Hepatic Venous Phase Research Articles

Enhancement Patterns of Malignant Gallbladder Masses at Multiphasic Contrast-enhanced CT: Associations With Clinicoradiopathological Features

PurposeTo assess the enhancement patterns of malignant gallbladder masses at multiphasic contrast enhanced computed tomography (CECT) and their association with the clinicoradiopathological features. Material and methodsIn this retrospective study, consecutive patients with mass-forming gallbladder cancer (GBC) who underwent biphasic [hepatic arterial phase (HAP) and portal venous phase (PVP)] CECT between January 2019 and January 2023 were included. The enhancement patterns at CT scans were assessed independently by two radiologists blinded to the clinicopathological data. The masses were categorized into the typical group (hypoattenuation relative to normal liver in HAP) and the atypical group (isoenhancement or hyperenhancement in HAP). Enhancement patterns in PVP were also evaluated. The association between enhancement characteristics and the pathological grade and type, radiological aggressiveness (biliary/ vascular involvement, lymph node, liver, and omental metastases), resectability, and overall survival was assessed. ResultsSixty-five patients (41 females, mean age was 52.5 ± 17.6 years) were included in the study. On HAP images, eight lesions (12.3%) were hyperattenuating, nine (13.8%) were isoattenuating, and 48 (73.8%) were hypoattenuating. Of the 17 masses in the atypical group, 8 (47.1%) lesions showed washout, and 9 showed persistent enhancement (52.9%) in the PVP. Heterogeneous peripheral and central enhancement in HAP was significantly associated with lymph node metastases (p=0.019). Enhancement pattern was not significantly associated with pathological grade/type, other radiological features, resectability, and overall survival. ConclusionMass-forming GBC has variable enhancement. Heterogeneous HAP enhancement is associated with lymph node metastases.

Utility of pelvic CT in patients undergoing surveillance for hepatocellular carcinoma: A retrospective multi-institutional study.

To determine the frequency, characteristics and clinical significance of incidental pelvic findings reported on abdominopelvic CT performed for hepatocellular carcinoma (HCC) surveillance in at-risk patients. This two-center retrospective study received institutional review board approval with a waiver of informed consent. The radiologic reports of the CT exams performed 1/1/2010-2/28/2023 for HCC surveillance were reviewed. Exams were obtained with intravenous contrast material and included hepatic arterial and portal venous phases of the abdomen; images of the pelvis were acquired during the portal venous phase. Reported imaging findings and imaging-related recommendations either by the radiologists or the corresponding caregiver, if present, were retrospectively tabulated. The patient's medical records were reviewed to determine if there were any recommendations that were considered clinically important and culminated in any further interventions or treatments. 259 adults (1st center: mean age, 60 ± 11 years, 49% male and 2nd center: 56.26 ± 6.2 years, 48% male) at risk for HCC underwent 327 abdominopelvic CT exams for HCC surveillance at two centers. A total of 622 pelvic findings (mean, 2.2/ exam) were reported, including 131 bladder, 120 alimentary tract, 133 vascular, 51 gynecologic, 37 prostate, 33 lymph node, 27 inguinal, 44 peritoneal, and 46 skeletal. 52 of 622 reported findings (8.3%) were associated with actionable recommendations. 24 of the 52 actionable recommendations/clinical suggestions were implemented as follows: five complimentary imaging, ten additional laboratory tests, and nine non-imaging recommendations. Of note, only eight applied recommendations culminated in a clinical outcome, which included four urinary tract infection treatments. Pelvic CT findings were associated with a clinical benefit to the patient in 1.3% of exams. These results suggest that pelvic imaging should be omitted from CT-based HCC surveillance. Without compromising valuable information, patients undergoing HCC surveillance-CT may not require additional pelvic coverage.

Transcatheter Arterial Embolization with Bleomycin-Lipiodol of Hepatic Hemangiomas: Safety, Efficacy and Predictors of Response.

To evaluate the safety, efficacy and predictors of response of transcatheter arterial embolization (TAE) to treat hepatic hemangiomas (HHs). A retrospective analysis was conducted of consecutive HH patients who received TAE with bleomycin-Lipiodol emulsion and gelatin sponge particles at three institutions from January 2014 to January 2021. TAE effectiveness was defined as more than 50% reduction of tumor volume. The effectiveness, safety, and CT changes of hemangiomas after TAE were assessed. Factors affecting TAE efficacy on tumor size were analyzed with logistic regression analysis. A total of 102 patients with 109 HHs were included. After treatment, both the tumor diameter and volume were significantly reduced from 8.5 ± 3.9 to 5.9 ± 3.8cm (P < 0.001) and 412.6 ± 742.3cm3 to 102.0 ± 232.7cm3 (P < 0.001), respectively. TAE effectiveness was achieved in 80.7% (88/109) of hemangiomas, which was characterized by progressive reduction in tumor volume over time with Lipiodol retention. Atypical enhancement pattern (tiny enhancing dots in the hepatic arterial and portal venous phase) (p = 0.001) and central arterioportal shunt (APS) (p = 0.002) associated with the tumor were independent predictors of TAE ineffectiveness. Postembolization syndrome and transient increase in liver enzymes were common without severe complications and death. TAE was safe and effective in reducing HH size. Lesion enhancement pattern and APS type were associated with TAE efficacy on tumor shrinkage. Level 3, non-controlled retrospective cohort study.

