Evidence of diagnostic enhancement pattern in hepatocellular carcinoma nodules ≤2 cm according to the AASLD/EASL revised criteria

Purpose

To define the percentage of small (≤2 cm) hepatocellular carcinoma (HCC) nodules showing the diagnostic enhancement pattern at CEUS, computed tomography (CT), and gadobenate dimeglumine (Gd-BOPTA)—enhanced magnetic resonance (MR) imaging.

Methods

42 cirrhotic patients (26 male, 16 female; 67 ± 12 years) with 46 biopsy-proven HCCs ≤2 cm were included. Each HCC was scanned by CEUS, contrast-enhanced CT, and Gd-BOPTA-enhanced MR imaging. Nodule enhancement was evaluated by two readers. Independent analysis was followed by consensual analysis and the proportion of HCCs with the diagnostic enhancement pattern (nodule hyperenhancing on hepatic arterial phase and hypoenhancing on portal venous—late phase) on CEUS, CT, and MR imaging was compared by chi-square test.

Results

Very good inter-reader agreement was observed on hepatic arterial phase and portal venous—late phase: CEUS, k = 0.89 and 0.85; CT, k = 0.91 and 0.88; MR imaging, k = 0.96 and 0.94. CEUS and CT did not differ in the percentage of HCC nodules with a diagnostic enhancement pattern (18/46 and 16/46; P = 0.66), while MR imaging revealed the diagnostic pattern in higher percentage of nodules (29/46; P = 0.012) in comparison to CEUS and CT.

Conclusions

CEUS and contrast-enhanced CT did not differ in the percentage of small HCC nodules with diagnostic enhancement pattern, while Gd-BOPTA-enhanced MR imaging revealed the diagnostic pattern in a higher nodule number in comparison to CEUS and CT.     

Dynamic enhancing vascular pattern of intrahepatic peripheral cholangiocarcinoma on contrast-enhanced ultrasound: the influence of chronic hepatitis and cirrhosis

Purpose

To analyse the dynamic enhancing features by real-time contrast-enhanced ultrasound (CEUS) of intrahepatic peripheral cholangiocarcinoma (ICC) in patients with chronic hepatitis and cirrhosis.

Materials and methods

CEUS was performed by using contrast pulse sequencing (CPS) imaging with mechanical index of <0.2 after injection of 2.4 mL of contrast agent. CEUS images of histologically confirmed ICC in 54 patents (15 patents with chronic hepatitis B, 16 patents with cirrhosis, and 23 patents with normal underlying liver) were analyzed.

Results

Heterogeneous hyperenhancement was more frequently identified in ICC with chronic hepatitis (9 of 15, 60.0%, p = 0.000) and cirrhosis (8 of 16, 50.0%, p = 0.010) than in patients with normal liver (6 of 23, 26.1%) during arterial phase. The majority of ICC in patients with normal liver displayed peripheral hyperenhancement (13 of 23, 56.5%), than in patients with chronic hepatitis (4 of 15, 26.7%, p = 0.000) and cirrhosis (5 of 16, 31.3%, p = 0.001). Intense contrast uptake during the arterial phase (heterogeneous hyperenhancement or global hyperenhancement) followed by washout in venous phases was more frequently displayed in ICC patients with chronic hepatitis (11 of 15, 73.3%, p = 0.000) and in patients with cirrhosis (11 of 16, 68.8%, p = 0.000) than in ICC patients with normal underlying liver (8 of 23, 34.8%).

Conclusion

The enhancing vascular pattern of ICC on CEUS in patients with chronic hepatitis and cirrhosis is different from that in ICC without underlying liver disease. The enhancing vascular pattern is indistinguishable from HCC on CEUS in most ICC patients with chronic hepatitis or cirrhosis.     

Efficacy of the American Association for the Study of Liver Disease and Barcelona criteria for the diagnosis of hepatocellular carcinoma

Objectives

Dynamic contrast-enhanced CT scan and MRI are essential for preoperative diagnosis of hepatocellular carcinoma (HCC), using the established Barcelona and AASLD criteria, which have been validated in only a few reports. The aim of this study is to retrospectively assess the diagnostic performance of these criteria in diagnosing or excluding HCC in at-risk patients with histopathology confirmation.

