Focal Nodular Hyperplasia Lesions Research Articles

Assessment of drainage vein of focal nodular hyperplasia using contrast-enhanced ultrasound.

Identification of drainage vessels is useful for differential diagnosis of hepatic tumors. Direct drainage to the hepatic vein has been reported to occur in focal nodular hyperplasia (FNH), but studies evaluating the drainage veins of FNH are limited. We aimed to investigate the detection rate of the FNH drainage vein and the factors related to visualization of the drainage vein on contrast-enhanced ultrasound (CEUS). Fifty consecutive patients with 50 FNH lesions were retrospectively evaluated in this study. We calculated and compared the detection rate of the FNH drainage vein on CEUS, contrast-enhanced magnetic resonance imaging (CEMRI), and contrast-enhanced computed tomography (CECT), and identified the factors correlated with visualization of the FNH drainage vein on CEUS by using multivariate logistic regression analyses. Visualization of the drainage vein was confirmed in 31 of 50 lesions (62%) using CEUS, three of 44 lesions (6.8%) using CEMRI, and one of 18 lesions (5.6%) using CECT. The detection rate of the FNH drainage vein on CEUS was significantly higher than that on CEMRI and CECT (p < 0.001). Multivariate analysis identified lesion size (≥ 25mm) and detection of the spoke-wheel pattern on Doppler US as independent factors for drainage vein detection in FNH. Our study showed that rapid FNH drainage to the hepatic vein was observed at a relatively high rate on CEUS, suggesting that CEUS focusing on detection of drainage veins is important for diagnosing FNH.

Superb Microvascular Imaging in Pediatric Focal Nodular Hyperplasia.

To investigate superb microvascular imaging (SMI), a novel Doppler ultrasound technique that can visualize low-velocity microvascular flow, for assessing pediatric focal nodular hyperplasia (FNH). Nine FNH lesions in 6 patients were enrolled. On SMI and color Doppler imaging (CDI), intralesional vascularity was assessed visually and categorized as typical spoke-wheel pattern (central vessel radiating from the center to the periphery), multifocal spoke-wheel pattern, and nonspecific pattern. We compared the vascular features of the lesions between SMI and CDI and evaluated vascular patterns according to lesion size. In terms of vascularity pattern, the typical spoke-wheel pattern of FNH was noted more frequently on SMI (67%) than on CDI (11%; P < 0.05). In addition, a multifocal spoke-wheel pattern was noted in all remaining lesions (33%) on SMI. On the contrary, a nonspecific vascular pattern was detected in the majority (78%) of CDI. Regarding the lesion size and vascularity on SMI, the typical spoke-wheel pattern was seen more frequently in the small FNH group than in the large FNH group. The intralesional vascular signal was detected more frequently on SMI (100%) than on CDI (89%). SMI is feasible in evaluating FNH in children and has a greater ability to demonstrate the spoke-wheel pattern than CDI.

ACG Clinical Guideline: Focal Liver Lesions.

Focal liver lesions (FLLs) have become an increasingly common finding on abdominal imaging, especially asymptomatic and incidental liver lesions. Gastroenterologists and hepatologists often see these patients in consultation and make recommendations for management of multiple types of liver lesions, including hepatocellular adenoma, focal nodular hyperplasia, hemangioma, and hepatic cystic lesions including polycystic liver disease. Malignancy is important to consider in the differential diagnosis of FLLs, and healthcare providers must be familiar with the diagnosis and management of FLLs. This American College of Gastroenterology practice guideline uses the best evidence available to make diagnosis and management recommendations for the most common FLLs.

Pedunculated Focal Nodular Hyperplasia: When in Doubt, Should We Cut It Out?

