Central lower attenuating lesion in the ablation zone on immediate follow-up CT after percutaneous radiofrequency ablation for hepatocellular carcinoma: Incidence and clinical significance

Purpose

The purpose of this study was to evaluate the incidence of central lower attenuating (CLA) lesion in the ablation zone seen on immediate follow-up CT images after percutaneous radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), and the correlation of CLA lesions and local tumor progression (LTP).

Subjects and methods

The study group included 146 patients with 167 ablation zones that had undergone follow-up CT examinations for more than 12 months after percutaneous RFA. CLA lesions corresponding to index tumors and ablative margins (safety margins) were evaluated in the ablation zones seen on immediate follow-up CT including coronal and sagittal multiplanar reformatted (MPR) images with narrow window width settings.

Results

CLA lesions were depicted on 48 of 167 ablation zones (28.7%) on immediate follow-up CT images. Among the 48 ablation zones with CLA lesions, 27 (56.3%, 27/48) had ablative margins on all three of the orthogonal MPR images and they showed no LTP (0%) on follow-up CT examinations. Three of the ablation zones with CLA lesions (6.3%, 3/48) having an ablative margin on one plane only also showed no LTP (0%). LTP was observed in 2 of 18 ablation zones (11.1%) that had CLA lesions without ablative margins on all three planes. In the remaining 119 ablation zones without CLA lesions, 5 (4.2%, 5/119) showed LTP.

Conclusion

CLA lesions in ablation zones were occasionally (28.7%) seen on immediate follow-up CT images after RFA for HCCs. The presence of CLA lesions with ablative margins might be a negative predictor of LTP.     

CT features of adenomyosis

Objectives

To determine the computed tomography (CT) features of adenomyosis in patients with known adenomyosis as established with magnetic resonance (MR) imaging.

Methods

A computerized search identified 16 women with pelvic MR diagnosis of adenomyosis who also had enhanced pelvic CT. Original CT reports were reviewed for potential prospective diagnosis of adenomyosis. CT images were reviewed for enhancement phase, inner and outer myometrium attenuation, uterine enlargement (width>6 cm), inner myometrial thickening (≥12 mm), and myometrial cysts.

Results

Adenomyosis was detectable on CT in 8 of 16 patients. For these 8 patients, inner and outer myometrium distinction was excellent in 7 (88%) and limited in 1 (12%), and mean inner myometrial thickness was 25 mm (range 14-47 mm). CT enhancement phase was parenchymal in 7 (88%), uterus was enlarged in 8 (100%), and 7 (88%) had myometrial cysts. Adenomyosis was focal in 5 (63%), diffuse in 2 (25%), and both in 1 (12%). None of the original CT reports included adenomyosis as a diagnosis.

Conclusions

CT can suggest a diagnosis of adenomyosis based on uterine enlargement, thickened inner myometrium, and/or myometrial cysts.     

Dynamic perfusion CT parameters and delayed contrast washout CT in characterization of adrenal tumors: A comparative study

Purpose

The study aims to compare the accuracy of washout and perfusion CT techniques in diagnosis of adrenal tumors.

Intrahepatic vascular shunts: Strategy for early diagnosis, evaluation and management

Purpose

To propose a strategy for early diagnosis and management of intrahepatic vascular shunts (IHVSs).

Patients and Methods

We systematically screened 3143 patients liable to develop IHVSs. Diagnosed patients were comprehensively evaluated using color Doppler and multiphasic CT. Our management strategy based on imaging and clinical findings and categorized patients into three groups with different lines of management and we assessed the degree of shunt occlusion and clinical outcome.

Results

IHVSs were diagnosed in 134 patients. Two types of shunts were identified; arteriovenous (72%) and venovenous (28%). Small simple shunts (32%) showed no morphological or hemodynamic changes. Small complex shunts (57%) showed mild alterations in Doppler spectra. Large and aneurismal shunts (11%) showed increased diameters and flow velocities of the shunt vessels with alteration of flow pattern. By CT the vessels opacified during the early arterial phases in arteriovenous, and during the portovenous phase in venovenous shunts. During management, group I included 42%; 38% were conservatively managed and 4% underwent TIPS. Group II included 57% who underwent successful embolization in 50%, and <80% reduction in 7% of patients who underwent surgery. Direct surgery was selected for 1% of patients.

