Benign Hepatic Lesions Research Articles

Hepatic capsular retraction: spectrum of diagnosis at MRI.

Hepatic capsular retraction is an imaging feature that deserves the attention of the radiologist. Hepatic capsular retraction is associated with a number of hepatic lesions, benign or malignant, treated or untreated. The purpose of this pictorial review is to discuss the most common benign and malignant hepatic lesions associated with this feature with an emphasis on magnetic resonance imaging (MRI).

Ocena przydatności obrazowania dyfuzji metodą rezonansu magnetycznego w diagnostyce różnicowej łagodnych i złośliwych zmian ogniskowych w wątrobie

Introduction. Despite the use of multiple diagnostic imaging techniques, a non-invasive differential diagnosis of focal lesions in the liver is still a challenging task. It is even more significant, considering the risk of complications related to liver biopsy. On the other hand, the availability of non-invasive radiological and diagnostic imaging methods has resulted in the increased detectability of incidental hepatic lesions. Therefore, further investigation of newer and more effective methods of differentiating benign from malignant hepatic lesions is extremely useful. The aim of the study was to assess the diagnostic value of Diffusion-Weighted Magnetic Resonance Imaging (DW MRI) in differentiating benign from malignant focal lesions in the liver. Material and methods. Fifty one patients with hepatic lesions detected by magnetic resonance (MR) examination were enrolled in the study. Each lesion was then verified histopathologically, cytologically, or by observation. Ninety five (71 malignant and 24 benign) hepatic focal lesions were analysed. Apart from a standard MR liver examination, an echo planar imaging spin echo diffusion weighted sequence was performed, with a slice thickness of 5 or 6 mm. The maximal b-value was 1000 s/mm 2 and the minimal 0 s/mm 2 .In the study, the following were assessed: the presence of restricted diffusion, an absolute ADC (apparent diffusion coefficient) value, the decrease of signal intensity in DW MRI with an increase in the b-value. Results. Confirming or ruling out the restricted diffusion is usually the first effective step in differentiating benign from malignant hepatic lesions, as indicated in the study results. In the material analysed, the diffusion restriction occurred statistically significantly more frequently in malignant (87.3 %) compared to benign lesions (12.5%), (p 1.04 × 10 -3 mm2/s to be benign and lesions with ADC value ≤ 1.04 × 10 -3 mm 2 /s to be malignant, 75.8% lesions were correctly classified. Conclusions. The results obtained indicate that restricted diffusion, as a marker for malignant lesions, has the highest value in DW MRI in differentiating benign from malignant lesions in the liver.

Differential diagnosis between hepatic metastases and benign focal lesions using DWI with parallel acquisition technique: a meta-analysis.

We aim to investigate the diagnostic capability of diffusion-weighted imaging using parallel acquisition technique for the differentiation between hepatic metastases and benign focal lesions with a meta-analysis. The meta-analysis included a total of 858 hepatic metastases and 440 benign liver lesions from nine studies. The pooled sensitivity and specificity of diffusion-weighted imaging (DWI) were 0.87 (95% CI, 0.84-0.89) and 0.90 (95% CI, 0.87-0.93), respectively. The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 8.50 (95% CI, 4.97-14.52) and 0.17 (95% CI, 0.11-0.26), respectively. The P value for χ (2) heterogeneity for all pooled estimates was <0.05. From the fitted summary receiver operating characteristics (SROC), the area under the curve (AUC) and Q* index were 0.95 and 0.88, respectively. Publication bias is not present (t = -0.76, P = 0.471). The meta-regression analysis indicated that evaluated covariates included patient number, patient population, mean age, maximum of b factor, number of cysts, number of hemangiomas, and field were not sources of heterogeneity (all P value >0.05). Diffusion-weighted imaging was useful for differentiation between hepatic metastases and benign focal lesions. The diffusion characteristics of the benign hepatocellular lesions, including cases of focal nodular hyperplasia (FNH) and adenoma, have rarely been reported and need further studies. The diagnostic capability of DWI with parallel acquisition technique for differentiation between metastases and benign hepatic focal lesions might be overestimated.