Focal nodular hyperplasia (FNH) is the second most common benign hepatic tumor and can rarely present as an exophytic solitary mass attached to the liver by a stalk. Most FNH cases are usually detected as incidental findings during surgery, imaging or physical examination and have a high female predominance. However, the pedunculated forms of FNH are particularly rare and commonly associated with severe complications and diagnostic challenges. Hence, our study aims to provide a comprehensive summary of the available data on the pedunculated FNH cases among adults and children. Furthermore, we will highlight the role of different therapeutic options in treating this clinical entity. The use of imaging techniques is considered a significant addition to the diagnostic toolbox. Regarding the optimal treatment strategy, the main indications for surgery were the presence of symptoms, diagnostic uncertainty and increased risk of complications, based on the current literature. Herein, we also propose a management algorithm for patients with suspected FNH lesions. Therefore, a high index of suspicion and awareness of this pathology and its life-threatening complications, as an uncommon etiology of acute abdomen, is of utmost importance in order to achieve better clinical outcomes.

Automated Assessment of T2-Weighted MRI to Differentiate Malignant and Benign Primary Solid Liver Lesions in Noncirrhotic Livers Using Radiomics

Distinguishing malignant from benign liver lesions based on magnetic resonance imaging (MRI) is an important but often challenging task, especially in noncirrhotic livers. We developed and externally validated a radiomics model to quantitatively assess T2-weighted MRI to distinguish the most common malignant and benign primary solid liver lesions in noncirrhotic livers. Data sets were retrospectively collected from three tertiary referral centers (A, B, and C) between 2002 and 2018. Patients with malignant (hepatocellular carcinoma and intrahepatic cholangiocarcinoma) and benign (hepatocellular adenoma and focal nodular hyperplasia) lesions were included. A radiomics model based on T2-weighted MRI was developed in data set A using a combination of machine learning approaches. The model was internally evaluated on data set A through cross-validation, externally validated on data sets B and C, and compared to visual scoring of two experienced abdominal radiologists on data set C. The overall data set included 486 patients (A: 187, B: 98, and C: 201). The radiomics model had a mean area under the curve (AUC) of 0.78 upon internal validation on data set A and a similar AUC in external validation (B: 0.74 and C: 0.76). In data set C, the two radiologists showed moderate agreement (Cohen's κ: 0.61) and achieved AUCs of 0.86 and 0.82. Our T2-weighted MRI radiomics model shows potential for distinguishing malignant from benign primary solid liver lesions. External validation indicated that the model is generalizable despite substantial MRI acquisition protocol differences. Pending further optimization and generalization, this model may aid radiologists in improving the diagnostic workup of patients with liver lesions.

Focal Nodular Hyperplasia of the Liver without a Central Scar: A Rare Case Report

Focal Nodular Hyperplasia (FNH) is most frequent benign tumour of liver just after the haemangioma, which makes about 3%-5% of all primary hepatic tumours. It occurs frequently in females during their middle age group. This is case report of 48-year-old female patient having complains of upper abdominal pain since last one year. Using abdominal ultrasonography and a CT scan, it was discovered that segment four of the liver contained a tumour measuring 11 cm in maximum diameter without a central scar, which made preoperative imaging scans for FNH difficult to diagnose. Lobectomy of left lobe was done. The gross specimen on cut section revealed a lesion with nodular appearance and absence of any central stellate scar. On the basis of histopathological finding the diagnosis of FNH without central stellet scar was made. To ensure adequate therapy, it is essential to differentiate between FNH and other hyper vascular liver lesions and metastases. Therefore, it is difficult to diagnose FNH before surgery if there are no typical radiological findings. This case report focused on FNH without the usual radiological findings and emphasised its importance to distinguish it from other malignant hyper vascular liver entities.

Microvascular flow imaging to differentiate focal hepatic lesions: the spoke-wheel pattern as a specific sign of focal nodular hyperplasia.

Microvascular flow imaging (MVFI) is an advanced Doppler ultrasound technique designed to detect slow-velocity blood flow in small-caliber microvessels. This technique is capable of realtime, highly detailed visualization of tumor vessels without using a contrast agent. MVFI has been recently applied for the characterization of focal liver lesions and has revealed typical vascularity distributions in multiple types thereof. Focal nodular hyperplasia (FNH) constitutes an important differential diagnosis of malignant liver tumors. In this essay, we provide iconographic documentation of the MVFI appearance of FNH and other common solid liver lesions. Identifying the typical patterns of vascularity, including the spoke-wheel pattern with MVFI, can expedite the diagnosis, spare patients from unnecessary procedures, and save costs.

