Quantification and Characterization of Pulmonary Emphysema in Multislice-CT

The new technology of the Multislice-CT provides volume data sets with approximately isotropic resolution, which permits a non invasive measurement of diffuse lung diseases like emphysema in the 3D space. The aim of our project is the development of a full automatic 3D CAD (Computer Aided Diagnosis) software tool for detection, quantification and characterization of emphysema in a thoracic CT data set. It should supply independently an analysis of an image data set to support the physician in clinical daily routine. In this paper we describe the developed 3D algorithms for the segmentation of the tracheo-bronchial tree, the lungs and the emphysema regions. We present different emphysema des…

A double-blind trial on prophylactic voriconazole (VRC) or placebo during induction chemotherapy for acute myelogenous leukaemia (AML).

Summary Objectives Invasive fungal infections remain a frequent cause of morbidity and mortality in long-term neutropenic patients. The availability of tolerable broad-spectrum antifungals like voriconazole stimulated the discussion about optimal timing of antifungal therapy. We conducted a trial to analyze the efficacy and safety of voriconazole in the prevention of lung infiltrates during induction chemotherapy for acute myelogenous leukaemia (AML). Methods This was a prospective, randomised, double-blind, placebo-controlled phase III trial in AML patients undergoing remission induction chemotherapy. Oral voriconazole 200mg twice daily or placebo was administered until detection of a lung…

Diagnosis of invasive fungal infections in hematology and oncology

Invasive fungal infections are a primary cause of morbidity and mortality in patients with hematological malignancies. Establishing a definite diagnosis of invasive fungal infection in febrile neutropenic patients is particularly challenging and time-consuming, but a delay of antifungal treatment leads to higher mortality. This situation has lead to the strategy of initiation "empirical" antifungal therapy prior to the detection of fungi. Meanwhile, improvements in diagnostic procedures are achieved, especially with imaging techniques and non-culture based methods which include antigen-based assays, metabolite detection and molecular detection of fungal DNA from body fluid samples using con…

Diagnosis and antimicrobial therapy of pulmonary infiltrates in febrile neutropenic patients

Patients with severe neutropenia lasting for more than 10 days, who develop fever and pulmonary infiltrates, are at high risk of treatment failure and infection-related death, under conventional broad-spectrum antibiotics. Early supplementation by a systemic antifungal therapy active against Aspergillus spp. has been shown to markedly improve their clinical outcome. Prognosis is significantly influenced by early identification of lung infiltrates by means of high-resolution thoracic computed tomography. Non-culture based diagnostic procedures using a highly sensitive Sandwich ELISA assay to detect circulating galactomannan, or PCR techniques to amplify circulating fungal DNA, may facilitate…

Spiral-CT zum Nachweis von Koronararterienverkalkungen und Vorhersage einer koronaren Herzerkrankung - Vergleich zur Durchleuchtung und Koronarangiographie

PURPOSE Evaluation of clinical relevance of coronary calcifications detected by helical CT. Evaluation of congruence with fluoroscopy (FS) and coronary angiography. Comparison with studies reporting on application of ultrafast computed tomography. MATERIALS AND METHODS 40 patients underwent helical CT (2 mm slice thickness, table-feed 3 mm/s). Coronary angiography and FS were performed in usual technique. Stenosis and calcifications were evaluated semiquantitatively. RESULTS 28 of 28 stenoses > or = 75% were detected via helical CT by evaluation of calcification (FS: 19). One non-detected solitary stenosis was calculated as 40%. FS did not detect 4 cases with 2-vessel and 3-vessel disease e…

Pulmonale Struktur und Funktion - Hochauflösende und dynamische Computertomographie bei Lungenemphysem und Erkrankungen der Atemwege -

Computed tomography (CT) is the method of choice for the morphological assessment of pulmonary structure. Airways. pulmonary parenchyma and their pathologies are shown with high spatial resolution. Airway diseases exhibit bronchial dilatation, wall thickening and an increased visibility in the lung periphery. CT is also the imaging gold standard for the detection and the characterisation of emphysema because a high degree of concordance with histopathological studies. Centrilobular, panlobular and paraseptal emphysema can be differentiated. CT can also provide functional information. Paired inspiratory and expiratory scans with or without spirometric triggering allow to evaluate obstruction…

Assessment of pulmonary hypertension by CT and MR imaging.

