Objective: To study the MR appearance of lymph nodes in relation to activity of chronic active hepatitis C, we correlated the findings on MR imaging with a histologic grading of the activity level.
Materials and methods: Fifty patients with chronic active hepatitis C, who had MR imaging examinations and a related histology report from a liver biopsy obtained within 1 month of the MR imaging were chosen from our radiology database and studied retrospectively. All patients were examined over a 4-year period at a single institution to detect cirrhosis or hepatocellular carcinoma. We divided the 50 patients into the mild, moderate, or severe activity groups, according to their histology reports. Two radiologists, unaware of the histologic classifications, individually reviewed the MR images to observe the perihepatic locations, number, size (defined as the sum of the length-by-width products of the largest three nodes), and intensity of the lymph nodes relative to the spleen. The clinical records of the patients were reviewed to check the results of their liver function tests. The lymph node findings on MR imaging were compared with the histologically confirmed activity level of chronic hepatitis C.
Results: Forty-four (88.0%) of 50 patients had perihepatic lymph nodes larger than 5 mm on MR images, including 64.2% (9/14) of the patients with mild activity, 96.3% (26/27) of the patients with moderate activity, and 100% (9/9) of the patients with severe activity (p = 0.0034). The average number +/- the standard deviation (SD) of perihepatic lymph nodes was 2.5 +/- 1.8 in patients with mild activity, 5.6 +/- 2.2 in patients with moderate activity, and 8.3 +/- 3.5 in patients with severe activity (p = 0.0001). The average size (+/- SD) of the lymph nodes was 151.0 +/- 104.9 mm(2) in the mild activity group, 366.8 +/- 143.0 mm(2) in the moderate activity group, and 488.2 +/- 244.8 mm(2) in the severe activity group (p = 0.0001). On fat-saturated fast spin-echo T2-weighted MR images, the average number (+/- SD) of hyperintense nodes was 0.17 +/- 0.25 in the mild activity group, 1.7 +/- 0.80 in the moderate activity group, and 2.4 +/- 0.60 nodes in the severe activity group (p = 0.0001). No relationship between histologic activity and results from liver function tests was found.
Conclusion: MR imaging depicts perihepatic lymph nodes in most patients with chronic hepatitis C. Lymph node number, size, and hyperintensity were related to the activity of chronic hepatitis C, but the results of liver function tests were not.