Small Liver Lesions Research Articles

The outcomes of endoscopic ultrasound-guided tissue acquisition for small focal liver lesions measuring ≤2 cm.

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) for focal liver lesions has gained attention as an alternative to percutaneous biopsy. Although the outcomes of EUS-TA for focal liver lesions have been reported to be favorable, no studies have focused on small focal liver lesions (≤2 cm). The aim of this study was to evaluate the outcomes of EUS-TA for small focal liver lesions (≤2 cm). The details of EUS-TA performed for focal liver lesions between 2016 and 2022 were retrospectively reviewed. The outcomes were compared between cases involving ≤2 cm lesions and those involving >2 cm lesions. The primary outcomes were diagnostic ability and adverse events. EUS-TA for focal liver lesions was performed in 109 cases. Of the 109 cases, 32 (29.3%) involved ≤2 cm lesions and 77 (70.6%) involved >2 cm lesions. Right lobe lesions and transduodenal puncture were significantly fewer in the ≤2 cm group. There were no significant differences in needle gauge, needle type, or number of punctures between the groups. The sensitivity, specificity, and accuracy rates were 96.8%, 100%, and 96.8%, respectively, in the ≤2 cm group and 97.4%, 100%, and 97.4%, respectively, in the >2 cm group, with no significant differences between the groups. There was no difference in adverse events between the groups (0% in the ≤2 cm group and 2.3% in the >2 cm group). EUS-TA for small focal liver lesions measuring ≤2 cm has favorable outcomes, which are similar to those for lesions measuring >2 cm.

Photon-counting computed tomography versus energy-integrating computed tomography for detection of small liver lesions: comparison using a virtual framework imaging.

Photon-counting computed tomography (PCCT) has the potential to provide superior image quality to energy-integrating CT (EICT). We objectively compare PCCT to EICT for liver lesion detection. Fifty anthropomorphic, computational phantoms with inserted liver lesions were generated. Contrast-enhanced scans of each phantom were simulated at the portal venous phase. The acquisitions were done using DukeSim, a validated CT simulation platform. Scans were simulated at two dose levels ( 1.5 to 6.0mGy) modeling PCCT (NAEOTOM Alpha, Siemens, Erlangen, Germany) and EICT (SOMATOM Flash, Siemens). Images were reconstructed with varying levels of kernel sharpness (soft, medium, sharp). To provide a quantitative estimate of image quality, the modulation transfer function (MTF), frequency at 50% of the MTF ( ), noise magnitude, contrast-to-noise ratio (CNR, per lesion), and detectability index ( , per lesion) were measured. Across all studied conditions, the best detection performance, measured by , was for PCCT images with the highest dose level and softest kernel. With soft kernel reconstruction, PCCT demonstrated improved lesion CNR and compared with EICT, with a mean increase in CNR of 35.0% ( ) and 21% ( ) and a mean increase in of 41.0% ( ) and 23.3% ( ) for the 1.5 and 6.0mGy acquisitions, respectively. The improvements were greatest for larger phantoms, low-contrast lesions, and low-dose scans. PCCT demonstrated objective improvement in liver lesion detection and image quality metrics compared with EICT. These advances may lead to earlier and more accurate liver lesion detection, thus improving patient care.

6728 Bilateral Adrenal Hemorrhage: Cause Or Consequence?

Abstract Disclosure: M.N. Rayan: None. R. Horner: None. A. Valenciaga: None. L.E. Ryan: None. Introduction: Before the advent of the CT scan, bilateral adrenal hemorrhage was primarily discovered post-mortem in patients who had succumbed to sepsis, burns, or anticoagulant therapy. Today, non-traumatic hemorrhage is recognized as an infrequent, yet potentially lethal diagnosis causing clinical deterioration in acutely ill patients. Clinical Case: Our patient is a 64-year-old-male with a medical history of Myelodysplastic Syndrome initially presented to an external ED with abdominal pain. CT abdomen revealed hepatomegaly, splenomegaly, and new bilateral adrenal masses—absent in an MRI conducted a year earlier. He was treated conservatively and subsequently discharged. Two weeks later, he returned to the hospital with severe right sided flank pain. His hemoglobin and platelet counts dropped from 11.5 g/dL and 309 K/uL during the previous ED visit to 7.7 g/dL and 80 K/uL, respectively. Additionally, his PT/INR, PTT, fibrinogen, and D-Dimer levels were elevated. A repeat CT scan indicated a significant enlargement of the right adrenal mass, raising suspicion of adrenal hemorrhage. He was appropriately transfused, and a BM biopsy was performed to evaluate for acute transformation of underlying MDS. Cortisol levels were monitored daily for adrenal insufficiency. A complicated hospital course ensued marked by worsening anemia, thrombocytopenia, and coagulopathy, accompanied by high fevers and new-onset atrial fibrillation. Mixing studies showed absence of a factor inhibitor ruling out acquired forms of Hemophilia. Infectious workup including fungal and viral serologies returned negative. A PET scan revealed several small hypermetabolic hypodense liver lesions, and hypermetabolic activity diffusely in the spleen, and adrenal glands leading to suspicion of metastasis. Results of the BM biopsy returned revealing hypercellularity, with aggregates of hemosiderin-laden macrophages replacing the bone marrow space with associated necrosis. Worsening abdominal pain with hematochezia prompted an endoscopy, confirming a diagnosis of metastatic melanoma. Concurrently, seizure activity and altered mentation led to a head CT, revealing new metastatic lesions that confirmed the rapid progression of the disease. Subsequently, the patient was transitioned to comfort care and passed away. Clinical Lesson: It is crucial to review the various causes of adrenal hemorrhage, understand the challenges associated with interpreting adrenal imaging, emphasize the need to monitor adrenal function, and consider the occasional necessity for tissue sampling. In this clinical scenario, metastases with hemorrhage were the most likely etiology. The causes of adrenal hemorrhage are not always apparent; in this presentation, the consequence of the underlying disease state ultimately led to the initial presenting symptom of abdominal pain. Presentation: 6/2/2024

