Assessment Of Hepatic Metastases Research Articles

Diffusion-weighted imaging versus superparamagnetic iron oxide (SPIO)-enhanced MRI: exclusive and combined values in the assessment of hepatic metastases

PurposeThe purpose was to validate diffusion-weighted imaging (DWI) in the assessment of hepatic metastases compared with superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging. Materials and MethodsFor 21 consecutive patients with 160 metastases from extrahepatic malignancy and 25 benign focal lesions, two radiologists evaluated four separate review sessions (I, SPIO-enhanced T2⁎-weighted images; II, precontrast DWI; III, SPIO-enhanced T2⁎-weighted images and precontrast DWI; IV, SPIO-enhanced T2⁎-weighted images plus precontrast and SPIO-enhanced DWI) and assigned confidence levels using a five-grade scale for each hepatic lesion. ResultsThe Az values after receiver operating characteristic curve analysis for Reader 1 and Reader 2 were 0.80 and 0.75 on session I, 0.91 and 0.91 on session II, 0.97 and 0.96 on session III and 0.96 and 0.96 on session IV, respectively. The Az value of session II was significantly higher than that of session I (Reader 1, P=.004; Reader 2, P<.001), and that of session III was significantly higher than that of session I (P<.001 for each reader) or session II (Reader 1, P=.004; Reader 2, P=.003). Although there was no significant difference of Az value between session III and session IV (Reader 1, P=.231; Reader 2, P=.878), the sensitivity improved for session IV compared with that for session III (Reader 1, P=.031; Reader 2, P=.039). ConclusionIn the assessment of hepatic metastases, DWI can provide more accurate information than can SPIO-enhanced images. Diagnostic accuracy can be increased even more through the combination of both techniques.

Role of contrast enhanced ultrasonography in the assessment of hepatic metastases: A review

Contrast enhanced ultrasonography (CEUS) has improved both the detection and characterization of focal liver lesions. It is now possible to evaluate in real time the perfusion of focal liver lesions in the arterial, portal and late contrast phases, and thus to characterize focal liver lesions with high diagnostic accuracy. As a result, CEUS has taken a central diagnostic role in the evaluation of focal liver lesions that are indeterminate upon computed tomography (CT) and magnetic resonance imaging. The combined use of second generation contrast agents and low mechanical index techniques is essential for the detection of liver metastases, and it now allows the examination of the entire liver in both the portal and late phases. Several studies have shown that using CEUS instead of conventional ultrasonography without contrast agents significantly improves sensitivity in detection of liver metastases. Furthermore, the detection rate with CEUS seems to be similar to that of CT. This review describes the clinical role of CEUS in detecting liver metastases, including details about examination techniques, features of metastases observed with CEUS, and clinical results and guidelines.

Prospective, Blinded Comparison of Helical CT and CT Arterial Portography in the Assessment of Hepatic Metastasis from Colorectal Carcinoma

This prospective blinded comparison of helical CT and helical CT arterial portography aimed to detect liver metastasis from colorectal carcinoma. 50 patients with colorectal carcinoma were evaluated comparing helical CT with helical CT arterial portography. Each imaging study was evaluated on a 5-point ROC scale by radiologists blinded to the other imaging findings, and the results were compared, with the surgical and pathologic findings as the gold standard. Of the 127 lesions found at pathology identified as metastatic colorectal cancer, helical CT correctly identified 85 (69%) and CT portography 96 (76%). When subgroups with lesions <3 cm (48 patients) and patients with maximum tumor size <3 cm (18 patients) were considered, CT portography was always better than helical CT in terms of sensitivity, specificity, positive predictive value, and negative predictive value. ROC analysis adjusting for multiple lesions per patient revealed significantly greater area under the curve (AUC) for the subgroup of lesions <3 cm (CT-AUC of 77% and CT portography AUC of 81%; P = 0.002). For identification of large metastases, helical CT and CT portography have similar yield. However, for detection of small liver metastases, CT portography remains superior for lesion detectability.

Improvement in diagnosis of liver metastases with the multi-detector CT

The introduction of multidetector computed tomography in clinical routine creates a new dimension of increased spatial and temporal resolution in CT scanning. On the basis of the very short acquisition time, the whole liver can now be scanned within one breathhold. Multidetector-CT allows the examination of the liver with nearly isotropic data sets. This is the prerequisite for the optimal assessment of very small liver lesions in all planes and excellent enhancement of liver lesions in defined organic perfusion phases. The speed of multidetector-CT can either be used to reduce the time to cover a given volume, or to use narrower beam collimation to increase the resolution of details along the z-axis and to reduce volume averaging. We report our clinical experiences in hepatic multidetector-CT examinations and optimized examination protocols in the assessment of hepatic metastases. Multidetector-CT and the use of interactive multiplanar reconstructions improve the detection and characterization of liver metastases. However, new problems in data management may arise from the large amount of data generated by multidetector-CT.

Combined ultrasounds and CEA in preoperative assessment of hepatic metastases from gastrointestinal malignancies.

A consecutive series of 100 patients affected by gastrointestinal malignancies entered a prospective controlled study of liver metastases performed by ultrasound echography, CEA, hepatic enzymes (only alkaline phosphatase (AP) was found to be somehow significant). Laparotomic inspection and palpation were taken as objective control of ultrasound scan. Eighteen out of the 100 patients showed diffuse hepatic metastases at surgery (all controlled histologically). Hepatic echography correctly diagnosed liver metastases in 15 out of these 18 patients (= 83.8% sensitivity); two more cases (hepatic fibroangiomas) were interpreted as metastases (= 89.9% specificity). CEA-RIA assay was pathologic (greater than 10 ng/ml) in all of the 18 patients with liver metastases; 21 out of the 82 without liver metastases were CEA positive (difference of mean values statistically significant at P less than 0.01). The only significant hepatic enzyme was AP, which was pathologic in 12 out of 18 patients with liver metastases. The comparative evaluation of the three tests showed that ultrasound scanning missed three cases of diffuse hepatic metastases, which, however, were CEA positive, while AP could not help to correct such misdiagnosis.