Single-pass CT of hepatic tumors: value of globular enhancement in distinguishing hemangiomas from hypervascular metastases

Chemotherapy-induced response of liver hemangiomas in a patient with a germ cell tumor: a case report

Liver hemangiomas are the most common benign primary tumors of the liver. Due to their high prevalence, incidental finding of hemangiomas during radiological workup of oncologic patients is not uncommon. We present the case of a patient diagnosed of an ovarian immature teratoma and hepatic lesions with typical radiological appearance of hemangiomas that decreased in size during adjuvant chemotherapy with BEP regimen (cisplatin, etoposide and bleomycin). Chemotherapy-induced shrinkage of hepatic hemangiomas can mimic the response of liver metastases to chemotherapy and may induce erroneous interpretations. The purpose of this report is to describe a chemotherapy-induced response of liver hemangiomas, especially when BEP combination is used. To date this observation has been barely reported in the literature and, to our knowledge, this is the first documented case of chemotherapy-induced response of liver hemangiomas in a patient diagnosed of an ovarian immature teratoma.

Liver lesions detected in a hepatitis B core total antibody-positive patient masquerading as hepatocellular carcinoma: a rare case of peliosis hepatis and a review of the literature

Peliosis Hepatis (PH) is a rare vascular disorder of the liver, characterized by the presence of cystic blood-filled cavities distributed throughout the hepatic parenchyma. The pathogenesis of PH remains controversial. The preoperative diagnosis of PH is difficult, due to the non-specific imaging characteristics of PH and almost all cases are diagnosed on histology post resection. This study presents a case of PH masquerading as hepatocellular carcinoma (HCC). The patient is a 45-year old Chinese lady, who presented with transaminitis. She was found to be hepatitis B virus core total antibody-positive with an alpha-fetoprotein (AFP) of 29.4 ng/ml. Triphasic liver computed tomography showed several arterial hypervascular lesions and hypoenhancing lesions on the venous phase, particularly in the segments 6/7. Subsequently, a magnetic resonance imaging scan showed multiple lesions in the right hemiliver with an indeterminate enhancement patterns. Subsequently, she decided to undergo a resection procedure. Histopathology revealed findings consistent with PH with some unusual features. This case demonstrates a clinical conundrum, in which PH presented with a raised AFP, in a patient with risk factors for the development of HCC. The clinical suspicion of PH should be high in patients, who present with multiple hepatic lesions with variable enhancement patterns.

A comparative study of contrast enhanced ultrasound and contrast enhanced magnetic resonance imaging for the detection and characterization of hepatic hemangiomas

This study aims to compare contrast enhanced ultrasound (CEUS) and contrast enhanced magnetic resonance imaging (CEMRI) for the detection and characterization of hepatic hemangiomas. Included in this retrospective study were 83 histopathologically confirmed lesions of hemangioma in 66 hospitalized patients who underwent both CEUS and CEMRI and received surgery. The enhancement patterns on CEUS and CEMRI in each lesion were compared and analyzed. In addition, data obtained by the two modalities were then compared with the pathological findings to determine their value in differential diagnosis of hepatic hemangiomas. CEUS diagnosed 78 lesions of hemangioma against 80 by CEMRI. There were no statistical significant differences in the diagnostic value between CEUS and CEMRI in terms of sensitivity (88.0% vs. 92.8%), specificity (99.0% vs. 99.4%), accuracy (97.3% vs. 98.4%), positive predictive value (93.6% vs. 96.3%), and negative predictive value (98.0% vs. 98.8%) (p > 0.05, all). In the arterial phase, the main enhancement pattern on both CEUS and CEMRI was peripheral nodular enhancement (73 vs. 76), but lesions with diffuse enhancement on CEUS outnumbered those on CEMRI (3 vs. 1) and lesions with circular enhancement on CEMRI outnumbered those on CEUS (3 vs. 2). In the portal venous phase and delayed phase, the main enhancement pattern was hyperechoic change on CEUS and hyperintense on CEMRI (66 vs. 65), some lesions presented isoechoic change (12 vs. 15). These results suggested CEUS, an equivalent to CEMRI, may have an added diagnostic value in hemangiomas.