Methods

After institutional review board approval, a HIPAA compliant study was performed. The study cohort consisted of 156 de novo hepatic nodules imaged by either dynamic contrast-enhanced CT or MRI within 90 days of histopathology. Images were retrospectively reviewed by two abdominal radiologists blinded to clinical details, and all nodules were categorized as either meeting or not meeting AASLD and Barcelona criteria. By AASLD or Barcelona criteria, HCC was defined as any nodule greater than or equal to 1 or 2 cm, respectively, with hyperenhancement relative to background liver on arterial phase and hypoenhancement relative to background liver on portal venous or delayed phases. Significant differences in cohorts were analyzed using chi squared analysis (p < 0.05).

Results

On biopsy, 141/156 (90.38%) nodules were diagnosed as HCC. The respective sensitivity, specificity, accuracy and positive predictive value of AASLD and Barcelona were 78.7% and 63.1% (sensitivity), 73.3% and 86.7% (specificity), 78.2% and 65.4% (accuracy), and 82% and 63% (positive predictive value) (p < 0.001).

Conclusions

Using established imaging criteria, up to 21.8% of presumed HCC nodules are inaccurately characterized and many small HCC nodules remain undiagnosed.     

Reliability of peripheral intraneural microhemodynamics evaluation by using contrast-enhanced ultrasonography

Purpose

The purpose of the study was to validate the reliability of quantitative intraneural enhancement patterns by using contrast-enhanced ultrasonography (CEUS).

Methods

Nine asymptomatic wrists underwent a total of three CEUS examinations each conducted at 1-month intervals. The CEUS enhancement pattern of median nerves was quantitatively evaluated. The area under the time–intensity curve was calculated by placing the regions of interest at the proximal, center, and distal regions of the median nerve. An intra-class correlation coefficient for intra-observer, inter-observer, and inter-examination reproducibility was calculated.

Results

The intra- and inter-observer reproducibility was almost perfect. Inter-examination reproducibility of the proximal, center, and distal regions was 0.891, 0.614, and 0.535, respectively. In this study, we found that the reproducibility of the distal and center regions of the median nerve in the carpal tunnel was lower than that of the proximal region.

Conclusion

High intra-observer, inter-observer, and inter-examination reproducibility of CEUS was obtained in the evaluation of the intraneural enhancement pattern when the region of interest was placed in the proximal region of the median nerve.     

Primary hepatic neuroendocrine carcinoma: MR imaging findings including preliminary observation on diffusion-weighted imaging

Purpose

To investigate MR imaging findings of primary hepatic neuroendocrine carcinoma (PHNEC) including preliminary observations on diffusion-weighted imaging (DWI).

Materials and methods

MR images of eight patients with pathologically confirmed PHNEC were retrospectively analyzed. The morphological characteristics and dynamic enhancement patterns were evaluated.

Results

One case showed a well-defined solitary nodule with homogenous hypointensity on T1-weighted imaging (T1WI) and hyperintensity on T2-weighted imaging (T2WI) and DWI. The remaining seven cases appeared as well-defined dominant masses with multiple satellite nodules. The dominant masses demonstrated heterogeneous hypointensity on T1WI and hyperintensity on T2WI, which all appeared as a marked enhancement at arterial phase and rapid washout at portal venous phase. Six cases demonstrated rim-like enhancement at equilibrium phase. The satellite lesions showed heterogeneous hypointensity on T1WI and marked hyperintensity on T2WI with variable enhancements, such as homogeneous, rim-like enhancement. All the dominant masses and satellite nodules appeared as markedly hyperintensity and reduced apparent coefficient (ADCs) values on DWI. The mean ADC value of the tumors was significantly lower than that of surrounding liver parenchyma (1.02 ± 0.57 vs. 2.24 × 10^?3 mm²/s, p = 0.000).

Conclusion

PHNECs typically appear as a large dominant hypervascular mass accompanied by satellite nodules, with rapid washout and capsular enhancement on dynamic MR imaging and restricted diffusion on DWI.     

Small intrahepatic mass-forming cholangiocarcinoma: target sign on diffusion-weighted imaging for differentiation from hepatocellular carcinoma

Purpose

To determine the differential MRI features of small mass-forming intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC).

