Small Hepatic Lesions Research Articles

MRI radiomics model differentiates small hepatic metastases and abscesses in periampullary cancer patients

This multi-center, retrospective study focused on periampullary cancer patients undergoing MRI for hepatic metastasis and abscess differentiation. T1-weighted, T2-weighted, and arterial phase images were utilized to create radiomics models. In the training-set, 112 lesions in 54 patients (median age [IQR, interquartile range], 73 [63–80]; 38 men) were analyzed, and 123 lesions in 55 patients (72 [66–78]; 34 men) comprised the validation set. The T1-weighted + T2-weighted radiomics model showed the highest AUC (0.82, 95% CI 0.75–0.89) in the validation set. Notably, < 30% T1-T2 size discrepancy in MRI findings predicted metastasis (Ps ≤ 0.037), albeit with AUCs of 0.64–0.68 for hepatic metastasis. The radiomics model enhanced radiologists’ performance (AUCs, 0.85–0.87 vs. 0.80–0.84) and significantly increased diagnostic confidence (P < 0.001). Although the performance increase lacked statistical significance (P = 0.104–0.281), the radiomics model proved valuable in differentiating small hepatic lesions and enhancing diagnostic confidence. This study highlights the potential of MRI-based radiomics in improving accuracy and confidence in the diagnosis of periampullary cancer-related hepatic lesions.

Can Modifications of LR-M Criteria Improve the Diagnostic Performance of Contrast-Enhanced Ultrasound LI-RADS for Small Hepatic Lesions up to 3 cm?

To assess the diagnostic performance of the contrast-enhanced ultrasound liver imaging reporting and data system (CEUS LI-RADS) version 2017 for small hepatic lesions of ≤3 cm before and after changing the LR-M criteria. We retrospectively analyzed the CEUS examination of 179 patients who were at high risk of hepatocellular carcinoma (HCC) with focal hepatic lesions ≤3 cm (194 lesions in total) and evaluated the diagnostic capability of the American College of Radiology and modified CEUS LI-RADS algorithms. Revision of the early washout time to 45 seconds increased the sensitivity of LR-5 in predicting HCC (P = .004), with no significant decrease in specificity (P = .118). It also made better the specificity of LR-M in predicting non-HCC malignancies (P = .001), with no significant decrease in sensitivity (P = .094). However, using within 3 minutes as the criterion for marked washout time improved the LR-5 sensitivity (P < .001) but decreased its specificity (P = .009) in predicting HCC, whereas the specificity of LR-M in predicting non-HCC malignancies increased (P < .001), but the sensitivity decreased (P = .027). CEUS LI-RADS (v2017) is a valid method for predicting HCC risk in high-risk patients. The diagnostic performance of LR-5 and LR-M could boost when the early washout time is revised to 45 seconds.

