MRI of hepatic lymphoma.

Thirteen patients with biopsy proven hepatic lymphoma (2 Hodgkin, 11 Non-Hodgkin) and a control group of 15 patients with hepatic metastases were analyzed quantitatively and qualitatively by MRI. Focal hepatic lymphoma was most reliably detected (eight of eight patients) and appeared hypointense relative to liver on T1 weighted (CNR - 7.4 +/- 2.3) and hyperintense on T2 weighted (CNR + 8.4 +/- 2.9) images. The mean T1 and T2 relaxation times of focal hepatic lymphoma (T1 = 832 +/- 234 msec, T2 = 84 +/- 16 ms) differed significantly from adjacent non-tumorous liver (T1 = 420 +/- 121 ms, T2 = 51 +/- 9 ms; p less than 0.05), however CNR values and relaxation times were similar to those of hepatic metastases. Diffuse hepatic lymphoma (microscopic periportal infiltration) was undetectable by MRI in three patients by either morphologic features or quantitative criteria. A mixed pattern of hepatic lymphoma (focal lesions and diffuse infiltration) showed focal areas of slightly decreased signal intensity on T1 weighted images (CNR = -1.7 +/- 0.4) while T2 weighted images revealed multiple regions of focal hyperintensity (CNR = +13.3 +/- 8.4) superimposed on a diffusely hyperintense liver. Our experience demonstrates that either T1 or T2 weighted techniques are useful in detecting focal and that T2 weighted techniques are useful in detecting mixed hepatic lymphoma. Conventional image derived relaxation time measurements and quantitative parameters were of no additional diagnostic value.