Max Schoebinger

Evaluation of Lung Volumetry Using Dynamic Three-dimensional Magnetic Resonance Imaging

Rationale and Objectives:We sought to investigate lung volume and surface measurements during the breathing cycle using dynamic three-dimensional magnetic resonance imaging (3D MRI). Materials and Methods:Breathing cycles of 20 healthy volunteers were examined using a 2D trueFISP sequence (3 images/second) in combination with a model and segmented 3D FLASH sequence (1 image/second) MR images using view sharing. Segmentation was performed semiautomatically using an interactive region growing technique. Vital capacity (VC) was calculated from MRI using the model (2D) and counting the voxels (3D) and was compared with spirometry. Results:VC from spirometry was 4.9 ± 0.9 L, 4.4 ± 1.2 L from 2D MRI measurement, and 4.7 ± 0.9 L for 3D MRI. Using the 3D technique, correlation to spirometry was higher than using the 2D technique (r > 0.95 vs. r > 0.83). Using the 3D technique, split lung volumes and lung surface could be calculated. There was a significant difference between the left and right lung volume in expiration (P < 0.05). Conclusions:Dynamic 3D MRI is a noninvasive tool to evaluate split lung volumes and lung surfaces during the breathing cycle with a high correlation to spirometry.

Three-dimensional visualisation improves understanding of surgical liver anatomy

Medical Education 2010: 44: 936–940

teaching with cognition: Three‐dimensional visualisation improves understanding of surgical liver anatomy

Medical Education 2010: 44: 936–940

Monitoring of lung motion in patients with malignant pleural mesothelioma using two-dimensional and three-dimensional dynamic magnetic resonance imaging : Comparison with spirometry

Purpose:To monitor lung motion in patients with malignant pleural mesothelioma (MPM) before and after chemotherapy (CHT) using 2-dimensional (2D) and 3-dimensional (3D) dynamic MRI (dMRI) in comparison with spirometry. Methods and Materials:Twenty-two patients with MPM were examined before CHT, as well as after 3 and 6 CHT cycles (3 months and 6 months) using 2D dMRI (trueFISP; 3 images/s) and 3D dMRI (FLASH 3D, 1 slab (52 slices)/s) using parallel imaging in combination with view-sharing technique. Maximum craniocaudal lung dimensions (2D) and lung volumes (3D) were monitored, separated into the tumor-bearing and nontumor-bearing hemithorax. Vital capacity (VC) was measured for comparison using spirometry. Results:Using 2D technique, there was a significant difference between the tumor-bearing and the nontumor-bearing hemithorax before CHT (P < 0.01) and after 3 CHT cycles (P < 0.05), whereas difference was not significant in the second control. In the tumor-bearing hemithorax, mobility increased significantly from the status before versus after 3 CHT cycles (4.1 ± 1.1 cm vs. 4.8 ± 1.4 cm, P < 0.05). Using 3D technique, at maximum inspiration, the volume of the tumor-bearing hemithorax was 0.6 ± 0.4 L and of the nontumor-bearing hemithorax 1.25 ± 0.4 L before CHT. In the follow-up exams, these volumes changed to 1.05 ± 0.4 L (P < 0.05) and 1.4 ± 0.5 L, respectively. Using spirometry, there was no significant change in VC (1.9 ± 0.4 L vs. 2.2 ± 0.7 L vs. 2.2 ± 0.9 L). Conclusion:dMRI is capable of monitoring changes in lung motion and volumetry in patients with MPM not detected by global spirometry. Thus, dMRI is proposed for use as a further measure of therapy response.

