Dynamic Enhancement Pattern Research Articles

Nodule-in-nodule architecture of hepatocellular carcinomas: enhancement patterns in the hepatobiliary phase and pathological features.

This study aimed to evaluate the enhancement patterns in the hepatobiliary phase (HBP) and pathological features of nodule-in-nodule-type hepatocellular carcinoma (NIN-HCC) patients. In this single-institution retrospective study, 27 consecutive cirrhosis patients with 29 histologically confirmed NIN-HCCs who underwent preoperative examination via Gd-EOB-DTPA-enhanced MRI were enrolled from January 2016 to September 2023. Two blinded radiologists assessed the imaging features of both the inner and outer nodules in NIN-HCCs to reach a consensus on the Liver Imaging Reporting & Data System (LI-RADS) categories of the lesions. Based on the different enhancement patterns of the inner and outer nodules in the HBP, NIN-HCCs were classified into different groups and further divided into different types. Imaging features and LI-RADS categories were subsequently compared among the groups. Pathological findings for NIN-HCCs were also evaluated. Among 29 NIN-HCCs, all inner nodules showed hypervascularity, with a maximum diameter of 13.2 ± 5.5mm; 51.7% (15/29) showed "wash-in with washout" enhancement; and 48.3% (14/29) showed "wash-in without washout" enhancement. All outer nodules showed hypovascularity, with a maximum diameter of 25.6 ± 7.3mm, and 51.9% (14/29) showed a washout appearance on PVP. Among all the lesions, the maximum diameter was 27.5 ± 6.8mm; 12 (41.4%) lesions were LR-4, and 17 (58.6%) lesions were LR-5. NIN-HCCs were classified into hypointense (62.1%, 18/29) and isointense (37.9%, 11/29) groups based on the signal intensity of the outer nodules in the HBP. In the hypointense group, 2 (6.9%) of the inner nodules were hypointense (type A), 11 (37.9%) were isointense (type B), and 5 (17.2%) were hyperintense (type C) compared to the background hypointense outer nodules. In the isointense group, 9 (31.0%) of the inner nodules were hypointense (type D), 2 (6.9%) were isointense (type E), and no (0%) was hyperintense (type F) compared to the background isointense outer nodules. There were no significant differences in the diameter, dynamic enhancement patterns of the inner or outer nodules, or LI-RADS scores of the lesions between the hypointense group and the isointense group (all P > 0.05). Histologically, the inner nodules of NIN-HCCs were mainly composed of moderately differentiated HCC (75.9% 22/29), whereas the outer nodules consisted of either well-differentiated HCC or high-grade dysplastic nodules (HGDNs). NIN-HCCs exhibit specific MRI findings closely associated with their pathological features. The spectrum of HBP enhancement patterns provides valuable insights into the underlying cell biological mechanisms of these lesions. NIN-HCC subtypes may be used as a morphologic marker in the early stage of multistep hepatocarcinogenesis.

Localization of contrast-enhanced breast lesions in ultrafast screening MRI using deep convolutional neural networks

ObjectivesTo develop a deep learning–based method for contrast-enhanced breast lesion detection in ultrafast screening MRI.Materials and methodsA total of 837 breast MRI exams of 488 consecutive patients were included. Lesion’s location was independently annotated in the maximum intensity projection (MIP) image of the last time-resolved angiography with stochastic trajectories (TWIST) sequence for each individual breast, resulting in 265 lesions (190 benign, 75 malignant) in 163 breasts (133 women). YOLOv5 models were fine-tuned using training sets containing the same number of MIP images with and without lesions. A long short-term memory (LSTM) network was employed to help reduce false positive predictions. The integrated system was then evaluated on test sets containing enriched uninvolved breasts during cross-validation to mimic the performance in a screening scenario.ResultsIn five-fold cross-validation, the YOLOv5x model showed a sensitivity of 0.95, 0.97, 0.98, and 0.99, with 0.125, 0.25, 0.5, and 1 false positive per breast, respectively. The LSTM network reduced 15.5% of the false positive prediction from the YOLO model, and the positive predictive value was increased from 0.22 to 0.25.ConclusionsA fine-tuned YOLOv5x model can detect breast lesions on ultrafast MRI with high sensitivity in a screening population, and the output of the model could be further refined by an LSTM network to reduce the amount of false positive predictions.Clinical relevance statementThe proposed integrated system would make the ultrafast MRI screening process more effective by assisting radiologists in prioritizing suspicious examinations and supporting the diagnostic workup.Key Points• Deep convolutional neural networks could be utilized to automatically pinpoint breast lesions in screening MRI with high sensitivity.• False positive predictions significantly increased when the detection models were tested on highly unbalanced test sets with more normal scans.• Dynamic enhancement patterns of breast lesions during contrast inflow learned by the long short-term memory networks helped to reduce false positive predictions.

