Objective To evaluate the real-time contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of retroperitoneal occupying lesions. Methods Thirty patients with retroperitoneal occupying lesions, including 10 benign and 20 malignant lesions, were performed with CEUS, thus describing the perfusion of contrast agent, the entering style of contrast agent and the vascular morphous. And the entering styles were divided into two patterns: peripheral type or central type while the vascular morphous were divided into 4 levels: level 0, level 1, level 2 and level 3. All of these were compared between benign and malignant lesions. Compared the results of diagnosis malignant lesions by common ultrasonography with CEUS. Results 1/5 case of benign substantive lesions presented as contrast agent perfusion defect, and 11/20 cases of substantive malignant lesions presented as contrast agent perfusion defect. 14/20 of malignant lesions were central type; 9/10 of benign lesions were peripheral type (P=0.005 2). In benign lesions, level 0 had 7/10， level 1 had 2/10 and level 3 had 1/10. In malignant lesions, level 0 had 1/20, level 1 had 3/20, level 2 had 8/20 and level 3 had 8/20, too (P=0.000 5). The rate of missed diagnosis was 40.00% and the accuracy was 66.67% by common ultrasonography, while the rate of missed diagnosis was 10.00% and the accuracy was 86.67% by CEUS combined with the entering style of contrast agent and the vascular morphous. Conclusion The CEUS applies a new way to discriminate malignant from benign in retroperitoneal occupying lesions.
Objective To investigate the value of a new double action MR contrast agent——Gd-BOPTA in the diagnosis of focal nodular hyperplasia (FNH) of the liver with correlation of pathology. Methods Dedicated MRI scans were performed for 5 patients suspected to have liver FNH on clinical and imaging basis (six lesions). The MR imaging protocol included axial T1W and T2W plain scan, coronal T2 weighted imaging, 3D MRCP, Gd-BOPTA enhanced LAVA dynamic tri-phasic acquisitions (scanning at 15 s, 55 s and 90 s respectively), enhanced 2D T1W scan, enhanced LAVA in delay phase (at 5 and 10 min) and in the hepatobiliary phase (at 40 and 80 min). The imaging features on each MR sequence were compared with surgical and pathological findings. Results Six lesions in 5 FNH patients were all correctly diagnosed (5 conformed by surgery and 1 by needle biopsy). ①The hemodynamic phase: The parenchyma of 5 lesions were markedly enhanced in the arterial phase, being isointense or slight hypointense in both the portal venous and delay phases, while 1 lesion was isointense in all phases except being slight hyperintense in the arterial phase; The central scar of 5 lesions were not enhanced in the dynamic phase, but showed delayed enhancement. ②The hepatobiliary (excretory) phase: The parenchyma of all 6 lesions were slight hyperintense or isointense, and tree-like bile ducts with hyperintensity were seen within one lesion. The scar showed no enhancement. ③Pathology: The parenchyma was consisted of disarranged normal hepatocytes but with cytoedema, lack of portal tracts and cholestatic change. The central scar showed rich fibrous tissue, a very thick-walled arteriole, proliferative bile ducts, infiltration of inflammatory cells and myxomatous changes. Conclusion As a dual-phase MR contrast agent capable of depicting both the hemodynamic attributes and hepatobiliary excretion, Gd-BOPTA enhanced MRI can reflect the pathological features of FNH and reach a high diagnostic accuracy.
Objective To determine the value of contrast-enhanced ultrasound (CEUS) in the differentiation of primary liver cancer (PLC) and hepatic alveolar echinococcosis (HAE). Methods The data of 56 patients with PLC or HAE were collected between January 2010 and May 2015. Grayscale and CEUS features of the patients were analyzed retrospectively. The frequency of each imaging finding, including calcification, arterial enhancement, and internal enhancement were evaluated and compared. Results Statistically significant difference of the proportion of gender and age were detected between the two groups (P=0.013, 0.002). Thirty-eight PLC lesions were detected in 32 patients. The diameters of PLC lesions were 3-10 cm with an average of (5.6±2.1) cm. Thirty-two HAE lesions were found in 24 patients. The diameters of HAE lesions were 4-12 cm with an average of (9.1±4.4) cm. Statistically significant difference of lesion size and the incidence rate of calcification (5.3% vs. 75.0%) were seen between PLC and HAE (P<0.001). Peripheral enhancement were seen in 100.0% (38/38) PLC lesions, including 84.2% (32/38) hyperenhancement and 15.8% (6/38) dendritic hyperenhancement. All PLC lesions demonstrated hypoenhancement in late phase. Irregular peripherally hyperenhancement both in arterial and late phase were detected in 43.8% (14/32) HAE lesions. The other 56.2% (18/32) HAE lesions showed no peripheral enhancement both in arterial and late phase. No internal enhancement were seen in HAE lesions. The presence of arterial enhancement (100.0% vs. 43.8%) and absence of internal enhancement (0 vs. 100.0%) were significantly different between PLC and HAE (P<0.001). Conclusions PLC is predicted by arterial phase hyperenhancement and late phase hypoenhancement on CEUS. HAE is predicted with calcification on baseline sonography and internal non-enhancement on CEUS. Arterial phase enhancement is less common and less intensive in HAE than in PLC which also contributes to the differentiation of these lesions.