Serous Cystadenocarcinoma of Pancreas: A Rare Find

Abstract Introduction/Objective Pancreatic cystic neoplasms comprise 1-2% of pancreatic lesions and most of these lesions are cystadenomas. Serous cystadenocarcinoma is an extremely rare but known malignant condition described in the literature and the diagnosis is restricted to cases with distant metastasis of tumor beyond the pancreas. Per WHO, cytologic atypia, vascular, perineural, and adjacent organ and lymph node involvement by direct spread are insufficient for the diagnosis of serous cystadenocarcinoma. Methods/Case Report We report an interesting case of serous cystadenocarcinoma of pancreas in a 55-year-old male with medical history of prostate cancer was found to have a 15 cm mass pancreatic tail suspicious for neuroendocrine tumor and 5 small hepatic lesions suspicious for metastasis. The patient underwent subtotal pancreatectomy and splenectomy, and wedge resection of liver lesions. On gross examination, a yellow cystic mass was present in the pancreatic tail measuring 13.2 cm in the maximum dimension. H&amp;E slides from the pancreas and liver demonstrated a neoplasm composed of cystic and solid areas, within a background of fibrosis and focal hemorrhage. Cystic areas showed microcysts composed of cells with clear cytoplasm and round to oval bland nuclei. Solid areas demonstrated almost no microcysts but sheets and clusters of cells with clear to scant cytoplasm, oval to round nuclei, few areas of atypical hyperchromatic cells, and occasional mitosis. Very focal clusters and cords of neuroendocrine cells, constituting less than 5% of the tumor volume were also identified. Immunohistochemical stains demonstrated the neoplastic cells both in cystic and solid areas were positive for CK7, CK19, MUC6, and inhibin. Ki67 demonstrated an overall proliferation index of 3%. Chromogranin and synaptophysin were negative within the solid and cystic components of the tumor, however, showed positive staining within neuroendocrine foci. Neoplastic cells were negative for all other tested markers including beta-catenin, ER, Hep-par 1, HMB45, IMP3, MART-1, PAX-8, and trypsin. RB1 expression was retained within neoplastic cells. Results (if a Case Study enter NA) N/A. Conclusion The differentiation between benign and malignant serous cystadenoma both histologically and clinically may be very difficult as some cases of serous cystadenocarcinoma may not show overt cytologic atypia. The presence of metastasis, which most often occurs in the liver is required for the diagnosis of serous cystadenocarcinoma.

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.

S3186 The Imaging Negative Hepatic Lesions: A Rare Case of Infiltrative Hepatocellular Carcinoma

Introduction: Hepatocellular Carcinoma (HCC) is the 6th most common cancer and the 4th leading cause of cancer-related death worldwide. The infiltrative subtype is the most difficult to diagnose with imaging because of its inherently ill-defined micronodules involving a segment or entire hepatic parenchyma without a distinguishable mass. Prognosis is poor and estimated at a 5-year survival rate of < 20%. Diagnosis of HCC requires a sensitive imaging test. In situations where imaging is not able to identify a mass, EUS-FNA has been shown to have a higher detection rate. Case Description/Methods: A 61-year-old female with a past medical history of HCV cirrhosis with sustained virology response (SVR), presented with abdominal pain and worsening lower extremity edema. Remarkable examination findings include a distended abdomen and bilateral pitting lower extremity edema. Significant work up showed platelet of 109k/cmm (150-440), AST of 159 unit/l (15-37), total bilirubin of 1.2mg/dl (0.2-1.0), AFP of >20,000ng/ml (0.5-8.0), peritoneal fluid cytology was negative. A right upper quadrant ultrasound, CT, and MRI showed no hepatic mass, Fig CD. With markedly elevated AFP and a high suspicion for HCC, the patient had EGD-EUS guided fine-needle aspiration showing multiple infiltrative hepatic lesions, Fig E. The biopsy report showed malignant cells positive for AFP with cells reactive for glypican-3 and negative for Hep-Par1 (Fig A), supporting the diagnosis of HCC. The patient was referred to oncology and a month later, she died. Discussion: SVR is associated with decreased risk of HCC, however, with a cirrhotic liver, patients still have an absolute risk of developing HCC. Initial diagnosis of HCC can be obtained non-invasively using abdominal ultrasound, CT, MRI, and EUS-FNA. Abdominal ultrasound is the best imaging modality recommended for HCC surveillance because it is readily available. However, its sensitivity for detecting early HCC is about 47%. AFP cut-off level of > 20ng/ml has a sensitivity of about 60% with low specificity. A level of > 400ng/ml is diagnostic for HCC with a specificity of almost 100%. Incremental changes in AFP are associated with an increased mortality rate. The median survival rate of infiltrative HCC with AFP of > 400 is estimated to be about 5 months. EUS is superior to CT in detecting small hepatic lesions, with a sensitivity of 100% compared to 71% of CT. We recommend that EUS be considered an integral modality while investigating the diagnosis of infiltrative HCC.Figure 1.: Fig A showing Hepatocellular carcinoma, 200x. Glypican-3 immunostain shows strong, diffuse staining in HCC (A). Background non-neoplastic liver is negative (B). Fig C is the cirrhotic liver with no identifiable mass. Fig D shows fluid around the liver and spleen. Fig E is the EUS showing multiple infiltrative hepatic lesions.

