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PURPOSE: Low mono-energetic CT has been shown to improve visualization of acute abdominal inflammatory processes. We aimed to determine its utility in patients with acute cholecystitis and potential added value in clinical decision making. METHODS: Sixty-seven consecutive patients with radiological signs of cholecystitis on contrast-enhanced dual-layer CT imaging were retrospectively identified over a four-year period (2/17-8/21). A ranked Likert scale was created for imaging findings present in acute cholecystitis, including gallbladder mucosal integrity and enhancement and pericholecystic liver parenchymal enhancement. These rankings were correlated with laboratory data, followed by sensitivity, specificity, and odds-ratios calculations. RESULTS: Mucosal integrity and pericholecystic liver enhancement were better seen on low-energetic images by unanimous consensus. Presence of pericholecystic liver enhancement and poorer mucosal wall integrity correlated with positive bile cultures (sensitivity: 93.8 % and 96.9 %, specificity: 37.5 and 50.0 %; odds-ratio: 9.0[1.1-68.1 95 %CI] and 31.0 [2.7-350.7 95 %CI], p = 0.017 and p ≤ 0.001) in patients undergoing cholecystostomy (n = 40/67). Moreover, binary regression modeling showed that the strongest predictor variable for bile culture positivity was the score for pericholecystic liver enhancement (Exp(B) = 0.6, P = 0.022). By contrast, other laboratory markers and other imaging findings (such as GB wall thickness) showed lower sensitivities (76-82 %), specificities (16-21 %) and odds ratios (0.2-4.4) for the prediction of infected bile. CONCLUSIONS: Pericholecystic liver enhancement and gallbladder wall integrity are better visualized on low-DECT images. These findings also potentially predict bile culture positivity in patients with cholecystitis, which may influence clinical management including the need for intervention.

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Background: To report the occurrence of abdominal symptoms in patients who presented with prolonged heterogeneous liver enhancement (PHLE) after injecting contrast agent SonoVue®. Methods: A total of 105 patients who indicated to have contrast-enhanced ultrasound (CEUS) examinations were consecutively observed. The liver scanning under ultrasound was performed before and after the contrast agent injection. Patients' basic information, clinical manifestations, and ultrasound images under B-mode and CEUS mode were respectively recorded. For patients exhibiting abdominal symptoms, the occurrence and last time of symptoms were recorded in detail. We subsequently compared the difference in clinical characteristics between patients with and without the PHLE phenomenon. Results: In 20 patients with the PHLE phenomenon, 13 showed abdominal symptoms. Eight patients (61.5%) appeared to have mild defecation sensation, and 5 (38.5%) showed apparent abdominal pain. The PHLE phenomenon began to appear within 15 minutes to 1.5 hours after the intravenous injection of SonoVue®. This phenomenon lasted for 30 minutes to 5 hours in ultrasound. Patients with severe abdominal symptoms showed large-area and diffuse PHLE patterns. Only sparse hyperechoic spots in the liver were detected in patients with mild discomfort. Abdominal discomfort resolved spontaneously in all patients. Meanwhile, the PHLE gradually disappeared without any medical treatment. In the PHLE-positive group, the proportion of patients with a history of gastrointestinal disease was significantly higher (P=0.02). Conclusions: Patients with the PHLE phenomenon can exhibit abdominal symptoms. We suggest gastrointestinal disorders may contribute to PHLE, which can be considered a harmless phenomenon that does not affect the safety profile of SonoVue®.

