Targeted Sonography for Small Hepatocellular Carcinoma Discovered by CT or MRI: Factors Affecting Sonographic Detection

Abstract

The overall detection rate for small (<or= 3 cm) HCC on targeted sonography was 78.5%. Small size and subphrenic location of the tumor were two independent predictors of sonographic invisibility.

Anatomical variation of the liver with elongated left lobe may be a trap forthe ultrasound detection of focal liver lesion.

“…Although computed tomography (CT) and magnetic resonance imaging (MRI) are popular, US is still the most common modality for the initial investigation of the liver worldwide. Normally, the liver can be detected satisfactorily using US except some parts of the subphrenic region [4,5]. Previous studies have found that a tumor located in the subphrenic region is not easy to be detected and it may lead to missed diagnosis [4,5].…”

“…Normally, the liver can be detected satisfactorily using US except some parts of the subphrenic region [4,5]. Previous studies have found that a tumor located in the subphrenic region is not easy to be detected and it may lead to missed diagnosis [4,5]. Having realized this, US operators always scan the subphrenic region of the liver to avoid the missing detection of focal lesions in clinical practice.…”

Contrast-enhanced ultrasound-guided radiofrequency ablation in inconspicuous hepatocellular carcinoma on B-mode ultrasound

“…However, because of the limitation of B-mode US in detecting very early and small HCCs with poor conspicuity, B-mode USguided RFA might result in missed targeting or incomplete ablation (6). The detection rate of small HCCs not greater than 3 cm in diameter was only about 70% with sonography (6,8).…”

“…However, because of the limitation of B-mode US in detecting very early and small HCCs with poor conspicuity, B-mode USguided RFA might result in missed targeting or incomplete ablation (6). The detection rate of small HCCs not greater than 3 cm in diameter was only about 70% with sonography (6,8). Although advanced imaging techniques including liver dynamic CT and MRI made it possible to overcome this limitation of sonography and to detect very early HCCs, the treatment for these very small HCCs using US guidance is still challenging.…”

“…Generally, RFA procedures are implemented under real-time guidance of unenhanced B-mode ultrasound (US). However, because the detection of HCC by Bmode US is considered to be related to tumor size and conspicuity, it might be difficult to identify and target very small or ill-defined HCCs on conventional US, even if they are visible with other imaging modalities such as dynamic liver computed tomography (CT) or magnetic resonance imaging (MRI) (6)(7)(8)(9). kyo, Tokyo, Japan) are second-generation contrast agents.…”