Conclusion

Using color Doppler ultrasonography complemented by multiphasic CT allowed early diagnosis and evaluation of IHVSs and selection of the suitable treatment. Our management strategy allowed practical therapeutic implications and yielded good results.     

Pulmonary imaging using dual-energy CT, a role of the assessment of iodine and air distribution

Aim

The aim of the study is to present the feasibility of using dual-energy CT and the evaluation of iodine and air distribution in differentiation of pathological conditions.

Material and method

We used the data of 50 CT examinations performed due to suspected pulmonary embolism with any pathological finding except consolidation of the parenchyma. The patients underwent CT angiography of the pulmonary arteries on a dual-source CT (DSCT), with the two tubes independently operated at 140 and 80 kV. By exploiting the dual-energy information, iodine distribution maps were obtained in addition to the conventional CT images which served as a marker of pulmonary perfusion. Minimum intensity projections (MinIP) were used as a marker of air content.

Results

By comparing the iodine distribution maps and MinIP images, it was possible to differentiate between the following templates of lung parenchyma: A - normal iodine and air distribution; B - iodine content deficit with minimal or with no redistribution of air; C - reduced iodine content and increased content of air; D - deficit of iodine content and increased content of air; E - increased iodine content and normal content of air; F - increased iodine content and reduced content of air; G - reduced perfusion and reduced content of air. The type A (five cases) was typical for the pulmonary embolism with preserved normal conditions of perfusion and ventilation. Type B (18 cases) occurred in pulmonary embolism; type C was found in case of inflammation of small respiratory airways (five cases); emphysema was typical for type D (nine cases); increased perfusion was observed in the parenchyma preserved from emphysema or preserved from embolism in cases of emphysema or pulmonary embolism; type F occurred in pulmonary interstitial edema (four cases) both with pulmonary infection; finally type G was found in interstitial lung diseases (five cases).

Conclusion

Imaging of the pulmonary circulation by means of dual-energy CT opens the potential to study pathological changes of circulatory and pulmonary perfusion impairments, our presented work signs the important relations between iodine and air distribution which have to be thought in the interpretation of dual-energy perfusion imaging of the lungs.     

Whole tumour quantitative measurement of first-pass perfusion of oesophageal squamous cell carcinoma using 64-row multidetector computed tomography: Correlation with microvessel density

Purpose

To assess correlations between whole tumour first-pass perfusion parameters obtained with 64-row multidetector computed tomography (MDCT), and microvessel density (MVD) in oesophageal squamous cell carcinoma.

Materials and Methods

Thirty-one consecutive patients with surgically confirmed oesophageal squamous cell carcinomas were enrolled into our study. All the patients underwent whole tumour first-pass perfusion scan with 64-row MDCT. Perfusion parameters, including perfusion (PF), peak enhanced density (PED), blood volume (BV), and time to peak (TTP) were measured using Philips perfusion software. Postoperative tumour specimens were assessed for MVD. Pearson correlation coefficient tests were performed to determine correlations between each perfusion parameter and MVD.

Results

Mean values for PF, PED, BV and TTP of the whole tumour were 28.85 ± 20.29 ml/min/ml, 23.16 ± 8.09 HU, 12.13 ± 5.21 ml/100 g, and 35.05 ± 13.85 s, respectively. Mean MVD in whole tumour at magnification (×200) was 15.75 ± 4.34 microvessel/tumour sample (vessels/0.723 mm²). PED and BV were correlated with MVD (r = 0.651 and r = 0.977, respectively, all p < 0.05). However, PF and TTP were not correlated with MVD (r = 0.070 and r = 0.100, respectively, all p > 0.05).

Conclusion

The BV value of first-pass perfusion CT could reflect MVD in oesophageal squamous cell carcinoma, and can be an indicator for evaluating the tumour angiogenesis.     

Dynamic CT Perfusion Imaging for the Detection of Crossed Cerebellar Diaschisis in Acute Ischemic Stroke

Objective

Although the detection of crossed cerebellar diaschisis (CCD) by means of different imaging modalities is well described, little is known about its diagnosis by computed tomography perfusion (CTP) imaging. We investigated the detection rate of CCD by CTP imaging and the factors related to CCD on CTP images in patients with acute ischemic stroke.

