Hepatic fat quantification in dual-layer computed tomography using a three-material decomposition algorithm.

OBJECTIVES: The purpose of this study was to evaluate a three-material decomposition algorithm for hepatic fat quantification using a dual-layer computed tomography (DL-CT) and MRI as reference standard on a large patient cohort. METHOD: A total of 104 patients were retrospectively included in our study, i.e., each patient had an MRI exam and a DL-CT exam in our institution within a maximum of 31 days. Four regions of interest (ROIs) were positioned blindly and similarly in the liver, by two independent readers on DL-CT and MRI images. For DL-CT exams, all imaging phases were included. Fat fraction agreement between CT and MRI was performed using intraclass correlation coefficients (ICC), determination coefficients R2, and Bland-Altman plots. Diagnostic performance was determined using sensitivity, specificity, and positive and negative predictive values. The cutoff for steatosis was 5%. RESULTS: Correlation between MRI and CT data was excellent for all perfusion phases with ICC calculated at 0.99 for each phase. Determination coefficients R2 were also good for all perfusion phases (about 0.95 for all phases). Performance of DL-CT in the diagnosis of hepatic steatosis was good with sensitivity between 89 and 91% and specificity ranging from 75 to 80%, depending on the perfusion phase. The positive predictive value was ranging from 78 to 93% and the negative predictive value from 82 to 86%. CONCLUSION: Multi-material decomposition in DL-CT allows quantification of hepatic fat fraction with a good correlation to MRI data. CLINICAL RELEVANCE STATEMENT: The use of DL-CT allows for detection of hepatic steatosis. This is especially interesting as an opportunistic finding CT performed for other reasons, as early detection can help prevent or slowdown the development of liver metabolic disease. KEY POINTS: • Hepatic fat fractions provided by the dual-layer CT algorithm is strongly correlated with that measured on MRI. • Dual-layer CT is accurate to detect hepatic steatosis ≥ 5%. • Dual-layer CT allows opportunistic detection of steatosis, on CT scan performed for various indications.

Transhepatic tract hemostasis using thermal-ablation after percutaneous portal vein access.

OBJECTIVES: Bleeding risk after percutaneous portal vein access procedures is not negligible. Various agents, coils and plug, have been used to minimize this risk, each with their own advantages and disadvantages. This study reports the results of coagulation using thermal-ablation (radiofrequency or microwave ablation) as an alternative to trans-hepatic puncture tract closure. METHODS: Ten patients who benefited from portal vein recanalization or portal hypertension-relative bleeding complication embolization using percutaneous portal vein access and who underwent thermal-ablation of the puncture tract between December 30, 2019 and July 16, 2020 were included. Early efficiency and safety were evaluated using imaging (ultrasound and/or CT scan) and laboratory data (hemoglobin, hepatic function) at 24 h. Follow-up was performed until August 2020. RESULTS: No bleeding from the puncture tract and no embolization-related complications were observed in all 10 patients at 24 h or during follow-up with median of 3 months (range 1-8 months), even in case of ascites or therapeutic coagulation. CONCLUSION: Thermal-ablation seems to be a safe, effective and rapid technique to avoid bleeding after percutaneous transhepatic direct portal vein access. ADVANCES IN KNOWLEDGE: Thermal-ablation could be an alternative for transhepatic puncture tract closure especially for patients with high bleeding risk.

Chest PET/MRI in Solid Cancers: Comparing the Diagnostic Performance of a Free-Breathing 3D-T1-GRE Stack-of-Stars Volume Interpolated Breath-Hold Examination (StarVIBE) Acquisition With That of a 3D-T1-GRE Volume Interpolated Breath-Hold Examination (VIBE) for Chest Staging During Whole-Body PET/MRI.

BACKGROUND: Whole-body positron emission tomography/magnetic resonance imaging (WB-PET/MRI) is increasingly used in oncology. However, chest staging remains challenging. PURPOSE: To compare the diagnostic performance of a free-breathing 3D-T1-GRE stack-of-stars volume interpolated breath-hold examination (StarVIBE) with that of a 3D-T1-GRE volume interpolated breath-hold examination (VIBE) during WB-PET/MRI for chest staging. STUDY TYPE: Retrospective, cohort study. POPULATION: One hundred and twenty-three patients were referred for initial staging of solid cancer, 46 of whom had pulmonary nodules and 14 had pulmonary metastasis. FIELD STRENGTH/SEQUENCE: Free-breathing 3D-T1-GRE stack-of-stars (StarVIBE) and Cartesian 3D-T1-GRE VIBE at 3.0 T. ASSESSMENT: Image quality was assessed using a 4-point scale and using the signal-to-noise ratio (SNR) of lung parenchyma and contrast-to-noise ratio (CNR) of pulmonary nodules. Diagnostic performances of both sequences were determined by three independent radiologists for detection of pulmonary nodules, lymph node involvement, and bone metastases using chest CT, pathology, and follow-up as reference standards. STATISTICAL TESTS: Paired Student's t-test; chi-squared; Fisher's exact test. A P value <0.05 was considered statistically significant. RESULTS: StarVIBE quality was judged as better in 34% of cases and at least equivalent to VIBE in 89% of cases, with significantly higher quality scores (4 [4-4] vs. 3 [3-4], respectively). SNR and CNR values were significantly higher with StarVIBE (8 ± 1.3 and 9.7 ± 4.6, respectively) than with VIBE (1.8 ± 0.2 and 5.5 ± 3.3, respectively). Compared to VIBE, StarVIBE showed significantly higher sensitivity (73% [95% CI 62-82] vs. 44% [95% CI 33-55], respectively) and specificity (95% [95% CI 88-99] vs. 67% [95% CI 56-77]) for pulmonary nodules detection and significantly higher sensitivity (100% [95% CI 89-100] vs. 67% [95% CI 48-82], respectively) for detection of lymph node involvement. Sensitivities for bone metastases detection were not significantly different (100% [95% CI 88-100] vs. 82% [95% CI 63-94], P = 0.054). DATA CONCLUSION: Owing to improved SNR and CNR and spatial resolution, a free-breathing 3D stack-of-stars T1-GRE sequence improves chest staging in comparison with standard 3D-T1-GRE VIBE and may be integrated in WB-PET/MRI acquisitions for initial staging of solid cancer. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Impact of the 18F-FDG-PET/MRI on Metastatic Staging in Patients with Hepatocellular Carcinoma: Initial Results from 104 Patients.