Dynamic contrast-enhanced CT and clinical features of sarcomatoid hepatocellular carcinoma

PurposeTo investigate the dynamic contrast-enhanced computed tomography (CECT) features and clinical characteristics of sarcomatoid hepatocellular carcinoma (S-HCC).MethodsWe retrospectively reviewed the CECT data and clinical findings of 13 patients (11 male and 2 female, with an average age of 58.6 ± 11.2 years) with pathologically proven S-HCC, including 9 patients with surgical resection and 4 patients with biopsy examination. All patients underwent CECT scans. Two radiologists reviewed and evaluated general features, CECT features and extratumoral features of each lesions based on a consensus.ResultsAmong the thirteen tumors, a mean size of 66.7 mm was observed, ranging in diameter from 30 to 146 mm. Seven of thirteen patients had hepatitis B virus (HBV) infection and an elevation of alpha-fetoprotein (AFP) level. Most of cases located in the right lobe of liver (84.6%, 11/13). Nine of thirteen tumors showed lobulated or wavy contours and infiltrative morphology, while eight tumors presented with unclear margin. The tumor textures were mainly heterogeneous for ischemia or necrosis, with solid components dominantly in all cases. Eight of thirteen tumors exhibited “slow-in and and slow-out” dynamic enhancement pattern in CECT, with a enhancement peak in the portal venous phase. Portal vein or hepatic thrombus, adjacent organs invasion and lymph node metastasis were observed in two patients, respectively. Four of thirteen lesions occurred intrahepatic metastasis and hepatic surface retraction respectively.ConclusionS-HCC gengerally seen in elderly male with HBV infection and elevated AFP level. The CT manifestations including: large diameter, frequently hepatic right lobe involvement, lobular or wavy contours, ill-defined margins, infiltrative morphology, obvious heterogeneity and dynamic enhancement pattern of “slow-in and and slow-out” , contributed to the diagnosis of S-HCC. These tumors usually occurred hepatic surface retraction and intrahepatic metastasis.

A Reliable and Repeatable Model for Predicting Microvascular Invasion in Patients With Hepatocellular Carcinoma

The reproducibility of imaging models for predicting microvascular invasion (MVI) in patients with hepatocellular carcinoma (HCC) remains questionable due to inconsistent interpretation of image signs. Our aim was to screen for high-consensus MRI features to develop a repeatable model for predicting MVI. We included 219 patients with HCC who underwent surgical resection, and patients were divided into a training cohort (n=145) and a validation cohort (n=74). Morphological characteristics, signal features on hepatobiliary phases, and dynamic enhancement patterns were qualitatively interobserver evaluated. Interobserver agreement was assessed using Cohen's κfor selecting features with high interobserver agreement. Risk factors that were significant in stepwise multivariate analysis and that could be measured with good interobserver agreement were used to construct a predictive model, which was assessed in the validation cohort. The diagnostic performance of the model was evaluated based on area under the receiver operating characteristic curve (AUC). Multivariate analysis identified nonsmooth tumor margin, absence of radiologic capsule, and intratumoral artery as independent risk factors of MVI. These MRI-based features showed good or nearly perfect interobserver agreement between radiologists (κ > 0.6). The predictive model predicted MVI well in the training (AUC 0.734) and validation cohorts (AUC 0.759) and fitted well to calibration curves. MRI features included nonsmooth tumor margin, absence of radiologic capsule, and intratumoral artery that can be assessed with high interobserver agreement can predict MVI in HCC patients. The predictive model described here may be useful to radiologists, regardless of experience level.

Chondromesenchymal hamartoma of sinonasal region in a young child: Computed tomography, MR imaging, and pathological findings with brief review

This report documents computed tomography and magnetic resonance imaging (MRI) findings for a case of sinonasal chondromesenchymal hamartoma and its recurrence occurring in an 11-year-old boy. We have described MRI dynamic contrast enhancement patterns in the recurrence of pathology, which, to the best of our knowledge, is the first documentation of such features. Sinonasal chondromesenchymal hamartoma is a rare pediatric benign hamartoma that can mimic aggressive inflammatory lesions or malignancies in the sinonasal region. A correct diagnosis is imperative to avoid unnecessary adjuvant therapy.

