The Practice of Using Contrast Sonography for the Differential Diagnosis of Liver Neoplasms

Abstract

Purpose: to improve the differential diagnosis of benign liver rumors and the liver metastasis of colorectal cancer with the ultrasound using contrast sonography.Materials and methods.There were evaluated 92 patients with liver neoplasms (44 (47.8%) women and 48 (52.2%) men) age 41 to 83, with a mean age of 62.8 ± 2.64. Ultrasound exam was carried out in three stages: I stage – liver ultrasound in B-mode, II stage – ultrasound in B-mode with addition of color Doppler imaging and power Doppler scanning, III stage – contrast liver sonography employing the contrast agent SonoVue (Bracco Imaging SpA, Milan, Italy). According to the results of the examination the patients were either surgically treated if there were indications, or the nature of the neoplasm was verified via the needle biopsy. Thus the patients formed two groups: I group (n = 35 (38.0%) – patients with benign liver neoplasms: cavernous hemangiomas – 17, hepatocellular adenomas – 3, focal modular hyperplasia of the liver – 5; II group (n = 57 (62.0%) – patients with metastasis of colorectal cancer.Results.With the use of the ultrasound in B-mode with addition of color Doppler imaging and power Doppler scanning in patients from group I (n = 35) with benign tumors of the liver – bilobar involvement in 2 cases, right lobe involvement in 28 cases, left lobe involvement in 5 cases. There were found both solitary (in 33 cases) and multiple (in 2 cases) neoplasms ranging from 2.5– 4.5 cm to conglomerates of 8–17 cm in diameter. In group II (n = 57), in patients with colorectal cancer metastasis who had an ultrasound examination in B-mode with addition of color Doppler imaging and power Doppler scanning, bilobar metastatic (91.2%) involvement of the liver prevailed over the monolobar, notably right lobe (84.21%) involvement was more frequent. Multiple metastasis were encountered more often (89.5%) then solitary. At the moment of metastatic liver disease discovery the size of the tumor nodules was over 5 cm in diameter in 33 (57.8%) patients. According to the results of contrast sonography in patients of group I (n = 35) with benign tumors of the liver, there was detected a prolonged enhancement of the neoplasm in the arterial, portal and delayed phases of enhancement. In patients of group II (n = 57) with metastasis of colorectal cancer to the liver, in the end of arterial phase there was noted a “washing out” of the contrast agent by 16th second – in 36 (63.1%) of the patients, by 23th se cond – in 17 (29.8%) and by the 26th second – in 4 (7.0%) of the patients. In portal and delayed phase of the enhancement all of the group II patients (100%) at the site of the metastasis there were located anechogenic round foci.Conclusions. 1. Complex 3-stage ultrasound examination (B-mode, color Doppler imaging and power Doppler scanning, contrast sonography) of the liver neoplasms allows to get a more detailed information and differentiate benign and metastatic disease of the liver; 2. During contrast sonography the benign liver tumors “keep” the contrast gent during the arterial, portal and delayed enhancement phases, but with metastasis in liver the contrast agent gets “washed out” already in the arterial phase of enhancement.