Optimal HCC therapeutic management relies on accurate tumor staging. Our aim was to assess the impact of 18F-FDG-WB-PET/MRI on HCC metastatic staging, compared with the standard of care CT-CAP/liver MRI combination, in patients with HCC referred on a curative intent or before transarterial radioembolization. One hundred and four consecutive patients followed for HCC were retrospectively included. The WB-PET/MRI was compared with the standard of care CT-CAP/liver MRI combination for HCC metastatic staging, with pathology, followup, and multidisciplinary board assessment as a reference standard. Thirty metastases were identified within 14 metastatic sites in 11 patients. The sensitivity of WB-PET/MRI for metastatic sites and metastatic patients was significantly higher than that of the CT-CAP/liver MRI combination (respectively 100% vs. 43%, p = 0.002; and 100% vs. 45%, p = 0.01). Metastatic sites missed by CT-CAP were bone (n = 5) and distant lymph node (n = 3) in BCLC C patients. For the remaining 93 nonmetastatic patients, three BCLC A patients identified as potentially metastatic on the CT-CAP/liver MRI combination were correctly ruled out with the WB-PET/MRI without significant increase in specificity (100% vs. 97%; p = 0.25). The WB-PET/MRI may improve HCC metastatic staging and could be performed as a "one-stop-shop" examination for HCC staging with a significant impact on therapeutic management in about 10% of patients especially in locally advanced HCC.

Incidence and Risk Factors for Diaphragmatic Herniation Following Esophagectomy for Cancer.

OBJECTIVE: To evaluate the incidence and risk factors of diaphragmatic herniation following esophagectomy for cancer (DHEC), and assess the results of surgical repair. SUMMARY BACKGROUND DATA: The current incidence of DHEC is discussed with conflicting data regarding its treatment and natural course. METHODS: Monocentric retrospective cohort study (2009-2018). From 902 patients, 719 patients with a complete follow-up of CT scans after transthoracic esophagectomy for cancer were reexamined to identify the occurrence of a DHEC. The incidence of DHEC was estimated using Kalbfleisch and Prentice method and risk factors of DHEC were studied using the Fine and Gray competitive risk regression model by treating death as a competing event. Survival was analyzed. RESULTS: Five-year DHEC incidence was 10.3% [95% CI, 7.8%-13.2%] (n = 59), asymptomatic in 54.2% of cases. In the multivariable analysis, the risk factors for DHEC were: presence of hiatal hernia on preoperative CT scan (HR = 1.72 [1.01-2.94], P = 0.046), previous hiatus surgery (HR = 3.68 [1.61-8.45], P = 0.002), gastroesophageal junction tumor location (HR = 3.51 [1.91-6.45], P < 0.001), neoadjuvant chemoradiotherapy (HR = 4.27 [1.70-10.76], P < 0.001), and minimally invasive abdominal phase (HR = 2.98 [1.60-5.55], P < 0.001). A cure for DHEC was achieved in 55.9%. The postoperative mortality rate was nil, the overall morbidity rate was 12.1%, and the DHEC recurrence rate was 30.3%. Occurrence of DHEC was significantly associated with a lower hazard rate of death in a time-varying Cox's regression analysis (HR = 0.43[0.23-0.81], P = 0.010). CONCLUSIONS: The 5-year incidence of DHEC is 10.3% and is associated with a favorable prognosis. Surgical repair of symptomatic or progressive DHEC is associated with an acceptable morbidity. However, the optimal surgical repair technique remains to be determined in view of the large number of recurrences.

Pneumatosis intestinalis and portal venous gas in mechanical small bowel obstruction: Is it worrisome?