Methods

Sixty-four patients with pathologically proven small ICCs (n = 32) and HCCs (n = 32) (≤3.0 cm in diameter) who had undergone preoperative gadoxetic acid-enhanced MRI and DWI were enrolled in this study. Images were analyzed for the shape of the lesions, the presence of biliary dilatation, hyperenhancement (>50 % of the tumor volume) or rim enhancement on the arterial phase, capsular enhancement, and the presence of target appearance (a central enhancement with hypointense rim) on the hepatobiliary phase and on DWI (a central hypointense area with a peripheral hyperintense rim). Statistical significance of these findings was determined by the χ² or Fisher’s exact test. Multivariate analysis was performed to identify independent imaging findings that allow differentiation of the two diseases.

Results

Univariate analysis revealed that the following significant parameters favor ICC over HCC: lobulating shape, rim enhancement on arterial phase, target appearance on the hepatobiliary phase, and DWI (P < 0.05). Multivariate logistic regression analysis revealed that only target appearance on the DWI was a significant and independent variable predictive of ICC, as 24 ICCs (75.0 %) and one HCC (3.1 %) showed this feature (P = 0.0003).

Conclusion

A target appearance on the DWI was the most reliable imaging feature for distinguishing small mass-forming ICC from small HCC.     

Contrast-enhanced magnetic resonance imaging of 102 nodules in cirrhosis: correlation with histological findings on explanted livers

Purpose

To analyze Gd-EOB-DTPA-enhanced magnetic resonance (MR) findings of nodules (low-grade dysplastic nodules—LGDNs; high-grade dysplastic nodules—HGDN, and hepatocellular carcinoma—HCC), histologically identified on cirrhotic, explanted livers.

Methods

IRB approval was obtained for this study. Thirty-four patients underwent Gd-EOB-DTPA-enhanced MR examinations (1.5T system), that included 20-min delayed hepatobiliary (HB) phase imaging, before undergoing orthotopic liver transplantation (OLT; mean time MR-OLT: 2.7 months). A total of 102 hepatic nodules were identified and analyzed at histopathological examination, and classified as LGDN, HGDN, and HCC. Two radiologists by consensus performed a quantitative (enhancement ratios, ERs) and a qualitative analyses of signal intensities of identified nodules on vascular dynamic phases (30–35 s after injection–arterial phase; 180–190 s after injection late phase) and on HB phases. Correlation between nodules MR patterns and histological classification was analyzed by means of dedicated statistical software.

Results

No differences were appreciable among ERs of HGDN and HCCs on HB phase (P > 0.001). Lesions’ enhancement on vascular dynamic and on HB phases significantly correlated to histological classification of nodules (P < 0.0001). Nodular hyperintensity on arterial phase and hypointensity on late phase were highly predictive for HCC (PPV 100%), with a moderate sensitivity (72.5%). Nodular hypointensity on HB phase was detected on 39/40 HCCs (sensitivity 97.5%) and in 21/30 HGDNs, whereas no LGDN showed it.

Conclusions

Hyperenhancement on arterial phase and hypointensity on late phase are the most specific clues for the diagnosis of HCC. Hypointensity on HB phase shows a PPV of 100% in suggesting nodular premalignancy/malignancy, independently from nodular dynamic vascular enhancement.     

Central vascular structures as a characteristic finding of regenerative nodules using hepatobiliary phase gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced MRI and arterial dominant phase contrast-enhanced US

Objective

We investigated the characteristic findings of regenerative nodules (RNs) for differentiating early hepatocellular carcinoma (HCC) from high-grade dysplastic nodules (HGDNs) using magnetic resonance imaging (MRI) with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA; EOB-MRI) and contrast-enhanced ultrasonography (CEUS) in patients with chronic liver disease.

Subjects and methods

Pathologically confirmed lesions (100 early HCCs, 7 HGDNs, and 20 RNs with a maximum diameter of more than 1 cm and mean maximal diameters of 15.5, 15.1, and 14.8 mm, respectively) were enrolled in this retrospective study. The signal intensities of these lesions during the hepatobiliary phase of EOB-MRI were investigated, and findings characteristic of RNs using this modality were also evaluated using CEUS.

