Springer Science and Business Media LLC

We discuss various imaging features that have been reported to be associated with the prognosis of hepatocellular carcinoma (HCC) but not included in the current staging systems: findings related with microvascular invasion, tumor encapsulation, intratumoral fat, presence of satellite nodules, peritumoral hypointensity on hepatobiliary phase images of gadoxetic-acid enhanced MRI, restricted diffusion, and irregular rim-like hyperenhancement. Current evidence suggests that larger (> 2 cm) tumor size, presence of satellite nodules, presence of irregular rim-like hyperenhancement of a tumor, peritumoral parenchymal enhancement in the arterial phase, and peritumoral hypointensity observed on hepatobiliary phase images are independent imaging features to portend a worse prognosis in patients with hepatocellular carcinoma.

To assess contrast-enhanced computed tomography (CE-CT) features for predicting malignant potential and Ki67 in small intestinal gastrointestinal stromal tumors (GISTs) and the correlation between them. We retrospectively analyzed the pathological and imaging data for 123 patients (55 male/68 female, mean age: 57.2 years) with a histopathological diagnosis of small intestine GISTs who received CE-CT followed by curative surgery from May 2009 to August 2019. According to postoperatively pathological and immunohistochemical results, patients were categorized by malignant potential and the Ki67 index, respectively. CT features were analyzed to be associated with malignant potential or the Ki67 index using univariate analysis, logistic regression and receiver operating curve analysis. Then, we explored the correlation between the Ki67 index and malignant potential by using the Spearman rank correlation. Based on univariate and multivariate analysis, a predictive model of malignant potential of small intestine GISTs, consisting of tumor size (p < 0.001) and presence of necrosis (p = 0.033), was developed with the area under the receiver operating curve (AUC) of 0.965 (95% CI, 0.915–0.990; p < 0.001), with 91.53% sensitivity, 96.87% specificity, 96.43% PPV, 92.54% NPV, 94.31% diagnostic accuracy. For high Ki67 expression, a model made up of tumor size (p = 0.051), presence of ulceration (p = 0.054) and metastasis (p = 0.001) may be the best predictive combination with an AUC of 0.785 (95% CI, 0.702–0.854; p < 0.001), 63.33% sensitivity, 76.34% specificity, 46.34% PPV, 86.59% NPV, 73.17% diagnostic accuracy. Ki67 index showed a moderate positive correlation with mitotic count (r = 0.578, p < 0.001), a weak positive correlation with tumor size (r = 0.339, p < 0.001) and with risk stratification (r = 0.364, p < 0.001). Features on CE-CT could preoperatively predict malignant potential and high Ki67 expression of small intestine GISTs, and Ki67 index may be a promising prognostic factor in predicting the prognosis of small intestine GISTs, independent of the risk stratification system.

To investigate the diagnostic efficacy of ZOOMit coronal diffusion-weighted imaging (Z-DWI) and MR texture analysis (MRTA) for differentiating benign from malignant distal bile duct strictures. We retrospectively enrolled a total of 71 patients with distal bile duct stricture who underwent magnetic resonance cholangiopancreatography (MRCP). For quantitative analysis, the average apparent diffusion coefficient (ADC) value at suspected stricture sites was assessed on both Z-DWI and conventional DWI (C-DWI). For qualitative analysis, two reviewers independently reviewed two image sets containing different diffusion-weighted images, and receiver operating characteristic (ROC) curve analysis was performed. Several MRTA parameters were extracted from the area of the stricture on the ADC map of the ZOOMit coronal diffusion-weighted images using commercially available software. Among 71 patients, 26 patients were diagnosed with malignant stricture. On quantitative analysis, the average ADC value of the malignant and benign strictures, using Z-DWI, was 1.124 × 10−3 mm2/s and 1.522 × 10−3 mm2/s, respectively (P < 0.001). The average ADC value of the malignant and benign strictures, using C-DWI, was 1.107 × 10−3 mm2/s and 1.519 × 10−3 mm2/s, respectively (P < 0.001). On qualitative analysis, for each reviewer, the area under the ROC curve (AUC) values for differentiating benign from malignant stricture was 0.928 and 0.939, respectively, for the ZOOMit diffusion set and 0.851 and 0.824, respectively, for the conventional diffusion set. Multiple MRTA parameters showed a significantly different distribution for the benign and malignant strictures, including mean, entropy, mean of positive pixels, and kurtosis at spatial filtration values of 0, 5, and 6 mm. The addition of Z-DWI to conventional MRCP is helpful in differentiating benign from malignant bile duct strictures, and some MRTA parameters also can be helpful in differentiating benign from malignant distal bile duct strictures.

The spectrum of renal cell carcinoma (RCC) includes many neoplasms with distinct cytogenetics, biologic behaviors, and imaging appearances. The advent of molecular therapies targeting different tumor types, new insights into the relative roles of biopsy and surveillance for small incidental tumors, and a growing array of nephron-sparing interventions have altered management of RCC. Similarly, the role of the radiologist is changing, and it is becoming increasingly important for radiologists to familiarize themselves with the various types of RCC. This article introduces the reader to the common and uncommon recognized types of renal cell carcinoma and discusses how these neoplasms differ in imaging appearance and behavior.