Hypervascular benign and malignant liver tumors that require differentiation from hepatocellular carcinoma: key points of imaging diagnosis

Most liver tumors are benign and hypervascular, and it is important to avoid unnecessary interventions for benign lesions. This review describes the typical and atypical imaging features of common hypervascular benign liver tumors and outlines a general approach to distinguishing between benign and malignant hepatic lesions. There are many types of benign liver tumors that need to be differentiated from hepatocellular carcinoma (HCC). Therefore, it is very important to know the imaging characteristics of benign tumors. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging is helpful in diagnosing hypervascular pseudotumors, focal nodular hyperplasia, and nodular lesions associated with alcohol-induced hepatitis. There are also some hypervascular malignant tumors, such as cholangiocarcinoma, cholangiolocellular carcinoma, mixed type tumors, and metastatic liver tumors, which also required differentiation from HCC.

Acoustic radiation force impulse elastography for focal hepatic tumors: usefulness for differentiating hemangiomas from malignant tumors

Objective

The purpose of this study is to investigate whether acoustic radiation force impulse (ARFI) elastography with ARFI quantification and ARFI 2-dimensional (2D) imaging is useful for differentiating hepatic hemangiomas from malignant hepatic tumors.

Materials and Methods

One-hundred-and-one tumors in 74 patients were included in this study: 28 hemangiomas, 26 hepatocellular carcinomas (HCCs), three cholangiocarcinomas (CCCs), 20 colon cancer metastases and 24 other metastases. B-mode ultrasound, ARFI 2D imaging, and ARFI quantification were performed in all tumors. Shear wave velocities (SWVs) of the tumors and the adjacent liver and their SWV differences were compared among the tumor groups. The ARFI 2D images were compared with B-mode images regarding the stiffness, conspicuity and size of the tumors.

Results

The mean SWV of the hemangiomas was significantly lower than the malignant hepatic tumor groups: hemangiomas, 1.80 ± 0.57 m/sec; HCCs, 2.66 ± 0.94 m/sec; CCCs, 3.27 ± 0.64 m/sec; colon cancer metastases, 3.70 ± 0.61 m/sec; and other metastases, 2.82 ± 0.96 m/sec (p < 0.05). The area under the receiver operating characteristics curve of SWV for differentiating hemangiomas from malignant tumors was 0.86, with a sensitivity of 96.4% and a specificity of 65.8% at a cut-off value of 2.73 m/sec (p < 0.05). In the ARFI 2D images, the malignant tumors except HCCs were stiffer and more conspicuous as compared with the hemangiomas (p < 0.05).

Conclusion

ARFI elastography with ARFI quantification and ARFI 2D imaging may be useful for differentiating hepatic hemangiomas from malignant hepatic tumors.

Hepatic hemangiomas: evaluation of enhancement patterns at dynamic MRI with gadoxetate disodium

OBJECTIVE

The aim of this retrospective study was to assess the enhancement patterns of hepatic hemangiomas on gadoxetate disodium.

MATERIALS AND METHODS

A total of 22 patients with 32 hepatic hemangiomas (23 typical type and nine high-flow type) in normal liver underwent gadoxetate disodium-enhanced MRI. Contrast-enhanced images were obtained before and after contrast injection, including arterial phase, portal phase, equilibrium phase, and three hepatobiliary phases (10, 15 and 20 minutes). Signal-to-phantom ratios of hemangiomas and the portal vein as well as lesion-to-liver contrast-to-phantom ratios were assessed.

