Use of Virtual Target Fluoroscopic Display of Three-Dimensional CO2 Wedged Hepatic Vein Portography for TIPS Placement.

PURPOSE: To describe and evaluate an image fusion technique for the portal vein puncture guidance during TIPS procedure: a three-dimensional (3D) virtual target fluoroscopic display obtained with an automated 3D carbon dioxide wedged hepatic vein portography (3D CO2-WHVP). MATERIALS AND METHODS: All the 37 TIPS creations performed in our institution between 3/2017 and 12/2018 were retrospectively reviewed. Seventeen procedures were guided using the 3D CO2-WHVP technique (group 1) and were compared with the other 20 procedures performed under conventional 2D fluoroscopic guidance (group 2). Image acquisition for the 3D CO2-WHVP consisted of combining a CBCT acquisition and an automatic CO2 injection. Once located on the multiplanar reformatted images of the CBCT acquisition, the portal bifurcation was manually segmented to create a virtual target that was overlaid onto live fluoroscopy allowing a real-time 3D guidance during portal vein puncture. RESULTS: Primary success was 100% in group1 and 95% in group2. Median intervention length, fluoroscopy time and dose area product (DAP) were, respectively, 124 min [IQR 94-137], 40 min [IQR 26-52] and 12140 cGy.cm2 [IQR 10147-18495] in group 1 and 146 min [IQR 118-199], 40 min [IQR 36-60] and 13290 cGy.cm2 [IQR 10138-19538] in group 2. No technical parameter was significantly different between the two groups. Intraprocedural complication rate was 0% in group 1 and 20% in group 2 (p = 0.05). CONCLUSION: Three-dimensional virtual target fluoroscopic display using a CBCT-acquired CO2 wedged portography is an effective and safe technique to ease intrahepatic puncture of the portal vein during TIPS procedures.

Low-dose chest CT for diagnosing and assessing the extent of lung involvement of SARS-CoV-2 pneumonia using a semi quantitative score.

OBJECTIVES: The purpose is to assess the ability of low-dose CT (LDCT) to determine lung involvement in SARS-CoV-2 pneumonia and to describe a COVID19-LDCT severity score. MATERIALS AND METHODS: Patients with SARS-CoV-2 infection confirmed by RT-PCR were retrospectively analysed. Clinical data, the National Early Warning Score (NEWS) and imaging features were recorded. Lung features included ground-glass opacities (GGO), areas of consolidation and crazy paving patterns. The COVID19-LDCT score was calculated by summing the score of each segment from 0 (no involvement) to 10 (severe impairment). Univariate analysis was performed to explore predictive factor of high COVID19-LDCT score. The nonparametric Mann-Whitney test was used to compare groups and a Spearman correlation used with p<0.05 for significance. RESULTS: Eighty patients with positive RT-PCR were analysed. The mean age was 55 years ± 16, with 42 males (53%). The most frequent symptoms were fever (60/80, 75%) and cough (59/80, 74%), the mean NEWS was 1.7±2.3. All LDCT could be analysed and 23/80 (28%) were normal. The major imaging finding was GGOs in 56 cases (67%). The COVID19-LDCT score (mean value = 19±29) was correlated with NEWS (r = 0.48, p<0.0001). No symptoms were risk factor to have pulmonary involvement. Univariate analysis shown that dyspnea, high respiratory rate, hypertension and diabetes are associated to a COVID19-LDCT score superior to 50. CONCLUSIONS: COVID19-LDCT score did correlate with NEWS. It was significantly different in the clinical low-risk and high-risk groups. Further work is needed to validate the COVID19-LDCT score against patient prognosis.

Image Fusion Guidance for In Situ Laser Fenestration of Aortic Stent graft for Endovascular Repair of Complex Aortic Aneurysm: Feasibility, Efficacy and Overall Functional Success.

OBJECTIVE: To evaluate feasibility, efficacy and overall functional success of image fusion guidance during laser-assisted in situ fenestration of aortic stent graft (LISFAS) for endovascular repair of complex aortic aneurysm (complex-EVAR) in a prospective study. METHODS: Between September 2016 and July 2018, 20 patients were included and treated with LISFAS for complex-EVAR. Aortic aneurysms were either para-renal (n = 15) or thoraco-abdominal (n = 5) with 57 mm [first quartile: 54; third quartile: 68] median aneurysm diameter in 69 years [68;78] patients. All interventions were performed using the same angiographic system and 3D image fusion software for overlying pre-intervention CTA on per-intervention 2D fluoroscopy with cone-beam CT images to display target vessels ostia. RESULTS: LISFAS for complex-EVAR with image fusion was performed in all patients, and no endovascular intervention required conversion to an open aortic repair. LISFAS of all target vessels was feasible in 18 patients (90%); 48 fenestrations out of 50 were performed successfully. Two fenestrations failed for renal arteries in two patients. Median ischemic times were as follows: 34 min [25;43] for superior mesenteric artery; 69 min [56;83] for left renal artery; 73 min [36;102] for right renal artery; and 93 min [89;96] for the celiac trunk. Median intervention and fluoroscopy times, iodinated contrast volume and X-ray exposure were 180 min [150;180], 74 min [64;87], 80 mL [59;113] and 338 Gy.cm2 [259;495], respectively. Efficacy was found in 17 patients (85%) on one-week follow-up CTA: Two patients had type 1 and 3 endoleaks, respectively, that were successfully embolized. Overall functional success was 90%. Median hospitalization stay was 9 days [8, 17]. The 30-day safety analysis was 90% (n = 2 deaths) owing to an undetermined cause and to bowel ischemia after low flow in intensive care unit. CONCLUSIONS: LISFAS using image fusion was feasible, efficient and overall functionally successful for complex-EVAR in this preliminary study.