Renal epithelioid angiomyolipoma: computed tomography manifestation and radiologic-pathologic correlation depending on different epithelioid component percentages.

Renal epithelioid angiomyolipoma (EAML) is a rare and potentially malignant mesenchymal lesion mainly composed of epithelioid cells. Although some case reports or small case series have been published, the computed tomography (CT) manifestations and radiologic-pathologic correlation depending on different epithelioid component percentages have not been studied before. To investigate the CT manifestation and radiologic-pathologic correlation between renal EAML and angiomyolipoma (AML) with epithelioid component. The clinicopathologic and imaging data of 53 patients with an original diagnosis of EAML or AML with epithelioid component were retrospectively collected from three hospitals. All tissue specimens were re-sectioned and re-observed under the microscope. Samples were divided into an EAML group (≥ 80% epithelioid component, n = 25) and AML with epithelioid component group (5% ≤ epithelioid component < 80%, n = 28). Two radiologists reviewed the images in consensus, describing and comparing the CT manifestation, including the long diameter of the tumor, morphology, presence of necrosis or cystic change, hemorrhage, fat, calcification, enlarged blood vessels, and dynamic enhancement pattern according to the Hounsfield unit value of each CT phase between the two groups. The radiologic-pathologic correlation depending on the different percentages of epithelioid component were studied. The long diameter of the tumor, presence of necrosis or cystic change, fat, enhancement pattern, and tumor-to-cortex enhancement ratio of the cortical phase between the two groups were significantly different (z = - 2.932, P = 0.003; χ2 = 18.020, P < 0.001; χ2 = 16.377, P < 0.001; P = 0.020; and T = - 3.944, P < 0.001, respectively). In multivariate logistic regression analysis, the significant predictive factors of EAML included the presence of necrosis or cystic change [odds ratio (OR) 11.864, P = 0.001] and absence of fat (OR 0.095, P = 0.003). Correlation analysis found that the presence of necrosis or cystic change (r = 0.679, P < 0.001) and fat (r = - 0.603, P < 0.001) were both moderately related to the epithelioid component percentage. The combined model based on the presence of necrosis or cystic change and absence of fat yielded the best diagnostic performance in discriminating EAML and AML with epithelioid component with the highest area under the curve (0.887). EAML has characteristic CT signs; these characteristic CT signs are closely related to the epithelioid component percentage. The presence of necrosis or cystic change and the absence of fat were independent predictors of EAML.

Changes in the Mean Intrahepatic Target Computed Tomography Attenuation Value During Treatment May Be a Useful New Predictor of the Post-progression Survival Associated with Lenvatinib Treatment.

Objective The relationship between the prognosis and magnitude of a decrease in tumor blood flow according to estimated tumor differentiation remains unclear. This study investigated the relationship between reductions in the rate of mean computed tomography (CT) attenuation values and the clinical prognosis. Methods We evaluated 63 consecutive patients who received lenvatinib treatment for unresectable hepatocellular carcinoma (HCC). The oncological aggressiveness of the tumors was estimated using classification by dynamic CT enhancement patterns. The utility of changes in mean CT attenuation values of intra-hepatic targets during treatment to estimate the prognosis was investigated by calculating the progression-free survival (PFS) and post-progression survival (PPS). A multivariate analysis was used to identify potential confounders for the survival after progression during lenvatinib therapy. Results The rate of decrease in the mean CT attenuation value gradually increased according to the degree of deterioration in estimated tumor differentiation, and the rate of a decrease in attenuation ≥40% showed a tendency to increase (p=0.064). This trend was reflected by a better objective response in oncological aggressiveness heterogeneous enhancement patterns (Type-3 and Type-4) than a homogeneous enhancement pattern (Type-2) (83% vs. 56% of modified Response Evaluation Criteria in Solid Tumors). This resulted in a similar PFS between the groups (p=0.773), whereas the PPS was significantly worse when the rate of decrease in the attenuation value was ≥40% (p=0.012). A multivariate analysis confirmed that a rate of decease in attenuation value ≥40% was a poor prognostic factor for the PPS (hazard ratio, 2.993; 95% confidence interval, 1.196-7.490; p=0.019). Conclusion A rate of decrease in attenuation ≥40% may reflect a good response of a highly malignant tumor to lenvatinib. Therefore, this value may have utility as a surrogate marker for estimating the oncological aggressiveness of tumors and their associated prognosis.