RESULTS

Mean signal-to-phantom ratios of all 32 hemangiomas showed the highest value on the arterial phase and subsequently decreased over time (p = 0.029 to p < 0.001). Mean lesion-to-liver contrast-to-phantom ratios of all 32 hemangiomas showed a positive value during the arterial phase and increasingly negative values at later time points (p = 0.001 to p < 0.001). The enhancement pattern of hemangiomas was equal to that of the portal vein at all time points. There was no significant difference in signal-to-phantom ratio between typical hemangiomas and high-flow hemangiomas at any time point.

CONCLUSION

Most hepatic hemangiomas showed hypointensity relative to surrounding liver parenchyma during the equilibrium phase and the hepatobiliary phase. In addition, hepatic hemangiomas showed a signal intensity matching the portal vein at all phases, a finding we believe may be characteristic for hepatic hemangiomas on gadoxetate disodium-enhanced MR images.

Ferucarbotran-enhanced T2-weighted magnetic resonance imaging: differentiation of hepatic cavernous hemangiomas from malignant solid lesions

BACKGROUND

To demonstrate the characteristic feature of hepatic cavernous hemangiomas on ferucarbotran-enhanced T2-weighted MR imaging as a new diagnostic finding.

METHODS

In 201 hepatic lesions (61 hemangiomas, 61 cysts, 41 hepatocellular carcinomas, 31 metastatic carcinomas, and 7 cholangiocarcinomas), lesion-to-liver contrast on ferucarbotran-enhanced T2-weighted images was qualitatively compared with pre-contrast images by three independent readers using a four-grade scale (group 1, marked increase; group 2, mild increase; group 3, no change; group 4, decrease). The change in the contrast-to-noise ratio (CNR) for each lesion was quantitatively measured.

RESULTS

Only hemangiomas showed a significant decrease in CNR; 10% and 90% of the hemangiomas were categorized as group 3 and 4 lesions, respectively. Besides the hemangiomas, there was no other lesion categorized into group 4 except for one cyst. When group 4 lesions were considered hemangiomas, the accuracy of identification was 96.4%.

CONCLUSION

Hemangiomas show a significant decrease in lesion-to-liver contrast on T2-weighted images after ferucarbotran injection, which might be another typical diagnostic imaging finding of hemangiomas distinguished from solid malignant lesions.

Neoplasias hepáticas: caracterização por métodos de imagem

Uma grande variedade de tumores benignos e malignos ocorre no fígado. Embora a caracterização de lesões hepáticas focais possa ser um desafio para o radiologista, a maioria das lesões se apresenta com características de imagem que permitem o seu diagnóstico. O objetivo deste trabalho é o de rever os principais aspectos de imagem dos tumores hepáticos benignos e malignos mais comumente encontrados no fígado adulto.

Distinguishing benign from malignant liver tumours

Liver masses are very common and most are benign. It is therefore important to avoid unnecessary interventions for benign lesions, while at the same time ensuring accurate diagnosis of hepatic malignancies. Many cancer patients, like the general population, have incidental benign liver lesions. In planning treatment for cancer patients, it is critical to avoid inappropriate treatment decisions based on misdiagnosis of a benign lesion as a metastasis or primary liver malignancy. This article describes the salient imaging features of the common benign liver masses and outlines a general approach to distinguishing between benign and malignant hepatic lesions.

MDCT of the Liver and Hypervascular Hepatocellular Carcinomas: Optimizing Scan Delays for Bolus-Tracking Techniques of Hepatic Arterial and Portal Venous Phases

OBJECTIVE

The purpose of our study was to determine the optimal scan delays required for hepatic arterial and portal venous phase imaging and for the detection of hypervascular hepatocellular carcinomas (HCCs) in contrast-enhanced MDCT of the liver using a bolus-tracking program.

