Clinical feasibility of a fully automated 3D reconstruction of rotational coronary X-ray angiograms

Background— Although fixed view x-ray angiography remains the primary technique for anatomic imaging of coronary artery disease, the known shortcomings of 2D projection imaging may limit accurate 3D vessel and lesion definition and characterization. A recently developed method to create 3D images of the coronary arteries uses x-ray projection images acquired during a 180° C-arm rotation and continuous contrast injection followed by ECG-gated iterative reconstruction. This method shows promise for providing high-quality 3D reconstructions of the coronary arteries with no user interaction but requires clinical evaluation. Methods and Results— The reconstruction strategy was evaluated by comparing the reconstructed 3D volumetric images with the 2D angiographic projection images from the same 23 patients to ascertain overall image quality, lesion visibility, and a comparison of 3D quantitative coronary analysis with 2D quantitative coronary analysis. The majority of the resulting 3D volume images were rated as having high image quality (66%) and provided the physician with additional clinical information such as complete visualization of bifurcations and unobtainable views of the coronary tree. True-positive lesion detection rates were high (90 to 100%), whereas false-positive detection rates were low (0 to 8.1%). Finally, 3D quantitative coronary analysis showed significant similarity with 2D quantitative coronary analysis in terms of lumen diameters and provided vessel segment length free from the errors of foreshortening. Conclusions— Fully automated reconstruction of rotational coronary x-ray angiograms is feasible, produces 3D volumetric images that overcome some of the limitations of standard 2D angiography, and is ready for further implementation and study in the clinical environmen

Sarcopenia and major complications in patients undergoing oncologic colon surgery.

Sarcopenia is a surrogate marker for malnutrition and frailty, which has been linked to higher complication rates and prolonged length of stay (LOS) after surgery. The study aim was to assess the correlation between computed tomography (CT)-based sarcopenia and short-term clinical outcomes after oncologic colon surgery. This retrospective study included consecutive patients operated between May 2014 and December 2019. Three radiological indices of sarcopenia were measured at the level of the third lumbar vertebra on preoperative CT scans: skeletal muscle area (SMA), skeletal muscle index (SMI) (both markers of muscle quantity), and skeletal muscle radiation attenuation (SMRA) (marker of muscle quality). Patients with major complications (grade ≥ 3b according to the Clavien classification) were compared with those without. Statistical correlation between sarcopenia indices, LOS, and comprehensive complication index (CCI) was tested with the Pearson correlation coefficient. A total of 325 patients were included. Mean age was 67 years [standard deviation (SD) 14.3], mean body mass index was 26.0 kg/m <sup>2</sup> (SD 5.3), and 193 (59%) were male. Fifty patients (15.4%) had major complications, while 275 (84.6%) did not. Patients with major complications had more open surgery (52 vs. 21%, P < 0.01), intraoperative blood loss (257 vs. 102 mL, P = 0.035), and intraoperative complications (22 vs. 9%, P = 0.012). Patients with major complications had significantly increased CCI scores (53 vs. 6, P < 0.01), reoperations (74 vs. 0%, P < 0.01), and LOS (33 vs. 7, P < 0.01). SMA and SMI were comparable between both groups (126.0 vs. 125.2 cm <sup>2</sup> , P = 0.974, and 43.4 vs. 44.3 cm <sup>2</sup> /m <sup>2</sup> , P = 0.636, respectively), while SMRA was significantly lower in patients with major complications (33.6 vs. 37.3 HU, P = 0.018). A lower SMRA was correlated with prolonged LOS (r = -0.207, P < 0.01) and higher CCI (r = -0.144, P < 0.01), while the other sarcopenia indices had no influence on surgical outcomes. Muscle quality (SMRA) as a specific sarcopenia marker was lower in patients with major complications and seems to prevail over muscle quantity (SMA and SMI) in the prediction of adverse outcomes after oncologic colon surgery

Three-dimensional reconstruction of coronary stents in vivo based on motion compensated X-ray angiography

The complete expansion of the stent during a percutaneous transluminal coronary angioplasty (PTCA) procedure is essential for treatment of a stenotic segment of a coronary artery. Inadequate expansion of the stent is a major predisposing factor to in-stent restenosis and acute thrombosis. Stents are positioned and deployed by fluoroscopic guidance. Although the current generation of stents are made of materials with some degree of radio-opacity to detect their location after deployment, proper stent expansion is hard to asses. In this work, we introduce a new method for the three-dimensional (3D) reconstruction of the coronary stents in-vivo utilizing two-dimensional projection images acquired during rotational angiography (RA). The acquisition protocol consist of a propeller rotation of the X-ray C-arm system of 180°, which ensures sufficient angular coverage for volume reconstruction. The angiographic projections were acquired at 30 frames per second resulting in 180 projections during a 7 second rotational run. The motion of the stent is estimated from the automatically tracked 2D coordinates of the markers on the balloon catheter. This information is used within a motion-compensated reconstruction algorithm. Therefore, projections from different cardiac phases and motion states can be used, resulting in improved signal-to-noise ratio of the stent. Results of 3D reconstructed coronary stents in vivo, with high spatial resolution are presented. The proposed method allows for a comprehensive and unique quantitative 3D assessment of stent expansion that rivals current X-ray and intravascular ultrasound techniques

4D coronary artery reconstruction based on retrospectively gated rotational angiography: first in-human results

A method is proposed that allows for a fully automated computation of a series of high-resolution volumetric reconstructions of a patient's coronary arteries based on a single rotational acquisition. During the 7.2 second acquisition the coronary arteries are injected with contrast material while the imaging system rotates around the patient to obtain a series of X-ray projection images over an angular range of 180 degrees. Based on the simultaneously recorded ECG-signal the projection images corresponding to the same cardiac cycle can be utilized to reconstruct three-dimensional (3D) high-spatial-resolution angiograms of the coronary arteries in multiple (3D+t) cardiac phases within the cardiac cycle. The proposed acquisition protocol has been applied to 22 patients and the tomograpic reconstructions depicted the main arteries as well as the main bifurcations in multiple cardiac phases in all enrolled patients. For the first time, this feasibility study shows that a three-dimensional description of the coronary arteries can be obtained intraprocedurally in a conventional interventional suite by means of tomographic reconstruction from projection images without any user interaction