Results

Ninety-eight of the 100 early HCCs that were hypo-intense (n = 95), iso-intense (n = 2), or hyper-intense (n = 1) and the seven HGDNs that were hypo-intense (n = 6) or hyper-intense (n = 1) during the hepatobiliary phase of EOB-MRI exhibited centripetal vessels during the arterial dominant phase of CEUS, although one early HCC that was hypo-intense exhibited both centrifugal and centripetal vessels. Eighteen of the 20 RNs and one early HCC that were hyper-intense with a small central hypo-intensity and the remaining two RNs that were hyper-intense on EOB-MRI exhibited centrifugal vessels during the arterial dominant phase of CEUS. The small central hypo-intense area corresponded to central vascular structures in the lesion, such as the hepatic artery and portal vein running from the center to the periphery, when viewed using CEUS.

Conclusion

Central vascular structures may be a characteristic finding of RNs when observed during the hepatobiliary phase of EOB-MRI and the arterial dominant phase of CEUS.

     

Pharmacotherapy Choice Is Associated with 2-Year Mortality for Patients with Heart Failure and Reduced Ejection Fraction

Introduction

Factors associated with mortality for patients with heart failure and reduced ejection fraction (HFrEF) are known; however, the association between initial pharmacotherapy (IPT) and mortality is unclear in real-world settings.

Methods

Using a retrospective design and claims database, 14,359 Medicare patients with HFrEF from August 2010 to July 2015 were identified. Index date was first HF claim. IPT was mono- or combo-angiotensin-converting enzyme inhibitor (ACEI), angiotensin II receptor blocker (ARB), beta-blocker (BB), hydralazine–nitrate (HN), and aldosterone antagonist (AA) within 1 year post-index. A multivariable time-dependent Cox model estimated associations between IPT and 2-year all-cause mortality.

Results

Patients’ median age was 76 (70–82) years; 45.1% were female. Within 1 month post-index, 61.4% had IPT, 6.1% started after the first month, and 32.4% had no IPT in the first year. Of IPTs, 47.5% were mono-vasodilators (ACEI, ARB or HN), 23.3% mono-vasodilator + BB, 16.9% mono-BB, and 3.5% triple therapy [(ACEI or ARB) + BB + (HN or AA)]. Two-year mortality rate was 27.9%. Compared to mono-vasodilator therapy, patients initiating triple therapy had 29.3% lower risk of 2-year mortality; those on mono-BB or no IPT had higher mortality risk.

Conclusion

IPT was associated with decreased 2-year mortality risk. Timely consideration of triple IPT therapies may be warranted once HFrEF diagnosis is confirmed.

Funding

Novartis Pharmaceuticals Corp. located in East Hanover, NJ, USA.

     

Improved outcome of percutaneous radiofrequency ablation in renal cell carcinoma: a retrospective study of intraoperative contrast-enhanced ultrasonography in 73 patients

Objectives

To evaluate the impact of contrast-enhanced ultrasonography (CEUS) during percutaneous radiofrequency ablation (PRFA) procedure in renal cell carcinoma (RCC).

Methods

From January 2008 to July 2010, 73 patients with sporadic unilateral RCC were enrolled to our study (57 men and 16 women, age range: 37–78 years, mean age 57.9 years). The diameter of the tumor was 1.7–5.8, 3.4 cm on average. The patients were divided into two groups depending on the intraoperative ultrasonography type: CEUS group and conventional ultrasound group. Patients in CEUS group received CEUS before insertion of the electrode, and the second CEUS was performed right after the initial ablation to dynamically evaluate the images. If there was highly suspicious residue, additional ablation and repeated CEUS were applied. Patients in the conventional ultrasound group received PRFA guided by gray-scale ultrasound. All of these patients received contrast-enhanced computed tomography (CT) examination 7 days after the procedure (patients in CEUS group received CEUS conducted with each CT scan), with subsequent CT and CEUS assessment at 3, 6, and every 6 months thereafter.