Differentiation of Small Hepatic Abscess From Hepatic Metastasis With a Combination of Imaging Parameters.

We aimed to evaluate the diagnostic performance of the combination imaging features to differentiate small (the lesion size of 3 cm or less) hepatic abscess from metastasis. This retrospective study included patients with preexisting malignancy and small hepatic lesions who underwent contrast-enhanced computed tomography (CT) and gadoxetic acid-enhanced magnetic resonance imaging (MRI) within 4 days between March 2017 and July 2020. Two radiologists independently evaluated the imaging features of each focal hepatic lesion. Laboratory parameters were also recorded. Significant parameters differentiating hepatic abscess from hepatic metastasis were identified by univariate generalized estimating equation regression. We compared the diagnostic performances of laboratory parameters, imaging features, and their combinations. We included 16 patients (10 males and 6 females) with 35 hepatic abscesses and 21 patients (13 males and 8 females) with 62 metastases with a mean age of 70.3 years in this study. Abnormal segmental neutrophil, pathy parenchymal enhancement on CT, and absence of dark rim on MRI were associated with hepatic abscess (all P < 0.01). The combination of CT and MRI parameters showed significantly higher specificity and positive predictive value than CT alone ( P ≤ 0.031), without significant difference in sensitivity and negative predictive value. We have demonstrated that the combination of CT and MRI imaging features is helpful for the differentiation of small hepatic abscess from metastasis.

Role of MRI in Detecting and Characterizing Small Hepatic Focal Lesions

Abstract Background Despite the recent advances in liver imaging, the detection and characterization of small hepatic focal lesions is still a real challenge. Particularly in cancer patients where the characterization of a small HFL as thus the precise tumor staging is critical for optimal treatment planning. Aim of the Work To explore the effectiveness, and hence the clinical utility, of MRI detection and characterization of small focal hepatic lesions either only discovered on MRI or as a further work up of CT/US-indeterminate lesions. Patients and Methods We reviewed our database for individuals who underwent liver MR imaging between March 2018 and March 2019 for the evaluation of small hepatic lesions that were discovered for the first time or had been previously visualized on routinely performed CT and had been considered indeterminate. Results The present study included 44 patients of which 26 were males (59.1%) and 18 were females (40.9%). The age range of the study group was 19 to 77 years. The mean age for Malignant lesions was 51 years. The right lobe of liver was involved in 23 cases (52.3%), left lobe in 5 cases (11.4%) and both lobes in 16 cases (36.4%). There were 30 (68.18%) benign, 13 (29.54%) malignant lesions and 1 (2.3%) indeterminate, hemangiomas were predominant in benign lesions whereas hepatocellular carcinomas were predominant in malignant lesions. N'TRI could characterize 92% cases. Conclusion The diagnostic process of small hepatic focal lesions, either detection or characterization or both, continues to represent a challenge. Contrast-enhanced MR can accurately detect and characterize majority of small hepatic focal lesions.

Role of EUS in detection of liver metastasis not seen by computed tomography or magnetic resonance imaging during staging of pancreatic, gastrointestinal, and thoracic malignancies.

