Detection of recurrent hepatocellular carcinoma after surgical resection: Non-contrast liver MR imaging with diffusion-weighted imaging versus gadoxetic acid-enhanced MR imaging

Abstract

Objective:: To compare the diagnostic performance of non-contrast liver MRI to whole MRI using gadoxetic acid for detection of recurrent hepatocellular carcinoma (HCC) after hepatectomy.

Methods:: This retrospective study analyzed 483 patients who underwent surveillance with liver MRI after hepatectomy for HCC (median time interval, 7.7 months). Non-contrast MRI set (T₁- and T₂ weighted and diffusion-weighted images) and whole MRI set (gadoxetic acid-enhanced and non-contrast MRI) were analyzed independently by two observers. Receiver operating characteristic analysis was used (with the observers' individual observations and consensus) to detect recurrent HCC. The accuracy, sensitivity, and specificity were calculated.

Results:: A total of 113 patients had 197 recurrent HCCs on first follow-up MRI. Although non-contrast MRI had fairly high sensitivity for recurrent HCC, there were significant differences in sensitivity (94.7% vs 99.1%, p = 0.025) and accuracy (97.5% vs 99.2%, p = 0.021) between the two image sets (per-patients base analysis). However, in patients followed for ≥1 year after surgery, the diagnostic performance of non-contrast MRI and whole MRI were not significantly different (p > 0.05).

Conclusion:: Non-contrast MRI may serve as an alternative follow-up method which can potentially replace whole MRI at least in selected patients followed up ≥1 year after surgery who have relatively lower risk of HCC recurrence.

Advances in knowledge:: There is no consensus regarding the ideal imaging modality or follow-up interval after resection of HCC. Non-contrast MRI had comparable performance to that of gadoxetic acid-enhanced MRI in the detection of HCC recurrence during surveillance ≥1 year after surgery.

Figure 1.

Flow diagram of this study. HCC, hepatocellular carcinoma.

Figure 2.

Recurrent hepatocellular carcinoma (1.2 cm), 17 months after left lateral sectionectomy in a 68-year-old male. A small recurrent tumor (arrow) shows hypointensity, arterial hyperenhancement, and hypointensity on (a) pre-contrast T₁ weighted image, (b) arterial phase, and (c) 20 min hepatobiliary phase images after administration of gadoxetic acid, respectively. Breath-hold T₂ weighted image shows (d) a nodular hyperintense lesion (arrow). This lesion (arrow) is hyperintense (e) on single-shot echoplanar diffusion-weighed imaging at b = 800 s mm^–2 and (f) dark on the ADC map. This lesion was categorized as recurrent hepatocellular carcinoma by observers on both non-contrast and whole MRI set. ADC, apparent diffusion coefficient.

Figure 3.

Recurrent hepatocellular carcinoma (0.8 cm), 6 months after wedge resection in a 65-year-old male. A small recurrent tumor (arrow) shows hypointensity, arterial hyperenhancement, and hypointensity on (a) pre-contrast T₁ weighted image, (b) arterial phase, and (c) 20 min hepatobiliary phase images after administration of gadoxetic acid, respectively. Breath-hold T₂ weighted imaging shows (d) a nodular hyperintense lesion (arrow) despite its small size. This lesion (arrow) is hyperintense (e) on single-shot echoplanar diffusion-weighed imaging at b = 800 s mm^–2. This lesion was categorized as recurrent hepatocellular carcinoma by observers on both the non-contrast MR and whole MRI set.

Figure 4.

Recurrent hepatocellular carcinoma (1.1 cm), 19 months after central hepatectomy in a 68-year-old male. A small recurrent tumor (arrow) shows slight hypointensity, arterial hyperenhancement, and hypointensity on (a) pre-contrast T₁ weighted image, (b) arterial phase, and (c) 20 min hepatobiliary phase images after administration of gadoxetic acid, respectively. This lesion was categorized as recurrent hepatocellular carcinoma by both observers on the whole MRI set. However, breath-hold T₂ weighted imaging shows (d) segmental hyperintensity (arrows) with no focal lesion at the corresponding area. There is a hyperintense, dilated bile duct (arrowheads) within the segment. Inferiorly, there is intrahepatic bile duct dilatation in the remnant right lobe due to stricture (not shown here). (e) Single-shot echoplanar diffusion weighed imaging at b = 800 s mm^–2 also shows segmental hyperintensity of the obstructed liver segment (arrows). This lesion was missed by both observers using non-contrast MRI.