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OBJECTIVE: To devise a patient-informed time series model that predicts liver contrast enhancement, by integrating clinical data and pharmacokinetics models, and to assess its feasibility to improve enhancement consistency in contrast-enhanced liver CT scans. METHODS: The study included 1577 Chest/Abdomen/Pelvis CT scans, with 70-30% training/validation-testing split. A Gaussian function was used to approximate the early arterial, late arterial, and the portal venous phases of the contrast perfusion curve of each patient using their respective bolus tracking and diagnostic scan data. Machine learning models were built to predict the Gaussian parameters of each patient using the patient attributes (weight, height, age, sex, BMI). Pearson's coefficient, mean absolute error, and root mean squared error were used to assess the prediction accuracy. RESULTS: The integration of the pharmacokinetics model with a two-layered neural network achieved the highest prediction accuracy on the test data (R2 = 0.61), significantly exceeding the performance of the pharmacokinetics model alone (R2 = 0.11). Applying the model demonstrated that adjusting the contrast administration directed by the model may reduce clinical enhancement inconsistency by up to 40 %. CONCLUSIONS: A new model using a Gaussian function and supervised machine learning can be used to build liver parenchyma contrast enhancement prediction model. The model can have utility in clinical settings to optimize and improve consistency in contrast-enhanced liver imaging.

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PURPOSE: Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) is a contrast agent for magnetic resonance imaging (MRI), which specifically taken up by hepatocytes through organic anion-transporting polypeptides (OATPs). Previous research in mice has shown that type 2 diabetes is associated with reduced uptake of Gd-EOB-DTPA into the liver parenchyma, reflecting reduced expression of OATP. Since considerable differences in OATP expression exist between mice and humans, human studies are necessary to clarify the effect of diabetes to Gd-EOB-DTPA uptake. The purpose of this study was to validate the effect of diabetes to Gd-EOB-DTPA liver uptake by a confirmatory study in humans. METHODS: Patients who underwent Gd-EOB-DTPA-enhanced MRI were retrospectively reviewed and divided into two groups: severe or uncontrolled diabetic group (patients with insulin therapy and/or HbA1c ≥ 8.4%) and the control group. Liver-to-spleen ratio (LSR) and relative enhancement of the liver (REL) were calculated to represent Gd-EOB-DTPA liver uptake. RESULTS: A total of 94 patients fulfilled the criteria. The severe or uncontrolled diabetic group (n = 15) showed significantly lower LSR (1.74 ± 0.26 vs. 1.98 ± 0.31, p = 0.007) and REL (0.69 ± 0.23 vs. 0.87 ± 0.31, p = 0.005), compared to the control group (n = 79). CONCLUSION: Our study revealed decreased uptake of Gd-EOB-DTPA into liver parenchyma in the severe or uncontrolled diabetic patients. Further studies to determine the impact of the reduced liver enhancement on clinical diagnostic practice will be needed.

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BACKGROUND: We intended to determine the usefulness of gadoxetic acid-enhanced magnetic resonance (MR) imaging on preoperative prediction of the risk of postoperative liver failure (PLF) using measurement of relative liver enhancement (RLE) in patients who underwent surgical resection of hepatocellular carcinoma (HCC). METHODS: A total of 121 HCC patients who had underwent gadoxetic acid-enhanced MRI before surgery between January 2012 and April 2015 at our hospital was retrospectively analyzed. RLE was calculated as the ratio of signal intensity measurements of the liver parenchyma in each liver segment before and 20 min after intravenous administration of gadoxetic acid. PLF was defined based on the "50-50 criteria" (prothrombin time <50% and serum bilirubin >5 mg/dL on 5 days after surgery). RESULTS: Of the 121 patients, 74 (61.2%) patients had liver cirrhosis, clinically. Median tumor size 2.8 cm (range, 1-14 cm), 106 (87.6%) patients had a single HCC, and 101 (83.5%) patients had HCC within Milan criteria. Based on the "50-50 criteria", PLF was observed in 7 (5.8%) patients. Mean RLE was significantly lower in patients with PLF than those without it (55.9% vs 85.5%, P < 0.01). In a multivariate analysis, decreased RLE was a significant independent risk factor for PLF in HCC patients (odds ratio 0.97, P = 0.03). Optimal cut-off RLE value was 82.36. CONCLUSIONS: RLE was significantly lower in patients with PLF than those without it. Measurement of RLE using gadoxetic acid-enhanced MR imaging before surgery can be useful for prediction of PLF in HCC patients who receive surgical treatment.

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