Results

The mean follow-up period was 22 months (range: 12–42 months). All tumors were biopsied before RFA. The local tumor control rate was 94.6% (35/37) in the CEUS group and 86.1% (31/36) in the conventional ultrasound group (P < 0.05); the cancer-specific survival rate and the overall survival rate were 100%. The post-RFA (12 months) mean GFR levels were 84.7 ± 27.5 mL/min/1.73 m² (P > 0.05, compared with pre-GFR: 86.4 ± 26.2 mL/min/1.73 m²) in the CEUS group and 81.9 ± 22.8 mL/min/1.73 m² (P > 0.05, compared with pre-GFR: 83.5 ± 23.7 mL/min/1.73 m²) in the conventional ultrasound group.

Conclusion

Intraoperative CEUS can “real-time” monitor the ablated area during PRFA procedure. This technique can help to achieve a higher success rate compared with conventional ultrasound. No impact of intraoperative CEUS has been found on GFR level.     

B-flow imaging of vascular structure for the diagnosis of liver tumor

Purpose

B-flow is a non-Doppler-based technology for visualizing blood flow and has a high spatial resolution. The aim of this study is to evaluate the blood flow information of liver tumors using B-flow in comparison with color Doppler sonography (CDS).

Methods

Seventy-nine patients with 82 hepatic nodules were studied using B-flow and CDS. The study group included 45 HCC nodules, 23 liver metastasis nodules, four intrahepatic cholangiocarcinomas (ICC), and 13 hemangiomas. The visualized vascularity and morphological findings of the hepatic tumor vessel were evaluated.

Results

B-flow showed multiple vessels in 48 nodules (58.5 %) and a single vessel in 13 nodules (15.9 %). CDS showed multiple vessels in 44 nodules (53.7 %) and a single vessel in 23 nodules (28.0 %). Multivariate analysis showed basket pattern was significant for HCC (OR 49.263; p = 0.0002), and penetrating vessel was significant for liver metastasis or ICC (OR 14.545; p < 0.0001).

Conclusion

B-flow detects hepatic tumor blood flow with sensitivity as high as that of CDS. Vascular structure information obtained using B-flow could be potentially used to diagnose liver tumors.     

Differentiating malignant from benign thrombosis in hepatocellular carcinoma: contrast-enhanced ultrasound

Background

To determine the accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating malignant and benign venous thrombosis complicating hepatocellular carcinoma (HCC).

Methods

Fifty patients (M:F = 41:9; age range 46–83 years) with HCC and venous thrombosis [portal vein (PV) in 45 and hepatic vein (HV) in 5] detected on CT or MR scan were evaluated with CEUS. Reference standard of malignant and benign thrombosis was based on serial clinicoradiologic follow-up (n = 43) or pathology (n = 7). Two independent, blinded readers retrospectively recorded the enhancement features of the venous thrombosis and diagnosed as benign or malignant thrombosis with a five-point confidence scale. Receiver operating characteristic (ROC) curves were calculated to determine the diagnostic performance of CEUS in differentiating malignant from benign thrombosis. Confidence level ratings were also used to calculate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the diagnosis of malignant thrombosis. Inter-reader agreement was calculated using κ statistics in each assessed finding. Gray scale and Doppler characteristics of primary tumor and thrombosis were also assessed.

Results

Of the 50 patients, 37 were malignant (33 with PV thrombosis and 4 with HV thrombosis) and 13 were benign (12 with PV thrombosis and 1 with HV thrombosis). In ROC curve analysis for differentiating malignant from benign thrombosis, Az was 0.947 (CI 0.841–0.991) for reader 1 and 0.958 (CI 0.861–0.995) for reader 2 with excellent inter-reader agreement (κ = 0.86). When the confidence level ratings of 1 or 2 were considered malignant thrombosis, the sensitivity, specificity, PPV, and NPV in differentiating malignant from benign thrombosis were 100%, 83%, 95%, and 100% for reader 1 and 100%, 92%, 97%, and 100% for reader 2.

Conclusion

CEUS is useful to differentiate malignant and benign venous thrombosis associated with HCC with high diagnostic accuracy.     