Influence of splenomegaly on aortic and liver parenchymal CT numbers during contrast-enhance CT in patients with cirrhosis

IntroductionTo compare CT (computed tomography) values for enhancement of the abdominal aorta and liver parenchyma during dynamic contrast enhancement (CE) CT in cirrhotic patients with and without splenomegaly (SM). MethodsWe considered 258 patients (83 males and 46 females for the splenomegaly group, and 83 males and 46 females for the control group) for this retrospective study. We measured CT values in the abdominal aorta and hepatic parenchyma during the hepatic arterial (HAP) and portal venous (PVP) phases. The aortic CE at HAP and the hepatic parenchymal CE at PVP were compared between the two groups. For success rate of scans, we also calculated the optimal CE rates (>280 HU in the abdominal aorta and >50 HU in the hepatic parenchyma) for each group. ResultsIn the SM group, the CE for abdominal aorta was decreased during the aortic phase for a dynamic CE-CT (p < 0.05). When evaluating the success rates, they were found to be 65.1 % and 58.9 % in the SM group and 81.4 % and 72.3 % in the non-SM group (p < 0.05). ConclusionThe success rate of scans and CE for the abdominal aorta during the aortic phase exhibited a significant decrease during dynamic CE-CT scans on patients with SM. Patients with SM may have reduced diagnostic ability with typical contrast injection protocols. Implications for practiceIt may be necessary to change the injection rates and contrast medium volume during CE-CT depending on the presence or absence of SM.

Analysis of MRI features of hepatocyte nuclear factor 1α-inactivated hepatocellular adenoma

Objective: To investigate the MRI imaging features of hepatocyte nuclear factor 1α- inactivated hepatocellular adenoma (H-HCA). Methods: Clinical data and MRI images of 19 H-HCA cases who were pathologically confirmed at Zhongshan Hospital Affiliated to Fudan University between August 2014 and July 2020 were retrospectively analyzed. Among them, there were 15 females and 4 males, aged 16-47 (32± 7) years old. Tumor number, location, shape, size, boundary, MRI plain scan signal intensity, dynamic enhancement features of each phase, presence or absence of intratumoral fat content, pseudocapsule, and others were analyzed. The differences in apparent diffusion coefficient (ADC) values between the lesion and the surrounding normal liver parenchyma were compared for statistical significance. t-test was used for statistical analysis. Results: There were a total of 24 lesions in 19 cases. 14 cases had solitary lesions, and five cases had multiple lesions. 15 and nine lesions were located in the right and left lobes of the liver, respectively. 20 lesions were round or quasi-round, and four were irregular or lobulated. The tumor's maximal diameter was 0.6-8.6 (3.5 ± 2.4) cm. T(1)-weighted image (WI) showed hyperintense to iso-intense signals in 20 lesions and hypointense signals in four. T(2)WI showed iso-to-slightly high signal intensity in 16 lesions, with two hyperintense and six hypointense signals. Diffusion-weighted image (DWI) revealed hyperintense to iso-intense signals. Lesions mean ADC value was (1.289 ± 0.222)×10(-3) mm(2)/s, while the adjacent normal liver parenchyma's mean ADC value was (1.307 ± 0.236)×10(-3) mm(2)/s, with no statistically significant difference between the two (P > 0.05). During the arterial phase, 15 of the 18 lesions that underwent dynamic contrast-enhanced scanning with gadoxetate disodium (Gd-DTPA) were mildly to moderately enhanced and three were strongly enhanced. The portal and hepatic venous phases had no continuous enhancement, while the delayed phase showed a hypointense signal. During the arterial phase, two of the six lesions scanned by gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid ((Gd-EOB-DTPA) dynamic enhancement were mildly to moderately enhanced, while four were strongly enhanced. The portal and hepatic venous phases had no continuous enhancement, while the transition and hepatobiliary-specific phases showed hypointense signals. Intracellular steatosis occurred in 21 lesions, of which 19 were diffuse steatosis and 16 formed pseudocapsules in the delayed phase. Conclusion: H-HCA often occurs in young females as solitary lesions and has certain MRI features. T1WI anti-phase diffuse signal reduction and post-enhanced hypovascular withdrawal enhancement patterns can aid in accurately diagnosing the disease condition.