Long-term outcomes of transarterial embolization with lipiodol-bleomycin emulsion plus polyvinyl alcohol particles versus the particles alone for large symptomatic focal nodular hyperplasia: a propensity score-matched analysis.

To compare the efficacy of transarterial embolization (TAE) with polyvinyl alcohol (PVA) particles alone and lipiodol-bleomycin emulsion (LBE) plus PVA particles for patients with unresectable large symptomatic focal nodular hyperplasia (FNH). We performed a retrospective analysis of patients who underwent TAE either with PVA particles alone (group A, n = 46) or LBE plus PVA particles (group B, n = 35) for large (≥ 7 cm) symptomatic FNH between January 2002 and February 2019. Propensity score matching (PSM) (1:1) was performed to adjust for potential baseline confounders. Technical success, adverse events (AEs), symptom relief, and changes in the lesion size after TAE were evaluated. Statistical analysis included Wilcoxon rank sum test and χ2 test. After PSM, no significant differences in baseline characteristics were found between the groups (31 in group A and 31 in group B, with a mean age of 31 years). Technical success was achieved in all patients (100%), without major AEs in both groups. Complete resolution of the abdominal symptoms was reported in 77.4% in group A and 100% in group B (p = 0.037) during a mean follow-up period of 72 months; complete resolution (CR) of the FNH rate was significantly higher in group B than in group A (93.6% vs. 67.7%; p = 0.019). Compared with the use PVA particles alone, TAE with LBE plus PVA particles in the treatment of patients with large symptomatic FNH had a significantly higher rates of CR of the FNH and complete relief of the symptoms. • Transarterial embolization (TAE) with lipiodol-bleomycin emulsion (LBE) plus PVA particles for the large symptomatic FNH yielded better results than with PVA particles alone, in terms of complete resolution of FNH lesions (93.6% vs 67.7%) and complete relief of the abdominal symptoms (100% vs 77.4%) during a mean follow-up period of 72 months (38-170 months). • No major complications were recorded in both groups, and no significant difference in the incidence of postembolization syndrome were observed between the two groups.

Diagnosis and Follow-up of Incidental Liver Lesions in Children.

Incidental liver lesions are identified in children without underlying liver disease or increased risk of hepatic malignancy in childhood. Clinical and imaging evaluation of incidental liver lesions can be complex and may require a multidisciplinary approach. This review aims to summarize the diagnostic process and follow-up of incidental liver lesions based on review of the literature, use of state-of-the-art imaging, and our institutional experience. Age at presentation, gender, alpha fetoprotein levels, tumor size, and imaging characteristics should all be taken into consideration to optimize diagnosis process. Some lesions, such as simple liver cyst, infantile hemangioma, focal nodular hyperplasia (FNH), and focal fatty lesions, have specific imaging characteristics. Recently, contrast-enhanced ultrasound (CEUS) was Food and Drug Administration (FDA)-approved for the evaluation of pediatric liver lesions. CEUS is most specific in lesions smaller than 3 cm and is most useful in the diagnosis of infantile hemangioma, FNH, and focal fatty lesions. The use of hepatobiliary contrast in MRI increases specificity in the diagnosis of FNH. Recently, lesion characteristics in MRI were found to correlate with subtypes of hepatocellular adenomas and associated risk for hemorrhage and malignant transformation. Biopsy should be considered when there are no specific imaging characteristics of a benign lesion. Surveillance with imaging and alpha fetoprotein (AFP) should be performed to confirm the stability of lesions when the diagnosis cannot be determined, and whenever biopsy is not feasible.

Comparison of IDEAL-IQ and IVIM-DWI for Differentiating between Alpha Fetoprotein-Negative Hepatocellular Carcinoma and Focal Nodular Hyperplasia