Characteristics of hepatic solitary necrotic nodules on contrast-enhanced ultrasonography

BackgroundTo summarize the characteristics of solitary necrotic nodules (SNN) in the liver observed under contrast-enhanced ultrasonography (CEUS).MethodsConventional ultrasonography (US) and CEUS were performed in 24 patients who were confirmed to have SNN by pathological assessment. The US data and dynamic enhancement patterns of CEUS were recorded and retrospectively analyzed.ResultsTen of 24 patients underwent surgical resection, while the other 14 patients underwent a puncture biopsy to be confirmed as SNN. Among the 24 patients, 13 patients had a single lesion and 11 patients had multiple lesions. The largest lesion was selected for CEUS examination for patients with multiple lesions. Eleven patients presented no enhancement in all three phases, while the other 13 patients presented with a peripheral thin rim-like enhancement in the arterial phase, an iso-enhancement in the portal phase and delayed phase. However, no enhancement in the interior of the lesions was detected during three phases of CEUS.ConclusionsSNN has characteristic findings on the CEUS, which play an important role in the differential diagnoses of liver focal lesions.

Differentiation of salivary gland tumors through tumor heterogeneity: a comparison between pleomorphic adenoma and Warthin tumor using CT texture analysis

We compared the diagnostic performance of CT texture analysis in single-phase CT scan with that of conventional enhancement pattern analysis in a two-phase CT scan for discrimination of salivary gland tumors, Warthin tumor (WT) from pleomorphic adenoma (PA). One hundred seventy-eight patients with PA and 84 patients with WT were selected and CT texture analysis was separately performed on early (40s) and delayed (180s) phases, after injection of the contrast agent, using commercially available software. The attenuation changes and enhancement patterns were visually and quantitatively assessed with Hounsfield units (HU). Differences between PAs and WTs were analyzed using χ2 test and independent t test. Diagnostic performance of texture parameters in single-phase CT was compared with that of dynamic enhancement pattern in two-phase CT using the McNemar test. Ratio of tumoral HU (delayed phase/early phase) was significantly higher in PAs compared with WTs (p < 0.001). Tumor heterogeneity parameters, standard deviation (SD) and entropy, were significantly lower in WTs regardless of the type of filter used (p ≤ 0.001). Mean with coarse filter (AUC = 0.944) on early phase scan and entropy with medium filter (AUC = 0.901) on delayed scan were best discriminators between PAs and WTs. Diagnostic accuracy of mean (90.5%) on early scan and entropy (84.7%) on delayed scan was not significantly different from the accuracy (89.3%) of conventional wash-out pattern for distinguishing WTs from PAs (p = 0.742, p = 0.088, respectively). Diagnostic performance of texture parameters was similar to that of quantitative enhancement pattern for differentiating WTs from PAs, with the advantage in lower radiation exposure.

MRI features predict microvascular invasion in intrahepatic cholangiocarcinoma

BackgroundThe presence of microvascular invasion (MVI) in intrahepatic cholangiocarcinoma (ICC) is a significant adverse prognostic factor. This study sought to investigate the correlation between preoperative imaging parameters and MVI in ICC.MethodsA total of 108 patients with surgically resected single ICC tumors (34 MVI-positive and 74 MVI-negative lesions) who underwent MRI examination, including T1WI, T2WI, DWI, and dynamic enhancement imaging, were enrolled in this retrospective study. The following qualitative and quantitative characteristics were evaluated: tumor morphology, signal features on T1WI and T2WI, intrahepatic duct dilatation, hepatic capsule retraction, target sign on DWI, dynamic enhancement pattern, arterial phase enhancement pattern, dot−/band-like enhancement inside the tumor, visible vessel penetration inside the tumor (hepatic artery, portal vein, or hepatic vein), integrity of the enhancement edge of the arterial phase, peripheral hepatic enhancement, tumor size, maximum enhancement edge thickness, arterial edge enhancement ratio, and delayed phase enhancement ratio. Other clinicopathological features were also used to predict and evaluate MVI in ICC. Chi-square test, Fisher’s exact test, and independent t-test were used for univariate analysis to determine the relationships among the presence of MVI and these MR parameters. Logistic regression analysis was used to identify predictors of MVI among these MR parameters.ResultsAmong MRI characteristics, tumor morphology, intrahepatic duct dilatation, arterial phase enhancement pattern, visible hepatic artery penetration sign, maximum diameter of the tumor and the arterial phase edge enhancement ratio were correlated with MVI (P = 0.007, 0.003, 0.008, 0.000, 0.003, and 0.002, respectively). Furthermore, higher CA19–9 levels (≥37 U/ml) and pathological tumor grade III were also related to MVI (P = 0.014 and 0.004, respectively). However, multivariate logistic regression analysis demonstrated that none of the parameters were independent risk factors for the diagnosis of MVI in ICCs.ConclusionFor the preoperative prediction of MVI in ICC, six qualitative and quantitative data obtained on preoperative MRI, as well as one tumorigenic marker and the pathological tumor grade, were statistically significant. More research is needed to identify MR characteristics that can be used as independent risk factors.