Contrast-enhanced ultrasonography for blood flow detection in hepatocellular carcinoma during lenvatinib therapy

Purpose

Blood flow reduction after initiation of lenvatinib therapy may not always indicate tumor necrosis. This study aimed to compare the blood flow detectability of contrast-enhanced ultrasonography (CEUS), contrast-enhanced computed tomography (CT), and contrast-enhanced magnetic resonance imaging (MRI) in hepatocellular carcinoma (HCC) during lenvatinib therapy.

Methods

A total of 12 cases underwent CEUS and contrast-enhanced CT/MRI within 2 weeks during lenvatinib therapy. Vascularity on CEUS and CT/MRI was compared.

Results

At the time of CEUS examination, the median period from the start of lenvatinib was 227?±?210 (31–570) days. CEUS showed hyperenhancement in eight cases (66.7%), hypoenhancement in two cases (16.7%), and no enhancement in one case (8.3%), while CT/MRI showed hyperenhancement in one case (8.3%), ring enhancement in three cases (25.0%), and hypoenhancement in eight cases (66.7%) (p?=?0.007). Transarterial chemoembolization (n?=?3), radiofrequency ablation (n?=?2), and stereotactic body radiation therapy (n?=?2) were performed after blood flow detection by CEUS.

Conclusions

The viability of the HCC should be confirmed using CEUS when contrast-enhanced CT/MRI reveals lesion hypoenhancement during lenvatinib therapy.

     

Evaluation of sorafenib for advanced hepatocellular carcinoma with low α-fetoprotein in arrival time parametric imaging using contrast-enhanced ultrasonography

Purpose

To determine the usefulness of arrival time parametric imaging (AtPI) using contrast-enhanced ultrasonography (CEUS) with Sonazoid in evaluating early response to sorafenib for hepatocellular carcinoma (HCC).

Methods

Twenty-one advanced HCC patients with low α-fetoprotein (AFP) levels (≤35 ng/ml) who received sorafenib for at least 4 weeks were enrolled in this study. CEUS was performed before and 2 weeks after treatment, and the images of the target lesion in the arterial phase were analyzed by AtPI. In the color mapping images obtained by AtPI, the mean arrival time of the contrast agent in the target lesion from the reference point (mean time: MT) was calculated. In each patient, differences between MT before and MT 2 weeks after treatment were compared. MT (+) and MT (?) groups were defined as difference of 0 s or greater and less than 0 s, respectively. Overall survival was evaluated between the two groups.

Results

In the MT (+) (11 patients) and MT (?) (10 patients) groups, the median survival time was 792 and 403 days, respectively, which was statistically significant.

Conclusions

The results suggested that AtPI was useful for evaluating early response to sorafenib for advanced HCC with low AFP level.

     

Hepatic angiosarcoma: cross-sectional imaging findings in seven patients with emphasis on dynamic contrast-enhanced and diffusion-weighted MRI

Objective

Primary hepatic angiosarcoma is a very rare and aggressive malignancy of vascular origin. We describe cross-sectional imaging findings of this entity with emphasis on dynamic contrast-enhanced (DCE) and diffusion-weighted (DWI) MR imaging.

Methods

Seven cases of pathologically confirmed hepatic angiosarcoma were retrospectively reviewed (CT and MRI examinations were available in seven and six patients, respectively). Two radiologists evaluated lesion growth patterns, attenuation, signal intensity characteristics, contrast enhancement patterns, and apparent diffusion coefficients (ADCs).

Results

Multifocal hepatic disease was present in six patients by means of a mixed pattern of large dominant masses and multiple small nodules; one patient had a solitary large mass. Unenhanced images depicted hemorrhagic areas and a markedly heterogeneous internal architecture within large tumors. Contrast-enhanced early phase images showed variable patterns including patchy peripheral or bizarre shaped intralesional foci of enhancement, peripheral rim enhancement, and small lesions without enhancement. On DCE images, the majority of lesions presented with varying degrees of progressive enhancement. Small nodules frequently displayed homogeneous enhancement on delayed phase images due to complete fill-in. DWI revealed a high interlesional variability of ADC values (range 0.57–2.41 × 10^?3 mm²/s, mean 1.37 × 10^?3 mm²/s).