SUBJECTS AND METHODS

CT images (2.5-mm collimation, 5-mm thickness with no intersectional gap) detected an increase in the CT value of 50 H in the lower thoracic aorta. The images were obtained after an IV bolus injection of 2 mL/kg of nonionic iodine contrast material (300 mg I/mL) at 4 mL/s in 171 patients, who were prospectively randomized into three groups with scans commencing at 5, 20, and 45 seconds; 10, 25, and 50 seconds; and 15, 30, and 55 seconds for the first (acquisition time: 4.3 seconds), second (4.3 seconds), and third (9.1 seconds) phases, respectively, after a bolus-tracking program. CT values of the aorta, spleen, proximal portal veins, liver parenchyma, and hepatic veins were measured. Increases in CT values from unenhanced to contrast-enhanced CT were assessed using a contrast enhancement index (CEI). Spleen-to-liver and HCC-to-liver contrasts were also assessed. A qualitative degree of contrast enhancement in each organ was prospectively assessed by two independent radiologists.

RESULTS

At 10-15 seconds, the CEI of the aorta reached 300-336 H and that of the spleen reached 97-108 H without significant enhancement of liver parenchyma (15-25 H). The CEI of the proximal portal veins moderately increased (75-104 H) at 10-15 seconds, but no significant enhancement of hepatic veins was observed (24-51 H). The CEI of liver parenchyma peaked (59-63 H) at 45-55 seconds, when the CEIs of the aorta (117-125 H) and spleen (73-82 H) decreased. Spleen-to-liver contrast (81-84 H) was highest at 10-20 seconds and HCC-to-liver contrast (39-44 H) was highest at 10-15 seconds. The qualitative results correlated well with quantitative results.

CONCLUSION

The optimal scan delays for hepatic arterial and portal venous phases after the bolus-tracking program detected threshold enhancement by 50 H in the lower thoracic aorta for the detection of hypervascular HCCs were 10-15 and 45-55 seconds, respectively.

Evaluation of nonmalignant liver masses

Nonmalignant liver masses are increasingly being recognized with the widespread use of imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging. The majority of these lesions are detected incidentally in asymptomatic patients. Based on the radiologic appearance, benign lesions can be categorized as solid or cystic, single or multiple, hypervascular or hypovascular. Based on histologic characteristics, they are classified as of hepatocellular, biliary, or mesenchymal origin. In the majority of patients, a proper diagnosis can be made based on these characteristics on imaging modalities alone. An invasive approach is seldom required. This review discusses the various characteristics of the most common benign liver lesions and recommends a practical approach.

Characterization of benign hepatic tumors arising in fatty liver with SonoVue and pulse inversion US

BACKGROUND

We describe the spectrum of contrast-enhancement patterns of benign hepatic tumors arising in fatty liver on contrast-enhanced ultrasound (US).

METHODS

Sixteen patients (12 women and four men) with 27 benign hepatic tumors (17 hemangiomas, eight focal nodular hyperplasias, and two hepatocellular adenomas) arising in fatty liver underwent baseline and pulse inversion US after administration of SonoVue. Two experienced radiologists evaluated baseline echogenicity and dynamic enhancement pattern of each lesion in comparison with adjacent liver parenchyma.

RESULTS

After administration of SonoVue, in the arterial phase 13 of 17 hemangiomas showed peripheral globular enhancement and one showed a rim of peripheral enhancement, followed by progressive centripetal fill-in, which was complete in 10 of 14 cases and incomplete in four. Three of 18 hemangiomas showed rapid and complete fill-in in the arterial phase. Eight of eight focal nodular hyperplasias became hyperechoic in comparison with adjacent liver parenchyma in the arterial phase and slightly hyperechoic or isoechoic in the portal venous and delayed phases. Both adenomas showed strong arterial contrast enhancement that became less intense in the portal venous and delayed phases.

CONCLUSION

Contrast-enhanced US after administration of SonoVue enables depiction of typical contrast-enhancement patterns in most benign hepatic tumors arising in fatty liver, thus providing useful clues for characterization.

Analysis of different contrast enhancement patterns after microbubble-based contrast agent injection in liver hemangiomas with atypical appearance on baseline scan

BACKGROUND

We describe different possible enhancement patterns in liver hemangiomas with atypical appearance on baseline ultrasound after microbubble-based contrast agent injection.

