomatous lymph nodes had significantly lower mean enhancement values than those of the control group and confirmed the findings from a pilot study. Before treatment the mean enhancement values of HL were significantly higher than those of NHL at 7 min. There was no significant difference between the curves after treatment.