Can DKI-MRI predict recurrence and invasion of peritumoral zone of hepatocellular carcinoma after transcatheter arterial chemoembolization?

BACKGROUND Hepatocellular carcinoma(HCC)is a major cause of cancer-related mortality worldwide.Transcatheter arterial chemoembolization(TACE)has been performed as a palliative treatment for patients with HCC.However,HCC is easy to recur after TACE.Magnetic resonance imaging(MRI)has clinical potential in evaluating the TACE treatment effect for patients with liver cancer.However,traditional MRI has some limitations.AIM To explore the clinical potential of diffusion kurtosis imaging(DKI)in predicting recurrence and cellular invasion of the peritumoral liver zone of HCC after TACE.METHODSSeventy-six patients with 82 HCC nodules were recruited in this study and underwent DKI afterTACE. According to pathological examinations or the overall modified response evaluationcriteria in solid tumors (mRECIST) criterion, 48 and 34 nodules were divided into true progressionand pseudo-progression groups, respectively. The TACE-treated area, peritumoral liver zone, andfar-tumoral zone were evaluated on DKI-derived metric maps. Non-parametric U test and receiveroperating characteristic curve (ROC) analysis were used to evaluate the prediction performance ofeach DKI metric between the two groups. The independent t-test was used to compare each DKImetric between the peritumoral and far-tumoral zones of the true progression group.RESULTSDKI metrics, including mean diffusivity (MD), axial diffusivity (DA), radial diffusivity (DR), axialkurtosis (KA), and anisotropy fraction of kurtosis (Fak), showed statistically different valuesbetween the true progression and pseudo-progression groups (P < 0.05). Among these, MD, DA,and DR values were higher in pseudo-progression lesions than in true progression lesions,whereas KA and FAk values were higher in true progression lesions than in pseudo-progressionlesions. Moreover, for the true progression group, the peritumoral zone showed significantlydifferent DA, DR, KA, and FAk values from the far-tumoral zone. Furthermore, MD values of theliver parenchyma (peritumoral and far-tumoral zones) were significantly lower in the trueprogression group than in the pseudo-progression group (P < 0.05).CONCLUSIONDKI has been demonstrated with robust performance in predicting the therapeutic response ofHCC to TACE. Moreover, DKI might reveal cellular invasion of the peritumoral zone by moleculardiffusion-restricted change.

Eustachian tube teratoma: A case report

BACKGROUND Mature teratoma composed of all three basic germ cell layers of the head and neck is a rare disease.Teratomas involving the temporal bone are particularly scarce.CASE SUMMARY A 48-year-old male patient with a history of chronic otitis of the left ear from infancy,for which he had been operated on twice,was referred to our hospital for chronic otitis,cholesteatoma and a middle ear mass.Computed tomography(CT)scan and magnetic resonance imaging(MRI)revealed a eustachian tube teratoma,in which the anterior lower part and posterior upper part were connected by a thin membranaceous tissue.The mass was removed completely under general anesthesia by mastoidectomy.As of last follow-up(2 years post-surgery),the disease had not relapsed.CONCLUSION Pre-operative CT and MRI are necessary for eustachian tube teratoma.Complete surgical resection provided excellent prognosis.