Conclusion

Cross-sectional imaging findings of hepatic angiosarcoma reflect the varied histopathological composition of the tumors. Multifocal disease, hemorrhage within large lesions, as well as progressive enhancement on DCE images are typical features of hepatic angiosarcoma. The mean ADC of lesions was found to be slightly elevated in comparison with other hepatic malignancies.

     

Comparison of CT and contrast-enhanced ultrasound findings in hepatic angiomyolipoma with pathological correlations

Objective

To compare imaging findings of CT and contrast-enhanced US (CEUS) in hepatic angiomyolipoma (HAML) and investigate their pathological correlations.

Methods

Imaging findings and preoperative diagnosis of CT and CEUS were retrospectively compared head to head in 46 patients with 54 histologically proven HAMLs. Correlations between imaging features and preoperative diagnosis with pathological types of HAMLs were analyzed.

Results

Fat was detected in 100% of lipomatous type, 84.6% of mixed type, and 7.1% of myomatous type (p = 0.000) of HAML at unenhanced CT. Well-defined hyper-echogenicity was displayed in 100% of lipomatous type, 88.5% of mixed type, 50% of myomatous type, and 66.7% of angiomatous type of HAMLs at unenhanced US. More arterial hyper-enhancement was noted on CEUS (100%) than on CT (73.1%) in mixed type (p = 0.015) and in lipomatous type (90.9% vs. 9.1%, p = 0.000) of HAMLs. Washout was present in more HAMLs on CT than on CEUS (42.6% vs. 18.5%, p = 0.007). Correct preoperative diagnosis was suggested in more HAMLs of myomatous type on CEUS than on CT (42.9% vs. 0%, p = 0.016) but showed no difference in other types of HAMLs.

Conclusion

There are considerable discrepancies between CT and CEUS findings of HAMLs, and the imaging appearance and preoperative diagnosis of HAMLs on CT and CEUS are significantly affected by pathological types of HAMLs.

     

Multi-modality imaging findings of splenic hamartoma: a report of nine cases and review of the literature

Purpose

To investigate the presentation of splenic hamartomas (SHs) on ultrasonography (US), CT and MRI.

Methods

Nine patients (5 males and 4 females, mean age, 52.8 years) with pathologically proven SHs were included in this study. US, CT and MRI images were analyzed retrospectively, and imaging features were correlated with pathological findings.

Results

SHs appeared solitary lesion (n = 8) and multiple lesions (n = 1) in the present study. (1) In 8 cases of solitary lesion, the lesions appeared as solid nodules or masses with well-defined margins and varying echogenicity (hyperecho = 5, hypoecho = 2, strong echo = 1) on ultrasound. The lesions showed iso-attenuation (n = 3) or slightly hypo-attenuation (n = 4) on unenhanced CT, and calcification were revealed in 3 lesions. MRI showed isointensity (n = 3) or hypointensity (n = 2) on the T1-weighted image, and heterogeneous hypointensity (n = 2), slightly hyperintensity (n = 2) and hyperintensity (n = 1) on the T2-weighted image. The enhanced patterns of SHs showed mild diffuse heterogeneous enhancement (n = 6) and prominent enhancement (n = 1) during arterial phase and above 7 lesions were demonstrated progressive enhancement at delayed phase on enhanced CT. One lesion without any enhancement was revealed in another patient. (2) One case of multiple lesions included 1 cystic lesion with irregular calcification and 7 solid lesions with progressive enhancement on CT images.

Conclusions

Combination of a variety of imaging modalities could more fully reflect the pathological characteristics and contribute to the diagnosis of SH.     

Hybrid method for the detection of pulmonary nodules using positron emission tomography/computed tomography: a preliminary study

Purpose

In this study, an automated scheme for detecting pulmonary nodules using a novel hybrid PET/CT approach is proposed, which is designed to detect pulmonary nodules by combining data from both sets of images.

Methods

Solitary nodules were detected on CT by a cylindrical filter that we developed previously, and in the PET imaging, high-uptake regions were detected automatically using thresholding based on standardized uptake values along with false-positive reduction by means of the anatomical information obtained from the CT images. Initial candidate nodules were identified by combining the results. False positives among the initial candidates were eliminated by a rule-based classifier and three support vector machines on the basis of the characteristic features obtained from CT and PET images.