METHODS

From a series of 253 consecutive lesions that were indeterminate on baseline ultrasound and then scanned after injection of air-filled microbubble contrast agent, 65 focal liver lesions were retrospectively selected on the basis of a diagnosis of liver hemangioma on multiphase contrast-enhanced computed tomography (n = 23), magnetic resonance imaging (n = 27), or histology (n = 15). Each lesion was scanned during arterial phase (30 s after microbubble injection) and late phase (5 min after injection). On-site sonologists performed retrospective assessment of contrast-enhancement patterns by consensus.

RESULTS

Centripetal fill-in preceded (n = 50) or not preceded (n = 3) by peripheral nodular/rim-like enhancement was the prevalently observed contrast-enhancement pattern, equivalent to the typical enhancement pattern of liver hemangiomas on contrast-enhanced computed tomography or magnetic resonance imaging. In the remaining lesions, additional enhancement patterns (diffuse contrast enhancement with rapid fill-in and a late hyper-isoechoic appearance, n = 6; peripheral nodular enhancement with a late hypoechoic appearance, n = 3; or persistent heterogeneous and hyperechoic appearance, n = 3) were observed.

CONCLUSION

Different contrast-enhancement patterns are possible in atypical liver hemangiomas after microbubble injection. Typical centripetal fill-in is the prevalent pattern and its evidence allows diagnosis.

Indeterminate small, low-attenuating hepatocellular nodules on helical CT in patients with chronic liver disease: 2-year follow-up

To evaluate the clinical significance of indeterminate, small, low-attenuating nodular lesions on helical dynamic computed tomography (CT) in chronic liver diseases, CT images were reviewed retrospectively in 281 patients. Indeterminate, low-attenuating nodular lesions less than 20 mm in diameter were followed for 24 to 35 months. Of 127 nodules in 73 patients, 21 nodules turned out to be hepatocellular carcinomas (16%), 25 nodules (20%) became larger, while the remaining 81 nodules (64%) remained unchanged or disappeared. Some low-attenuating nodules larger than 10 mm in diameter may develop into hepatocellular carcinoma.

Computed tomography and magnetic resonance imaging evaluation of liver cancer

Focal liver lesions occur commonly and with varying histology, each requiring radically different management. There are a multitude of imaging modalities currently being used for detecting and characterizing focal liver neoplasms. The primary modalities include ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), and rarely, angiography. CT and MRI have benefited from rapid technologic advances, and MRI, in particular, from the advent of new contrast agents.

Benign liver neoplasms

A variety of benign focal liver lesions are easily characterized with currently available imaging techniques and contrast agents. The most common benign liver lesions, such as hemangioma, bile duct cyst, and FNH, reveal characteristic cross-sectional imaging features that allow an accurate diagnosis. For atypical variants and more uncommon lesions, including HCA, angiomyelioma, infantile hemagioendothelioma, and mesenchymal hamartoma, integration of clinical data can often help in the interpretation of imaging studies. Finally, for the remaining lesions, such as hepatic adenomatosis, the imaging findings may not be specific enough to negate the need for a tissue biopsy.

Computed tomography and magnetic resonance imaging of hepatic metastases

The detection and characterization of liver metastases is well performed with either computed tomography or magnetic resonance imaging. The administration of intravenous contrast is essential for almost all indications, with multiphasic imaging aiding in lesion characterization and detection. The use of multidetected CT (MDCT) provides the ability for optimized vascular and multiplanar imaging, but has also resulted in increased examination complexity. Tissue-specific MR contrast agents can yield the highest rate of lesion detection and thus may be useful in presurgical planning.

Hepatic cavernous hemangiomas: patterns of contrast enhancement on MR fluoroscopy imaging

PURPOSE

The purpose of this study was to assess the patterns of contrast enhancement of hepatic hemangiomas on gadolinium-enhanced MR fluoroscopy imaging prospectively.

