Treatment of hepatocellular carcinoma by chemoembolization: evaluation with 3DFT MR imaging.

Abstract

We evaluated the usefulness of an MR imaging technique that used dynamic three-dimensional Fourier transformation (3DFT) fast imaging with steady-state precession (FISP) with gadopentetate dimeglumine for detecting viable regions of hepatocellular carcinoma following transcatheter arterial chemoembolization with iodized oil (Lipiodol). Images obtained with the 3DFT FISP technique were directly correlated with hepatectomy specimens. Dynamic 3DFT FISP MR imaging was performed after transcatheter arterial chemoembolization and before partial hepatectomy in 10 patients with 10 tumors of hepatocellular carcinoma. Imaging parameters were 20/8/30 degrees (TR/TE/flip angle) with a slab thickness of 21-75 mm and seven or 15 partitions. 3DFT FISP images were obtained at the slice level where a tumor had been detected on T1- and/or T2-weighted spin-echo MR images before, just after (early phase), and 1 and 2 min after (late phase) IV administration of gadopentetate dimeglumine (0.1 mmol/kg). We directly compared the dynamic MR images of the 10 patients with the gross and microscopic findings. On early-phase images, tumors of hepatocellular carcinoma showed no enhancement in three patients and partial intense enhancement in seven. Viable regions of the tumor showed intense enhancement relative to the surrounding liver parenchyma in the early phase, whereas necrotic regions showed no enhancement in either the early or the late phase. Both viable and necrotic regions had lower signal intensities than did the surrounding liver parenchyma in the late phase. By using dynamic 3DFT MR imaging, we were able to accurately assess the effect of transcatheter arterial chemoembolization with iodized oil in nine of the 10 patients. However, in one patient in whom microscopically viable cells were seen in the capsule of the carcinoma, viable regions could not be detected with our technique. Dynamic 3DFT MR imaging was useful in differentiating viable regions of hepatocellular carcinoma from necrotic regions following transcatheter arterial chemoembolization with iodized oil.