Hepatocellular carcinoma with indeterminate or false-negative findings at initial MR imaging: Effect on Eligibility for Curative Treatment - Initial Observations

Purpose: To retrospectively evaluate the effect of indeterminate or false-negative findings at magnetic resonance (MR) imaging on eligibility for curative treatment of hepatocellular carcinoma (HCC). Materials and Methods: This HIPAA-compliant retrospective study was approved by the institutional review board; the need for informed consent was waived. Of 166 patients with cirrhosis in whom HCC was detected with MR imaging, 21 (13 men, eight women; mean age, 60 years) had 33 proved HCCs that were not detected on previous MR images obtained 6-24 months earlier. MR imaging included T1-weighted, T2-weiglited, and dynamic contrast material-enhanced T1-weighted imaging. Serial MR images and treatment records were reviewed to evaluate nodule growth and the effect of delayed diagnosis on treatment eligibility. Results: Of 33 HCCs in 21 patients, 24 corresponding nodules (73%) were described on previous MR images as benign or indeterminate. Five additional nodules were visible at retrospective evaluation, but only on arterial phase images,. The diameters of these 29 visible but indeterminate nodules were initially 0.6-1.9 cm (mean, 1.1 cm) and increasedto 0.9-4.5 cm (mean, 1.9 cm) at HCC diagnosis (mean follow-up, 378 days). The mean doubling time was 856 days for diameter and 285 days for volume. All nine HCCs with a delayed diagnosis of less than 1year were smaller than 3 cm at diagnosis, and the patients had tindergone liver transplantation (n = 3) or technically successful ablation or embolization (n = 6). All 10 subcentimeter indeterminate nodules were smaller than 2 cm at HCC diagnosis, and none progressed to untreatable HCC. Conclusion: Indeterminate nodules smaller than 2 cm did not become untreatable HCC with delayed HCC diagnosis of 6-12 months.