Comparison between neuroendocrine carcinomas and well-differentiated neuroendocrine tumors of the pancreas using dynamic enhanced CT.

To identify CT features distinguishing neuroendocrine carcinomas (NECs) of pancreas from well-differentiated neuroendocrine tumors (NETs) according to the World Health Organization 2017 and 2019 classification systems. This retrospective study included 69 patients with pathologically confirmed pancreatic neuroendocrine neoplasms who underwent dynamic CT (17, 17, 18, and 17 patients for well-differentiated grade 1, 2, 3 NET and NEC, respectively). CT was used to perform qualitative analysis (component, homogeneity, calcification, peripancreatic infiltration, main pancreatic ductal dilatation, bile duct dilatation, intraductal extension, and vascular invasion) and quantitative analysis (interface between tumor and parenchyma [delta], arterial enhancement ratio [AER], portal enhancement ratio [PER], and dynamic enhancement pattern). Uni- and multivariate logistic regression analyses were performed to identify features indicating NEC. Optimal cutoff values for enhancement ratios were determined. NECs demonstrated significantly higher frequencies of main pancreatic ductal dilatation, bile duct dilatation, vascular invasion, and significantly lower delta (i.e., lower conspicuity), AER, and PER than well-differentiated NET (p < 0.05). On multivariate analysis, PER was the only independent factor selected by the model for differentiation of NEC from well-differentiated NET (odds ratio, < 0.001; 95% confidence interval [CI], < 0.001-0.012). PER < 0.8 showed the sensitivity of 94.1% (95% CI, 71.3-99.9) and the specificity of 88.5% (95% CI, 76.6-95.6). When three significant CT features were combined, the sensitivity and specificity for diagnosing NEC were 88.2% and 88.5%, respectively. Tumor-parenchyma enhancement ratio in portal phase is a useful CT feature to distinguish NECs from well-differentiated NETs. Combining qualitative and quantitative CT features may aid in achieving good diagnostic accuracy in the differentiation between NEC and well-differentiated NET. • Neuroendocrine carcinoma of the pancreas should be distinguished from well-differentiated neuroendocrine tumor in line with the revised grading and staging system. • Neuroendocrine carcinoma of the pancreas can be differentiated from well-differentiated neuroendocrine tumor on dynamic CT based on assessment of the portal enhancement ratio, arterial enhancement ratio, tumor conspicuity, dilatation of the main pancreatic duct or bile duct, and vascular invasion. • Tumor-parenchyma enhancement ratio in portal phase of dynamic CT is a useful feature, which may help to distinguish neuroendocrine carcinoma from well-differentiated neuroendocrine tumor of the pancreas.

MRI in the differential diagnosis between well-differentiated hepatocellular carcinomas and high-grade dysplastic nodules in cirrhotic liver