Is DWI/ADC a useful tool in the characterization of focal hepatic lesions suspected of malignancy?

ObjectiveApparent diffusion coefficient (ADC) values calculated through magnetic resonance imaging have been proposed as a useful tool to distinguish benign from malignant liver lesions. Most studies however included simple cysts in their analysis. Liver cysts are easy to diagnose, have very high ADC values and their inclusion facilitates differentiation in the ADC values between benign and malignant liver lesions groups. We prospectively evaluated the ability of ADC values to differentiate metastatic liver lesions from all benign or only solid benign liver lesions.Material and MethodsSixty-seven adult cancer patients with 188 liver lesions were evaluated. Lesions were categorized as metastatic or benign throughout imaging and clinical evaluation. One hundred and five (105) metastatic lesions and 83 benign lesions including hemangiomas (37), cysts (42), adenomas (2) and focal nodular hyperplasias (2) were evaluated. ADC values were calculated for each lesion utilizing two b values (0 and 600 sec/mm2).ResultsThe average ADC value for cysts was 2.4×10−3 mm2/sec (CI: 2.1–2.6), for solid benign lesions was 1.4×10−3 mm2/sec (CI: 1.1–1.7) and for metastases was 1.0×10−3 mm2/sec (CI: 0.8–1.3). There was a difference between the ADC values of metastases and benign solid lesions (p<0.0001). With the ADC value of 1.5×10−3 mm2/sec as a cut off it is possible to distinguish metastatic from benign liver lesions, including cysts, with an accuracy of 78%. But to distinguish metastatic from benign solid liver lesions the best ADC cut off value was 1.2×10−3 mm2/sec and the accuracy drops to 71%.ConclusionsADC values proved to be helpful in the distinction between metastasis and benign solid hepatic lesions. But the exclusion of cysts in the analysis point out to a lower cut off value and lower accuracy than previously reported.

Diffusion tensor imaging of cysts, hemangiomas, and metastases of the liver

Although diffusion-weighted magnetic resonance imaging imaging (DW-MRI) is commonly used to characterize hepatic lesions, the literature is sparse about the use of MR diffusion tensor imaging (DTI) in this regard. By using DTI, one is able to obtain not only apparent diffusion coefficients (ADCs) but also fractional anisotropy (Fa) values. To evaluate DTI using ADC and Fa values in the imaging of hepatic cysts, hemangiomas, and metastases. Sixty-six patients with 77 lesions were examined with DTI. There were 32 metastases, 13 cysts, and 32 hemangiomas. Two radiologists performed ADC and Fa measurements. Inter-observer agreement was evaluated using Bland-Altman plots. ADCs and Fa values were correlated using Pearson correlation. The differences were compared using ANOVA and Tukey tests. A ROC analysis was applied; sensitivities and specificities were calculated. The inter-observer agreement was very good. The correlation between ADC and Fa was negative, weak, and significant (r = -0.36). The mean ADC value of cysts (3.30 ± 0.8 × 10(-3) mm(2)/s) was significantly higher than that of hemangiomas (2.23 ± 0.5 × 10(-3) mm(2)/s) and metastases (1.62 ± 0.4 × 10(-3) mm(2)/s). The mean Fa value of cysts (0.2 ± 0.05) was significantly lower than hemangiomas (0.37 ± 0.1) and metastases (0.46 ± 0.1). The Az values for discriminating metastases from benign hepatic lesions for ADC and Fa value were 0.885 and 0.731, respectively. The sensitivity and specificity of ADC and Fa were 87.5% and 84.4%, and 78.1% and 57.8%, respectively. The Az value for discriminating cysts from hemangiomas for Fa was 0.96. The sensitivity and specificity were 90.6% and 92.3%, respectively. Fa values may play a supportive role in the imaging of liver lesions. Whereas metastases tend to have low ADCs and high Fa values, cysts have high ADCs and low Fa values and hemangiomas have high ADCs and high Fa values.