Relevance of lesion size in navigator-triggered and free-breathing diffusion-weighted liver MRI.

The purpose of this study was to investigate the relevance of focal liver lesions (FLL) size for lesion detection comparing navigator triggering (TRIG) to free breathing (FB) liver Diffusion-weighted magnetic resonance imaging (DWI). Patients with known or suspected FLL were prospectively (registry number 276_19 B) included from October to December 2019 in this study, out of which 32 had liver lesions. Echo planar spin-echo DWI data both with TRIG and FB were with approximately constant acquisition times acquired at 1.5 T. Lesions were segmented in the b = 800 s/mm² images in both the TRIG and FB images. The lesion size, location (liver segment), liver lesion visibility, as well as contrast-to-noise ratio (CNR) were recorded. The CNR was assessed with the Wilcoxon-Mann-Whitney test and the number of visible lesions with the Fisher test. Data from 43 patients (22 female) were analyzed. The mean patient age was 58 ± 14 years. A total of 885 FLL (Ntotal) were segmented. Among these, 811 lesions (Nboth) were detected with TRIG and FB, 65 lesions exclusively with TRIG (NTRIG_Only), and nine exclusively in FB (NFB_Only). The largest additional lesion in TRIG/FB had a diameter of 10.4 mm/7.6 mm. The number of additional lesions detected with TRIG decreased with size. Among all lesions ≤ 4.7 mm, the relative number of additional lesions was 15.6%. Additional lesions were found in all liver segments with TRIG. In the left liver lobe, the relative proportion was 9.2%, and in the right liver lobe 5.4%. CNR and visibility were significantly higher in TRIG than in FB (p < 0.001). In relation to size, the difference is significant in terms of visibility and CNR for lesion diameters ≤ 8 mm. Respiration triggering can improve the detection of small liver lesions with diameters up to approx. 1 cm in the whole liver. Question Can respiration triggering (TRIG) improve the detection of small FLL compared to FB diffusion-weighted imaging? Findings Among 885 segmented FLL, TRIG was superior to FB for lesions smaller than 8 mm and had improved CNR and visibility. Clinical relevance Diffusion-weighted magnetic resonance imaging is used for the detection of focal liver lesions and image quality is influenced by breathing motion. Navigator triggering becomes more important for smaller lesions, and seems recommendable for the detection of small focal liver lesions.

Enhancing liver surgery and transplantation: the role of 3D printing and virtual reality

This review explores the significant advancements in liver surgery and transplantation, particularly focusing on the integration of 3D printing and virtual reality (VR) technologies. The core objective is to enhance preoperative planning, simulation, and intraoperative navigation. The review discusses several studies that underscore the accuracy and utility of 3D printed models derived from medical imaging, which are instrumental in identifying small liver lesions, improving surgical education, and facilitating patient comprehension. Additionally, the role of VR in surgical simulation is examined, highlighting its superiority in tumor identification and its potential in training systems. While clinical outcomes data suggest a need for further randomized trials to establish the impact on surgical efficiency and recovery, the review also touches upon the promising future of augmented reality (AR) for intraoperative guidance and liver segment identification, with prospects of artificial intelligence (AI) integration. The conclusion underscores the importance of continued clinical evidence and technological advancements for wider adoption in liver surgery and transplantation.

