Phase-Inversion Sonography During the Liver-Specific Late Phase of Contrast Enhancement: Improved Detection of Liver Metastases

• Published in: American journal of roentgenology (1976) Vol. 176; no. 5; pp. 1191 - 1198
• Main Authors: Albrecht, Thomas, Hoffmann, Christian W, Schmitz, Stephan A, Schettler, Stefan, Overberg, Aline, Germer, Christoph T, Wolf, Karl-Jurgen
• Format: Journal Article
• Language: English
• Published: Leesburg, VA Am Roentgen Ray Soc 01-05-2001; American Roentgen Ray Society
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Contrast Media; Digestive system. Abdomen; False Positive Reactions; Female; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Investigative techniques, diagnostic techniques (general aspects); Liver Neoplasms - diagnosis; Liver Neoplasms - diagnostic imaging; Liver Neoplasms - secondary; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Male; Medical sciences; Middle Aged; Polysaccharides; Prospective Studies; Sensitivity and Specificity; Tumors; Ultrasonic investigative techniques; Ultrasonography - methods; Sonography; Human; B mode echography; Liver; Size; Hepatic disease; Phase reversal; Metastasis; Optimization; Sensitivity; Specificity; Echography; Digestive diseases; Medical imagery; Diagnosis; Contrast threshold; Comparative study; Contrast media
• ISSN: 0361-803X; 1546-3141
• DOI: 10.2214/ajr.176.5.1761191

The purpose of our study was to assess whether phase-inversion sonography during the late, liver-specific phase of contrast enhancement using Levovist improves the detection of hepatic metastases relative to unenhanced conventional B-mode sonography.
Sixty-two patients were studied with unenhanced B-mode sonography and phase-inversion sonography 2.5 min after the injection of Levovist. All patients underwent one reference examination (CT, MR imaging, or intraoperative sonography). The conspicuity, number, size, and distribution of metastases before and after contrast administration as judged by a sonographer (who was unaware of other imaging findings) were compared with each other and with reference imaging.
The conspicuity of metastases was improved by contrast-enhanced phase inversion in 94% of patients. Thirty-nine patients showed metastases on reference imaging; 36 of these were positive on baseline sonography and 38 on phase-inversion sonography. Phase-inversion sonography showed more reference imaging-confirmed metastases than baseline sonography in 28 patients (45%). The average number of confirmed metastases per patient was 3.06 for baseline sonography and 5.42 for contrast-enhanced phase-inversion sonography (p < 0.01). The average sensitivity for detecting individual metastases improved from 63% to 91%. Metastases of less than 1 cm were shown in 14 patients on baseline sonography, in 24 patients on phase-inversion sonography, and in 26 on reference imaging. Both sonographic techniques showed false-positive lesions in six patients.
Contrast-enhanced phase-inversion sonography in the liver-specific phase of contrast enhancement using Levovist provides a marked improvement in the detection of hepatic metastases relative to unenhanced conventional sonography, without loss of specificity. Phase-inversion sonography was particularly advantageous in detecting small metastases and may be a competitive alternative to CT and MR imaging.