Comparison of image quality, contrast administration, and radiation doses in pediatric abdominal dual-layer detector dual-energy CT using propensity score matching analysis

PurposeTo compare the image quality, contrast administration, and radiation dose between single-energy CT (SECT) and dual-energy CT (DECT) in pediatric patients. MethodsFrom March to December 2021, children who underwent abdominal SECT or DECT were retrospectively included in this study. The DECT group received 10–30 % less contrast than the routine dose. CT images were obtained at hepatic venous phase using a routine reconstruction method (iDose4). DECT scans were additionally reconstructed with a virtual monoenergetic image (VMI) at 40 and 65 keV. Quantitative image evaluations compared the contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the liver, portal vein, and pancreas. Qualitative analysis assessed degree of contrast enhancement, lesion or organ conspicuity, image noise, artificiality, and overall image quality. ResultsAmong 318 patients, 112 (median age, 16 years; 56 in each group) were included after propensity score matching. Compared with the SECT group, DECT group with iDose4 demonstrated lower CNRs and SNRs, while VMI at 40 or 65 keV showed no significant difference. In qualitative analysis, iDose4 produced higher scores on artificiality, and VMI at 40 keV demonstrated superior contrast enhancement and lesion conspicuity in the DECT group. Overall image quality was higher with VMI 65 keV among the DECT patients, and there was no significant difference compared to SECT. The volume CT dose index (CTDIvol) did not differ significantly between the two groups (median, 2.8 mGy vs. 2.9 mGy; p = 0.802). The injected contrast volume was reduced by 10 % in the DECT group. ConclusionPediatric abdominal DECT with reduced contrast administration showed no significant differences in image quality and radiation dose compared to SECT.

Hepatocellular adenoma subtyping by qualitative MRI features and machine learning algorithm of integrated qualitative and quantitative features: a proof-of-concept study

Aim To evaluate hepatocellular adenoma (HCA) subtyping using qualitative magnetic resonance imaging (MRI) features and feasibility of differentiating HCA subtypes using machine learning (ML) of qualitative and quantitative MRI features with histopathology as the reference standard. Materials And Methods This retrospective study included 39 histopathologically subtyped HCAs (13 hepatocyte nuclear factor (HNF)-1-alpha mutated [HHCA], 11 inflammatory [IHCA], one beta-catenin-mutated [BHCA], and 14 unclassified [UHCA]) in 36 patients. HCA subtyping by two blinded radiologists using the proposed schema of qualitative MRI features and using the random forest algorithm was compared against histopathology. For quantitative features, 1,409 radiomic features were extracted after segmentation and reduced to 10 principle components. Support vector machine and logistic regression was applied to assess HCA subtyping. Results Qualitative MRI features with proposed flow chart yielded diagnostic accuracies of 87%, 82%, and 74% for HHCA, IHCA, and UHCA respectively. The ML algorithm based on qualitative MRI features showed AUCs (area under the receiver operating characteristic curve [ROC] curve) of 0.846, 0.642, and 0.766 for diagnosing HHCA, IHCA, and UHCA, respectively. Quantitative radiomic features from portal venous and hepatic venous phase MRI demonstrated AUCs of 0.83 and 0.82, with a sensitivity of 72% and a specificity of 85% in predicting HHCA subtype. Conclusions The proposed schema of integrated qualitative MRI features with ML algorithm provided high accuracy for HCA subtyping while quantitative radiomic features provide value for diagnosis of HHCA. The key qualitative MRI features for differentiating HCA subtypes were concordant between the radiologists and the ML algorithm. These approaches appear promising to better inform clinical management for patients with HCA.

"ASSESSING THE EFFECTIVENESS OF OPTIMIZED CONTRAST AGENT USAGE IN CT SCANNING"