Introduction of day-case robotic liver surgery: a case series from a tertiary hepatobiliary and pancreatic centre

BackgroundLiver surgery is associated with a significant hospital stay regardless the type of liver resection. A large incision is essential for open liver surgery which is a major factor in the course of the patient’s recovery. For patients with small parenchyma liver lesions requiring surgical resection, robotic surgery potentially offers the opportunity to transform the patient’s post-operative course. A day-case robotic liver resection pathway was formulated and implemented at our institution when patients were planned for discharge within 24 h of admission for liver surgery.MethodsSingle surgeon case series of cases performed at a tertiary hepatobiliary and pancreatic centre between September 2022 and November 2023. The inclusion criteria were non-anatomical wedge resections, < 2 anatomical segmental resections, left lateral hepatectomy and minimally invasive surgery.ResultsThis is the first series of robotic day-case minor liver resection in the United Kingdom. 20 patients were included in this case series. The mean operative time was 86.6 ± 30.9 min and mean console time was 58.6 ± 24.5 min. Thirteen patients (65%) were discharged within 24 h of surgery. The main cause of hospitalisation beyond 24 h was inadequate pain relief. There were no Clavien–Dindo grade III or above complications, no 30-day readmission and 90-day mortalities.ConclusionThis case series demonstrates that robotic day-case liver resection is safe and feasible. Robust follow-up pathways must be in place to allow for the safe implementation of this approach, to monitor for any complications and to allow intervention as required in a timely manner.

Correlation between CEUS LI-RADS categorization of HCC < 20 mm and clinic-pathological features

ObjectiveTo retrospectively evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) LI-RADS in liver nodules < 20 mm at high risk of hepatocellular carcinoma (HCC) and their correlation with clinic-pathological features.MethodsA total of 432 pathologically proved liver nodules < 20 mm were included from January 2019 to June 2022. Each nodule was categorized as LI-RADS grade (LR)-1 to LR-5 through LR-M according to CEUS LI-RADS. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of CEUS LI-RADS were evaluated using pathological reference standard. Correlations between clinic-pathological features and CEUS LI-RADS categorization, together with major CEUS features, were further explored.ResultsWith LR-5 to diagnose HCC, the sensitivity, specificity, PPV, NPV, and AUC were 50.3%, 70.0%, 91.2%, 18.5%, and 0.601, respectively. The proportion of LR-5 in primary HCCs was significantly higher than that in recurrent ones (p = 0.014). HCC 10–19 mm showed significantly more frequent arterial phase hyper-enhancement (APHE) and late washout (p < 0.05) and less no-washout (p = 0.003) compared with those in HCC < 10 mm. Well-differentiated HCCs showed more frequent non-APHE and no-washout than moderate- and poor-differentiated HCCs (p < 0.05). Upgrading “APHE without washout” LR-4 nodules 10–19 mm with HCC history and “APHE with late mild washout” LR-4 nodules < 10 mm to LR-5 could improve the diagnostic performance of LR-5. The corresponding sensitivity, specificity, PPV, NPV, and AUC are 60.2%, 70.0%, 92.6%, 22.1%, and 0.651, respectively.ConclusionsCEUS LI-RADS is valuable in the diagnosis of HCC < 20 mm and performance can be improved with the combination of clinic-pathological features.Critical relevance statementCEUS LI-RADS was valuable in the diagnosis of HCC < 20 mm and its diagnostic performance can be improved by combining clinic-pathological features. Further research is needed to define its value in this set of lesions.Key PointsContrast-enhanced ultrasound can detect small liver lesions where LI-RADS accuracy is uncertain.Many LI-RADS Grade-4 nodules were upgraded to Grade-5 by combining imaging with clinic-pathological factors.The reclassification of LI-RADS Grade-5 can improve sensitivity without decreasing positive predictive value.Graphical

Boundary-Sensitive Segmentation of Small Liver Lesions.

Early diagnosis plays a pivotal role in handling the global health challenge posed by liver diseases. However, early-stage lesions are typically quite small, presenting significant difficulties due to insufficient regions for developing effective features, indistinguishable boundaries of small lesions, and a lack of tiny liver lesion masks. To address these issues, we approach the solution in two-fold: an efficient model and a high-quality dataset. The model is built upon the advantages of path signature and camouflaged object detection. The path signature narrows down the ambiguous boundaries between lesions and other tissues while the camouflaged object detection achieves high accuracy in detecting inconspicuous lesions. The two are seamlessly integrated to ensure high accuracy and fidelity. For the dataset, we collect more than ten thousand liver images with over four thousand lesions, approximately half of which are small. Experiments on both an established dataset and our newly constructed one show that the proposed model outperforms state-of-the-art semantic segmentation and camouflaged object detection models, particularly in detecting small lesions. Moreover, the decisive and faithful salience maps generated by the model at the boundary regions demonstrate its strong robustness.