Background and Objectives:Liver metastases might not be detected by computed tomography (CT) and magnetic resonance imaging (MRI) due to their small size, but they can be detected by EUS. Furthermore, EUS-FNA has a significant impact on improving the diagnostic accuracy of EUS. The purpose of this study was to assess the feasibility of EUS in detection of occult small hepatic focal lesions at the time of primary tumor staging, not seen by CT or MRI.Methods:This prospective study included 730 patients who underwent EUS for staging or sampling of gastrointestinal, pancreatic, or thoracic malignancy. The liver was examined thoroughly for detection of occult lesions. CT or MRI was done within 1 week of EUS examination.Results:EUS examination of the liver detected focal lesions in 150 patients (20.5%) and metastases in 118 patients (16.2%); meanwhile, CT and MRI detected focal lesions in 99 patients (13.6%) and metastases in 82 patients (11.2%). EUS missed focal lesions in 7 patients, 6 of which were liver metastases (1.0% and 0.8%, respectively), while CT and MRI missed focal lesions in 58 patients, 42 of which were metastases (7.9% and 5.8%, respectively), which were detected by EUS.Conclusion:Thorough dedicated EUS examination of the liver is a feasible useful tool for detection of small hepatic lesions missed by CT and MRI. It is not considered an extra financial burden to the patient or health-care system because those patients are indicated for EUS examination for evaluation of their original lesion in the first place. Furthermore, EUS-FNA can add another advantage in diagnosing the etiology of such lesions.

Indeterminate Liver Lesions - A Virtual Epidemic: A Cohort Study over 8 Years

Background: Within the last decade, advances and availability in radiologic imaging have led to an increase in the detection of incidental liver lesions (ILL) in the asymptomatic patient population. This poses a diagnostic conundrum. This study was undertaken to review the outcome of liver lesions labelled as “indeterminate” in asymptomatic patients without a biopsy-proven concomitant primary tumour. The secondary aim was to assess the impact on health care resources and cost-effectiveness with regards to the frequency and modality of radiological scans, MDT discussions and clinic reviews. Methods: The study consisted of a retrospective analysis of prospectively collected data from the University Hospitals of Leicester MDT database. The study period ranged from 2010-2015. All patients were followed-up for 3 years to ensure no late re-occurrences with malignancy. Result: Ninety two patients with ILL were identified. The median age was 72. The median size of these ILLs was 10mm. Eighty seven patients required supplementary imaging and 42 required a third imaging. Ninety one patients had benign lesions. Only one case was biopsy proven to be malignant. Conclusion: Small (< 15 mm) hepatic lesions discovered incidentally in patients with no known primary malignancy and risk factors are virtually always benign, with a 1% risk of malignancy. There is a need for a classification system, which stratifies ILLs by malignant potential based on a standardized and evidence-based approach. This is important to prevent unnecessary investigations. A multidisciplinary approach in an experienced HPB centre is recommended until such a classification exists.

Indeterminate liver lesions - a virtual epidemic: a cohort study over 8 years.

Within the last decade, advances and availability in radiological imaging have led to an increase in the detection of incidental liver lesions (ILLs) in the asymptomatic patient population. This poses a diagnostic conundrum. This study was undertaken to review the outcome of liver lesions labelled as 'indeterminate' in asymptomatic patients without a biopsy-proven concomitant primary tumour. The secondary aim was to assess the impact on healthcare resources and cost-effectiveness with regards to the frequency and modality of radiological scans, multidisciplinary team discussions and clinic reviews. The study consisted of a retrospective analysis of prospectively collected data from the University Hospitals of Leicester multidisciplinary team database. The study period ranged from 2010 to 2015. All patients were followed-up for 3 years to ensure no late re-occurrences with malignancy. A total of 92 patients with ILL were identified. The median age was 72 years. The median size of these ILLs was 10 mm. Eighty-seven patients required supplementary imaging and 42 required a third imaging. Ninety-one patients had benign lesions. Only one case was biopsy proven to be malignant. Small (<15 mm) hepatic lesions discovered incidentally in patients with no known primary malignancy and risk factors are virtually always benign, with a 1% risk of malignancy. There is a need for a classification system, which stratifies ILLs by malignant potential based on a standardized and evidence-based approach. This is important to prevent unnecessary investigations. A multidisciplinary approach in an experienced hepatobiliary and pancreatic centre is recommended until such a classification exists.