Background: To compare the differential diagnostic value of iterative decomposition of water and fat with the echo asymmetrical and least-squares estimation quantitation sequence (IDEAL-IQ) with that of intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI) in differentiating between alpha fetoprotein (AFP)-negative hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH). Materials and Methods: A total of 28 AFP-negative HCC cases and 15 FNH cases were scanned using the IDEAL-IQ and IVIM-DWI magnetic resonance imaging (MRI) protocols. Two radiologists independently assessed the fat fraction (FF) and the iron level surrogate (R2*) derived from the IDEAL-IQ images and the apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) derived from the IVIM-DWI images. The intraclass correlation coefficients (ICC) were estimated to evaluate the agreement repeatability between the two readers. The area under the curve (AUC) of a receiver operating characteristics curve was used to compare the diagnostic efficiency of the parameters extracted from the two techniques. Results: The lesions in the HCC group had significantly higher FF than the FNH group (8.284 ± 5.756 vs. 2.559 ± 1.247, P < 0.05). ADC and D values were lower in the HCC lesions when compared with the FNH lesions (1.310 ± 0.253 and 0.909 ± 0.192, respectively, vs. 1.624 ± 0.304 and 1.230 ± 0.314; ×10−3 mm2 /s). The FF parameter had the highest AUC (0.923) followed by D (0.864) and ADC (0.854). Conclusions: FF derived from IDEAL-IQ, and ADC and D derived from IVIM-DWI were able to differentiate AFP-negative HCC from FNH. IDEAL-IQ showed better performance for the differentiation of FNH from HCC than the IVIM-DWI-derived parameters.

Machine Learning-Based Ultrasomics Improves the Diagnostic Performance in Differentiating Focal Nodular Hyperplasia and Atypical Hepatocellular Carcinoma.

BackgroundThe typical enhancement patterns of hepatocellular carcinoma (HCC) on contrast-enhanced ultrasound (CEUS) are hyper-enhanced in the arterial phase and washed out during the portal venous and late phases. However, atypical variations make a differential diagnosis both challenging and crucial. We aimed to investigate whether machine learning-based ultrasonic signatures derived from CEUS images could improve the diagnostic performance in differentiating focal nodular hyperplasia (FNH) and atypical hepatocellular carcinoma (aHCC).Patients and MethodsA total of 226 focal liver lesions, including 107 aHCC and 119 FNH lesions, examined by CEUS were reviewed retrospectively. For machine learning-based ultrasomics, 3,132 features were extracted from the images of the baseline, arterial, and portal phases. An ultrasomics signature was generated by a machine learning model. The predictive model was constructed using the support vector machine method trained with the following groups: ultrasomics features, radiologist’s score, and combination of ultrasomics features and radiologist’s score. The diagnostic performance was explored using the area under the receiver operating characteristic curve (AUC).ResultsA total of 14 ultrasomics features were chosen to build an ultrasomics model, and they presented good performance in differentiating FNH and aHCC with an AUC of 0.86 (95% confidence interval [CI]: 0.80, 0.89), a sensitivity of 76.6% (95% CI: 67.5%, 84.3%), and a specificity of 80.5% (95% CI: 70.6%, 85.9%). The model trained with a combination of ultrasomics features and the radiologist’s score achieved a significantly higher AUC (0.93, 95% CI: 0.89, 0.96) than that trained with the radiologist’s score (AUC: 0.84, 95% CI: 0.79, 0.89, P < 0.001). For the sub-group of HCC with normal AFP value, the model trained with a combination of ultrasomics features, and the radiologist’s score remain achieved the highest AUC of 0.92 (95% CI: 0.87, 0.96) compared to that with the ultrasomics features (AUC: 0.86, 95% CI: 0.74, 0.89, P < 0.001) and radiologist’s score (AUC: 0.86, 95% CI: 0.79, 0.91, P < 0.001).ConclusionsMachine learning-based ultrasomics performs as well as the staff radiologist in predicting the differential diagnosis of FNH and aHCC. Incorporating an ultrasomics signature into the radiologist’s score improves the diagnostic performance in differentiating FNH and aHCC.

Bland Embolization of Benign Liver Tumors: Review of the Literature and a Single Center Experience.