Enhancing gadoxetic acid–enhanced liver MRI: a synergistic approach with deep learning CAIPIRINHA-VIBE and optimized fat suppression techniques

ObjectiveTo investigate whether a deep learning (DL) controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-volumetric interpolated breath-hold examination (VIBE) technique can improve image quality, lesion conspicuity, and lesion detection compared to a standard CAIPIRINHA-VIBE technique in gadoxetic acid–enhanced liver MRI.MethodsThis retrospective single-center study included 168 patients who underwent gadoxetic acid–enhanced liver MRI at 3 T using both standard CAIPIRINHA-VIBE and DL CAIPIRINHA-VIBE techniques on pre-contrast and hepatobiliary phase (HBP) images. Additionally, high-resolution (HR) DL CAIPIRINHA-VIBE was obtained with 1-mm slice thickness on the HBP. Three abdominal radiologists independently assessed the image quality and lesion conspicuity of pre-contrast and HBP images. Statistical analyses involved the Wilcoxon signed-rank test for image quality assessment and the generalized estimation equation for lesion conspicuity and detection evaluation.ResultsDL and HR-DL CAIPIRINHA-VIBE demonstrated significantly improved overall image quality and reduced artifacts on pre-contrast and HBP images compared to standard CAIPIRINHA-VIBE (p < 0.001), with a shorter acquisition time (DL vs standard, 11 s vs 17 s). However, the former presented a more synthetic appearance (both p < 0.05). HR-DL CAIPIRINHA-VIBE showed superior lesion conspicuity to standard and DL CAIPIRINHA-VIBE on HBP images (p < 0.001). Moreover, HR-DL CAIPIRINHA-VIBE exhibited a significantly higher detection rate of small (< 2 cm) solid focal liver lesions (FLLs) on HBP images compared to standard CAIPIRINHA-VIBE (92.5% vs 87.4%; odds ratio = 1.83; p = 0.036).ConclusionDL and HR-DL CAIPIRINHA-VIBE achieved superior image quality compared to standard CAIPIRINHA-VIBE. Additionally, HR-DL CAIPIRINHA-VIBE improved the lesion conspicuity and detection of small solid FLLs. DL and HR-DL CAIPIRINHA-VIBE hold the potential clinical utility for gadoxetic acid–enhanced liver MRI.Clinical relevance statementDL and HR-DL CAIPIRINHA-VIBE hold promise as potential alternatives to standard CAIPIRINHA-VIBE in routine clinical liver MRI, improving the image quality and lesion conspicuity, enhancing the detection of small (< 2 cm) solid focal liver lesions, and reducing the acquisition time.Key Points• DL and HR-DL CAIPIRINHA-VIBE demonstrated improved overall image quality and reduced artifacts on pre-contrast and HBP images compared to standard CAIPIRINHA-VIBE, in addition to a shorter acquisition time.• DL and HR-DL CAIPIRINHA-VIBE yielded a more synthetic appearance than standard CAIPIRINHA-VIBE.• HR-DL CAIPIRINHA-VIBE showed improved lesion conspicuity than standard CAIPIRINHA-VIBE on HBP images, with a higher detection of small (< 2 cm) solid focal liver lesions.

Clinical benefits of MRI-guided freehand biopsy of small focal liver lesions in comparison to CT guidance

ObjectivesTo compare clinical success, procedure time, and complication rates between MRI-guided and CT-guided real-time biopsies of small focal liver lesions (FLL) < 20 mm.MethodsA comparison of a prospectively collected MRI-guided cohort (n = 30) to a retrospectively collected CT-guided cohort (n = 147) was performed, in which patients underwent real-time biopsies of small FLL < 20 mm in a freehand technique. In both groups, clinical and periprocedural data, including clinical success, procedure time, and complication rates (classified according to CIRSE guidelines), were analyzed. Wilcoxon rank sum test, Pearson’s chi-squared test, and Fisher’s exact test were used for statistical analysis. Additionally, propensity score matching (PSM) was performed using the following criteria for direct matching: age, gender, presence of liver cirrhosis, liver lobe, lesion diameter, and skin-to-target distance.ResultsThe median FLL diameter in the MRI-guided cohort was significantly smaller compared to CT guidance (p < 0.001; 11.0 mm vs. 16.3 mm), while the skin-to-target distance was significantly longer (p < 0.001; 90.0 mm vs. 74.0 mm). MRI-guided procedures revealed significantly higher clinical success compared to CT guidance (p = 0.021; 97% vs. 79%) as well as lower complication rates (p = 0.047; 0% vs. 13%). Total procedure time was significantly longer in the MRI-guided cohort (p < 0.001; 38 min vs. 28 min). After PSM (n = 24/n = 38), MRI-guided procedures still revealed significantly higher clinical success compared to CT guidance (p = 0.039; 96% vs. 74%).ConclusionDespite the longer procedure time, freehand biopsy of small FLL < 20 mm under MR guidance can be considered superior to CT guidance because of its high clinical success and low complication rates.Clinical relevance statementBiopsy of small liver lesions is challenging due to the size and conspicuity of the lesions on native images. MRI offers higher soft tissue contrast, which translates into a higher success of obtaining enough tissue material with MRI compared to CT-guided biopsies.Key Points• Image-guided biopsy of small focal liver lesions (FLL) is challenging due to inadequate visualization, leading to sampling errors and false-negative biopsies.• MRI-guided real-time biopsy of FLL < 20 mm revealed significantly higher clinical success (p = 0.021; 97% vs. 79%) and lower complication rates (p = 0.047; 0% vs. 13%) compared to CT guidance.• Although the procedure time is longer, MRI-guided biopsy can be considered superior for small FLL < 20 mm.Graphical