A small hepatic nodule (\u2009\u22642\u2009cm) in cirrhotic liver: doTriphasic MRI and Diffusion-weighted image help in diagnosis

BackgroundDiagnosis of a small hepatic focal lesion (≤ 2 cm) in a cirrhotic liver by MRI depending on its characteristic signal intensities at different sequences, contrast enhancement, and diffusion-weighted image (DWI). Liver nodules were divided into malignant or benign according to the combination of different imaging features such as contrast uptake pattern, presence of fat, necrosis, diffusion pattern, and ADC value. We study about hepatic nodules which are difficult to diagnose using triphasic CT study due to a small size which make a characteristic pattern of enhancement of these focal lesions confusing and inadequate. Triphasic MRI and DWI increase the accuracy of the diagnosis of small nodule ≤ 2 cm and help in better treatment and intervention. The purpose of the study is to clarify the role of triphasic MRI and diffusion in differentiating a small hepatic nodule less than 2 cm in cirrhotic liver.ResultsOut of 60 patients with 124 hepatic nodules, MRI findings revealed 40 cases with malignant nodules (66.7%), 12 cases with premalignant nodules (20%), and 8 cases with benign nodules (hemangioma) (13.3%).ConclusionCombined triphasic MRI and diffusion WI increase the accuracy of the diagnosis of small hepatic focal lesions in the cirrhotic liver which may be difficult to diagnose by other imaging modalities, and help in early management and intervention.

Characterization of small (≤3 cm) hepatic lesions with atypical enhancement feature and hypointensity in hepatobiliary phase of gadoxetic acid-enhanced MRI in cirrhosis: A STARD-compliant article.

It is difficult to characterize the nodular lesions in cirrhotic liver if typical enhancement pattern is not present on dynamic contrast-enhanced imagings. Although the signal intensity of the hepatobiliary phase in gadoxetic acid-enhanced magnetic resonance imaging (MRI) is helpful for characterization of the lesions, some dysplastic nodules may also exhibit low signal intensity in the hepatobiliary phase. We aimed to assess the usefulness of gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI including diffusion-weighted imaging (DWI) for differentiation between atypical small hepatocellular carcinomas (HCCs) and dysplastic nodules showing low signal intensity (SI) in the hepatobiliary phase, and to evaluate the MRI findings in determining the histological grade of atypical HCCs in patients with cirrhosis.A total of 43 cirrhotic patients with a small (≤3 cm) liver nodule (n = 25, HCC; n = 18, dysplastic nodule) who underwent Gd-EOB-DTPA-enhanced MRI and pathologic confirmation were retrospectively reviewed. Atypical HCC was defined as not showing arterial hyperenhancement and delayed washout on dynamic MRI.High SI on both T2WI and DWI (sensitivity 80.0%, specificity 100%, positive predictive value 100%, negative predictive value 78.3%) was the most specific feature to differentiate atypical HCCs from dysplastic nodules. High SI on both T2WI and DWI (100% vs 61.5%, P = .039) or low SI on pre-enhanced T1WI (83.3% vs 30.8%, P = .021) was more frequent observed in Edmonson grade II–III HCCs compared with those in grade I HCCs.The combination of DWI and T2WI is most useful for the differentiation of atypical small HCCs from dysplastic nodules showing low SI in the hepatobiliary phase. Combination of DWI and T2WI or pre-enhanced T1WI seems to be useful for predicting the histological grade of atypical HCCs.