Background: To assess individually optimized protocol of contrast medium injection in enhanced CT scan for liver imaging.Materials &amp; methods: 50 patients who underwent liver CT scan were included in the present study.Random division of all the patients was done into two study groups as follows:Group A and group B (25 patients in each group).All the patients were scanned using CT machine.All patients underwent both unenhanced and enhanced CT scans during hepatic arterial phase (HAP) and portal venous phase (PVP).All the enhanced CT scans during HAP and PVP started at thirty-five seconds and sixty-five seconds respectively, after the contrast injection, from the level of diaphragm to inferior hepatic edge. Both groups received the same contrast medium. Group A adopted an individually optimized protocol of the platform, which automatically calculated the contrast medium dose. Patients of group B received a standard contrast medium injection protocol with a contrast medium to weight dose of 1.5 ml/kg. CT values of unenhanced liver parenchyma, CT values of liver parenchyma during HAP and PVP, and CT values of the portal vein during PVP were measured.CT examinations were performed in both group A and group B patients.Analysis of results was done using SPSS software.Results: Mean CT value of liver parenchyma during HAP (HU) among patients of group A and group B was 78.3 and 77.1 respectively. Mean CT value of liver parenchyma during PVP (HU) among patients of group A and group B was 103.1 and 108.3 respectively.Mean CT value of portal vein during PVP (HU) among patients of group A and group B was 145.3 and 158.7 respectively.Mean Contrast medium dose (ml) among patients of group A and group B was 79.2 and 95.3 respectively.Significant results were obtained while comparing the outcome variables among the two study groups. Conclusion: From the above results, the authors concluded that in enhanced CT scan for liver imaging,individualizing the contrast dose on the basis of body weight through contrast medium injection protocol could efficaciously decrease contrast medium dose

S2993 Extensive Hepatic Fibrosis Mimicking Primary Liver Malignancy

Introduction: Liver cirrhosis is a pathophysiological outcome of sustained liver inflammation. Sustained hepatic insults generate a process of fibrogenesis, in which an excessive extracellular matrix deposition replaces normal liver parenchyma. We present a patient with newly diagnosed liver cirrhosis who was found to have a liver mass suggestive of primary liver malignancy on imaging; however, multiple biopsies confirmed the mass to be fibrosis with mild hepatitis. Case Description/Methods: A 40-year-old male presented for the evaluation of new bilateral lower extremity edema. He reported a long history of alcohol use but otherwise denied prior medical history and no medication use. Laboratory work on admission was pertinent for a total bilirubin of 3.5, AST 162, ALT 57, alkaline phosphatase 176, albumin 3.0, and a non-reactive viral hepatitis panel. CT abdomen/pelvis revealed a heterogeneous liver suggestive of cirrhosis along with a 6.8 cm x 8.7 cm mass with irregular margins situated between the right and left lobes of the liver. On 3-phase MR imaging, the lesion demonstrated progressive enhancement in the portal venous phase and hepatic venous phase, with retention of contrast on 5-minute delayed images [Image 1a, b, c]. Overall, these findings suggested infiltrative cholangiocarcinoma. Additional imaging ruled out multifocal disease, and tumor markers CEA and AFP were unremarkable. Subsequently, a diagnostic laparotomy with liver biopsy was performed. The biopsy demonstrated fibrosis with atypical ductular proliferation, but the presence of low-grade infiltrative cholangiocarcinoma could not be ruled out. To rule out biopsy sampling error, two additional biopsies later that month concurred cirrhotic liver segments with areas of mild hepatitis. Tumor markers CK20 and CDX2 were negative, and no atypical cells were present. It was concluded that this liver lesion represented extensive hepatic fibrosis and mild hepatitis due to ongoing alcohol use, but no malignancy. Discussion: Liver cirrhosis is a major risk factor for the development of primary liver cancers such as hepatocellular carcinoma and cholangiocarcinoma. Triple-phase CT or MR imaging plays a key role in diagnosing these cancers; however, as demonstrated in our case, certain benign lesions such as liver fibrosis can mimic primary liver malignancy. Improved recognition of these benign lesions is necessary to avoid unnecessary and potentially harmful interventions.Figure 1.: 1a) Pre-contrast MR T2 weighted image showing a large central hepatic mass and lobular contour of liver consistent with cirrhosis. 1b) Post-gadolinium T1 fat-saturated MR image demonstrating enhancement of the liver lesion in the hepatic venous phase. The lesion showed high retention index of contrast on 5-minute delayed images (not included). 1c) Diffusion-weighted MR image showing the liver lesion with significantly restricted diffusion suggestive of infiltrative type of cholangiocarcinoma.

Portal Vein and Hepatic Vein Segmentation in Multi-Phase MR Images Using Flow-Guided Change Detection.

Segmenting portal vein (PV) and hepatic vein (HV) from magnetic resonance imaging (MRI) scans is important for hepatic tumor surgery. Compared with single phase-based methods, multiple phases-based methods have better scalability in distinguishing HV and PV by exploiting multi-phase information. However, these methods just coarsely extract HV and PV from different phase images. In this paper, we propose a unified framework to automatically and robustly segment 3D HV and PV from multi-phase MR images, which considers both the change and appearance caused by the vascular flow event to improve segmentation performance. Firstly, inspired by change detection, flow-guided change detection (FGCD) is designed to detect the changed voxels related to hepatic venous flow by generating hepatic venous phase map and clustering the map. The FGCD uniformly deals with HV and PV clustering by the proposed shared clustering, thus making the appearance correlated with portal venous flow robustly delineate without increasing framework complexity. Then, to refine vascular segmentation results produced by both HV and PV clustering, interclass decision making (IDM) is proposed by combining the overlapping region discrimination and neighborhood direction consistency. Finally, our framework is evaluated on multi-phase clinical MR images of the public dataset (TCGA) and local hospital dataset. The quantitative and qualitative evaluations show that our framework outperforms the existing methods.