Estimation of Pulmonary Motion in Healthy Subjects and Patients with Intrathoracic Tumors Using 3D-Dynamic MRI: Initial Results

Objective To estimate a new technique for quantifying regional lung motion using 3D-MRI in healthy volunteers and to apply the technique in patients with intra- or extrapulmonary tumors. Materials and Methods Intraparenchymal lung motion during a whole breathing cycle was quantified in 30 healthy volunteers using 3D-dynamic MRI (FLASH [fast low angle shot] 3D, TRICKS [time-resolved interpolated contrast kinetics]). Qualitative and quantitative vector color maps and cumulative histograms were performed using an introduced semiautomatic algorithm. An analysis of lung motion was performed and correlated with an established 2D-MRI technique for verification. As a proof of concept, the technique was applied in five patients with non-small cell lung cancer (NSCLC) and 5 patients with malignant pleural mesothelioma (MPM). Results The correlation between intraparenchymal lung motion of the basal lung parts and the 2D-MRI technique was significant (r = 0.89, p < 0.05). Also, the vector color maps quantitatively illustrated regional lung motion in all healthy volunteers. No differences were observed between both hemithoraces, which was verified by cumulative histograms. The patients with NSCLC showed a local lack of lung motion in the area of the tumor. In the patients with MPM, there was global diminished motion of the tumor bearing hemithorax, which improved siginificantly after chemotherapy (CHT) (assessed by the 2D- and 3D-techniques) (p < 0.01). Using global spirometry, an improvement could also be shown (vital capacity 2.9 ± 0.5 versus 3.4 L ± 0.6, FEV1 0.9 ± 0.2 versus 1.4 ± 0.2 L) after CHT, but this improvement was not significant. Conclusion A 3D-dynamic MRI is able to quantify intraparenchymal lung motion. Local and global parenchymal pathologies can be precisely located and might be a new tool used to quantify even slight changes in lung motion (e.g. in therapy monitoring, follow-up studies or even benign lung diseases).

Does preoperative analysis of intrahepatic venous anastomoses improve the surgeon's intraoperative decision making? Pilot data from a case report

BackgroundThree-dimensional (3D) visualization is thought to improve the anatomical understanding of clinicians, thus improving patient safety.Case presentationA 58-year-old male was admitted to our hospital in April 2007 with a suspected metastasis of a sigmoid cancer in the Couinaud segment (CS) 7. The anatomical situation of this patient was analyzed using both a CT scan and 3D images. The initial CT scan revealed that the proximal part of the middle hepatic vein was completely missing and the metastasis in the CS 7 was closely attached to the right hepatic vein. After analyzing additional 3D images, it became clear that due to the close proximity of metastasis and right hepatic vein, the resection of the right hepatic vein was inevitable. Based on this 3D analysis, it was decided to perform a right-sided hemihepatectomy. In this case report, 3D visualization resulted in a faster and clearer understanding of the unique anatomical situation in a patient with complicated liver anatomy than transversal CT images.ConclusionThe here presented data shows for the first time 3D visualization of intravenous anastomoses in the human liver. The information offered by 3D visualization is not redundant but rather serves as a true source of additional information, indicating the potential benefit of 3D visualization in surgical operation planning.

An unusual cause of peripheral artery embolism: floating thrombus of the thoracic aorta surgically removed.

Intraluminal mobile thrombus of the descending aorta are rare disorders. They are at high risk for peripheral embolism and therefore indication for treatment is mandatory. We report on a 54-year-old patient with peripheral arterial embolization who was treated by surgical thrombus removement by thoracotomy and staged peripheral bypass grafting. New diagnostic tools are presented, therapy and prognosis are discussed.

Vena cava leiomyosarcoma: Preoperative planning with complex vessel reconstruction using 3D surface rendering algorithms

(MD-CT) revealed a 5.0 4.0 2.7 cm tumor of soft tissue density, heterogeneous contrast medium enhancement derivation from the infrarenal vena cava and infiltrating the surrounding tissue. Panel A shows contrast-enhanced CT in the axial (a) and coronal (b) reconstructed view demonstrating an abdominal mass (arrow). A primary leiomyosarcoma of the vena cava inferior was assumed. Staging using CT thorax and bone scintigraphy presented no evidence of metastatic spread. Phlebography of the vena cava inferior confirmed an obstruction of lumen (Panel B, arrow) with prominent lumbar veins for collateral venous blood flow via azygos and hemiazygos veins. For surgical planning, multiphasic magnetic resonance angiography (CE-MRA) (Panel C, arrow) was performed to evaluate the degree of vascular involvement (local tumor infiltration and renal vessel involvement), but tumor involvement of renal venous vasculature was still uncertain. Therefore, computer-assisted surgical planning using the three-dimensional (3D) surface rendering technique was performed based on multiphasic CE-MRA raw data (Panel D). The virtual imaging techniques allowed an intra-luminal view and revealed left and right renal veins without direct tumor involvement (Panel D). Results of computer-assisted planning are as follows: vena cava (blue) and tumor (hatched) (Panel D, left) have been Vascular Medicine 2005; 10: 55–57

