The cause analysis of missing primary hepatic carcinoma lesions in conventional ultrasonography

Objective To analyse the causes of missing primary hepatic carcinoma lesions in conventional ultrasonography.Methods Totally 464 lesions in 344 patients were retrospectively analyzed.All lesions considered as primary hepatic carcinoma(PHC) in accordance with current American Association for the Study of Liver Diseases(AASLD)guidelines were included in this study.All lesions underwent conventional ultrasonography and CT/MRI scan and were finally diagnosed as PHC.The sizes and locations of the lesions identified on CT/MRI images were regard as the reference standards.In conventional ultrasonography,lesions were divided into detected and undetected groups.Comparing the detected group with the undetected group,factors such as sizes and segmental locations of lesions and the background of liver parenchyma that may cause PHC undetected by ultrasound were analyzed.Results The detected group had 332 lesions.The detection rate was 71.6%(332/464).The maximum diameters of the lesions were 8-198 mm[(48.9±40.3)cm].The undetected group has 132 lesions.The missed diagnosis rate was 28.4%(132/464).The maximum diameters of the lesions were 5-68 mm[(15.2±8.5) cm].The difference of lesion diameters between two groups was statistically significant(t=9.52,P0.001).The proportions of lesions which maximum diameters were≤30 mm,was located near diaphragm and had cirrhosis background in the detected and undetected group were 51.5%(171/332) vs 96.2%(127/132),χ2=82.16,P0.001;44.3%(147/332) vs 69.7%(92/132),χ2=24.43,P0.001;81.0%(269/332) vs 97.7%(129/132),χ2=21.60,P0.001.Conclusion The sizes and segmental locations of PHC lesions and the background of the liver parenchyma may cause sonographic invisibility.