Colonic basidiobolomycosis masquerading as colon cancer with liver metastasis: A case report and review of literature

AbstractBasidiobolomycosis is a rare subcutaneous fungal infection caused by Basidiobolus ranarum. Gastrointestinal Basidiobolomycosis GIB has been increasingly reported in the literature.We present a case of a 50-year-old male patient who presented by abdominal pain and weight loss. Imaging showed a left colon mass with a small liver lesion. Provisional diagnosis of colon cancer with liver metastasis was made. Endoscopic stenting and biopsy were done, and the results of the biopsy were not conclusive. The condition was complicated by perforation, and emergency laparotomy was done. The diagnosis of colon Basidiobolomycosis was reached from surgical histopathology. Unfortunately, the patient's condition deteriorated post operatively and the patient passed away a few days after surgery.GIB is a rare fungal infection commonly presenting as a colonic neoplastic mass or inflammatory bowel disease. The endoscopy biopsy usually fails to provide definitive diagnosis. Post-operative histopathological examination with or without culture provides a definite diagnosis. Treatment of GIB includes surgical resection with appropriate antifungal therapy which revealed dramatic response in most of the cases. However, delayed diagnosis and treatment lead to dissemination of the disease which is life-threatening condition.

Application of a preoperative scoring system for small liver lesions in predicting small hepatocellular carcinoma

Application of a preoperative scoring system for small liver lesions in predicting small hepatocellular carcinoma

Deep-learning CT reconstruction in clinical scans of the abdomen: a systematic review and meta-analysis.

To perform a systematic literature review and meta-analysis of the two most common commercially available deep-learning algorithms for CT. We used PubMed, Scopus, Embase, and Web of Science to conduct systematic searches for studies assessing the most common commercially available deep-learning CT reconstruction algorithms: True Fidelity (TF) and Advanced intelligent Clear-IQ Engine (AiCE) in the abdomen of human participants since only these two algorithms currently have adequate published data for robust systematic analysis. Forty-four articles fulfilled inclusion criteria. 32 studies evaluated TF and 12 studies assessed AiCE. DLR algorithms produced images with significantly less noise (22-57.3% less than IR) but preserved a desirable noise texture with increased contrast-to-noise ratios and improved lesion detectability on conventional CT. These improvements with DLR were similarly noted in dual-energy CT which was only assessed for a single vendor. Reported radiation reduction potential was 35.1-78.5%. Nine studies assessed observer performance with the two dedicated liver lesion studies being performed on the same vendor reconstruction (TF). These two studies indicate preserved low contrast liver lesion detection (>5mm) at CTDIvol 6.8mGy (BMI 23.5kg/m2) to 12.2mGy (BMI 29kg/m2). If smaller lesion detection and improved lesion characterization is needed, a CTDIvol of 13.6-34.9mGy is needed in a normal weight to obese population. Mild signal loss and blurring have been reported at high DLR reconstruction strengths. Deep learning reconstructions significantly improve image quality in CT of the abdomen. Assessment of other dose levels and clinical indications is needed. Careful choice of radiation dose levels is necessary, particularly for small liver lesion assessment.

Recall patterns and risk of primary liver cancer for subcentimeter ultrasound liver observations: a multicenter study

Patients with cirrhosis and subcentimeter lesions on liver ultrasound are recommended to undergo short-interval follow-up ultrasound because of the presumed low risk of primary liver cancer (PLC). The aim of this study is to characterize recall patterns and risk of PLC in patients with subcentimeter liver lesions on ultrasound. We conducted a multicenter retrospective cohort study among patients with cirrhosis or chronic hepatitis B infection who had subcentimeter ultrasound lesions between January 2017 and December 2019. We excluded patients with a history of PLC or concomitant lesions ≥1cm in diameter. We used Kaplan Meier and multivariable Cox regression analyses to characterize time-to-PLC and factors associated with PLC, respectively. Of 746 eligible patients, most (66.0%) had a single observation, and the median diameter was 0.7cm (interquartile range: 0.5-0.8cm). Recall strategies varied, with only 27.8% of patients undergoing guideline-concordant ultrasound within 3-6 months. Over a median follow-up of 26 months, 42 patients developed PLC (39 HCC and 3 cholangiocarcinoma), yielding an incidence of 25.7 cases (95% CI, 6.2-47.0) per 1000 person-years, with 3.9% and 6.7% developing PLC at 2 and 3 years, respectively. Factors associated with time-to-PLC were baseline alpha-fetoprotein >10ng/mL (HR: 4.01, 95% CI, 1.85-8.71), platelet count ≤150 (HR: 4.90, 95% CI, 1.95-12.28), and Child-Pugh B cirrhosis (vs. Child-Pugh A: HR: 2.54, 95% CI, 1.27-5.08). Recall patterns for patients with subcentimeter liver lesions on ultrasound varied widely. The low risk of PLC in these patients supports short-interval ultrasound in 3-6 months, although diagnostic CT/MRI may be warranted for high-risk subgroups such as those with elevated alpha-fetoprotein levels.