PURPOSE: The purpose of this study was to evaluate the clinical significance of pneumatosis intestinalis (PI) and portal venous gas (PVG) in patients with mechanical small bowel obstruction (SBO), using surgical findings or clinical follow-up as standard of reference. MATERIALS AND METHODS: Fourteen patients with mechanical SBO associated with PI and PVG were retrospectively included. There were 7 men and 7 women with a mean age of 59±19 (SD) (range: 25-93 years). CT examinations were reviewed by two radiologists to confirm the diagnosis of mechanical SBO and make a description of PI. Interobserver agreement was calculated. The reference standard was intraoperative appearance of the bowel wall (10/14; 71%) or the recovery of a normal bowel function in patients who were managed conservatively (4/14; 29%). RESULTS: Among the 10 patients who underwent surgery, a normal appearance of the bowel in association with PI on CT was found intraoperatively in 8/10 (80%) patients and a reversible ischemia in the remaining 2/10 (20%) patients. The four patients who were managed conservatively recovered normal bowel function. Two patients died within two weeks following SBO. CONCLUSION: PI and PVG are not specific signs of bowel necrosis in mechanical SBO.

Transarterial Radioembolization for the Treatment of Advanced Hepatocellular Carcinoma Invading the Right Atrium.

Hepatocellular carcinoma (HCC) has the tendency to invade the portal and/or hepatic venous system. The invasion of the right atrium is uncommonly observed and constitutes a treatment challenge. We report the case of a patient with HCC invading the right atrium treated with 90Yttrium-transarterial radioembolization (90Y-TARE). Following the treatment, organizing pneumonia secondary to nivolumab occurred, raising the question of an interaction between 90Y-TARE and nivolumab.

Compressed sensing real-time cine imaging for assessment of ventricular function, volumes and mass in clinical practice.

OBJECTIVES: This study was conducted in order to evaluate the accuracy of a compressed sensing (CS) real-time single-breath-hold cine sequence for the assessment of left and right ventricular functional parameters in daily practice. METHODS: Cardiac magnetic resonance (CMR) cine images were acquired from 100 consecutive patients using both the reference segmented multi-breath-hold steady-state free precession (SSFP) acquisition and a prototype single-breath-hold real-time CS sequence, providing the same slice number, position, and thickness. For both sequences, the left (LV) and right ventricular (RV) ejection fractions (EF) and end-diastolic volumes (EDV) were assessed as well as LV mass (LVM). The visualization of wall-motion disorders (WMD) and signal void related to mitral or tricuspid regurgitation was also analyzed. RESULTS: The CS sequence mean scan time was 23 ± 6 versus 510 ± 109 s for the multi-breath-hold SSFP sequence (p < 0.001). There was an excellent correlation between the two sequences regarding mean LVEF (r = 0.995), LVEDV (r = 0.997), LVM (r = 0.981), RVEF (r = 0.979), and RVEDV (r = 0.983). Moreover, inter- and intraobserver agreements were very strong with intraclass correlations of 0.96 and 0.99, respectively. On CS images, mitral or tricuspid regurgitation visualization was good (AUC = 0.85 and 0.81, respectively; ROC curve analysis) and wall-motion disorder visualization was excellent (AUC ≥ 0.97). CONCLUSION: CS real-time single-breath-hold cine imaging reduces CMR scan duration by almost 20 times in daily practice while providing reliable measurements of both left and right ventricles. There was no clinically relevant information loss regarding valve regurgitation and wall-motion disorder depiction. KEY POINTS: • Compressed sensing single-breath-hold real-time cine imaging is a reliable sequence in daily practice. • Fast CS real-time imaging reduces CMR scan time and improves patient workflow. • There is no clinically relevant information loss with CS regarding heart valve regurgitation or wall-motion disorders.

Impact of sarcopenia on outcomes of patients undergoing pancreatectomy: A retrospective analysis of 107 patients.

To evaluate the prevalence of sarcopenia in patients undergoing pancreatic surgery and to examine its impact on the surgical outcomes and survival of patients.Skeletal muscle index (SMI) was measured on preoperative CT. A patient was considered sarcopenic if SMI was <38.5 cm/m for a female or <52.4 cm/m for a male. Postoperative pancreatic fistula (POPF) and severe morbidity (Clavien≥3) were analyzed. Survival of patients with cancer was calculated using the Kaplan-Meier method.In total, 107 consecutive patients were included. Among them, 50 (47%) patients were sarcopenic and 65 (60%) were undernourished. The rates of severe morbidity and mortality were comparable between sarcopenic and nonsarcopenic groups. However, all POPF grade B or C and deaths occurred in the sarcopenic or nonsarcopenic overweight group (BMI > 25) with significantly lengthened hospital stays (P = .003). After pancreatectomy for cancer, 31 (40.2%) patients showed postoperative recurrence and 23 (29.9%) died after a median follow-up of 15 ±â€Š13.5 months. Despite comparable histological types and stages, the median overall and disease-free survivals were lower in sarcopenic patients (16 months vs not reached, P = .02 and 11.1 months vs 22.5 months; P = .04, respectively). The multivariate analysis revealed that, sarcopenia trended to increase the risk of death (HR = 2.04, P = .07).Sarcopenia negatively impacted short- and long-term outcomes in patients undergoing pancreatectomy.