Application of virtual touch tissue quantification in the differential diagnosis of benign and malignant hepatic lesions

Objective To explore the clinical application value of virtual touch tissue quantification (VTQ) in the differential diagnosis of focal liver lesions.Methods 174 patients with 194 focal liver lesions and 60 healthy volunteers were enrolled in this study,shear wave velocity(SWV) of lesions,background liver parenchyma and healthy liver were evaluated with VTQ examination.Statistical analysis was performed on the SWV for the differentiation of normal liver,background liver parenchyma and lesions.The cut-off point for SWV was obtained by using ROC curve analysis which was used to predict malignancy lesions.Results The SWV of malignant lesions was significantly higher than that of benign ones [(2.83 ± 0.91)m/s vs (1.83 ± 0.64)m/s,P =0.000].The SWV of healthy liver was significantly lower than both malignant and benign lesions(P ＜0.01).Based on 2.19m/s as the cut-off point of SWV value,the sensitivity,specificity,accuracy,positive predictive value and negative predictive value for diagnosing malignancies were 82.5％,75.4％,77.03％,81.16％,78.9％ respectively.Conclusions VTQ technology could provide complementary information regarding the tissue stiffness,which is useful for the differential diagnosis of focal liver lesions. Key words: Ultrasonography; Liver neoplasms; Virtual touch tissue quantification

Expression of novel metastasis-promoting gene 1 and its clinical significance in hepatocellular carcinoma

To explore the expression of NVM-1(novel metastasis-promoting gene 1) in hepatocellular carcinoma (HCC) tissue and examine its clinical significance. The expression of NVM-1 in 92 cases of HCC tumor tissues and non-tumor tissues was detected by immunohistochemical staining with SP (streptavidin-perosidase). And its clinical significance was evaluated. The staining of NVM-1 was predominantly located in the nucleus of HCC tumor tissue. The positive rate of NVM-1 was 52.2% in all detected cancers and it was higher than that in control non-tumor tissues (28.3%) and benign hepatic lesions (0) . A significant difference of positive rates existed between tumor and non-tumor tissues (P < 0.05). The expression of NVM-1 in HCC was not correlated with hepatic B virus (HBV), size, amount or cirrhosis, etc. However, it was correlated with TNM (P = 0.016), BCLC stage (P = 0.015), poor differentiation (P = 0.000), intrahepatic metastasis (P = 0.002), portal vein tumor thrombus (P = 0.023) and recurrence (P = 0.001). By Kaplan-Meier analysis, the median tumor-free survival time was 5 months in positive expression group and it was significantly shorter than 13 months in negative expression group (P = 0.001). There is probably a close relation between recurrence and metastasis and the expression of NVM-1 in HCC.

Risk factors for bleeding in hepatocellular adenoma.

Hepatocellular adenoma (HCA) is a benign hepatic lesion that may be complicated by bleeding, although the risk of bleeding is ill-defined. The aim of this study was to assess risk factors for bleeding in patients diagnosed with HCA. Patients with HCA were included prospectively from January 2008 to July 2012. Patient characteristics were noted. Patients underwent dynamic magnetic resonance imaging (MRI) and/or computed tomography (CT) at presentation and during follow-up. Lesion characteristics on (follow-up) imaging were noted, and bleeding was graded as intratumoral (grade I), intrahepatic (grade II) or extrahepatic (grade III). The standard of reference for diagnosis was histopathology, or dynamic MRI and/or CT findings. Possible risk factors were included if mentioned in literature (lesion size, body mass index), or based on clinical experience (lesion location, visible vessels on imaging). A total of 45 patients (median age 39 (range 22-60) years; 44 women) with 195 lesions (median size 24 (10-250) mm) were evaluated. Bleeding occurred in 29 patients (64 per cent) and in 42 lesions (21.5 per cent) with a median size of 62 (10-160) mm. Size was a risk factor for bleeding (P < 0.001), with an increased number of bleeding events in lesions of 35 mm or more. Exophytic lesions (protruding from liver) had more bleeding (16 of 24, 67 per cent) than intrahepatic (9 of 82, 11 per cent) or subcapsular (17 of 89, 19 per cent) lesions (P < 0.001). Lesions in segments II and III had more bleeds than those in the right liver (11 of 32 versus 31 of 163; P = 0.049), as did lesions in which peripheral or central arteries were visualized on imaging (10 of 13 versus 32 of 182 lesions with no visible vascularization; P < 0.001). Risk factors for bleeding of HCA include diameter of 35 mm or more, visualization of lesional arteries, location in the left lateral liver, and exophytic growth.