Transarterial embolization has shown promise as a safe, effective, and less invasive treatment modality for benign liver lesions (hemangioma, focal nodular hyperplasia (FNH), and hepatic adenoma (HA)) with fewer complications compared to surgical intervention. There is no consensus regarding the most appropriate embolization material(s) for the treatment of benign liver tumors. The purpose of this study was to review the current literature regarding the transarterial embolization of benign liver tumors and to share our single center experience. This was a non-blinded, retrospective, single-institution review of the bland embolization of benign liver tumors. Clinical data and imaging before and after embolization were used to evaluate lesion response to transarterial embolization. Twelve patients were included in the study. Five patients with six hemangiomas were treated. Pain was a presenting complaint in all five of these patients. The median change in tumor volume was −12.4% and ranged from −30.1% to +42.3%. One patient with two FNH lesions was treated, and both lesion volumes decreased by more than 50%. Six patients with 10 adenomas were treated. Pain was a presenting complaint in three patients, and five patients had a lesion >5 cm. The median change in tumor volume was −67.0% and ranged from −92.9% to +65.8%. Bland transarterial embolization of liver hemangiomas, FNH, and HA can be an effective and minimally invasive treatment modality to control the size and/or symptoms of these lesions. There is a variable response depending on tumor type and the embolization materials used.

Embolization of a rare case of focal nodular hyperplasia in an adolescent boy

This report highlights a special case of focal nodular hyperplasia (FNH) in a 14-year-old boy. FNH is a benign liver lesion which typically presents in middle-aged women. Symptomatic FNH lesions, lesions of large size, or lesions in problematic locations are often surgically resected. Surgical treatment options such as resection or liver transplantation were discussed in our case, however the mass was deemed unresectable due to its central location and proximity to vascular structures. Super-selective particle embolization of this hypervascular benign mass proved to be an effective treatment resulting in complete resolution of symptoms and significant reduction of the size of the mass, with no post-procedural complications.

Imaging Features of Fibrolamellar Hepatocellular Carcinoma withContrast-Enhanced Ultrasound.

Fibrolamellar hepatocellular carcinoma (f-HCC) is a rare primary liver tumor. Imaging plays an important role in diagnosis. The aim of this retrospective study was to analyze contrast-enhanced ultrasound (CEUS) features of histologically proven f-HCC in comparison to benign focal nodular hyperplasia (FNH). 16 patients with histologically proven f-HCC lesions and 30 patients with FNH lesions were retrospectively reviewed regarding CEUS features to determine the malignant or benign nature of the focal liver lesions (FLL). Five radiologists assessed the CEUS enhancement pattern and came to a consensus using the EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) guideline criteria. Fibrolamellar hepatocellular carcinoma manifested as a single and huge FLL. On CEUS, f-HCC showed heterogeneous hyperenhancement in the arterial phase and hypoenhancement (16/16, 100 %) in the portal venous and late phases (PVLP) as a sign of malignancy. In contrast to the hypoenhancement of f-HCC in the PVLP, all patients with FNH showed hyperenhancement as the most distinctive feature (P < 0.01). 8 f-HCC lesions showed a central scar as an unenhanced area (8/16, 50.0 %), which could also be detected in 53.3 % (16/30) of FNH lesions (P > 0.05). By analyzing the hypoenhancement in the PVLP, CEUS imaging reliably diagnosed f-HCC as a malignant FLL. CEUS also showed differentiation between f-HCC and FNH lesions, showing similar non-enhanced central scars, whereas f-HCC lesions showed peripheral hyperenhancement in the arterial phase and early washout in the PVLP.

Enhancement characteristics of liver focal nodular hyperplasia (less than 3 cm) by contrast-enhanced ultrasound