ObjectiveTo assess the diagnostic efficacy of magnetic resonance imaging (MRI) in the differential diagnosis between well-differentiated hepatocellular carcinomas (WD-HCCs) and high-grade dysplastic nodules (HGDNs) in cirrhotic liver. MethodsFrom January 2012 to April 2018, we retrospectively analyzed 91 cirrhotic nodules (HGDN, n = 31, WD-HCC, n = 60) which were confirmed by surgery or pathology. Each patient underwent gadobenate dimeglumine-enhanced hepatic MRI. The MRI characteristics and enhancement effects were calculated and analyzed. ResultsHyperintensity on diffusion-weighted imaging (DWI), the typical enhancement pattern and hypo-intensity on T1-Weighted imaging (T1WI)were showed with statistically significant difference between WD-HCCs and HGDNs in cirrhotic live (P = 0.002, 0.008, 0.002, respectively). And high signal intensity (SI) on DWI (sensitivity, 66.7%, specificity, 67.7%) was the most specific feature to differentiated WD-HCCs from HGDNs. The combination of DWI and the dynamic enhancement pattern improved the differentiation of WD-HCCs from HGDNs(specificity 83.9%). ConclusionDWI is the most specific technique to differentiate WD-HCCs from HGDNs. The combination of DWI and the typical dynamic enhancement pattern can improve the differentiation of WD-HCCs from HGDNs. Pre-enhanced T1WI, as well as a capsule, provides additional diagnostic values.

Lenvatinib-Transarterial Chemoembolization Sequential Therapy as an Effective Treatment at Progression during Lenvatinib Therapy for Advanced Hepatocellular Carcinoma

Background: The aims of this study were to evaluate the efficacy of additional treatment, especially lenvatinib-transarterial chemoembolization (TACE) sequential therapy, for unresectable hepatocellular carcinoma (HCC). Methods: Consecutive 56 patients who underwent lenvatinib treatment were reviewed. Oncological aggressiveness of tumor was estimated using a dynamic CT enhancement pattern classification, and clinical impact of subsequent treatment was investigated through analysis of progression-free survival (PFS), post-progression survival (PPS), and multivariate analysis of potential confounders for survival after progression during lenvatinib therapy. Results: Heterogeneous enhancement patterns (Type-3 and -4), which are reportedly associated with higher oncological aggressiveness of HCC, were associated with better objective response to lenvatinib compared to homogeneous enhancement pattern (Type-2) (86 and 85% vs. 53% in modified Response Evaluation Criteria in Solid Tumors), resulting in similar PFS (p = 0.313). Because of significantly worse PPS, overall survival of Type-4 tumor was poor compared to Type-2 or -3 tumors (p = 0.009). However, subgroup of patients who achieved subsequent treatment showed significantly better PPS, regardless of CT enhancement pattern. Multivariate analysis confirmed that use of lenvatinib-TACE sequential treatment after progression during lenvatinib therapy was associated with better PPS (hazard ratio [HR], 0.08; 95% CI, 0.01–0.71; p = 0.023), while Type-4 enhancement pattern was correlated with worse PPS (HR, 2.92; 95% CI, 1.06–8.05; p = 0.039). Conclusion: Oncological aggressiveness of HCC estimated by CT enhancement pattern was predictive of PPS after progression during lenvatinib. Successful subsequent treatment with lenvatinib-TACE sequential therapy may offer survival benefit regardless of CT enhancement pattern of HCC.

Heterogeneity of Hepatocellular Carcinoma on Imaging.

Tumor heterogeneity in hepatocellular carcinomas (HCC) occurs at different levels. On conventional imaging modalities, the spectrum of tumor heterogeneity is evident in the dynamic enhancement pattern, where the characteristic wash-in and wash-out is present in only 60% of small HCCs. In larger HCCs, heterogeneity within the tumor, known as the mosaic pattern, can reflect the presence of different grades of HCC differentiation. The advent of functional imaging techniques has not improved the diagnostic sensitivity of imaging techniques for the diagnosis of HCC. However, the combination of conventional and functional imaging techniques potentially allows the identification of heterogeneity in tumor vascularity, cellularity, and molecular expression.

Predicting peritumoral Glisson's sheath invasion of intrahepatic cholangiocarcinoma with preoperative CT imaging.

To investigate the differences of clinicopathological characteristics and computed tomography (CT) features between intrahepatic cholangiocarcinomas (ICC) with and without peritumoral Glisson's sheath invasion (PGSI), and to construct a nomogram to predict PGSI of ICCs preoperatively. The clinicopathological characteristics and CT features of 84 ICCs were retrospectively analyzed and compared between ICCs with (30/84, 35.7%) and without PGSI (54/84, 64.3%). Multivariate logistic regression analysis was used to identify preoperative independent predictors of PGSI in ICCs. A nomogram was constructed to predict PGSI preoperatively. ICCs with and without PGSI differed significantly in the presence of abdominal pain, serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels, TNM and T stages, tumor location, intratumoral calcifications, intrahepatic bile duct dilatation, intrahepatic bile duct calculus, morphologic type and dynamic enhancement pattern on CT images (all P<0.05). Abdominal pain, serum CEA level, intrahepatic bile duct dilatation, and morphologic type were independent predictors of PGSI in ICCs. A nomogram based on those predictors was constructed to predict PGSI preoperatively with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.908 (P<0.001). Clinicopathological characteristics and CT features differed significantly between ICCs with and without PGSI. A nomogram including abdominal pain, serum CEA level, intrahepatic bile duct dilatation, and morphologic type could predict PGSI accurately.