The role of MR diffusion in differentiation of malignant and benign hepatic focal lesions

AimTo determine if focal liver masses could be differentiated as benign or malignant by DWI and ADC maps. Methods and materialsSixty focal liver lesions were scanned using 1.5T MRI. DWI was performed with b 0, b 500 and b 1000 gradients with ADC measurements. Comparison of mean ADC values between each benign and malignant lesion was done. Reference standard of diagnosis was obtained by correlating DWI with histopathologic findings and imaging follow-up. The accuracies of DWI and ADC values were assessed with the Student’s t test, and cut-off values were determined with receiver operating characteristic curve analysis. ResultsWhen ADC value of 1.0×10−3mm2/s was used as a threshold value for differentiation of malignant tumors from benign lesions, sensitivity was 90.3%, specificity 78.57% and accuracy 86.7%. The best result was obtained with the use of ADC cut off value (at b 500) of 1.5×10−3mm2/s and ADC cut off value (at b 1000) of 1.0×10−3mm2/s, with 90.3% sensitivity, 92.86% specificity, 91.1% accuracy, 96.6% positive predictive value and 81.3% negative predictive value. ConclusionDWI and ADC map is a useful tool in differential diagnosis of malignant from benign liver lesions.

Tumors of the Liver and Biliary Tract

This review discusses several different types of tumors that affect the liver, biliary tree, and gallbladder. Primary and secondary liver cancers are discussed, including hepatocellular carcinoma, intrahepatic cholangiocarcinoma, colorectal metastases, neuroendocrine metastases, and noncolorectal, nonneuroendocrine metastases. Clinical evaluation, investigative studies, tumor staging, and treatment options are presented for each. Benign or premalignant hepatic lesions are also discussed, including the appropriate workup and surgical options for hemangioma, hepatic adenoma, focal nodular hyperplasia, and nonparasitic cystic tumors. Cancers of the biliary tract (cholangiocarcinomas) are subdivided into intrahepatic and extrahepatic cholangiocarcinomas. The latter are subdivided into hilar and distal cholangiocarcinoma; their clinical evaluation, investigative studies, staging, and management are discussed. The clinical evaluation, investigative studies, testing, imaging, staging, and management are presented for gallbladder cancer, including incidentally discovered gallbladder cancer and gallbladder polyps. Figures include the anatomic divisions of the liver and Brisbane terminology for resections, CT and MR images showing characteristic features of the liver and biliary tract tumors, Bismuth-Corlette classification of hilar cholangiocarcinoma, and algorithms for the management of hepatocellular carcinoma and neuroendocrine metastases. Tables include the American Joint Committee on Cancer’s classification and staging systems for hepatocellular carcinoma, cholangiocarcinoma, and gallbladder cancer; Brisbane terminology for liver resections; and neuroendocrine tumors with their corresponding biochemical markers. This review contains 14 figures, 7 tables, and 83 references.