Semiquantitative characterization of dynamic magnetic resonance perfusion of the liver in pediatric Fontan patients.

Dynamic contrast-enhanced magnetic resonance imaging (MRI) of the liver in pediatric Fontan patients often shows peripheral reticular areas of hypoenhancement, which has not been studied in detail. To semiquantitatively score the hepatic MR perfusion abnormality seen in pediatric Fontan patients, and to correlate the perfusion abnormality with functional clinical and hemodynamic parameters. All children (< 18years old) after Fontan palliation with combined clinical cardiac and liver MRI performed between May 2017 and April 2019 were considered for inclusion. A semiquantitative perfusion score was used to assess the severity of the hepatic reticular pattern seen on dynamic contrast-enhanced liver imaging. The liver was divided into four sections: right posterior, right anterior, left medial and left lateral. Each liver section was assigned a score from 0 to 4 depending on the amount of abnormal reticular hypoenhancement. Scoring was assigned for each section of the liver across eight successive dynamic contrast-enhanced modified spoiled gradient echo runs. Scores were correlated with clinical and hemodynamic parameters. All Fontan children showed hepatic reticular hypoenhancement by MRI, most severe in the early portal venous phase with a median maximum total perfusion abnormality score of 12 (range: 9-14). All perfusion abnormalities progressively resolved during the hepatic venous phase. Perfusion abnormality scores were greatest in the right compared to left hepatic lobes (7 range: [6-8] vs. 5 [range: 3-6], P < 0.01). The maximum left hepatic lobe perfusion abnormality scores were greatest in children with versus without imaging signs of portal hypertension (8 [range: 7-8] vs. 4 [range: 3-5], P < 0.01). High unconjugated bilirubin and low platelets correlated with greater perfusion abnormality (R = 0.450, P = 0.024, and R = - 0.458, P < 0.01, respectively). Age at MRI, time from Fontan, focal liver lesions and cardiac MRI hemodynamic parameters did not show significant correlations with the severity of the liver perfusion abnormality. All Fontan children have hepatic reticular hypoenhancement abnormalities seen with MRI that are most severe in the right hepatic lobe and universally show gradual resolution through the hepatic venous phase. Perfusion abnormality in the left hepatic lobe is worse in children with portal hypertension.

Integrated prognostication of intrahepatic cholangiocarcinoma by contrast-enhanced computed tomography: the adjunct yield of radiomics

PurposeTo test radiomics for prognostication of intrahepatic mass-forming cholangiocarcinoma (IMCC) and to develop a comprehensive risk model.MethodsHistologically proven IMCC (representing the full range of stages) were retrospectively analyzed by volume segmentation on baseline hepatic venous phase computed tomography (CT), by two readers with different experience (R1 and R2). Morphological CT features included: tumor size, hepatic satellite lesions, lymph node and distant metastases. Radiomic features (RF) were compared across CT protocols and readers. Univariate analysis against overall survival (OS) warranted ranking and selection of RF into radiomic signature (RSign), which was dichotomized into high and low-risk strata (RSign*). Models without and with RSign* (Model 1 and 2, respectively) were compared.ResultsAmong 78 patients (median follow-up 262 days, IQR 73–957), 62/78 (79%) died during the study period, 46/78 (59%) died within 1 year. Up to 10% RF showed variability across CT protocols; 37/108 (34%) RF showed variability due to manual segmentation. RSign stratified OS (univariate: HR 1.37 for R1, HR 1.28 for R2), RSign* was different between readers (R1 0.39; R2 0.57). Model 1 showed AUC 0.71, which increased in Model 2: AUC 0.81 (p < 0.001) and AIC 89 for R1, AUC 0.81 (p = 0.001) and AIC 90.2 for R2.ConclusionThe use of RF into a unified RSign score stratified OS in patients with IMCC. Dichotomized RSign* classified survival strata, its inclusion in risk models showed adjunct yield. The cut-off value of RSign* was different between readers, suggesting that the use of reference values is hampered by interobserver variability.