Results

We validated the proposed method using 100 cases of PET/CT images that were obtained during a cancer-screening program. The detection performance was assessed by free-response receiver operating characteristic (FROC) analysis. The sensitivity was 83.0 % with the number of false positives/case at 5.0, and it was 8 % higher than the sensitivity of independent detection systems using CT or PET images alone.

Conclusion

   Detection performance indicates that our method may be of practical use for the identification of pulmonary nodules in PET/CT images.     

MRI manifestations of adult choledochal cysts associated with biliary malignancy: a report of ten cases

Background

To retrospectively review the MRI imaging features of adult choledochal cysts associated with biliary malignancy.

Patients and methods

Ten out of 72 cases of adult choledochal cysts were found to be associated with biliary malignancy between January 1, 2003 and April 1, 2011 in our hospital database. The following MRI findings of these ten patients were retrospectively reviewed: the type of choledochal cysts, the presence of anomalous union of the pancreaticobiliary duct (AUPBD), manifestations of biliary malignancy, and concomitant findings.

Results

Among the ten patients, there were five type I and five type IVA choledochal cysts. AUPBD was noted in four cases. The biliary malignancy was diagnosed as cholangiocarcinoma in seven cases (70.0%) and as gallbladder cancer in three cases. Cholangiocarcinoma manifested with irregularly thickened cyst wall (n = 2), mass with irregularly thickened cyst wall (n = 4), or multiple papillary nodules without thickened cyst wall (n = 1). Most of them showed mark enhancement (n = 4) after contrast administration. Gallbladder cancer appeared as mass with irregular thickening of the gallbladder wall with inhomogeneous enhancement. Concomitant findings included liver invasion or metastases in five cases, lymph node metastases in two cases, cholangitis and/or hepatic abscess in two cases, biliary stones in three cases. The type of choledochal cysts and the extent of malignant tumor invasion revealed by MRI were consistent with the surgical findings.

Conclusion

Most malignancies associated with choledochal cysts are cholangiocarcinoma and gallbladder cancer. MRI is a reliable method for the detection of choledochal cysts with biliary malignant changes. MR features such as irregular thickening of the gallbladder wall or cyst wall, mass or papillary nodules are suggestive of biliary malignant changes.     

Half-dose gadobenate dimeglumine versus standard-dose gadodiamide in dynamic magnetic resonance imaging of non-cirrhotic livers: a retrospective intra-individual crossover comparison

Purpose

The purpose of this study was to compare enhancement characteristics of half-dose gadobenate dimeglumine (0.05 mmol kg^?1) with standard-dose gadodiamide (0.10 mmol kg^?1), in the assessment of hepatic vessels and lesions, using retrospective intra-individual crossover comparison methodology.

Methods

Ethics committee approval was obtained. From 2004 to 2012, 21 patients underwent MRI examination with both standard-dose gadodiamide and half-dose gadobenate dimeglumine, using the same liver MRI protocol at 1.5 T. Eighteen patients whose scans showed no artifacts were selected. Quality of liver lesion [12 hemangiomas, 7 focal nodular hyperplasias (FNHs)] and liver vessel enhancement, and the global diagnostic quality of studies were ranked on a scale of 1–4 by two independent radiologists. Contrast-to-noise ratio (CNR) and % enhancement of liver vessels and lesions were calculated based on region of interest, signal intensity, and noise standard deviation measurements performed at 0, 20 s, 1, 3, and 5 min post-contrast injection. Qualitative and quantitative results were compared using the paired Wilcoxon signed rank and Student’s t-tests, respectively.

Results

No qualitative differences were noted in enhancement of liver vessels, hemangiomas, and FNHs. There was no statistically significant difference between the global diagnostic qualities of scans performed with the two contrast agents. Quantitatively, liver vessels and hemangiomas did not demonstrate statistically significant differences in contrast enhancement. At 20 s, FNHs achieved higher CNR (P = 0.02) with gadodiamide.

Conclusion

Half-dose gadobenate dimeglumine results in similar contrast enhancement compared to standard-dose gadodiamide in assessment of liver vessels, hemangiomas, and FNHs, and is a reasonable alternative to standard doses of extracellular agents in dynamic liver MRI.