Diffusion-Weighted MR Imaging of the Benign Hepatic Focal Lesions

Purpose: To determine the role of diffusion weighted MR imaging and apparent diffusion coefficient (ADC) in benign hepatic focal lesions. Method and Materials: This study included 47 patients (29 M, 18 F with mean age of 43 years) with benign hepatic focal lesions. They were cyst (n = 8), hemangioma (n = 23), abscess (n = 5), adenoma (n = 5), focal nodular hyperplasia (n = 4) and nodular regenerative hyperplasia (n = 2). They underwent routine MR imaging and diffusion MR weighted imaging using 1.5 tesla MR unit (Symphony-Siemens). Diffusion MR imaging was done using spin echo type of single shot echo planar imaging (EPI) with b value of 0, 500 & 1000 sec/mm2. The apparent diffusion coefficient (ADC) map was reconstructed and ADC value was measured. The mean ADC values correlated with histo-pathological results as well as follow-up imaging results. Results: Adequate ADC maps were obtained in 47 patients. The mean ADC values were 3.4 ± 0.12 × 10-3 mm2/sec in cystic lesion, 2.23 ± 0.08 × 10-3 mm2/sec in hemangioma, 1.94 ± 0.05 × 10-3 mm2/sec in abscess, 1.72 ± 0.07 × 10-3 in focal nodular hyperplasia, 1.65 ± 0.06 × 10-3 mm2/sec in adenoma, 1.62 ± 0.07 × 10-3 mm2/sec in nodular regenerative hyperplasia. The mean ADC values were significantly different within benign hepatic focal lesions (P < 0.001). The differences between the mean ADC values of FNH, adenoma and NRH were not statistically significant (P < 0.23). Conclusion: Diffusion weighted MR imaging is a new imaging modality for diagnosis and characterization of different benign hepatic focal lesions, particularly in patient with renal dysfunction.

Aldoketoreductase family 1B10 (AKR1B10) as a biomarker to distinguish hepatocellular carcinoma from benign liver lesions

Hepatocellular carcinoma (HCC) is one of the most common highly aggressive malignant tumors worldwide. Aldoketoreductase 1B10 (AKR1B10) was first isolated from HCC and further identified to be over-expressed in many cancers from various organs. AKR1B10 contributes to detoxification of xenobiotics by lipid peroxidation and metabolizes physiological substrates such as farnesal, retinal, and carbonyls. Metabolizing these lipid substrates plays a crucial role in promoting carcinogenesis. In the present study, immunohistochemical analysis was performed to determine the prevalence/pattern of AKR1B10 expression in HCC and its usefulness to differentiate benign liver lesions from HCC. Oncogenic function of AKR1B10 was examined in hepatocellular carcinoma cells in vitro using Western blotting and shRNA knockdown approaches, with emphasis on cell apoptosis and response to chemotherapy. Immunohistochemistry analysis revealed AKR1B10 was overexpressed in 97% (86/89) of hepatocellular carcinomas, with minimal to no expression in adjacent hepatic tissue, while hepatic adenomas and focal nodular hyperplasia did not exhibit expression of AKR1B10. shRNA-mediated silencing of AKR1B10 expression in hepatocellular carcinoma cells resulted in (1) increased cell apoptosis, (2) decreased colony formation and size, and (3) enhanced cytoreductive response following exposure to doxorubicin chemotherapy. Our findings provide first time evidence that AKR1B10 is a unique biomarker involved in hepatocellular carcinogenesis via modulation of proliferation, cell apoptosis and chemoresistance and is a potential promising biomarker to differentiate HCCs from benign hepatic lesions.

Added value of Gd-EOB-DTPA-enhanced Hepatobiliary phase MR imaging in evaluation of focal solid hepatic lesions

BackgroundCorrect characterization of focal solid hepatic lesions has always been a challenge and is of great diagnostic and therapeutic relevance. The purpose of this study was to determine the added value of hepatobiliary phase images in Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) for differentiating focal solid hepatic lesions.MethodsIn this retrospective trial 84 consecutive patients underwent Gd-EOB-DTPA-enhanced MR examinations. MRI was conducted for 64 patients with malignant focal hepatic lesions (34 hepatocellular carcinoma (HCC), 30 metastases) and for 20 patients with benign hepatic lesions (14 focal nodular hyperplasia (FNH), 3 adenoma, 3 hemangioma). Five radiologists independently reviewed three sets of MR images by means of a 5-point confidence scale from score 1 (definitely benign) to score 5 (definitely malignant): set 1: unenhanced images; set 2: unenhanced and Gd-EOB-DTPA-enhanced dynamic images; set 3: hepatobiliary phase images in addition to set 2. Accuracy was assessed by the alternative free-response receiver operating characteristic curve (Az) and the index of diagnostic performance was calculated.ResultsDiagnostic accuracy was significantly improved by the addition of Gd-EOB-DTPA-enhanced dynamic images: Az in set 1 was 0.708 and 0.833 in set 2 (P = 0.0002). The addition of hepatobiliary phase images increased the Az value to 0.941 in set 3 (set 3 vs set 2, P < 0.0001; set 3 vs set 1, P < 0.0001). The index of diagnostic performance was lowest in set 1 (45%), improved in set 2 (71%), and highest in set 3 (94%).ConclusionsHepatobiliary phase images obtained after Gd-EOB-DTPA-enhanced dynamic MRI improve the differentiation of focal solid hepatic lesions.