Objective To analyze the typical contrast-enhanced ultrasound (CEUS) enhancement characteristics of hepatic focal nodular hyperplasia (FNH) within 3 cm, and to discuss the diagnostic value of CEUS in small FNH lesions. Methods Forty-eight cases of FNH were retrospectively studied. All lesions were confirmed histopathologically after surgical resection. CEUS examinations with SonoVue were performed to characterize the enhancement patterns of lesions in 5 minutes. The whole wash in and wash out enhancement procedure of lesions were recorded and analyzed. Results All FNH lesions displayed a rapid hyper-enhancement in arterial phase by CEUS, 39 lesions of which showed spring-like enhancement; 8 lesions showed spoke-like enhancement; 1 lesion showed dendritic enhancement. 6.3%(3/48) of the lesions showed central scar, and feeding arteries was found in 52.1%(25/48) lesions. According to echogenicity shift of the lesions in various phases, 20.8%(10/48) FNH showed fast-in and slow-out , 64.6%(31/48) showed fast-in and synchronous-out , and 14.6%(7/48) showed fast-in and fast-out . According to fast-in and synchronous-out or fast-in and slow-out by CEUS, the accuracy rate of benignity reached 85.4%(41/48). According to any of the spring-like enhancement, spoke-like enhancement, central scars or feeding arteries, the accuracy rate of diagnosis of FNH within 3 cm reached 97.9%(47/48), and 81.3%(39/48) of which were diagnosed through spring-like enhancement. Conclusions CEUS is helpful in diagnosis of FNH within 3 cm by showing various characteristic enhancement patterns, and spring-like enhancement is the most important sign in diagnosis of FNH less than 3 cm. CEUS has high diagnostic value for FNH less than 3 cm. Key words: Contrast-enhanced ultrasound; Liver focal nodular hyperplasia; Enhancement pattern

Focal Nodular Hyperplasia After Treatment With Oxaliplatin: A Multiinstitutional Series of Cases Diagnosed at MRI.

Benign hepatic lesions may occur after chemotherapy treatment and may mimic metastases at imaging. We describe focal nodular hyperplasia (FNH) lesions diagnosed at MRI that occurred de novo after treatment with oxaliplatin. This is a multiinstitutional case series. We report 14 adult patients with cancer (eight men and six women) with a history of treatment with oxaliplatin and development of new hepatic lesions diagnosed as FNH at pathologic analysis or MRI or both. Imaging and pathology features of the included lesions, the interval since chemotherapy, and the temporal evolution were reviewed. The mean interval between the completion of oxaliplatin treatment and the identification of new hepatic FNH at imaging was 47.6 months. In seven of 14 (50%) patients, the index lesion was diagnosed at pathologic analysis (biopsy or resection) as FNH. In the remaining seven cases, the diagnosis was based on highly accurate MRI features (e.g., hyper- or isointensity of the lesion on hepatobiliary phase images). Lesion growth or occurrence of new lesions was present in 75% of patients at imaging follow-up. FNH lesions can occur de novo after treatment with oxaliplatin. Recognizing the typical MRI appearance of these lesions may avoid unnecessary biopsy or surgery and reduce patients' anxiety.

Contrast-enhanced ultrasound of benign liver lesions.

Liver lesions are often incidentally detected on ultrasound examination and may be incompletely characterized, requiring further imaging. Contrast-enhanced ultrasound (CEUS) was recently approved by the Food and Drug Administration in the United States for liver lesion characterization. CEUS has the ability to characterize focal liver lesions and has been shown to be superior to color Doppler and power Doppler ultrasound in the detection of tumor vascularity. Differentiating benign from malignant liver lesions is essential to characterizing liver lesions. The CEUS imaging characteristics of benign liver lesions are reviewed, including hepatic cysts, hemangiomas, focal fat, focal nodular hyperplasia, hepatocellular adenomas, abscesses, and traumatic lesions.

Visualization of draining vein in focal nodular hyperplasia by superb microvascular imaging: report of two cases

Focal nodular hyperplasia (FNH) is the second most common benign tumor of the liver, and diagnosis and follow-up without invasive procedures are now highly recommended. FNH shows a characteristic vascular structure called "spoke-wheel appearance". However, this appearance relies on the mode of the feeding artery, and the mode of the draining vein has not been sufficiently studied until recently. Superb microvascular imaging (SMI) is a new Doppler technology designed to improve visualization of the blood flow, especially slow flow signals from fine vessels, using a new algorithm. Thus, we can expect to see an improvement in visualization of fine vessels in FNH using SMI. Here, we present two cases in which SMI clearly demonstrated not only the typical spoke-wheel appearance but also draining to the hepatic veins. Our observation is believed to be noteworthy in the diagnosis of FNH. In conclusion, we have reported two cases of hepatic FNH in which SMI revealed clearly not only its feeding vessels and intratumoral vasculature but also its draining vessels communicating with the hepatic vein. SMI is considered to increase our diagnostic confidence by revealing fine vessels within and around the FNH lesion.