Material decomposition using iodine quantification on spectral CT for characterising nodules in the cirrhotic liver: a retrospective study

BackgroundThere is limited scientific evidence on the potential of spectral computed tomography (SCT) for differentiation of nodules in the cirrhotic liver. We aimed to assess SCT-generated material density (MD) parameters for nodule characterisation in cirrhosis.MethodsDynamic dual-energy SCT scans of cirrhotic patients performed over 3 years were retrospectively reviewed. They were classified as hepatocellular carcinoma (HCC), regenerative or indeterminate, according to the European Association for the Study of the Liver criteria. MD maps were generated to calculate the area under the curve (AUC) and cutoff values to discriminate these nodules in the hepatic arterial phase (HAP) and portal venous phase (PVP). MD maps included iodine concentration density (ICD) of the liver and nodule, lesion-to-normal liver ICD ratio (LNR) and difference in nodule ICD between HAP and PVP.ResultsThree hundred thirty nodules belonging to 300 patients (age 53.0 ± 12.7 years, mean ± standard deviation) were analysed at SCT (size 2.3 ± 0.8 cm, mean ± SD). One hundred thirty-three (40.3%) nodules were classified as HCC, 147 (44.5%) as regenerative and 50 (15.2%) as indeterminate. On histopathology, 136 (41.2%) nodules were classified as HCC, 183 (55.5%) as regenerative and 11 (3.3%) as dysplastic. All MD parameters on HAP and the nodule difference in ICD could discriminate pathologically proven HCC or potentially malignant nodules from regenerative nodules (p < 0.001). The AUC was 82.4% with a cutoff > 15.5 mg/mL for nodule ICD, 81.3% > 1.8 for LNR-HAP and 81.3% for difference in ICD > 3.5 mg/mL.ConclusionSCT-generated MD parameters are viable diagnostic tools for differentiating malignant or potentially malignant from benign nodules in the cirrhotic liver.

Abstract No. 32 ▪ FEATURED ABSTRACT Predicting tumor grade and mutation status of pancreatic neuroendocrine liver metastases using computed tomography radiomic features

Tumor grade and mutation status are putative biomarkers of response to trans-arterial embolization of pancreatic neuroendocrine liver metastases (PNLM). We sought to evaluate the effectiveness of using CT radiomic features to classify grade and mutation status of PNLM. 40 patients with PNLM who underwent CT scans and biopsies at a single center from April 2009 to February 2018 were included in the database. Biopsied tumors with recorded tumor grade (Grade 1-3) and mutation status (presence or absence of MEN1/DAXX/ATRX mutation) were segmented in both the hepatic arterial (HAP) and portal venous (PV) phases using 3D Slicer. Quantitative features (n = 115) from each scan were extracted from segmented tumors using PyRadiomics. Standard feature normalization was performed. Principal component analysis (PCA) was used for dimensionality reduction. Linear and radial basis function support vector machine (SVM) were used for training. K-fold cross-validation was used to estimate testing accuracy. Permutation testing was used to assess statistical significance. There were 25/40 (62.5%) patients with MEN1, DAXX, and/or ATRX mutation. There were 9/40 (22.5%) G1 tumors, 16/40 (40%) G2 tumors, and 37.5% G3 tumors. Over 95% of the variance in the data was described by the top 6 principal components, which were used for training and testing. Testing accuracy was 75% ± 11% for predicting mutation status (P = 0.008). Testing accuracy was 52.5% ± 11% for predicting tumor grade (P = 0.004). CT radiomic features can be used to predict mutation status and tumor grade in patients with PNLM.

Enhancement pattern of differentiated and undifferentiated gastric carcinoma on multiphasic contrast-enhanced computed tomography.

PurposeTo study the enhancement pattern of differentiated and undifferentiated gastric carcinoma on multiphasic contrast-enhanced computed tomography (CT).Material and methodsSeventy patients with biopsy-proven gastric cancer underwent multiphasic contrast-enhanced CT. The CT protocol include plain, arterial, portal venous, and hepatic venous phase. Tumour size, location, peak-enhancement characteristics, and staging were evaluated.ResultsThe peak-enhancement type was ‘arterial’ in 20 out of 28 within the differentiated-type GCAs and ‘portalvenous’ in 37 out of 42 within the undifferentiated-type GCAs (c2 statistic with Yates correction = 23.3981, p < 0.00001). The maximum attenuation value was statistically significant for the arterial phase between differentiated and undifferentiated GCAs (p < 0.05).ConclusionsAssessing peak-enhancement in a multiphasic CT can help identify the histological subcategory of gastric carcinomas that has prognostic significance. Arterial phase peak-enhancement is frequently seen in differentiated carcinomas whereas venous phase peak-enhancement is seen in undifferentiated carcinomas.

Decreasing the radiation dose for contrast-enhanced abdominal spectral CT with a half contrast dose: a matched-pair comparison with a 120 kVp protocol.

