Detection of early gastric cancer using hydro-stomach CT:Blinded vs unblinded analysis

AIM:To evaluate the difference in diagnostic performance of hydro-stomach computed tomography(CT) to detect early gastric cancer(EGC) between blinded and unblinded analysis and to assess independent factors affecting visibility of cancer foci.METHODS:Two radiologists initially blinded and then unblinded to gastroscopic and surgical-histological findings independently reviewed hydro-stomach CT images of 110 patients with single EGC.They graded the visibility of cancer foci for each of three gastric segments(upper,middle and lower thirds) using a 4-point scale(1:definitely absent,2:probably absent,3:probably present,and 4:definitely present).The sensitivity and specificity for detecting an EGC were calculated.Intraobserver and interobserver agreements were analyzed.The visibility of an EGC was evaluated with regard to tumor size,invasion depth,gastric segments,histological type and gross morphology using univariate and multivariate analysis.RESULTS:The respective sensitivities and specificities [reviewer 1:blinded,20%(22/110) and 98%(215/220);unblinded,27%(30/110) and 100%(219/220)/reviewer 2:blinded,19%(21/110) and 98%(216/220);unblinded,25%(27/110) and 98%(215/220)] were not significantly different.Although intraobserver agreements were good(weighted κ = 0.677 and 0.666),interobserver agreements were fair(blinded,0.371) or moderate(unblinded,0.558).For both univariate and multivariate analyses,the tumor size and invasion depth were statistically significant factors affecting visibility.CONCLUSION:The diagnostic performance of hydrostomach CT to detect an EGC was not significantly different between blinded and unblinded analysis.The tumor size and invasion depth were independent factors for visibility.

High-risk esophageal varices in patients treated with locoregional therapy for hepatocellular carcinoma:Assessment with liver computed tomography

AIM:To assess the diagnostic performance of followup liver computed tomography(CT) for the detection of high-risk esophageal varices in patients treated with locoregional therapy for hepatocellular carcinoma(HCC).METHODS:We prospectively enrolled 100 patients with cirrhosis who underwent transcatheter arterial chemoembolization,radiofrequency ablation or both procedures for HCCs.All patients underwent upper endoscopy and subsequently liver CT.Three radiologists independently evaluated the presence of high-risk esophageal varices with transverse images alone and with three orthogonal multiplanar reformation(MPR) images,respectively.With endoscopic grading as the reference standard,diagnostic performance was assessed by using receiver operating characteristic(ROC) curve analysis.RESULTS:The diagnostic performances(areas under the ROC curve) of three observers with transverse images alone were 0.947 ± 0.031,0.969 ± 0.024,and 0.916 ± 0.038,respectively.The mean sensitivity,specificity,positive predicative value(PPV),and negative predicative value(NPV) with transverse images alone were 90.1%,86.39%,70.9%,and 95.9%,respectively.The diagnostic performances,mean sensitivity,specificity,PPV,and NPV with three orthogonal MPR images(0.965 ± 0.025,0.959 ± 0.027,0.938 ± 0.033,91.4%,89.5%,76.3%,and 96.6%,respectively) were not superior to corresponding values with transverse images alone(P > 0.05),except for the mean specificity(P = 0.039).CONCLUSION:Our results showed excellent diagnostic performance,sensitivity and NPV to detect high-risk esophageal varices on follow-up liver CT after locoregional therapy for HCC.

Extracolonic findings of computed tomographic colonography in Koreans

AIM:To determine the frequency and characteristics of extracolonic lesions detected using computed tomographic(CT)colonography.METHODS:The significance of extracolonic lesions was classified as high,intermediate,or low.Medical records were reviewed to establish whether further investigations were carried out pertaining to the extracolonic lesions that were detected by CT colonography.RESULTS:A total of 920 cases from 7 university hospitals were included,and 692 extracolonic findings were found in 532(57.8%)patients.Of 692 extracolonic findings,60 lesions(8.7%)were highly significant,250(36.1%)were of intermediate significance,and 382(55.2%)were of low significance.CT colonography revealed fewer extracolonic findings in subjects who were without symptoms(P<0.001),younger(P<0.001),or who underwent CT colonography with no contrast enhancement(P=0.005).CT colonography with contrast enhancement showed higher cost-effectiveness in detecting highly significant extracolonic lesions in older subjects and in subjects with symptoms.CONCLUSION:Most of the extracolonic findings detected using CT colonography were of less significant lesions.The role of CT colonography would be optimized if this procedure was performed with contrast enhancement in symptomatic older subjects.