Tumoral and non-tumoral trachea stenoses: evaluation with three-dimensional CT and virtual bronchoscopy

<p>Abstract</p> <p>Background</p> <p>We evaluated the ability of 3D-CT and virtual bronchoscopy to estimate trachea stenosis in comparison to conventional axial CT and fiberoptic bronchoscopy, with a view to assist thoracic surgeons in depicting the anatomical characteristics of tracheal strictures.</p> <p>Methods</p> <p>Spiral CT was performed in 16 patients with suspected tracheal stenoses and in 5 normal subjects. Tracheal stenoses due to an endoluminal neoplasm were detected in 13 patients, whilst post-intubation tracheal stricture was observed in the other 3 patients. Multiplanar reformatting (MPR), volume rendering techniques (VRT) and virtual endoscopy (VE) for trachea evaluation were applied and findings were compared to axial CT and fiberoptic bronchoscopy. The accuracy of the procedure in describing the localization and degree of stenosis was tested by two radiologists in a blinded controlled trial.</p> <p>Results</p> <p>The imaging modalities tested showed the same stenoses as the ones detected by flexible bronchoscopy and achieved accurate and non-invasive morphological characterization of the strictures, as well as additional information about the extraluminal extent of the disease. No statistically significant difference was observed between the bronchoscopic findings and the results of axial CT estimations (P = 1.0). No statistically significant differences were observed between bronchoscopic findings and the MPR, VRT and VE image evaluations (P = 0.705, 0.414 and 0.414 respectively).</p> <p>Conclusion</p> <p>CT and computed generated images may provide a high fidelity, noninvasive and reproducible evaluation of the trachea compared to bronchoscopy. They may play a role in assessment of airway patency distal to high-grade stenoses, and represent a reliable alternative method for patients not amenable to conventional bronchoscopy.</p

Ureteropelvic Junction Obstruction: An Innovative Approach Combining Metallic Approach Combining Metallic Stenting and Virtual Endoscopy

Purpose: We report our experience with auto-expandable metallic stents for treating ureteropelvic junction obstruction

Real-time tumor ablation simulation based on the dynamic mode decomposition method

The Dynamic Mode Decomposition (DMD) method is used to provide a reliable forecasting of tumor ablation treatment simulation in real time, which is quite needed in medical practice. To achieve this, an extended Pennes bioheat model must be employed, taking into account both the water evaporation phenomenon and the tissue damage during tumor ablation

Computational representation and hemodynamic characterization of in vivo acquired severe stenotic renal artery geometries using turbulence modeling

The present study reports on computational fluid dynamics in the case of severe renal artery stenosis (RAS). An anatomically realistic model of a renal artery was reconstructed from CT scans, and used to conduct CFD simulations of blood flow across RAS. The recently developed Shear Stress Transport turbulence model was pivotally applied in the simulation of blood flow in the region of interest. Blood flow was studied in vivo under the presence of RAS and subsequently in simulated cases before the development of RAS, and after endovascular stent implantation. The pressure gradients in the RAS case were many orders of magnitude larger than in the healthy case. The presence of RAS increased flow resistance, which led to considerably lower blood flow rates. A simulated stent in place of the RAS decreased the flow resistance at levels proportional to, and even lower than, the simulated healthy case without the RAS. The wall shear stresses, differential pressure profiles, and net forces exerted on the surface of the atherosclerotic plaque at peak pulse were shown to be of relevant high distinctiveness, so as to be considered potential indicators of hemodynamically significant RAS

CT angiography with three-dimensional techniques for the early diagnosis of intracranial aneurysms. Comparison with intra-arterial DSA and the surgical findings

Introduction: Cerebral CT angiography (CTA) is an established method applied to both the detection and treatment planning of intracranial aneurysms. The aim of our study was to compare CTA and digital subtraction angiography (DSA) findings with the surgical results mainly in patients with acute SAH and to evaluate the clinical usefulness of CTA. Materials and methods: During the last 2 years, 82 consecutive patients were admitted under clinical symptoms and signs suggestive of harboring an intracranial aneurysm. CT angiography performed immediately afterwards the plain CT, while DSA was performed within the first 48 h of admission. All aneurysms detected were confirmed during surgery or endovascular embolization. Repeat DSA was performed in all patients having both the initial CTA and the DSA 15 days after the onset of symptoms negative. CT angiograms and conventional angiographies were studied by a consensus of two radiologists for each technique, who performed aneurysm detection, morphological features characterization and evaluation of the technique. Results: Surgical or/and endovascular treatment was performed in 45 patients and 53 aneurysms were confirmed. Using 3D-CT angiography, we detected 47 aneurysms in 42 patients. Conventional angiography depicted 43 aneurysms in 39 patients. The sensitivity of CTA for the detection of all aneurysms versus surgery was 88.7%, the specificity 100%, the positive predictive value (PPV) 100%, the negative predictive value (NPV) 80.7% and the accuracy 92.3%. Accordingly, the sensitivity of DSA was 87.8%, the specificity 98%, the PPV 97.7%, the NPV 89.1% and the accuracy 92.9%. Considering aneurysms mm, CTA showed a sensitivity ranging from 93.3 to 100%, equal to that of DSA. Conclusion: Cerebral CT angiography has an equal sens..