Objectives:To compare the estimated radiation dose of 50% reduced iodine contrast medium (halfCM) for virtual monochromatic images (VMIs) with that of standard CM (stdCM) with a 120 kVp imaging protocol for contrast-enhanced CT (CECT).Methods:We enrolled 30 adults with renal dysfunction who underwent abdominal CT with halfCM for spectral CT. As controls, 30 matched patients without renal dysfunction using stdCM were also enrolled. CT images were reconstructed with the VMIs at 55 keV with halfCM and 120 kVp images with stdCM and halfCM. The Monte-Carlo simulation tool was used to simulate the radiation dose. The organ doses were normalized to CTDIvol for the liver, pancreas, spleen, and kidneys and measured between halfCM and stdCM protocols.Results:For the arterial phase, the mean organ doses normalized to CTDIvol for stdCM and halfCM were 1.22 and 1.29 for the liver, 1.50 and 1.35 for the spleen, 1.75 and 1.51 for the pancreas, and 1.89 and 1.53 for the kidneys. As compared with non-enhanced CT, the average increase in the organ dose was significantly lower for halfCM (13.8% ± 14.3 and 26.7% ± 16.7) than for stdCM (31.0% ± 14.3 and 38.5% ± 14.8) during the hepatic arterial and portal venous phases (p < 0.01).Conclusion:As compared with stdCM with the 120 kVp imaging protocol, a 50% reduction in CM with VMIs with the 55 keV protocol allowed for a substantial reduction of the average organ dose of iodine CM while maintaining the iodine CT number for CECT.Advances in knowledge:This study provides that the halfCM protocol for abdominal CT with a dual-layer-dual-energy CT can significantly reduce the increase in the average organ dose for non-enhanced CT as compared with the standard CM protocol.

Texture analysis on preoperative contrast-enhanced magnetic resonance imaging identifies microvascular invasion in hepatocellular carcinoma

BackgroundRadiomic texture analysis quantifies tumor heterogeneity. The aim of this study is to determine if radiomics can predict biologic aggressiveness in HCC and identify tumors with MVI. MethodsSingle-center, retrospective review of HCC patients undergoing resection/ablation with curative intent from 2009 to 2017. DICOM images from preoperative MRIs were analyzed with texture analysis software. Texture analysis parameters extracted on T1, T2, hepatic arterial phase (HAP) and portal venous phase (PVP) images. Multivariate logistic regression analysis evaluated factors associated with MVI. ResultsMVI was present in 52.2% (n = 133) of HCCs. On multivariate analysis only T1 mean (OR = 0.97, 95%CI 0.95–0.99, p = 0.043) and PVP entropy (OR = 4.7, 95%CI 1.37–16.3, p = 0.014) were associated with tumor MVI. Area under ROC curve was 0.83 for this final model. Empirical optimal cutpoint for PVP tumor entropy and T1 tumor mean were 5.73 and 23.41, respectively. At these cutpoint values, sensitivity was 0.68 and 0.5, respectively and specificity was 0.64 and 0.86. When both criteria were met, the probability of MVI in the tumor was 87%. ConclusionTumor entropy and mean are both associated with MVI. Texture analysis on preoperative imaging correlates with microscopic features of HCC and can be used to predict patients with high-risk tumors.

Liver metastases of neuroendocrine tumors: is it possible to diagnose different histologic subtypes depending on multiphasic CT features?

To assess and compare the multiphasic computed tomography (CT) features of neuroendocrine tumor (NET) liver metastases and to investigate the possibility to predict the histologic subtype of the primary tumor. Between January 2013 and December 2017 patients with biopsy proven NET with at least one liver metastasis who underwent multiphasic CT were enrolled in this study. All cases were acquired using a standardized multiphasic liver CT protocol, arterial, portal, and hepatic venous phases were obtained. Images were retrospectively analyzed in consensus by two abdominal radiologists blinded to clinical data and histologic subtype. The size, number, and location of lesions were noted. Enhancement patterns of each lesion on arterial, portal, and hepatic venous phases were assessed. For quantitative analysis, CT attenuation of tumors, liver parenchyma, and aorta were measured using a circular region of interest (ROI) on arterial, portal, and hepatic venous phases for reflecting the blood supply of the tumor. Tumor-to-aorta and tumor-to-liver ratio were calculated in all three phases. Differences between subtypes of NET liver metastases were studied using ROC analysis of clustered data. A total of 255 neuroendocrine tumor liver metastases divided into 101 (39.6%) pancreatic, 60 (23.5%) gastroenteric and 94 (36.8%) lung NET liver metastases were analyzed. Contrast enhancement of lesions was homogeneous in 78% of patients (n = 199), which was significantly more frequent in patients with pancreatic group than in those with gastroenteric origin (n = 90, 89.1% vs. n = 28, 46.7%; p < 0.001). Gastroenteric NET metastases frequently showed heterogeneous enhancement, which was significantly higher than in the other two groups (50% vs. 3% and 2%). With respect to the location of the primary tumor, the difference in enhancement patterns of the liver lesions was statistically significant (p < 0.001). Pancreatic NET metastases were mostly hyperdense on arterial images and isodense on portal and hepatic venous phase images (79.2%, n = 80). Gastroenteric NET metastases were mostly hyperdense on arterial phase images and hypodense on portal and hepatic venous phase images (n = 28, 46.7%). The most frequent pattern for lung NET metastases was hypoattenuation on all three phase images (n = 44, 46.8%). ROC analysis of clustered data revealed statistically significant differences between pancreatic NET liver metastases, gastroenteric NET liver metastases, and lung NET liver metastases in terms of tumor-to-aorta (T-A) ratio and tumor-to-liver (T-L) ratio (p < 0.001). We observed statistically significant differences in multiphasic CT features (enhancement pattern, T-A ratio, and T-L ratio) between histologic subtypes of NET liver metastases. As the difference in histological subtypes of NET liver metastases results in a different prognosis and different management strategy, these CT features might help to identify the primary tumor when it is not known to ensure accurate tumor staging and to provide optimal treatment.