Nivolumab as salvage treatment in a patient with HIV-related relapsed/refractory Hodgkin lymphoma and liver failure with encephalopathy

BackgroundWe report the first case to our knowledge of a patient with relapsed/refractory classical hodgkin lymphoma and liver failure with encephalopathy along with human immunodeficiency virus/acquired immunodeficiency syndrome infection, successfully treated with nivolumab without major side effects and encouraging prolonged disease control.Case presentationIn December 2015, at the time of the patient’s progression from his Hodgkin lymphoma after fourth line treatment, he developed persistent fevers, abdominal distension, jaundice and worsening of his liver function tests. Magnetic resonance imaging of abdomen/pelvis demonstrated hepatomegaly with innumerable new liver lesions, splenomegaly with multiple splenic nodules and several new mediastinal, intraperitoneal and retroperitoneal lymphadenopathy. In accordance with the patient’s wishes before admission, and after agreement with the family, nivolumab (3 mg/kg every 2 weeks) was given. Of note, antiretroviral therapy was on hold due to liver function tests, his viral load was undectable and cluster of differentiation 4 counts were 103/uL at the time of nivolumab administration. One week after the first dose of nivolumab both his hepatic encephalopathy and constitutional symptoms started to improve, and after 2 doses, (January 2016) his LFTs were almost back to normal. After 5 months of nivolumab treatment (10 doses), restaging (computerized tomography scans of neck, chest, abdomen, pelvis) done on May 2016 showed resolution of hepatosplenomegaly with two residual small hepatic lesions, heterogeneous spleen with no splenic lesions, and stable non-enlarged retroperitoneal lymph nodes without intraabdominal lymphadenopathy; consistent with partial response.ConclusionsWe report a case of a patient with human immunodeficiency virus/acquired immunodeficiency syndrome -related relapsed/refractory classical Hodgkin lymphoma and acute liver failure with encephalopathy successfully treated with nivolumab after failing all standard therapeutic options. Unlike classic cytotoxic chemotherapy, which relies on preserved organ function to ameliorate potential severe side effects (i.e. myelosuppression), elimination of monoclonal antibodies is fairly independent of baseline renal and hepatic function since they are usually metabolized by circulating phagocytes and/or by their target antigen-expressing cell.

42. Assessment of new model-based iterative reconstruction kernels for the detectability of small hypervascular liver lesions: A phantom study

Introduction The purpose of this study was to evaluate the new kernels associated to Model Based Iterative Reconstruction (MBIR) for the detection of low contrast hepatic lesions based on a Non-PreWhitening matched filter with Eye filter (NPWE) model observer. Methods An image quality phantom (CATPHAN 600, The Phantom Laboratory, NY) was imaged on a Discovery CT750 HD scanner (GE Healthcare, Wisconsin) under variable tube current configurations (Noise Index (NI) ranged from 15 to 70). Images were reconstructed using filtered back projection (FBP), Adaptive Statistical Iterative Reconstruction (ASIR) 50% and MBIR associated to Standard, Noise Reduction (NR05, NR40) and Resolution Improvement (RP05, RP20) kernels. Noise Power Spectrum and Task based Modulation Transfer Function measurements were combined into a NPWE observer to assess the detectability index (d ′ ) for a clinical imaging task representative of the detection of small liver lesions (contrast of 20 HU and 11 mm diameter). The dose potential reduction of each MBIR kernel was evaluated regarding the protocol clinically used at our institution (NI 25, ASIR 50%). Results At comparable dose, the d’ for MBIR Standard, NR05 and NR40 was higher than the one of FBP by 20%, 24% and 53%; and ASIR by 5%, 10% and 34% respectively. The d’ for MBIR RP05 and RP20 wasn’t improved compared to ASIR. In comparison to our routine protocol, MBIR Standard, NR05 and NR40 can lead to dose reductions of 15%, 22% and 56% respectively. Conclusions New MBIR NR05 and NR40 can offer further dose reduction than Standard kernel. Alternatively, at fixed dose, they can improve detectability of small hepatic lesions.