Relationship between the expressions of indoleamine 2, 3-dioxygenase in hepatocellular carcinoma and clinicopathological parameters

To explore the expressions of indoleamine 2, 3-dioxygenase (IDO) in hepatocellular carcinoma and analyze its relationship with clinicopathological parameters. Quantitative real-time polymerase chain reaction (PCR), fluorogenic quantitative PCR, immunohistochemical and immunofluorescence were used to detect the expression of indoleamine 2, 3-dioxygenase in hepatocellular carcinoma. The IDO mRNA expression in cancerous tissues increased markedly than that in the corresponding non-cancerous tissues (2(-ΔΔCT) = 1.71, P = 0.001) . The immunohistochemical and immunofluorescence results showed that IDO protein was expressed in cytoplasm of hepatocellular carcinoma and tumor-surrounding tissues. But there was no expression in normal liver tissues from benign hepatic lesions and corresponding non-cancerous tissues. An over-expression of IDO protein was detected in 43 patients (48.3%) , a low expression in 25 (28.1%) and no expression in 21 (23.6%). Relationship between IDO expression and clinicopathological parameters: an over-expression of IDO in HCC was associated with recurrence, survival time, metastasis and TNM stage (P < 0.05), but not associated with patient's cirrhosis, AFP level, histological differentiation type, Barcelona clinic liver cancer stage, gender, age, HbsAg positivity, number of tumors and tumor size (P > 0.05). An over-expression of IDO in HCC patients may affect patient prognosis.

Can diffusion weighted MRI differentiate between benign and malignant hepatic focal lesions?

The aim of this study is to evaluate the role of diffusion-weighted magnetic resonance imaging in differentiation between benign and malignant hepatic focal lesions. Patients and methodsFifty-five hepatic focal lesions in 40 patients. All those patients were subjected to full clinical evaluation and radiological assessment using conventional MRI study of the liver and diffusion-weighted MRI (Different b values: 100, 500 and 750s/mm2). All lesions were evaluated regarding size, signal intensity, enhancement pattern, qualitative assessments by the different b values and quantitative assessment by measurement of the ADC values. ResultsADCs of focal hepatic lesions were significantly different between benign (2.869×10−3mm2/s±0.652) and malignant (0.995×10−3mm2/s±0. 274) hepatic focal lesions. The mean ADCs were 0.76×10−3mm2/s±0.53 for metastases, 1.3×10−3mm2/s±0.55 for HCCs, 1.95×10−3mm2/s±0.24 for benign hepatocellular lesions, 2.92×10−3mm2/s±0.102 for hemangiomas, and 3.64×10−3mm2/s±0.14 for cysts. ConclusionDiffusion-weighted imaging (DWI) offers the possibility to obtain criteria for characterization of focal liver lesions with subsequent differentiation between benign and malignant hepatic focal lesions without the need for contrast agent administration-by quantifying diffusion effects via apparent diffusion coefficient (ADC) measurements.