Assessment of the link between quantitative biexponential diffusion-weighted imaging and contrast-enhanced MRI in the liver

PurposeTo investigate if intravoxel incoherent motion (IVIM) modeled diffusion-weighted imaging (DWI) can be linked to contrast-enhanced (CE-)MRI in liver parenchyma and liver lesions. MethodsTwenty-five patients underwent IVIM-DWI followed by multiphase CE-MRI using Gd-EOB-DTPA (n=20) or Gd-DOTA (n=5) concluded with IVIM-DWI. Diffusion (Dslow), microperfusion (Dfast), its fraction (ffast), wash-in-rate (Rearly) and late-enhancement-rate (Rlate) of Gd-EOB-DTPA were calculated voxel-wise for the liver. Parenchyma and lesions were segmented. Pre-contrast IVIM was compared 1) between low, medium and high Rearly for parenchyma 2) to post-contrast IVIM substantiated with simulations 3) between low and high Rlate per lesion type. ResultsDfast and ffast increased (P<0.001) with 25.6% and 33.8% between low and high Rearly of Gd-EOB-DTPA. Dslow decreased (−15.0%; P<0.001) with increasing Rearly. Gd-DOTA demonstrated similar observations. ffast (+10%; P<0.001) and Dfast (+6.6%; P<0.001) increased after Gd-EOB-DTPA, while decreasing after Gd-DOTA (−4.2% and −5.7%, P<0.001) and were confirmed by simulations. For focal nodular hyperplasia lesions (n=5) Dfast and ffast increased (P<0.001) with increasing Rlate, whereas for hepatocellular carcinoma (n=4) and adenoma (n=7) no differences were found. ConclusionMicroperfusion measured by IVIM reflects perfusion in a way resembling CE-MRI. Also IVIM separated intra- and extracellular MR contrast media. This underlines the potential of IVIM in quantitative liver imaging.

Trans-arterial Embolization of Focal Nodular Hyperplasia in a Teenager: Beyond Pain Control

Background: Focal nodular hyperplasia (FNH) is the most common benign non-vascular liver tumor. It is predominantly found in women (9:1 ratio) between ages 30 to 50 years. Intervention is usually reserved for symptomatic FNH lesions. Trans-arterial embolization has been shown to be a reasonable alternative to surgical resection. Budd-Chiari syndrome is a potentially deadly phenomenon in which the hepatic venous outflow tract is obstructed, which can lead to liver failure. Secondary Budd-Chiari is caused by compression of the hepatic veins or inferior vena cava (IVC) by lesions originating outside of the vein (e.g. tumors). Case: A 19 year old girl was referred to Hepatology Clinic for management of symptomatic FNH, progressive in size and associated right upper quadrant pain and fullness over a period of five years. At the time of presentation she had two MRIs of the abdomen over a three month interval, showing an 3.5 X 5.7 cm enlarging mass abutting the IVC involving segment VIII, extending into the caudate lobe. Physical exam was significant for reproducible right upper quadrant tenderness. Labs including liver function tests were normal. After an unremarkable EGD was performed to evaluate for alternative causes of abdominal pain, and Hepatobiliary Surgery had deemed resection a highrisk intervention, the patient was referred to Interventional Radiology for embolization of her FNH. During the procedure, by arteriogram, a hypertrophied branch of right hepatic artery was found to be the primary vascular supply of the FNH. This branch was embolized with lipiodiol and ethanol which until cessation of flow into the artery supplying the targeted mass. Follow up MRI imaging of abdomen at 6 months post-procedure show positive response with progressively diminishing size of residual FNH (2.8 X 1.7 cm). At 6 month post-procedural follow up patient reported complete resolution of symptoms at rest. Discussion: Although typically presenting in adult women ages 30-50, this case highlights the need to recognize FNH as a potential cause for right upper quadrant in teenage girls. In this case the medical teams decided to pursue embolization not only because of the mass effect, but also because of the abutment on the hepatic veins and IVC. Early recognition and therapeutic embolization of FNH can not only safely lead to significant symptomatic pain relief, it can also decrease risk of venous outflow obstruction and by extension prevent secondary Budd-Chiari syndrome.