CT attenuation values and enhancing characteristics of thoracoabdominal lymphomatous adenopathies.

OBJECTIVE

Thoracoabdominal lymphomatous adenopathies have been described as homogeneous and typically showing little enhancement on postcontrast CT. After observing pronounced adenopathic contrast enhancement in one patient with lymphoma, we prospectively investigated the CT enhancing characteristics and attenuation values of pathologic thoracic and abdominal lymph nodes in 25 patients with lymphoma.

MATERIALS AND METHODS

Unenhanced CT of the chest, abdomen and pelvis was performed in all cases. The enhancing characteristics and attenuation values of the largest node or group of nodes were evaluated at 1, 2, 5, and 10 min after a 100 ml intravenous bolus injection of contrast medium.

RESULTS

On unenhanced CT the nodes were of soft-tissue attenuation (42 +/- 5 HU) in 23 cases and of low attenuation (31 and 28 HU) in 2 cases. The maximum enhancement was achieved at 1 or 2 min postinjection and was low (16 +/- 6 HU) or moderate (31 +/- 6 HU) in 21 cases and pronounced (61 +/- 5 HU) in 4. The patterns of enhancement were classified as homogeneous (no. = 23) inhomogeneous (no. = 1), and peripheral (no. = 1).

CONCLUSION

Thoracic and abdominal lymphomatous adenopathies are usually of soft-tissue attenuation on unenhanced CT and can show slight, moderate, or even pronounced enhancement on postcontrast CT.