Screening and Early Diagnosis of Hepatocellular Cancer and Optimization of Diagnostic Imaging Techniques: A Review and Conclusion of the Expert Panel

Аim: to describe modern approaches for screening and early diagnosis of hepatocellular carcinoma (HCC).Key points. Screening for HCC in high-risk groups (cirrhosis of any etiology, patients with chronic viral hepatitis B and patients with F3 liver fibrosis) should be organized as regular (every 6 months) liver ultrasound in combination with determination of the serum alpha-fetoprotein (AFP) level. At an AFP level of ≥ 20 ng/ml, even in the absence of changes according to ultrasound data, it is advisable to perform MRI with a hepatospecific contrast agent (gadoxetic acid) which makes it possible to detect very small focal liver lesions. If focal liver lesions of 1–2 cm are detected on ultrasound, additional imaging of the liver using MRI with a hepatospecific contrast agent gadoxetic acid helps to identify HCC at an earlier stage or high degree dysplastic nodes. When planning surgical treatment and liver transplantation, it is preferable to use MRI with a hepatospecific contrast agent, since the presence of the hepatobiliary phase may allow the detection of additional smaller focal liver lesions and assess the nature of the focal liver lesion. When a patient is included in the waiting list for liver transplantation, the optimal frequency of liver MRI is 1 time in 3 months.Conclusion. MRI with hepatospecific contrast agent gadoxetic acid is effective in screening, early diagnosis and treatment planning for HCC.

High frame-rate contrast enhanced ultrasound (HIFR-CEUS) in the characterization of small hepatic lesions in cirrhotic patients.

To show the effectiveness of plane wave HighFrame-Rate CEUS (HiFR-CEUS) compared with "conventional" (plane wave) CEUS (C-CEUS) in the characterization of small (< 2cm) focal liver lesions (FLLs) not easily detected by CT in cirrhotic patients. HiFR-CEUS exploit an ultra-wideband nonlinear process to combine fundamental, second and higher-order harmonic signals generated by ultrasound contrast agents to increase the frame rate. C-CEUS is limited by the transmission principle, and its frame-rate is around 10 FPS. With HiFR-CEUS (Shenzhen Mindray Bio-Medical Electronics Co., China), the frame-rate reached 60 FPS. Ultrasound detected small FLLs (< 2cm) in 63 cirrhotic patients during follow-up (June 2019-February 2020); (7 nodules < 1cm and were not evaluable by spiral CT). Final diagnosis was obtained with MRI (47) or fine needle aspiration (16 cases) C-CEUS was performed and HiFR-CEUS was repeated after 5min; 0.8-1.2ml of contrast media (SonoVue, Bracco, Italy) was used. 57 nodules were better evaluable with HiFR-CEUS; 6 nodules were equally evaluable by both techniques; final diagnosis was: 44 benign lesions (29 hemangiomas, 1 amartoma, 2 hepatic cysts; 2 focal nodular hyperplasias, 3 regenerative macronodules, 3 AV-shunts, 3 hepatic sparing areas and 1 focal steatosis) and 19 malignant one (17 HCCs, 1 cholangioca, 1 metastasis); statistical evaluation for better diagnosis with X2 test (SPSS vers. 26); we used LI-RADS classification for evaluating sensitivity, specificity PPV, NPV and diagnostic accuracy of C- and HFR-CEUS. Corrispective AU-ROC were calculated. C-CEUS and HiFR-CEUS reached the same diagnosis in 29 nodules (13 nodules > 1 < 1.5cm; 16 nodules > 1.5 < 2cm); HiFR-CEUS reached a correct diagnosis in 32 nodules where C-CEUS was not diagnostic (6 nodules < 1cm; 17 nodules > 1 < 1.5cm; 9 nodules > 1.5 < 2cm); C-CEUS was better in 2 nodules (1 < 1cm and 1 > 1 < 1.5cm). Some patient's (sex, BMI, age) and nodule's characteristics (liver segment, type of diagnosis, nodule's dimensions (p = 0.65)) were not correlated with better diagnosis (p ns); only better visualization (p 0.004) was correlated; C-CEUS obtained the following LI-RADS: type-1: 18 Nodules, type-2: 21; type-3: 7, type-4: 7; type-5: 8; type-M: 2; HiFR-CEUS: type-1: 38 Nodules, type-2: 2; type-3:4, type-4: 2; type-5: 15; type-M: 2; In comparison with final diagnosis: C-CEUS: TP: 17; TN: 39; FP: 5; FN:2; HIFR-CEUS: TP: 18; TN: 41; FP: 3; FN:1; C-CEUS: sens: 89.5%; Spec: 88.6%, PPV: 77.3%; NPV: 95.1%; Diagn Acc: 88.6% (AU-ROC: 0.994 ± SEAUC: 0.127; CI: 0.969-1.019); HiHFR CEUS: sens: 94.7%; Spec: 93.2%, PPV: 85.7%; NPV: 97.6%; Diagn Acc: 93.2% (AU-ROC: 0.9958 ± SEAUC: 0.106; CI: 0.975-1.017) FLL vascularization in the arterial phase was more visible with HiFR-CEUS than with C-CEUS, capturing the perfusion details in the arterial phase due to a better temporal resolution. With a better temporal resolution, the late phase could be evaluated longer with HiFR-CEUS (4min C-CEUS vs. 5min HiFR-CEUS). Both C-CEUS and HIFR-CEUS are good non invasive imaging system for the characterization of small lesions detected during follow up of cirrhotic patients. HiFR-CEUS allowed better FLL characterization in cirrhotic patients with better temporal and spatial resolution capturing the perfusion details that cannot be easily observed with C-CEUS.