Materials and Methods

CT perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) obtained from 81 consecutive patients affected by an acute ischemic stroke were retrospectively reviewed. Whole-brain perfusion maps were obtained with a multichannel CT scanner using the toggling-table technique. The criteria for CCD was a unilateral supratentorial ischemic lesion and an accompanying decrease in perfusion of the contralateral cerebellar hemisphere on the basis of CTP maps by visual inspection without a set threshold. Maps were quantitatively analyzed in CCD positive cases.

Results

The criteria for CCD were fulfilled in 25 of the 81 cases (31%). Detection rates per CTP map were as follows: MTT (31%) > TTP (21%) > CBF (9%) > CBV (6%). Supratentorial ischemic volume, degree of perfusion reduction, and infratentorial asymmetry index correlated strongly (R, 0.555-0.870) and significantly (p < 0.05) with each other in CCD-positive cases.

Conclusion

It is possible to detect CCD on all four of the CTP-based maps. Of these maps, MTT is most sensitive in detecting CCD. Our data indicate that CTP imaging is a valid tool for the diagnosis of CCD in patients affected by an acute hemispheric stroke.     

Upper gastrointestinal tract heterotopic pancreas: findings from CT and endoscopic imaging with histopathologic correlation

Objective

To evaluate and describe computed tomographic (CT) and endoscopic (ES) imaging findings in patients with pathologically confirmed upper gastrointestinal (GI) tract heterotopic pancreas (HP).

Methods

Findings from imaging examinations in 11 patients with pathologically confirmed HP were retrospectively reviewed (CT images obtained from 11 patients and ES images from 6 patients were available for review). Two radiologists evaluated lesion location, size, shape and border as well as growth pattern, enhancement pattern, enhancement grade and number of tumors. The presence of surface dimpling, prominent enhancement of overlying mucosa, and low intralesional attenuation were also evaluated.

Results

HP in the upper GI tract showed typical features in CT imaging: submucosal masses, ill-defined borders, endoluminal growth patterns, bright enhancement similar to the normal pancreas, surface dimpling and low intralesional attenuation. Endoscopic photographs manifested an endoluminal, ill-defined, submucosal mass in the upper GI tract wall, typically with central umbilication. The LD (long diameter)/SD (short diameter) ratios were found to be significantly different between HP in the stomach and HP in the duodenum (P<.05 for each finding). In addition, HP in the duodenum tended to be small and round.

Conclusions

HP exhibits typical pancreatic pathologic features. Images showed characteristic features in CT imaging: submucosal masses, ill-defined lesions with an endoluminal growth pattern, bright enhancement similar to the normal pancreas, surface dimpling and low intralesional attenuation. ES imaging showed an endoluminal, ill-defined, submucosal mass, typically with central umbilication.     

Radiofrequency ablation of subcapsular hepatocellular carcinoma: Single center experience

Purpose

To present a single center results, regarding radiofrequency ablation (RFA) of subcapsular hepatocellular carcinoma (HCC).

Materials and methods

Forty patients with subcapsular HCC were treated with RFA under CT guidance for fifty-two discrete lesions in our institution. Twenty-eight patients underwent ablation of a solitary tumor and twelve patients underwent RFA of two tumors. Six patients had a subcapsular HCC with an exofitic location. All lesions had a diameter of <4 cm. We used two types of generators and electrodes: spiral electrode and expandable electrode. Needle track ablation was performed in all cases. Follow-up consisted of an abdomen computed tomography (CT) scan after contrast administration immediately after each session and then after one, three, six, and twelve months.

Results

In forty-eight lesions complete tumor ablation was depicted at the one month CT scan. In four lesions with residual viable tumor, a second session was performed. After the second ablation no residual tumor was observed in any patient. No major complications occurred in any of our patients. Fever with a temperature up to 39 °C was documented during the first days as part of the post-ablation syndrome in thirteen patients (32.2%). Seeding along the needle track was observed in none of our patients. Local tumor progression, was observed in ten lesions (19.25%) and in all cases a second RFA session was performed with optimal results.

