Hyperenhancing focal liver lesions: differential diagnosis with helical CT

Ultrasonographyand Magnetic Resonance Imaging Findings of Solitary Fibrous Tumor of the Liver

Solitary fibrous tumor of the liver is a rare neoplasm which has been reported in only 27 patients in the English literature. A limited number of reports have described the radiological findings of this tumor. We report the radiological and pathological findings in a patient with solitary fibrous tumor located in the liver.

Material density iodine images in dual-energy CT: Detection and characterization of hypervascular liver lesions compared to magnetic resonance imaging

PURPOSE

To determine the diagnostic potential of Material Density (MD) iodine images in dual-energy CT (DECT) for the detection and characterization of hypervascular liver lesions compared to monenergetic 65keV images, using MRI as the standard.

MATERIALS AND METHODS

The study complied with HIPAA guidelines and was approved by the institutional review board. Fifty-two patients (36 men, 16 women; age range, 29-87 years) with 236 hypervascular liver lesions (benign, n=31; malignant, n=205; mean diameter, 29.4mm; range: 6-90.6mm) were included. All of them underwent both contrast-enhanced single-source DECT and contrast-enhanced abdominal MRI within three months. Late arterial phase CT imaging was performed with dual energies of 140 and 80kVp. Protocol A showed monoenergetic 65keV images, and protocol B presented MD-iodine images. Three radiologists qualitatively evaluated randomized images, and lesion detection, characterization, and reader confidence were recorded. Liver-to-lesion ratio (LLR) and contrast-to-noise ratio (CNR) were assessed on protocol A, protocol B, and MRI. Paired t-tests were used to compare LLR, CNR, and the number of detected lesions.

RESULTS

LLR was significantly increased in protocol B (2.8±2.33) compared to protocol A (0.77±0.55) and MRI (0.61±0.66). CNR was significantly higher in protocol B (0.08±0.04) compared to protocol A (0.01±0.01) and MRI (0.01±0.01). All three observers correctly identified more liver lesions using protocol B vs protocol A: 83.13% vs 63.64%, 84.57% vs 68.09%, and 79.37% vs 65.52%. There was no significant difference between the three observers in classification of a lesion as benign or malignant. However, higher diagnostic confidence was reported more frequently by the experienced radiologist when using protocol B vs protocol A (84.6% vs 75%).

CONCLUSION

MD-iodine images in DECT help to increase the conspicuity and detection of hypervascular liver lesions.

Extracardiac Findings at Cardiac CT

Noncardiac findings occur in 10% to 60% of cases depending on the patient population studied. Although most of the abnormalities will turn out to be benign, important findings such as pulmonary embolism and lung cancer occur. Not all important abnormalities will occur within the coned down field-of-view for evaluating the coronary arteries, and the entire study should also be reviewed with an expanded field-of-view. In particular, the typical screen detected cancer occurs in the lung periphery. It is important to have a practical approach in detecting and evaluating incidental findings so as not to cause undue cost or patient anxiety, while ensuring timely management of critical diseases.

Arterially Enhancing Liver Lesions

Benign hepatic vascular neoplasms and vascular pseudolesions are commonly encountered in magnetic resonance (MR) imaging. Most of these benign lesions demonstrate not only arterial-phase hyperintensity, but also persistent enhancement on venous and delayed imaging, unlike most malignant hepatic masses. These features, along with other MR findings and morphological characteristics, may allow for more confident diagnosis and distinction from hepatic malignancy. The objective of our study was to illustrate the MR imaging findings of hepatic lesions that demonstrate both early arterial and sustained enhancement on hepatic venous and delayed phase.

CT in hepatic cirrhosis and chronic hepatitis

Cirrhosis is a diffuse liver disease with premalignant potential in which hepatocellular carcinoma (HCC) frequently develops. The hemodynamics of contrast material are the key to diagnosis of focal liver lesions with computed tomography (CT). Lesions with arterial-dominant vascularity, such as HCC, show brisk enhancement during the arterial phase, whereas lesions with portal blood supply can appear as hyperenhancing lesions in the portal phase. The advent of helical CT has significantly improved the CT examination of the liver because the arterial phase can be displayed independently of the portal phase. The addition of arterial phase imaging to conventional portal phase imaging seems to improve tumor detection and characterization. Although HCC is the single most frequent tumor seen in chronic liver disease, other lesions such as peripheral cholangiocarcinoma and hemangioma should be considered in the differential diagnosis. Optimization of helical CT techniques may allow better detection and characterization of these lesions. In addition to tumor detection, CT plays an important role in preoperative staging of HCC as well as in preoperative assessment of patient candidates to hepatic transplantation. The use of CT angiography with maximum intensity projection techniques may allow for better preoperative work-up and vascular mapping in HCC patients. This article shows the spectrum of helical CT findings in chronic liver disease and specifically in the imaging of HCC and other focal lesions.

Solitary fibrous tumor of the liver: imaging findings

OBJECTIVE

This study describes the imaging features of solitary fibrous tumor of the liver in three patients.

CONCLUSION

A single large, well-circumscribed, heterogeneously enhancing hepatic mass was present in each patient. These imaging features are suggestive of, but not diagnostic for, solitary fibrous tumor of the liver. The two benign and one malignant solitary fibrous tumors of the liver in this series were indistinguishable from one another on imaging studies.