Vascular pattern and diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in spleen alterations.

Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique in order to clarify rare focal splenic lesions (FSL). CEUS is a safe and cost-effective modality for assessment of perfusion. To validate contrast enhancement pattern and evaluate the diagnostic accuracy of CEUS in unclear FSL. CEUS examinations of the spleen in 50 patients between 2012 and 2018 were included in the study. Examinations were performed using B-mode, colour-coded Doppler ultrasound (CCDS) and CEUS after injection of sulphur hexafluoride microbubbles and interpreted in consensus by two experienced radiologists. Reference standard was defined as histopathological report and clinical course (treatment response, long term follow up). All patients were successfully examined by CEUS without an adverse reaction. CEUS presented the correct differentiation of benign and malignant alterations in 49/50 (98%). Lesion washout was found in all malignant but also 16.7% of all benign lesions. Matched to the histopathological report and clinical follow up, CEUS represented a sensitivity of 100% (95% -CI, 57-100), a specificity of 98% (95% -CI, 88-100), a positive predictive value (PPV) of 83% (95% -CI, 44-97) and a negative predictive value (NPV) of 100% (95% -CI, 92-100). CEUS may provide additional information by visualization of dynamic contrast enhancement pattern to differentiate benign and malignant lesions. Nevertheless, established criteria for malignancy (early enhancement or washout) in FSL should be considered with caution since they are also found in benign lesions.

Mass-forming intrahepatic cholangiocarcinoma: Can diffusion-weighted imaging predict microvascular invasion?

Microvascular invasion (MVI) is a risk factor influencing the survival rate of patients with mass-forming intrahepatic cholangiocarcinoma (IMCC). To investigate whether diffusion-weighted imaging (DWI) could be useful in predicting MVI of IMCC. Retrospective. Eighty patients with surgically resected single IMCC (21 MVI-positive lesions and 59 MVI-negative lesions). Preoperative hepatic MRI (1.5T), including T1 - and T2 -weighted images (T1 WI, T2 WI), DWI, and dynamic enhancement imaging. Morphologic characteristics including contour of the lesion, biliary dilation and hepatic capsule retraction, signal features on T1 WI, T2 WI, and DWI, and dynamic enhancement patterns were qualitatively evaluated. The quantitative analysis was performed for the size and apparent diffusion coefficient (ADC) values. Chi-square test, Fisher's exact test, and the independent t-test were used for univariate analysis to determine the relationships between these radiological parameters and the presence of MVI. Logistic regression analysis was used to identify the independent predictors of MVI among these radiological parameters. Receiver operating characteristic curve analysis was performed to evaluate their diagnostic performance. Larger tumor size (P = 0.006) and higher ADC values (P < 0.001) were positively correlated with MVI. Multivariate logistic regression analysis demonstrated that the ADC value (odds ratio, 3.099; P = 0.001) was an independent predictor for MVI of IMCC. The ADC value for MVI of IMCC showed an area under the receiver operating characteristic curve of 0.782 (optimal cutoff value was 1.59 × 10-3 mm2 /s). Larger tumor size was associated with MVI and higher ADC values can be a useful predictor of MVI during the preoperative evaluation of IMCC. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:315-324.

Diagnostic accuracy of contrast-enhanced dynamic CT for small hypervascular hepatocellular carcinoma and assessment of dynamic enhancement patterns: Results of two-year follow-up using cone-beam CT hepatic arteriography.

