Dual-phase helical CT of the liver: value of arterial phase scans in the detection of small (< or = 1.5 cm) malignant hepatic neoplasms.

Using triphasic helical CT to detect focal hepatic lesions in patients with neoplasms.

“…Unenhanced scans have lower sensitivity for identification of small lesions becauseof difficulty in differentiation from unopacified vessels or biliary dilatation, which may be dif ficult even with contrast-enhancedCT avail able for comparison [4]. Most of the differences were seenin patients with smaller massesbecausethe larger masseswere seenon all phases.Arterial phaseimagescan help de lineate the hypervascular lesions that enhance more than surrounding liver (positive contrast) [1 1].…”

“…As in other studies [3,4,13,14], a lesion-by-lesion pathologic evaluation was not performed. These patients are often on proto cols that require frequent CT examinations.…”

Diagnostic Performance of Imaging in Detection and Characterization of Liver Lesions

“…In addition, the fast data acquisition allows successive scanning of the entire liver at different moments after injection of contrast material, thus creating the possibility of multiphasic liver CT. In our cases multiple of liver lesions were detected as presented in table (2) similarly recent studies have reported an improvement in lesion detection when imaging is performed using contrast enhancement patterns especially in the presence of hyper vascular neoplasm, such as hepatocellular Carcinoma (HCC) [33][34][35][36].According to the literature and previous experience with dynamic liver CT, many different enhancement patterns were defined [37][38][39] Imaging plays an essential role in diagnosis and management of patients with hepatocellular carcinoma. Although ultrasound is currently the main examination imaging tool for HCC [40], dynamic crosssectional CT imaging techniques were also applied for diagnosis and staging of HCC.…”

“…Table (5,6) presented the enhancement pattern of the HCC and the liver cirrhoses .A liver mass in a cirrhotic liver should be viewed as an HCC until proven otherwise. The diagnosis of liver masses in a cirrhotic liver includes malignant and benign lesions [34][35][36] After detecting hepatic mass on ultrasound, the mass was characterized with contrast enhanced multi detector computed tomography .Each modality has its own description of the hepatic lesion and cirrhosis depending on number of nodules and other factors [34]This current study showed the various characteristics of the liver masses /lesions in cirrhotic and non cirrhotic liver .HCC appears as peripheral [28] who mentioned that on CT; cysts appear as a well defined intrahepatic lesion having water attenuation (0-15 HU), round or oval in shape with smooth thin walls and homogeneous appearance with no internal structures and no enhancement after contrast administration. In the current study and regarding the liver abscess; it has been described as peripheral nodular enhancement, rounded hypo dense focal hepatic lesion in 3(6%) of the cases.…”

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“…Its ability to acquire images of the entire organ within a single breath-hold eliminates the problem of respiratory misregistration, thus allowing confident detection of subcentimeter lesions, and facilitating optimal contrast delivery. 1,2 The rapid scan time also allows helical CT to capture the liver during both the arterial phase (20-30 seconds after the beginning of contrast administration) and venous or portal phase of contrast perfusion (60-70 seconds after contrast administration). 3,4 The advantages of this ability are obvious.…”