METHOD

Investigation was performed on a 0.3-T open MR unit. Gadolinium-enhanced MR fluoroscopy images were obtained in 24 patients with 28 hepatic hemangiomas. Each MR fluoroscopy image was obtained in 2 s and MR fluoroscopy lasted for 10-25 min for each investigation.

RESULTS

Three patterns of contrast enhancement were observed in 24 patients on MR fluoroscopy images. Four small lesions were not detected on MR fluoroscopy images. Uniform enhancement was seen in nine lesions (29%), peripheral nodular enhancement progressing centripetally to uniform enhancement was seen in nine lesions (29%), and peripheral nodular enhancement with persistent central hypointensity was seen in six lesions (22%).

CONCLUSION

Enhanced MR fluoroscopy technique could obtain dynamic images of hepatic hemangiomas. It can be suggested as a useful technique for the showing of enhancement of hepatic hemangiomas, keeping in mind its low sensitivity in the diagnosis of small hemangiomas.

Discrimination of Small Hepatic Hemangiomas from Hypervascular Malignant Tumors Smaller than 3 cm with Three-Phase Helical CT

PURPOSE

To compare the appearance of small hepatic hemangiomas at nonenhanced and contrast material-enhanced helical computed tomography (CT) with that of small (<3-cm) hypervascular malignant liver tumors and to evaluate the accuracy of multiphase helical CT for differentiating small hemangiomas from small hypervascular malignant tumors.

MATERIALS AND METHODS

Radiologists reviewed multiphase helical CT liver images in 86 patients with 37 hemangiomas and 49 malignant liver tumors. They evaluated lesion type and degree of enhancement for change from arterial to portal venous phase. They rated their confidence in the discrimination of hemangiomas from malignant tumors.

RESULTS

At arterial phase CT, enhancement similar to aortic enhancement was observed in 19%-32% of hemangiomas and 0%-2% of malignant tumors; globular enhancement, in 62%-68% and 4%-12%, respectively. At portal venous phase CT, enhancement similar to blood pool enhancement was observed in 43%-54% of hemangiomas and 4%-14% of malignant tumors; globular enhancement, in 46%-49% and 0%-2%, respectively. For all readers and all phases of enhancement, the area under the receiver operating characteristic curves was 0.81-0.87, indicating that inherent accuracy of CT is high and that there was no significant difference (P >.28) in overall accuracy. Readers diagnosed hemangiomas with 47%-53% mean sensitivity with all enhancement phases and diagnosed malignant lesions with 95% mean specificity.

CONCLUSION

Small hemangiomas frequently show atypical appearances at CT. Two-phase helical CT does not improve sensitivity but does improve specificity for differentiating hemangiomas from hypervascular malignant tumors.

Hepatic cavernous hemangioma: temporal peritumoral enhancement during multiphase dynamic MR imaging

PURPOSE

To determine whether temporal parenchymal enhancement around hepatic cavernous hemangiomas can be correlated with the rapidity of intratumoral contrast material enhancement and/or tumor volume at dynamic magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Dynamic MR images obtained in 94 patients with 167 hemangiomas were retrospectively reviewed for peritumoral enhancement. Tumor volume was estimated by using the longest dimension on nonenhanced images. Speed of intratumoral contrast material enhancement was determined with early nonequilibrium phase images and was categorized as rapid (>75% of tumor volume), intermediate (25%-75% of tumor volume), or slow (<25% of tumor volume).

RESULTS

Thirty-two of the 167 hemangiomas (19%) had temporal peritumoral enhancement, which was more common in hemangiomas with rapid enhancement (20 of 49 [41%]) than in those with intermediate (12 of 62 [19%]) and slow (0 of 56 [0%]) enhancement (P: <.001). The mean diameter of the hemangiomas with peritumoral enhancement was not significantly different from that of hemangiomas without peritumoral enhancement (P: >.05). Hemangiomas with rapid enhancement (mean diameter, 16 mm +/- 8), however, were significantly smaller than those with intermediate enhancement (mean diameter, 33 mm +/- 34) (P: <.001).