Effects of low-dose energy spectrum scanning combined with adaptive statistical iterative reconstruction on the quality of imaging in Budd-Chiari syndrome.

ObjectiveTo assess the quality and diagnostic accuracy of monochromatic images combined with adaptive statistical iterative reconstruction (ASIR) performed via spectral computed tomography (CT) in patients with Budd-Chiari syndrome (BCS).MethodsSixty-two patients with BCS underwent pectral CT with upper abdominal two-phase contrast-enhanced scanning to generate a 60keV monochromatic energy level combined with ASIR (ranging from 0% -100%) during the portal venous phase (PVP) and the hepatic venous phase (HVP). One-way ANOVA was used to compare vessel-to-liver contrast-to-noise ratio (CNR) for the portal vein (PV), hepatic vein (HV), and inferior vena cava (IVC). Subjective evaluations of the images in the three groups were conducted by image quality assessors and compared via Kruskal-Wallis H test.ResultsThe CNR values of the PV trunk, HV, IVC, liver parenchyma and pancreas were within ASIR (ranging from 0% - 100%) weight, and the difference were statistically significant (p <0.05). The highest overall image score was distributed at 50% ASIR weight value. Higher CNR values of HV, hepatic parenchyma and pancreas were obtained in the IVC type than in mixed and HV types (respective p values = 0.035, 0.019 and 0.042). Higher CNR values of the IVC were obtained in the HV type than in mixed and IVC types (p = 0.032). The CNR value of the IVC in the mixed type was less than that of the HV type (p = 0.028). The CNR values of the HV and liver parenchyma in mixed type were lower than those of the IVC type (p = 0.016 and 0.038, respectively). The CNR value of pancreas in IVC type was higher than that of the HV type (p = 0.037). The diagnostic value of CNR in patients with the IVC type was higher than that in patients with mixed and HV type, while the diagnostic value of CNR was found to be the lowest for the HV type (p = 0.043).ConclusionA monochromatic energy level of 60 keV with 50% ASIR can significantly improve image quality in cases of BCS.

Evaluation of texture analysis for the differential diagnosis of focal nodular hyperplasia from hepatocellular adenoma on contrast-enhanced CT images.

To explore the value of CT texture analysis (CTTA) for differentiation of focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA) on contrast-enhanced CT (CECT). This is a retrospective, IRB-approved study conducted in a single institution. A search of the medical records between 2008 and 2017 revealed 48 patients with 70 HCA and 50 patients with 62 FNH. All lesions were histologically proven and with available pre-operative CECT imaging. Hepatic arterial phase (HAP) and portal venous phase (PVP) were used for CTTA. Textural features were extracted using a commercially available research software (TexRAD). The differences between textural parameters of FNH and HCA were assessed using the Mann-Whitney U test and the AUROC were calculated. CTTA parameters showing significant difference in rank sum test were used for binary logistic regression analysis. A p value < 0.05 was considered statistically significant. On HAP images, mean, mpp, and skewness were significantly higher in FNH than in HCA on unfiltered images (p ≤ 0.007); SD, entropy, and mpp on filtered analysis (p ≤ 0.006). On PVP, mean, mpp, and skewness in FNH were significantly different from HCA (p ≤ 0.001) on unfiltered images, while entropy and kurtosis were significantly higher in FNH on filtered images (p ≤ 0.018). The multivariate logistic regression analysis indicated that the mean, mpp, and entropy of medium-level and coarse-level filtered images on HAP were independent predictors for the diagnosis of HCA and a model based on all these parameters showed the largest AUROC (0.824). Multiple explored CTTA parameters are significantly different between FNH and HCA on CECT.