To assess the impact of elevated blood pressure on the rate of major hemorrhagic complication after renal transplant biopsy. Pre-procedural systolic (SBP), diastolic (SBP), and mean arterial (MAP) blood pressure for consecutive patients undergoing US-guided renal transplant biopsies from 08/01/2015 to 7/31/2017 were retrospectively recorded. Patients who had a major bleeding complication were identified. The risk of complication as a function of SBP, DBP, and MAP was statistically analyzed, with significance set at p < 0.05. Of 1689 biopsies, there were 10 bleeding complications (10/1689, 0.59%). There was no statistically significant difference between biopsies with complication compared to those without complication based on SBP (p = 0.351), DBP (p = 0.088), or MAP (p = 0.132). Using risk dichotomization criteria, the odds ratio for hemorrhagic complication when the patient had SBP ≥ 180 mmHg and DBP ≥ 95 mmHg was 75.63 (95% CI 6.87–516.8, p = 0.002). The rate of hemorrhagic complication from renal transplant biopsy is low, and there is no statistically significant threshold for increased biopsy risk based on SBP, DBP, or MAP alone. The risk of complication was significantly higher only when both the SBP is ≥ 180 mmHg and DBP is ≥ 95 mmHg.

To describe liver imaging findings and complications on computed tomography (CT) or magnetic resonance imaging (MRI) in adults with Fontan palliation and investigate whether imaging features show correlations with clinical and physiological parameters. Our Institutional Review Board approved this retrospective study. Two blinded abdominal radiologists reviewed abdominal CT (n = 21) and MRI (n = 16) images between September 2011 and October 2017 in 37 adults (median age 27 years, interquartile range 21–36 years, 14 males [38%]) with a Fontan palliation (median post-Fontan duration 22 years, interquartile range 19–28 years). Correlation between CT/MRI findings and clinical parameters including laboratory results within 6 months of CT/MRI examinations was assessed by Spearman’s rank correlation coefficient. Lobulated hepatic surface and blunt hepatic edge were seen in 92% (34/37) and 95% (35/37) of patients, respectively. Surface nodularity was noted in 32% (12/37). In 7 patients, there were 11 hepatic nodules which showed arterial-phase hyperenhancement and washout. Among them, 2 were biopsy-proven hepatocellular carcinomas (HCCs), and the remaining 9 were focal nodular hyperplasia (FNH)-like nodules. Suprahepatic inferior vena cava (IVC) diameter showed positive correlations with post-Fontan duration (p < 0.01), serum gamma-glutamyl transferase (p < 0.01), and total bilirubin (p < 0.01). The livers in post-Fontan adults show a unique morphology of blunt edge and lobulating surface with occasional nodularity. There is a diagnostic challenge in distinguishing HCCs from FNH-like nodules in post-Fontan population due to overlapping imaging findings. Suprahepatic IVC diameter is a potentially useful imaging marker that reflects hepatic dysfunction in Fontan palliation.

The identification of high recurrence risk stage II colon cancer patients was critical to adjuvant chemotherapy decision. However, current definition of high-risk features remains inadequate. This study aimed to construct a model for predicting recurrence risk based on tumor enhancement ratio (TER) on abdominal contrast-enhanced CT scan. 282 stage II colon cancer patients were included and randomly divided into training and validation sets in the ratio of 7:3. TER was calculated using maximum tumor attenuation value in contrast-enhanced CT scan divided by the minimum. Kaplan–Meier survival analyses were adopted to evaluate the prognostic value of variables. A model based on TER was built to predict recurrence risk through the LASSO Cox model. The recurrence risk score of patients was calculated based on this model. The optimal cut-off value of TER was 1.83 derived from the time-dependent ROC (tdROC) curve. Patients with high-TER showed increasingly poorer disease-free survival (DFS) in both training (p < 0.001) and validation (p < 0.001) sets. A model was built based on TER demonstrated satisfactory performance to recurrence risk prediction (C-index: 0.784 in the training set and 0.725 in the validation set). Patients were regrouped into modified high-risk and non-high risk according to recurrence risk score (cut-off value: 1.75) and a significant DFS difference was observed (training set: p < 0.001; validation set: p < 0.001). TER can serve as a high-risk feature of stage II colon cancer. And a model based on TER provided a new approach to assess recurrence risk of stage II disease.

Cirrhosis of liver is often a silent disease and need early diagnosis for effective treatment strategy. The present article aims to describe new imaging signs for early diagnosis of cirrhosis on routine CT. These are ‘hepato-diaphragmatic fat interposition’ (HDFI) and ‘increased right hemi-diaphragmatic thickness’ (increased r-DT sign). This was a retrospective study based on the presence or absence of cirrhosis of liver (n = 100). ‘HDFI sign’ was labeled as positive if F is more than 50% of D; where F is the medio-lateral extent of the intra-abdominal fat along the postero-medial margin of liver and D is the distance from the lateral vertebral margin to the medial margin of the outer-most rib in the same axial image. Increased ‘r-DT sign’ is labeled when the dimension on right side exceeds left side by at least 0.2 cm. Pearson χ2 was performed to calculate the p value. A p value of < 0.05 was considered to indicate a significant difference. There was a significant difference between cirrhotic and normal group, The sensitivity, specificity, positive predictive value and the negative predictive value of HDFI sign was found to be 94%, 62%, 71.21% and 91.17%, while that of increased r-DT sign was found to be 96%,52%, 66.66% and 92.85%. The area under the ROC curve for the HDFI sign was found to be 0.78 as compared to 0.74 for the increased r-DT sign. Both these new signs should be used as additional imaging signs for early diagnosis of cirrhosis.