Liver Imaging with a Novel Hepatitis B Surface Protein Derived SPECT-Tracer

Diagnostic imaging of the liver by ultrasound, computed tomography (CT) and magnetic resonance tomography (MRT) is generally limited to the visualization of the morphology. In order to exploit the intriguing liver tropism of the human hepatitis B virus (HBV) for molecular imaging of the liver, peptidic tracers derived from the HBV large envelope protein (L) were studied. An N-terminally stearoylated tracer comprising amino acids 2-48 of the PreS1-domain of the L protein was synthesized by solid phase peptide synthesis. Mercaptoacetyltriglycerin (MAG3) was linked to this peptide to enable (99m)Tc labeling. Biodistribution studies in mice showed an excellent liver accumulation of this novel class of radiotracer with 84%, 84%, 65%, and 16% of the injected dose in the liver after 10 min, 1 h, 4 h, and 24 h, respectively. Imaging studies on a gamma camera showed a clear visualization of the liver already 10 min post intravenous injection. These studies confirmed the exclusive accumulation of the tracer in the liver with negligible background in other organs. Owing to a significant biliary clearance rate of the (99m)Tc bound via a linker, the tracer enabled imaging of the bile ducts starting 30 min after injection. Analysis of the route of excretion revealed complete clearance within 24 h post injection. Clearance was predominantly via renal secretion. In conclusion, the novel class of tracers shows excellent pharmacokinetic, biodistribution, and clearance kinetics. It provides unique biological information different from the current imaging modalities. Its primary application is likely to be the evaluation of liver cancer patients. Specific indications may include tumor staging, the differentiation of malignant versus benign hepatic lesions, and liver tumors of nonhepatocellular origin.

Gadoxetate-enhanced versus diffusion-weighted MRI for fused Ga-68-DOTANOC PET/MRI in patients with neuroendocrine tumours of the upper abdomen

To compare fused gadoxetate-enhanced Ga-68-DOTANOC PET/MRI and Ga-68-DOTANOC PET/DWI (diffusion-weighted imaging) for the assessment of abdominal neuroendocrine tumours (NETs). Eighteen patients with suspected or histologically proven NETs of the abdomen were enrolled in this retrospective study. All patients underwent Ga-68-DOTANOC PET/CT for a primary search, staging, or restaging, and received an additional MRI, including dynamic gadoxetate-enhanced T1-weighted sequences and DWI (b-values 50, 300 and 600). Co-registered gadoxetate-enhanced PET/MRI and PET/DWI were separately analysed for NET lesions by a nuclear medicine physician and a radiologist in consensus. Sensitivity and specificity were calculated on a per-region, per-organ and per-patient basis. Eighty-seven out of 684 anatomical regions, and 23 out of 270 organs, were NET-positive in 14 out of 18 patients. Region-based sensitivities and specificities were 97.7 % and 99.7 % for gadoxetate-enhanced PET/MRI and 98.9 % and 99.7 % for PET/DWI. Organ-based sensitivities and specificities were 91.3 % and 99.6 % for gadoxetate-enhanced PET/MRI and 95.7 % and 99.6 % for PET/DWI. Finally, patient-based sensitivities and specificities were 100 % and 100 % for gadoxetate-enhanced PET/MRI and 100 % and 75 % for PET/DWI. Sensitivities and specificities of the two methods did not differ significantly. Gadoxetate-enhanced Ga-68-DOTANOC PET/MRI and Ga-68-DOTANOC PET/DWI are equally useful for the assessment of abdominal NETs. • Positron emission tomography and magnetic resonance imaging can both assess neuroendocrine tumours. • Fusion of PET/MR imaging provides helpful information. • Gadoxetate-enhanced Ga-68-DOTANOC PET/MRI and Ga-68-DOTANOC PET/DWI assess neuroendocrine tumours equally well. • PET/DWI is inherently simpler than gadoxetate-enhanced PET/MRI. • Only benign hepatic lesions pose a potential diagnostic dilemma for PET/DWI.