ObjectiveTo evaluate the accuracy of CT for small, hypervascular hepatocellular carcinomas (HCCs) and assess the enhancement patterns on CT.Materials and methodsNinety-nine patients who underwent cone-beam CT hepatic arteriography (CBCT-HA) during initial chemoembolization for HCC suspected on CT were enrolled in this study. A total of 297 hypervascular HCCs (142 ≥ 1 cm, 155 < 1 cm) were confirmed as HCCs based on two-year follow-up CT and CBCT-HA images. During the two-year follow-up, pre-existing hypervascular foci on CBCT-HA were regarded as HCCs at the initial presentation. Two radiologists categorized HCCs according to the following enhancement patterns on CT: type I, arterial enhancement and washout; type II, arterial enhancement without washout; and type III, no arterial enhancement. Two blinded reviewers rated the possibility of HCC.ResultsFor the 297 HCCs, the enhancement patterns according to size were as follows: type I ≥1 cm in 114 HCCs; type I <1 cm in 40 HCCs; type II ≥1 cm in 16 HCCs; type II <1 cm in 37 HCCs; type III ≥1 cm in 12 HCCs; and type III <1 cm in 10 HCCs. The remaining 68 HCCs (22.9%) were not detected on CT. The detection rates of HCCs ≥ 1 cm were 83.1%, 76.8%, and 83.1% in the formal report for reviewer 1 and reviewer 2. In comparison, the detection rates of HCCs < 1 cm were 20.6%, 17.4%, and 17.4% in the formal report for reviewer 1 and reviewer 2.ConclusionMany subcentimeter sized hypervascular HCCs were frequently missed or not evident on CT at the initial diagnostic workup. CT has limitations for diagnosing HCCs that are <1 cm in size or have atypical enhancement patterns.

Intrapancreatic accessory spleen: Evaluation with CT and MRI.

The aim of the present study was to evaluate the characteristics of computed tomography (CT) and magnetic resonance imaging (MRI), particularly diffusion-weighted imaging (DWI), in the imaging of intrapancreatic accessory spleen (IPAS). The clinical and pathological records of 9 patients, including 8 patients with IPAS and 1 patient with splenosis, were reviewed. The patients had undergone plain and triple-phase enhanced CT scanning (n=9) and MRI scanning (n=8). The lesions of the 8 IPAS patients were located in the pancreatic tail, and were round (n=3), oval (n=4) or triangular (n=1) in shape. The CT and/or MRI densities, signal intensities and dynamic enhanced patterns of the lesions were similar to those of the orthotopic spleen. In DWI images (n=5), the IPAS regions presented high signal intensity (SI), and no significant difference in the apparent diffusion coefficient determined using a b-value of 600 sec/mm2 was identified between the IPAS and orthotopic spleen (P>0.05). One patient with splenosis complicated with cirrhosis had a nodule located in the pancreatic tail with an unenhanced CT value of 65 HU. In MRI examination, with the exception of the dynamic enhancement pattern, the T1-weighted, T2-weighted and DWI signals of splenosis were inconsistent with those of the normal spleen. In conclusion, in pre-contrast and post-contrast-enhanced CT and MRI images, IPAS exhibits similar characteristics to the orthotopic spleen. CT and MRI used in combination with DWI are important in the diagnosis of IPAS.

MR Imaging Features of Tubular Carcinoma: Preliminary Experience in Twelve Masses.

We retrospectively analyzed the magnetic resonance (MR) imaging features and diffusion-weighted imaging findings of the 12 masses of 10 patients with tubular carcinoma (TC), including mammography and sonography findings. Mammographic, sonographic and magnetic resonance imaging features in 12 histopathologically confirmed masses diagnosed as TC of the breast within 10 patients were evaluated. Morphologic characteristics, enhancement features, apparent diffusion coefficient (ADC) values were reviewed. On mammography (n=5), TC appeared as high density masses with indistinct, spiculated or obscured margins. Sonographically, TC appeared as a hypoechoic appearance (n=12) with posterior acoustic shadowing in nine. On MR imaging, the margins of ten of twelve masses were irregular. Internal enhancement patterns were heterogeneous in 10 patients. Dynamic enhancement patterns illustrated plateau kinetics (n=8). On the T2-weighted images 4 masses were hypointense, and 8 were hyperintense; hypointense internal septation was found in seven of these. Tubular carcinoma appeared as hyperintense on diffusion-weighted imaging with ADC values of 0.85±0.16×10-3 mm2/s that was lower than the normal parenchyma of 1.25±0.25×10-3 mm2/s. According to our study with a limited number of cases, tubular carcinomas can be described as hyperintense breast carcinomas with or without dark internal septation like appearance on T2-weighted images. Low ADC values from DW imaging can be used to differentiate TC from hyperintense benign breast lesions.