Conclusion

Subcapsular location should not be considered as a contraindication for liver RFA.     

Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

Purpose

It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT.

Materials and methods

Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses.

Results

In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance.

Conclusion

The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.     

Performance of integrated FDG-PET/contrast-enhanced CT in the staging and restaging of colorectal cancer: Comparison with PET and enhanced CT

Objective

The purpose of this study was to assess the diagnostic value of PET/CT as a one step examination in patients with colorectal cancer. Therefore we proved whether diagnostic PET/CT adds information over PET or contrast-enhanced CT alone for staging or restaging of patients with colorectal cancer.

Methods

Seventy-three patients (46 males and 27 females; age range: 50-81 years; mean age: 67 years) with known colorectal cancer underwent 18F-FDG-PET/CT for staging or restaging.

Results

Of the 73 patients 26 patients underwent PET/CT for staging and 47 for restaging. 266 metastases could be detected in 60 patients. Contrast-enhanced PET/CT had a lesion-based sensitivity of 100%, contrast-enhanced CT of 91% and PET of 85%. PET/CT identified 2 lesions as false positive. PET/CT could also reach a patient-based sensitivity of 100%, which was superior to contrast-enhanced CT and PET.

Conclusion

Our study clearly demonstrated the added value of contrast-enhanced PET/CT in staging and restaging patients with colorectal cancer over CT and PET alone.     

Assessment of triple-phase CT findings for the differentiation of fat-deficient hepatic angiomyolipoma from hepatocellular carcinoma in non-cirrhotic liver

Background

To evaluate the triple-phase CT findings for the differentiation of fat-deficient angiomyolipoma from hepatocellular carcinoma in non-cirrhotic liver.

Methods

We retrospectively reviewed contrast-enhanced triple-phase CT images of 10 patients with fat-deficient hepatic angiomyolipoma and 28 patients with 29 hepatocellular carcinomas in non-cirrhotic liver proved on histologic examination. The CT findings for the two types of tumors were compared using Fisher's exact test.

Results

Early draining vein depicted on arterial or portal phases was seen in eight (80%) angiomyolipomas and two hepatocellular carcinomas (7%) (p < 0.001), in which the early draining vein was connected with tumoral vessels. The tumoral vessels in the angiomyolipoma were more prominent and ectatic, were distributed both centrally and peripherally, and were seen in smaller tumors than in the hepatocellular carcinoma. Tumor capsule enhancement was absent in all angiomyolipomas as compared with two (7%) hepatocellular carcinomas with no tumor capsule (p < 0.001). The other CT findings were not significantly different for the two different types of tumors.

Conclusions

The presence of early draining vein connecting with prominent tumoral vessels and absent tumor capsule were useful CT findings for the differentiation of fat-deficient angiomyolipoma from hepatocellular carcinoma in non-cirrhotic liver.     

ServiceBlueprinting as a service management tool in radiology

Purpose

To describe the ServiceBlueprint model as a suitable method of service management in clinical medicine using the example of the routine clinical setting of a radiological department.

Materials and methods

ServiceBlueprinting is a concept for the analysis, visualization, and optimization of service processes. To investigate whether the model will also provide a suitable representation of medical services, particularly the provision of radiological services, ServiceBlueprints were created for the modality computed tomography (CT). To this end, an independent observer analyzed the workflow of 40 consecutive CT examinations.

Results

The ServiceBlueprint provided an analysis of the status quo of the service processes in CT imaging modality. Weak points in the processes thus became immediately apparent. The model could also be used for personnel management in that it helped to define the roles of staff members from different categories in the value-added process. It served as a basis for the implementation of quality management systems according to Total Quality Management (TQM) and DIN-EN-ISO-9001:2000.

Conclusions

The ServiceBlueprint model is a service management concept that is also suitable to visualize medical service processes in routine clinical settings like in a radiology department and has a multifarious potential in process optimization, implementation of quality management systems, and human resources management.     

Perfusion maps of the whole liver based on high temporal and spatial resolution contrast-enhanced MRI (4D THRIVE): Feasibility and initial results in focal liver lesions

Purpose

To prospectively evaluate a new imaging sequence (4D THRIVE) for whole liver perfusion in high temporal and spatial resolution. Feasibility of parametric mapping and its potential for characterizing focal liver lesions (FLLs) are investigated.