Benign Hepatic Nodular Lesions After Treatment for Childhood Cancer

Benign nodular hepatic regenerating lesions such as focal nodular hyperplasia (FNH) have been reported as rare complications of the antineoplastic therapy received during infancy. Little is known about the risk factors associated with the onset of these lesions and their diagnostic management. We have analyzed a series of benign hepatic nodular lesions occurring in children previously treated for malignant tumors in our institution in a period of 11 years. An extensive description of the imaging presentation of the lesions has been provided to facilitate the differential diagnosis, and a risk factor analysis has been conducted. A total of 14 diagnoses (10 FNH and 4 hemangiomas) of benign nodular hepatic lesions have been found. Hematopoietic stem cell transplantation is the most important statistically independent risk factor associated with the development of these lesions, especially for FNH. No malignant transformation of nodules has been recorded during a median follow-up time of 4 years. In our experience, FNH is the most frequent benign nodular hepatic lesions occurring after treatment for childhood cancer. Hematopoietic stem cell transplantation is the most important risk factor to be taken in account. After a secure diagnosis of these benign lesions, only a close imaging follow-up is recommended.

Glypican‐3: a marker and a therapeutic target in hepatocellular carcinoma

Glypican-3 (GPC3) is a member of the glypican family. Glypicans are proteoglycans that are attached to the cell surface by a glycosyl-phosphatidylinositol anchor. They regulate the signaling activity of several growth factors, including Wnts. This regulation is based on the ability of glypicans to stimulate or inhibit the interaction of these growth factors with their respective signaling receptors. It has been clearly established that whereas GPC3 is expressed by most hepatocellular carcinomas (HCCs), this glypican is not detected in normal and cirrhotic liver, or in benign hepatic lesions. Consequently, immunostaining of liver biopsies for GPC3 is currently being used by clinical pathologists to confirm HCC diagnosis when the malignant nature of the lesion is difficult to establish. In addition to being a marker of HCC, GPC3 plays a role in the progression of the disease. GPC3 promotes the growth of HCC by stimulating canonical Wnt signaling. It has been proposed that this stimulation is based on the ability of GPC3 to increase the binding of Wnt to its signaling receptor, Frizzled. Two therapeutic approaches for HCC that target GPC3 are currently being tested in phase II clinical trials. One of them is based on the use of a humanized GPC3 monoclonal antibody that inhibits the invivo growth of HCC xenografts by inducing antibody-dependent cellular cytotoxicity. The second approach employs a vaccine that consists of two GPC3-derived peptides that induce cytotoxic T lymphocytes against these peptides. Targeting of GPC3 might offer a new tool for the treatment of HCC.

MR Imaging in Patients with Suspected Liver Metastases: Value of Liver-Specific Contrast Agent Gadoxetic Acid

ObjectiveTo compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance (MR) imaging with that of triple-phase multidetector-row computed tomography (MDCT) in the detection of liver metastasis.Materials and MethodsOur institutional review board approved this retrospective study and waived informed consent. The study population consisted of 51 patients with hepatic metastases and 62 patients with benign hepatic lesions, who underwent triple-phase MDCT and gadoxetic acid-enhanced MRI within one month. Two radiologists independently and randomly reviewed MDCT and MRI images regarding the presence and probability of liver metastasis. In order to determine additional value of hepatobiliary-phase (HBP), the dynamic-MRI set alone and combined dynamic-and-HBP set were evaluated, respectively. The standard of reference was a combination of pathology diagnosis and follow-up imaging. For each reader, diagnostic accuracy was compared using the jackknife alternative free-response receiver-operating-characteristic (JAFROC).ResultsFor both readers, average JAFROC figure-of-merit (FOM) was significantly higher on the MR image sets than on the MDCT images: average FOM was 0.582 on the MDCT, 0.788 on the dynamic-MRI set and 0.847 on the combined HBP set, respectively (p < 0.0001). The differences were more prominent for small (≤ 1 cm) lesions: average FOM values were 0.433 on MDCT, 0.711 on the dynamic-MRI set and 0.828 on the combined HBP set, respectively (p < 0.0001). Sensitivity increased significantly with the addition of HBP in gadoxetic acid-enhanced MR imaging (p < 0.0001).ConclusionGadoxetic acid-enhanced MRI shows a better performance than triple-phase MDCT for the detection of hepatic metastasis, especially for small (≤ 1 cm) lesions.