CONCLUSION

Temporal peritumoral enhancement on dynamic MR images of hepatic hemangiomas correlates well with the speed of intratumoral contrast material enhancement and was most commonly encountered in rapidly enhancing small lesions. There was no statistically significant relationship, however, between peritumoral enhancement and tumor volume.

Imaging of atypical hemangiomas of the liver with pathologic correlation

Compared with the imaging features of typical hepatic hemangiomas, the imaging features of atypical hepatic hemangiomas have not been well studied or well described. Knowledge of the entire spectrum of atypical hepatic hemangiomas is important and can help one avoid most diagnostic errors. A frequent type of atypical hepatic hemangioma is a lesion with an echoic border at ultrasonography. Less frequent types are large, heterogeneous hemangiomas; rapidly filling hemangiomas; calcified hemangiomas; hyalinized hemangiomas; cystic or multilocular hemangiomas; hemangiomas with fluid-fluid levels; and pedunculated hemangiomas. Adjacent abnormalities consist of arterial-portal venous shunt, capsular retraction, and surrounding nodular hyperplasia; hemangiomas can also develop in cases of fatty liver infiltration. Associated lesions include multiple hemangiomas, hemangiomatosis, focal nodular hyperplasia, and angiosarcoma. Types of atypical evolution are hemangiomas enlarging over time and hemangiomas appearing during pregnancy. Complications consist of inflammation, Kasabach-Merritt syndrome, intratumoral hemorrhage, hemoperitoneum, volvulus, and compression of adjacent structures. In some cases, such as large heterogeneous hemangiomas, calcified hemangiomas, pedunculated hemangiomas, or hemangiomas developing in diffuse fatty liver, a specific diagnosis can be established with imaging, especially magnetic resonance imaging. However, in other atypical cases, the diagnosis will remain uncertain at imaging, and these cases will require histopathologic examination.

Hepatocellular adenoma: multiphasic CT and histopathologic findings in 25 patients

PURPOSE

To evaluate multiphasic computed tomographic (CT) findings of hepatic adenomas and to correlate these findings with those of histopathologic analysis.

MATERIALS AND METHODS

Multiphasic helical CT was performed in 25 patients with 44 hepatic adenomas. Nonenhanced scans were obtained in all cases, along with hepatic arterial-dominant phase (HAP) and portal venous-dominant phase (PVP) images at 25-28 and 60-70 seconds after intravenous contrast material injection at 3-5 mL/sec. Twelve patients with 24 adenomas also underwent delayed-phase (5-10-minute) CT. Two independent readers retrospectively reviewed each case for the number of detectable lesions in each CT phase, morphologic features of tumors, and degrees of enhancement.

RESULTS

Thirteen patients had solitary adenomas; 12 patients had two or three adenomas. Both observers agreed on the numbers of lesions detected in all cases and in all phases of enhancement. The detection rate for all 44 adenomas per type of examination was as follows: nonenhanced, 86% (38 of 44); HAP, 100% (44 of 44); PVP, 82% (36 of 44), and delayed, 88% (21 of 24). Tumor margins were well defined in 38 adenomas (86%), and the surface was smooth in 42 adenomas (95%). The right hepatic lobe was the only site of adenoma or was a site along with the left lobe in 29 cases (66%). Tumor fat and calcifications were uncommon (three cases [7%] and two cases [5%], respectively). Other than areas of fat, hemorrhage, or necrosis, the adenomas enhanced nearly homogeneously, especially on PVP and delayed-phase scans. Five patients had coexistent hepatic masses, which were focal nodular hyperplasia (n = 3) or hepatocellular carcinoma (n = 2).

CONCLUSION

Hepatic adenomas often have characteristic features at multiphasic CT that may allow their distinction from other hepatic masses.