A Rare Case of DILI

Idiosyncratic drug-induced liver injury (DILI) results in mild transaminitis, hyperbilirubinemia or acute fulminant liver failure from 5 to 90 days after consumption of the causal medication. We present a case of DILI presenting with elevated CA 19-9. 74 year old non alcoholic female with Hypertension, Osteoarthritis and Diabetes presented with a four day history of nausea, jaundice and fatigue. She endorsed 2-3 months of weight loss, and darkening of skin. Home medications were furosemide, lisinopril, hydrochlorthiazide, brimonidine and fluticasone without recent changes. She reported taking green tea for many years and one to two doses of green-lipped mussel oil extract in the past month. On presentation, her body mass index was 34.15 and exam revealed icteric sclerae, hyperpigmented skin and 3+ pitting lower extremity edema. Labs were significant for AST 785, ALT 432, alkaline phosphatase 302, bilirubin 18.9, albumin 3.1. Further work-up revealed elevated CA 19-9 of 1656, AFP of 8.1, IgG of 1900, CEA of 2.1. Autoimmune and hepatitis panel resulted negative, except for positive Hepatitis B core and surface antibodies. Magnetic resonance cholangiopancreatography showed small hepatic lesions consistent with hemangiomas or cysts. Endoscopic ultrasound resulted in no pathology. Liver biopsy revealed chronic cholestatic hepatitis, markedly active bridging necrosis, parenchymal collapse, with focal fibrous septum formation, suggestive of drug or toxin induced liver injury. The patient's hospital course was uneventful and she was discharged on day 8 with instructions to discontinue her herbal supplements. Upon further review, she had a similar admission one month prior, where she was admitted for transaminitis that resolved with cessation of all possibly hepatotoxic medications. After the current admission, she was started on ursodiol and prednisone taper with resolution of her jaundice, transaminitis and hyperbilirubinemia. Most recent laboratory findings included AST 27, ALT 17, Alkaline phosphatase 79, bilirubin 0.8, albumin 4.0. This case illustrates the potential for rare drug-induced liver injury secondary to herbal supplements. These products, including lyprinol and green tea, may affect the liver individually or synergistically. CA 19-9 is increased in malignancy and sometimes in benign conditions such as gall bladder disease, pancreatitis or cirrhosis but rarely with DILI. Early recognition is critical for prevention of fulminant liver failure.

P0370 : Role of gadoxetic acid-enhanced magnetic resonance imaging in the long-term follow-up of small equivocal hepatic lesions in patients with colorectal cancer

P0370 : Role of gadoxetic acid-enhanced magnetic resonance imaging in the long-term follow-up of small equivocal hepatic lesions in patients with colorectal cancer

Added value of arterial enhancement fraction color maps for the characterization of small hepatic low-attenuating lesions in patients with colorectal cancer.

ObjectiveTo assess the added value of arterial enhancement fraction (AEF) color maps for the differentiation of small metastases from hepatic benign lesions.Subjects and MethodsWe retrospectively analyzed 46 patients with colorectal cancer who underwent multiphasic liver CT imaging and had low-attenuating liver lesions smaller than 3 cm (123 total lesions; metastasis: benign = 32:91). AEF color maps of the liver were created from multiphasic liver CT images using dedicated software. Two radiologists independently reviewed multiphasic CT image sets alone and in combination with image sets with AEF color maps using a five-point scale. The additional diagnostic value of the color maps was assessed by means of receiver-operating characteristic (ROC) analysis.ResultsThe area under the ROC curve (Az) increased when multiphasic CT images were combined with AEF color map analysis as compared with evaluation based only on multiphasic CT images (from 0.698 to 0.897 for reader 1, and from 0.825 to 0.945 for reader 2; P < 0.001 and 0.002, respectively). The increase Az was especially significant for lesions less than 1 cm (from 0.702 to 0.888 for reader 1, and from 0.768 to 0.958 for reader 2; P = 0.001 and P = 0.001, respectively). The mean AEF of tumor-adjacent parenchyma (35.07 ± 27.2) was significantly higher than that of tumor-free liver parenchyma (27.3 ± 20.6) (P = 0.04).ConclusionsAEF color mapping can improve the diagnostic performance for small hepatic metastases from colorectal cancer and may allow for the elimination of additional examinations.