S3327 Angiosarcoma Presenting as Hemorrhagic Shock: A Rare Diagnosis of Liver Lesions in a Young Patient

Introduction: Angiosarcoma is an aggressive tumor and rare in young healthy patients. Angiosarcoma is associated with exposure to arsenic, vinyl chloride, and oral contraceptives1. This is an unusual case of angiosarcoma in a young patient presenting with an acute abdomen from hemorrhagic shock. Angiosarcoma has poor prognosis and even removal and transplantation of the Liver is no sufficient 1. It is important to include angiosarcoma in the differential for patients presenting with acute abdomen and explore aggressive medical therapy along with surgical resection. Case Description/Methods: A 19-year-old male with no past medical history presented with sudden severe diffuse abdominal pain, difficulty breathing, nausea, vomiting, and diarrhea. FAST exam showed large volume of free fluid in the abdomen. Initial labs showed elevated liver associated enzymes, Hgb 5.4, lactic acidosis, fibrinogen 171. CT of abdomen and pelvis showed hepatomegaly with multiple small hypervascular lesions in liver [Figure 1]. Massive transfusion protocol was initiated, and he subsequently required emergent exploratory laparotomy with 3L of old-appearing blood drained. Intraoperatively, the liver was found to be multinodular, woody, enlarged, and cirrhotic with fresh heme. Final surgical pathology showed angiosarcoma with atypia over epithelioid hemangioendothelioma. Patient continued losing blood and required a hepatic angiogram with embolization. He continued to worsen, developing acute liver failure. Patient continued to decompensate and eventually required palliative care. (Figure) Discussion: Angiosarcoma often presents in elderly patients with nonspecific symptoms such as abdominal distention, abdominal discomfort, weight loss, and fatigue2,3,4. Differentiating liver tumors such as hepatoma, adenoma, or vascular malformations on imaging is challenging and surgical resection is essential. Average survival of patients with untreated liver angiosarcoma is approximately 6 months and it increases by 2 years with treatment2,3,4. The standard treatment for liver angiosarcoma is surgical resection. Liver transplant is not indicated because of the high recurrence rate and poor prognosis2,3,4. There are no standardized treatments for patients presenting with hemorrhagic shock besides embolization and resection. More treatments need to be explored for aggressive treatment for hepatic angiosarcoma, as this case highlights a healthy 19-year-old patient dying one month after initial diagnosis with limited options for therapeutic intervention.Figure 1.: CT Abdomen and Pelvis with multiple hypervascular lesions.

Radiologic-pathologic correlation of lesions in resected liver specimens with an ex vivo MRI-compatible localization device.

