1.5 TESLA MRI OF FOCAL NODULAR HYPERPLASI A - A REPORT OF 7 CASES ANDA REVIEW OF THE LITERATURE

Six patients with 7 focal nodular hyperplasia lesions were investigate d with 1.5 Tesla magnetic resonance imagery (MRI). Surgical specimens were obtained in all cases and histological examination confirmed the diagnosis of focal nodular hyperplasia. In all cases, the tumour was i sointense on the T1 weighted sequences. On the T2 weighted sequences i n six cases, the tumour gave a hypersignal compared with the surroundi ng healthy liver tissue. Central scar tissue was found in all the lesi ons. On the T2 weighted images, the center gave a hypersignal 4 times and a hyposignal 3 times. Gadolinium injection on the echo gradient se quences (GRASS) showed product uptake suggestive of vessels within the central scar in one case. The report in the literature confirm the va riability of focal nodular hyperplasia depending on the magnetic field used. In 1.5 Tesla MRI an isointense signal on at least one sequence would appear to be sufficient for the diagnosis of focal nodular dyspl asia if the tumour is homogeneous and if the central scar is hyperinte nse in T2 sequences.