Role of gadoxetic acid-enhanced magnetic resonance imaging in the preoperative evaluation of small hepatic lesions in patients with colorectal cancer.

The initial abdominal computed tomography (CT) scans of patients with colorectal cancer (CRC) sometimes reveal equivocal hepatic lesions. In this study, we evaluated the outcomes of equivocal hepatic lesions found by abdominal CT and the diagnostic accuracy of subsequent liver magnetic resonance imaging (MRI). We evaluated data of patients who underwent CRC resection between January 1, 2009 and December 31, 2009. Equivocal hepatic lesions of <1 cm in size on preoperative staging CT scans were included in this study. Gadoxetic acid-enhanced liver MRI was subsequently performed in all patients. Hepatic lesions that grew during the follow-up period (≥ 3 years) were considered potential metastases. Overall, 121 equivocal hepatic lesions were detected on preoperative staging CT in 65 out of 494 patients (13.2 %) who underwent colorectal surgery. Based on subsequent MRI, 11 lesions were classified as definitive metastatic lesions and 100 were classified as definitive benign lesions, including simple cysts or hemangiomas. Findings in the other 10 lesions were still inconclusive even after examining CT and MRI. Of the 11 lesions that were classified as metastatic by MRI and were resected, 10 were pathologically confirmed as metastases and one lesion was a pathologically benign nodule. All 100 benign lesions were stable on follow-up imaging and were classified as benign. Of the 10 equivocal lesions, 6 increased in size during the follow up, suggesting they were early metastases, while 4 were stable. The sensitivity and specificity for detecting liver metastases by gadoxetic acid-enhanced MRI of small equivocal hepatic lesions found by CT were 100 % (16/16) and 95.2 % (100/105), respectively, if MRI was equivocal or indicated definite metastasis. The negative predictive value was 100 % (100/100). Gadoxetic acid-enhanced MRI is a useful diagnostic tool for assessing equivocal hepatic lesions on preoperative CT of CRC patients that allows increased diagnostic accuracy and detection of additional colorectal liver metastasis lesions.

Application of dual phase imaging of 11C-acetate positron emission tomography on differential diagnosis of small hepatic lesions.

ObjectivePreviously we observed that dual phase 11C-acetate positron emission tomography (AC-PET) could be employed for differential diagnosis of liver malignancies. In this study, we prospectively evaluated the effect of dual phase AC-PET on differential diagnosis of primary hepatic lesions of 1–3 cm in size.Methods33 patients having primary hepatic lesions with size of 1–3 cm in diameter undertook dual phase AC-PET scans. Procedure included an early upper-abdomen scan immediately after tracer injection and a conventional scan in 11–18 min. The standardized uptake value (SUV) was calculated for tumor (SUVT) and normal tissue (SUVB), from which 11C-acetate uptake ratio (as lesion against normal liver tissue, SUVT/SUVB) in early imaging (R1), conventional imaging (R2), and variance between R2 and R1 (ΔR) were derived. Diagnoses based on AC-PET data and histology were compared. Statistical analysis was performed with SPSS 19.0.Results20 patients were found to have HCC and 13 patients had benign tumors. Using ΔR>0 as criterion for malignancy, the accuracy and specificity were significantly increased comparing with conventional method. The area under ROC curve (AUC) for R1, R2, and ΔR were 0.417, 0.683 and 0.831 respectively. Differential diagnosis between well-differentiated HCCs and benign lesions of FNHs and hemangiomas achieved 100% correct. Strong positive correlation was also found between R1 and R2 in HCC (r2 = 0.55, P<0.001).ConclusionsDual phase AC-PET scan is a useful procedure for differential diagnosis of well-differentiated hepatocellular carcinoma and benign lesions. The dynamic changes of 11C-acetate uptake in dual phase imaging provided key information for final diagnosis.

Eosinophilic organ infiltration without eosinophilia or direct parasite infection

Eosinophilic organ infiltration without eosinophilia or direct parasite infection