PRECISION IMAGING SONOGRAPHY

Precision Imaging Sonography: A New Technique in the Evaluation of Focal Liver Lesions

Precision Imaging Sonography: A New Technique in the Evaluation of Focal Liver Lesions

Outline

Objective

The objective of this study is to examine whether precision imaging improves image quality in the assessment of focal liver lesions comparing with conventional sonography.

Materials and Methods

This study includes 69 lesions in 60 patients who have focal lesions in the liver. The lesions consist of hemangiomas, hepatocellular carcinomas, cysts, metastases, focal nodular hyperplasias, adenoma, focal fatty infiltration and focal sparing (Shattuck 1982, p. 93). Conventional sonography and precision images were obtained in the same plane. All lesions are examined independently in terms of lesion conspicuity, sharpness of margin, and overall image quality using a 3 point scale by two readers. Posterior acoustic enhancement was also analyzed in the cystic lesions. A Wilcoxon signed-rank test was used for statistical comparisons of the two techniques for all parameters.

Results

Statistical analysis showed that for sharpness of margin, lesion conspicuity, and overall image quality precision sonography was superior to conventional ultrasonography. Also, according to lesion types precision imaging sonography was significantly superior to conventional sonography for all parameters (Shapiro 1998, p. 1203). For posterior enhancement there was no significantly difference between precision imaging and conventional sonography.

Conclusion

Precision imaging is superior to conventional sonography for sharpness of margin, lesion conspicuity and overall image quality in the evaluation of focal liver lesions. With respect to posterior enhancement for cystic lesions precision imaging was not significantly different than conventional sonography (Scanlan 1991, p. 1267).

Introduction

Ultrasonography (US) is usually initial diagnostic modality in the evaluation of patients with suspected abdominal disease. Ultrasound is the imaging modality most widely used for detection of lesions focal liver. However, once detected one or more lesions, usually for characterization necessary to perform a needle biopsy or aspiration, or other imaging techniques like CT (CT) or magnetic resonance imaging (MRI), since only simple cysts can be reliably diagnosed by ultrasound at baseline (Saleh 2001, p. 368). The administration of intravenous contrast on CT and MRI allows evaluation of tumor vascularization characteristics and type of feedback from reaching a diagnosis.

The ultrasound contrast, which consist of gas microbubbles stabilized by other substances are also administered intravenously and dynamically to assess the type tumor vascularization in a manner similar to CT. One characteristic of the contrast ultrasound is that they are strictly intravascular therefore not passed to the interstitial space, so that the rate of uptake in the late phase or equilibrium is sometimes different from that of CT or MRI. Another feature is that today can be assessed in real time so we can assess the type and duration of blood collection in a more accurate than other imaging techniques (Rosen 2001, p. 379). The type of feedback to diagnose a high percentage of focal liver lesions Ultrasound contrast (over 85% in most published series). The pattern enhancement of metastases in the arterial phase hypervascular depends on whether they are or not. Metastases capture hypervascular in the arterial phase but there ...