Comparative analysis of mutational robustness of the intrinsically disordered viral protein VPg and of its interactor eIF4E.

Conformational intrinsic disorder is a feature present in many virus proteins. Intrinsically disordered regions (IDRs) have weaker structural requirement than ordered regions and mutations in IDRs could have a lower impact on the virus fitness. This could favor its exploration of adaptive solutions. The potyviral protein VPg contains IDRs with determinants for adaptation to its host plant. To experimentally assess whether IDRs are more resistant to mutations than ordered regions, the biologically relevant interaction between mutant libraries of both VPg and the eukaryotic translation initiation factor 4E (eIF4E) and their respective wild type partner was examined using yeast two hybrid assay. Our data shows that VPg is significantly more robust to mutations than eIF4E and as such belongs to a particular class of intrinsically disordered proteins. This result is discussed from the standpoint of IDRs involvement in the virus adaptive processes.

Does Ipsilateral-Dependent Positioning During Percutaneous Lung Biopsy Decrease the Risk of Pneumothorax?

OBJECTIVE: The purpose of this study is to determine whether placing patients in an ipsilateral-dependent position during percutaneous CT-guided transthoracic biopsy reduces the pneumothorax rate. MATERIALS AND METHODS: Between July 2013 and August 2017, a total of 516 patients (317 men and 199 women; mean age, 66.4 years) underwent core needle biopsies performed using 17- and 18-gauge needles. The overall pneumothorax rate and the rate of pneumothorax requiring drainage catheter insertion were compared between group A (patients placed in an ipsilateral-dependent position) and group B (patients placed in a position other than the ipsilateral-dependent position), with use of a chi-square test or Fisher exact test, as appropriate. Linear regression analysis and multiple regression analysis were performed for risk factors of pneumothorax, including patient characteristics (e.g., emphysema along the needle track), lesion characteristics (e.g., size and position), and biopsy technique characteristics (e.g., needle path length, needle-pleura angle, and fissure crossing). RESULTS: For patients in group A and group B, the overall pneumothorax rate (21/94 [22.3%] and 95/422 [22.5%], respectively; p = 0.97) and the rate of pneumothorax requiring drainage catheter insertion (6/94 [6.4%] and 28/422 [6.6%], respectively; p = 0.90) were not statistically different. After multiple regression analysis, the only independent risk factors for pneumothorax and insertion of a drainage catheter were needle path length (p < 0.001 and p = 0.02, respectively), emphysema along the needle track (p = 0.01 and p < 0.001, respectively), and fissure crossing (p = 0.04 and p < 0.001, respectively). CONCLUSION: Even though the pneumothorax rate does not appear to be reduced, with the limits of a retrospective evaluation considered, other advantages of the ipsilateral decubitus position exist, including protection of the contralateral lung in patients with severe hemoptysis.

Subsolid Lung Nodule Classification: A CT Criterion for Improving Interobserver Agreement.

Purpose To evaluate an objective computed tomographic (CT) criterion for distinguishing between part-solid (PS) and nonsolid (NS) lung nodules. Materials and Methods This study received institutional review board approval, and patients gave informed consent. Preoperative CT studies in all patients who underwent surgery for subsolid nodules between 2008 and 2015 were first reviewed by two senior radiologists, who subjectively classified the nodules as PS or NS. A second reading performed 1 month later used predefined classification criteria and involved a third senior radiologist as well as three junior radiologists. Subsolid nodules were classified as PS if a solid portion was detectable in the mediastinal window setting (nonmeasurable, < 50%, or > 50% of the entire nodule) and were otherwise classified as NS (subclassified as pure or heterogeneous). Interreader agreement was assessed with κ statistics and the intraclass correlation coefficient (ICC). Results A total of 99 nodules measuring a median of 20 mm (range, 5-47 mm) in lung window CT images were analyzed. Senior radiologist agreement on the PS/NS distinction increased from moderate (κ = 0.54; 95% confidence interval [CI]: 0.37, 0.71) to excellent (κ = 0.89; 95% CI: 0.80, 0.98) between the first and second readings. At the second readings, agreement among senior and junior radiologists was excellent for PS/NS distinction (ICC = 0.87; 95% CI: 0.83, 0.90) and for subcategorization (ICC = 0.82; 95% CI: 0.77, 0.87). When a solid portion was measurable in the mediastinal window, the specificity for adenocarcinoma invasiveness ranged from 86% to 96%. Conclusion Detection of a solid portion in the mediastinal window setting allows subsolid nodules to be classified as PS with excellent interreader agreement. If the solid portion is measurable, the specificity for adenocarcinoma invasiveness is high. © RSNA, 2017 Online supplemental material is available for this article.