Liver lesion characterization is limited by the lack of an established gold standard for precise correlation of radiologic characteristics with their histologic features. The objective of this study was to demonstrate the feasibility of using an ex vivo MRI-compatible sectioning device for radiologic-pathologic co-localization of lesions in resected liver specimens. In this prospective feasibility study, adults undergoing curative partial hepatectomy from February 2018 to January 2019 were enrolled. Gadoxetic acid was administered intraoperatively prior to hepatic vascular inflow ligation. Liver specimens were stabilized in an MRI-compatible acrylic lesion localization device (27 × 14 × 14 cm3) featuring slicing channels and a silicone gel 3D matrix. High-resolution 3D T1-weighted fast spoiled gradient echo and 3D T2-weighted fast-spin-echo images were acquired using a single channel quadrature head coil. Radiologic lesion coordinates guided pathologic sectioning. A final histopathologic diagnosis was prepared for all lesions. The proportion of successfully co-localized lesions was determined. A total of 57 lesions were identified radiologically and sectioned in liver specimens from 10 participants with liver metastases (n = 8), primary biliary mucinous cystic neoplasm (n = 1), and hepatic adenomatosis (n = 1). Of these, 38 lesions (67%) were < 1 cm. Overall, 52/57 (91%) of radiologically identified lesions were identified pathologically using the device. Of these, 5 lesions (10%) were not initially identified on gross examination but were confirmed histologically using MRI-guided localization. One lesion was identified grossly but not on MRI. We successfully demonstrated the feasibility of a clinical method for image-guided co-localization and histological characterization of liver lesions using an ex vivo MRI-compatible sectioning device. • The ex vivo MRI-compatible sectioning device provides a reliable method for radiologic-pathologic correlation of small (< 1 cm) liver lesions in human liver specimens. • The sectioning method can be feasibly implemented within a clinical practice setting and used in future efforts to study liver lesion characterization. • Intraoperative administration of gadoxetic acid results in enhancement in ex vivo MRI images of liver specimens hours later with excellent image quality.

Reliability of extracellular contrast versus gadoxetic acid in assessing small liver lesions using liver imaging reporting and data system v.2018 and European association for the study of the liver criteria.

The diagnostic accuracy of Liver Imaging Reporting and Data System (LI-RADS) v.2018 and European Association for the Study of the Liver (EASL) criteria for the diagnosis of HCC have been widely evaluated, but their reliability should be investigated. We aimed to assess and compare the reliability of LI-RADS v.2018 and EASL criteria for the diagnosis of HCC using MRI with extracellular contrast agents (ECAs) and gadoxetic acid (GA) and determine the effect of ancillary features on LI-RADS reliability. Ten readers reviewed MRI studies of 92 focal liver lesions measuring <3 cm acquired with ECAs and GA <1 month apart from two prospective trials, assessing EASL criteria, LI-RADS major and ancillary features, and LI-RADS categorization with and without including ancillary features. Inter-reader agreement for definite HCC diagnosis was substantial and similar for the two contrasts for both EASL and LI-RADS criteria. For ECA-MRI and GA-MRI, respectively, inter-reader agreement was k = 0.72 (95% CI, 0.63-0.81) and k = 0.72 (95% CI, 0.63-0.80); for nonrim hyperenhancement, k = 0.63 (95% CI, 0.54-0.72) and k = 0.57 (95% CI, 0.48-0.66); and for nonperipheral washout, k = 0.49 (95% CI, 0.40-0.59) and k = 0.48 (95% CI, 0.37-0.58) for enhancing capsule. The inter-reader agreement for LI-RADS after applying ancillary features remained in the same range of agreement. Agreement for definite HCC was substantial and similar for both scoring systems and the two contrast agents in small focal liver lesions. Agreement for LI-RADS categorization was lower for both contrast agents, and including LI-RADS ancillary features did not improve agreement.

The clinical value of dual-energy computed tomography and diffusion-weighted imaging in the context of liver cancer: A narrative review.

The dual-energy computed tomography (DECT) and diffusion-weighted magnetic resonance imaging (DWI-MRI) are used to diagnose liver cancer. The clinical value of these two examination methods needs to be further summarized. We collected and summarized relevant literature published from 2011 to 2021. The diagnostic performance of DECT was assessed between conventional computed tomography and DWI-MRI. DWI-MRI had a 69% sensitivity for detecting small hepatocellular carcinoma (HCC) lesions and a 60% diagnostic specificity for differentiating between types of HCC lesions. DECT had a sensitivity to small liver lesions (<1cm) of 69%, and the diagnostic specificity for HCC and metastasis was about 60%. DWI was more sensitive (90.3% vs. 74.9%) and accurate (91.9% vs. 76.9%) in diagnosing HCC compared with conventional MRI sequencing. With the aid of contrast media, DWI-MRI had 90.0% specificity for detecting small HCCs (smaller than 1cm). Furthermore, DWI-MRI not only provided physicians with valuable diagnostic information but also delivered histological grading information, with 78% accuracy for all benign lesions and 71% for solid lesions. DECT had relatively high sensitivity and required a lower contrast medium dose. With standardized quantitative parameters, it can be an extremely useful tool for HCC surveillance. DWI-MRI is the preferred imaging process as it produces high-contrast images for supporting an early diagnosis (high sensitivity and specificity) and provides histological information using non-ionizing radiation.