Materials and methods

Fifteen patients suspected for colorectal liver metastases (LMs) were included. Parametric maps were evaluated qualitatively (ring-enhancement and lesion heterogeneity) and compared to three-phased contrast-enhanced MRI. Quantitative analysis was based on average perfusion values of entire FLLs. Reference standard comprised surgery with histopathology or follow-up imaging. Fisher's exact test was used for qualitative and Kruskal-Wallis test for quantitative analysis.

Results

In total 29 LMs, 17 hemangiomas and 4 focal nodular hyperplasias were evaluated. FLLs could be differentiated by qualitative assessment of parametric maps respectively three-phased contrast-enhanced MRI (Fisher's p < 0.001 for comparisons between LMs and hemangiomas and LMs and FNHs for both ring-enhancement and lesion heterogeneity) rather than by quantitative analysis of parametric maps (Chi-square for Kep = 0.33 (p = 0.847) and Chi-square for Kel = 1.35 (p = 0.509)).

Conclusion

This preliminary study shows potential of 4D THRIVE for whole liver imaging enabling calculation of parametric maps. Qualitative rather than quantitative analysis was accurate for differentiating malignant and benign FLLs.     

320-Multidetector row whole-head dynamic subtracted CT angiography and whole-brain CT perfusion before and after carotid artery stenting: Technical note

Introduction

Multidetector CT (MDCT) is increasingly used for the investigation of neurovascular disorders, but restricted z-axis coverage (3.2 cm for 64-MDCT) currently limits perfusion to a small portion of the brain close to the circle of Willis, and precludes dynamic angiographic appreciation of the entire brain circulation. We illustrate the clinical potential of recently developed 320-MDCT extending the z-axis coverage to 16 cm in a patient with symptomatic carotid artery stenosis.

Methods

In a 74-year-old patient presenting with critical symptomatic stenosis of the left CCA, pre- and post-carotid artery stenting whole-head subtracted dynamic MDCT angiography and perfusion were obtained in addition to CT angiography of the supra-aortic trunks. Both whole-head subtracted MDCT angiography and perfusion demonstrated delayed left ICA circulation, which normalized after carotid stenting.

Discussion

320-MDCT offers unprecedented z-axis coverage allowing for whole-brain perfusion and subtracted dynamic angiography of the entire intracranial circulation. These innovations can consolidate the role of MDCT as a first intention imaging technique for cerebrovascular disorders, in particular for the acute management of stroke.     

Co-registered perfusion SPECT/CT: Utility for prediction of improved postoperative outcome in lung volume reduction surgery candidates

Purpose

To directly compare the capabilities of perfusion scan, SPECT, co-registered SPECT/CT, and quantitatively and qualitatively assessed MDCT (i.e. quantitative CT and qualitative CT) for predicting postoperative clinical outcome for lung volume reduction surgery (LVRS) candidates.

Materials and methods

Twenty-five consecutive candidates (19 men and six women, age range: 42-72 years) for LVRS underwent preoperative CT and perfusion scan with SPECT. Clinical outcome of LVRS for all subjects was also assessed by determining the difference between pre- and postoperative forced expiratory volume in 1 s (FEV₁) and 6-min walking distance (6MWD). All SPECT examinations were performed on a SPECT scanner, and co-registered to thin-section CT by using commercially available software. On planar imaging, SPECT and SPECT/CT, upper versus lower zone or lobe ratios (U/Ls) were calculated from regional uptakes between upper and lower lung fields in the operated lung. On quantitatively assessed CT, U/L for all subjects was assessed from regional functional lung volumes. On qualitatively assessed CT, planar imaging, SPECT and co-registered SPECT/CT, U/Ls were assessed with a 4-point visual scoring system. To compare capabilities of predicting clinical outcome, each U/L was statistically correlated with the corresponding clinical outcome.

Results

Significantly fair or moderate correlations were observed between quantitatively and qualitatively assessed U/Ls obtained with all four methods and clinical outcomes (−0.60 ≤ r ≤ −0.42, p < 0.05).