Cervical Origin of the Subclavian Artery: Imaging of a Rare but Clinically Relevant Anomaly

A 4-year-old boy was referred to our hospital for further treatment of pulmonary atresia (Fallot type), multiple systemic to pulmonary collateral arteries, and hypoplastic central pulmonary arteries. Echocardiography revealed cervical origin of the right subclavian artery, which originated close to the bifurcation of the internal and external carotid arteries (Figure 1, Movie I, and Movie II). The anomaly of the subclavian artery was confirmed with cardiac catheterization (Figure 2A, Movie III). In addition, the boy had dysmorphic features of conotruncal anomaly facies syndrome, and monosomy 22q11 was confirmed by cytogenetic testing. To improve antegrade perfusion of the …A 4-year-old boy was referred to our hospital for further treatment of pulmonary atresia (Fallot type), multiple systemic to pulmonary collateral arteries, and hypoplastic central pulmonary arteries. Echocardiography revealed cervical origin of the right subclavian artery, which originated close to the bifurcation of the internal and external carotid arteries (Figure 1, Movie I, and Movie II). The anomaly of the subclavian artery was confirmed with cardiac catheterization (Figure 2A, Movie III). In addition, the boy had dysmorphic features of conotruncal anomaly facies syndrome, and monosomy 22q11 was confirmed by cytogenetic testing. To improve antegrade perfusion of the …

Coronary CT Angiography–derived Fractional Flow Reserve: Machine Learning Algorithm versus Computational Fluid Dynamics Modeling

Purpose To compare two technical approaches for determination of coronary computed tomography (CT) angiography-derived fractional flow reserve (FFR)-FFR derived from coronary CT angiography based on computational fluid dynamics (hereafter, FFRCFD) and FFR derived from coronary CT angiography based on machine learning algorithm (hereafter, FFRML)-against coronary CT angiography and quantitative coronary angiography (QCA). Materials and Methods A total of 85 patients (mean age, 62 years ± 11 [standard deviation]; 62% men) who had undergone coronary CT angiography followed by invasive FFR were included in this single-center retrospective study. FFR values were derived on-site from coronary CT angiography data sets by using both FFRCFD and FFRML. The performance of both techniques for detecting lesion-specific ischemia was compared against visual stenosis grading at coronary CT angiography, QCA, and invasive FFR as the reference standard. Results On a per-lesion and per-patient level, FFRML showed a sensitivity of 79% and 90% and a specificity of 94% and 95%, respectively, for detecting lesion-specific ischemia. Meanwhile, FFRCFD resulted in a sensitivity of 79% and 89% and a specificity of 93% and 93%, respectively, on a per-lesion and per-patient basis (P = .86 and P = .92). On a per-lesion level, the area under the receiver operating characteristics curve (AUC) of 0.89 for FFRML and 0.89 for FFRCFD showed significantly higher discriminatory power for detecting lesion-specific ischemia compared with that of coronary CT angiography (AUC, 0.61) and QCA (AUC, 0.69) (all P < .0001). Also, on a per-patient level, FFRML (AUC, 0.91) and FFRCFD (AUC, 0.91) performed significantly better than did coronary CT angiography (AUC, 0.65) and QCA (AUC, 0.68) (all P < .0001). Processing time for FFRML was significantly shorter compared with that of FFRCFD (40.5 minutes ± 6.3 vs 43.4 minutes ± 7.1; P = .042). Conclusion The FFRML algorithm performs equally in detecting lesion-specific ischemia when compared with the FFRCFD approach. Both methods outperform accuracy of coronary CT angiography and QCA in the detection of flow-limiting stenosis.