Conclusion

Co-registered perfusion SPECT/CT has better correlation with clinical outcome in LVRS candidates than do planar imaging, SPECT or qualitatively assessed CT, and is at least as valid as quantitatively assessed CT.     

Slice-accelerated gradient-echo echo planar imaging dynamic susceptibility contrast-enhanced MRI with blipped CAIPI: effect of increasing temporal resolution

Purpose

To assess the influence of high temporal resolution on the perfusion measurements and image quality of perfusion maps, by applying simultaneous-multi-slice acquisition (SMS) dynamic susceptibility contrast-enhanced (DSC) magnetic resonance imaging (MRI).

Materials and methods

DSC-MRI data using SMS gradient-echo echo planar imaging sequences in 10 subjects with no intracranial abnormalities were retrospectively analyzed. Three additional data sets with temporal resolution of 1.0, 1.5, and 2.0 s were created from the raw data sets of 0.5 s. Cerebral blood flow (CBF), cerebral blood volume, mean transit time (MTT), time to peak (TTP), and time to maximum tissue residue function (T _max) measurements were performed, as was visual perfusion map analysis. The perfusion parameter for temporal resolution of 0.5 s (reference) was compared with each synthesized perfusion parameter.

Results

CBF, MTT, and TTP values at temporal resolutions of 1.5 and 2.0 s differed significantly from the reference. The image quality of MTT, TTP, and T _max maps deteriorated with decreasing temporal resolution.

Conclusion

The temporal resolution of DSC-MRI influences perfusion parameters and SMS DSC-MRI provides better image quality for MTT, TTP, and T _max maps.

     

Radiographic study of severe Influenza-A (H1N1) disease in children

Objective

To characterize the radiographic findings of pediatric patients with severe Influenza-A (H1N1) disease.

Methods

A retrospective study of data from chest X-ray, CT and MRI exam of 29 pediatric patients treated in intensive care unit for severe Influenza-A (H1N1) disease.

Results

Disease developed quickly at early stage. Here are four types of radiographic findings. The disease continued to progress for 2-3 days and X-ray showed that all 29 patients had increased solid lesions with the existence of interstitial lesions. Four days later, all lung lesions showed absorption to certain degree. Fifteen days later, X-ray and CT showed complete or significant absorption in 19 cases (85.5%); delayed recovery was identified in 8 cases (27.6%), pulmonary fibrosis was found in 3 cases (10.3%), and 3 patients (10.3%) died. But the latter identified more lesions. Cranial CT and MRI were performed for 8 patients who had neurological symptoms. Of them, 3 cases (10.3%) were abnormal, showed symmetrical long T1 and T2 signal shadow in bilateral thalamus and longer T1 and T2 signals in the between. 3 cases had autopsy completed.

Conclusion

The severe Influenza-A (H1N1) among children progression was generally rapid in the first 3 days. The overall radiographic findings are similar to acute respiratory distress syndrome (ARDS). A small portion of the patients occurred acute necrotizing encephalopathy and plastic bronchitis.     

Imaging of cholangiolocellular carcinoma of the liver

Aim

Cholangiolocellular carcinoma (CoCC) is currently considered to originate from hepatic progenitor cells. The purpose of this study was to evaluate the imaging features of cholangiolocellular carcinoma of the liver.

Materials and methods

Five cases of surgically resected cases of CoCC from 4 institutions were retrospectively evaluated. All of the five patients underwent contrast-enhanced dynamic CT. MRI and angio-CT including CT during arterioportography (CTAP) and CT during hepatic arteriography were performed in 3 and 2 patients, respectively. Histological evaluation was also performed and was correlated with radiographic findings.

Results

On dynamic CT or MRI, the lesions presented hypervascular tumors with delayed washout in 2 cases and in the other 3 cases, the lesions showed peripheral enhancement with concentric delayed filling. On CTAP, the continued existence of portal veins or tiny spots of portal flow was identified in the tumors. Fibrous capsule or tumor necrosis was not observed.

Conclusion

CoCC tumors have the dual imaging characteristics of hepatocellular carcinoma and cholangiocarcinoma. The absence of a fibrous capsule, the absence of tumor necrosis, peripheral location within the liver, and the presence of portal venous penetration within the tumor also appear to be characteristic features.