In the recent World Health Organization (WHO) classification the group of pulmonary arterial hypertension (PH) comprises the classic primary pulmonary hypertension and several conditions with definite or very high risk factors to develop pulmonary arterial hypertension. Therapeutic advances drive the need for a comprehensive pre-therapeutic evaluation for optimal treatment. Furthermore, follow-up examinations need to be performed to monitor changes in disease status and response to therapy. Up to now, the diagnostic imaging work-up of PH comprises mainly echocardiography, invasive right heart catheterization and ventilation/perfusion scintigraphy. Due to technical advances helical computed …

Dose Escalation of Caspofungin for Invasive Aspergillosis - A Phase II Trial

Abstract Abstract 2309 Objectives. Treatment of invasive aspergillosis (IA) fails in up to 50% of all cases and the mortality rate is at least 30%. Antifungal combination treatment has not been proven to be beneficial and dose escalation with liposomal amphotericin B did not improve outcome. New approaches are needed for patients with severe immunosuppression. Methods. Escalating high dosages of caspofungin were investigated in IA defined according to modified EORTC/MSG criteria. The tested cohort of patients received 70mg, 100mg, 150mg or 200mg QD, 8 patients each were to receive caspofungin first-line treatment for proven/probable IA for up to 28 days. Dose limiting toxicity was defined a…

Early detection of pneumonia in febrile neutropenic patients: use of thin-section CT.

The purpose of this study was to evaluate the usefulness of thin-section CT for early detection of pneumonia in neutropenic patients with an unknown site of infection and normal or nonspecific findings on chest radiographs.Eighty-seven patients with febrile neutropenia that persisted for more than 2 days despite empiric antibiotic treatment underwent 146 prospective examinations. If findings on chest radiographs were normal (n = 126) or nonspecific (n = 20), thin-section CT (1-mm collimation, 10-mm increment) was done. If thin-section CT scans showed opacities, bronchoalveolar lavage was recommended.Findings on chest radiographs were nonspecific for pneumonia in 20 (14%) of 146 cases, and C…

Value of contrast-enhanced MR angiography and helical CT angiography in chronic thromboembolic pulmonary hypertension.

The aim of this study was to evaluate the diagnostic value of contrast-enhanced MR angiography (ce MRA) and helical CT angiography (CTA) of the pulmonary arteries in the preoperative workup of patients with chronic thromboembolic pulmonary hypertension (CTEPH). The ce MRA and CTA studies of 32 patients were included in this retrospective evaluation. Image quality was scored by two independent blinded observers. Data sets were assessed for number of patent segmental, subsegmental arteries, and number of vascular segments with thrombotic wall thickening, intraluminal webs, and abnormal proximal to distal tapering. Image quality for MRA/CTA was scored excellent in 16 of 16, good in 11 of 14, m…

Gadodiamide and gadopentetate dimeglumine in MRI versus spiral CT in the diagnosis of liver lesions.

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Neue Entwicklungen in der MRT des Thorax

Wegen technischer und physikalischer Einschrankungen wurde die MRT bisher nur selten zur Darstellung der Lunge eingesetzt. Neue Entwicklungen haben allerdings die Moglichkeiten der anatomischen Darstellung mittels MRT erheblich verbessert und gleichzeitig neue Perspektiven fur funktionelle Darstellungen eroffnet. Dazu gehoren Techniken zur funktionellen Untersuchung der Perfusion (Kontrastmittel, MR-Angiographie) und der Ventilation der Lunge (inhalierte aerosolierte Kontrastmittel, Sauerstoff, hochpolarisierte Edelgase [He-3, Xe-129] und fluorinierte Gase [SF6]). Die Gleichmasigkeit der Ventilation, Bestimmung von Lungenvolumina, Grose der Luftraume, intrapulmonale Sauerstoffkonzentration,…

Hepatic Granuloma Due to Propionibacterium acnes in a Patient with Acute Myelogenous Leukemia

Hochauflösende Computertomographie der Lunge bei neutropenischen Patienten mit Fieber

Purpose To determine the sensitivity and clinical impact of high-resolution CT (HRCT) of the lung in febrile neutropenic patients under antibiotic therapy. Material and methods Chest X-ray and HRCT were prospectively performed to exclude pneumonia in 34 patients (53 examinations) suffering from febrile neutropenia following antitumor therapy. Diagnosis was confirmed by bronchoalveolar lavage or sputum cultures. Results Chest X-ray showed pneumonia in 13/53 examinations, in 12/13 a micro-organism was found. HRCT demonstrated pneumonia in 39/53, in 31/39 a micro-organism was found. All cases with positive cultures showed suspicious HRCT findings. Changes in antibiotic treatment resulted in fi…

Segmentation and virtual exploration of tracheobronchial trees

Abstract The tracheobronchial tree as part of the lung is part of one of the most important organs of the human body. Inhaled air is distributed to the alveolus where oxygen and carbon dioxide exchange between air and blood takes place. In this paper, we introduce the virtual endoscopy system VIVENDI to perform virtual inspections of tracheobronchial trees based on their segmentation and of the complementing blood vessels. It is based on a hybrid segmentation pipeline which enables the segmentation of vascular and tracheobronchial structures down to the seventh generation of the bronchi.

Measurements of alveolar pO2 using 19F-MRI in partial liquid ventilation.

Rationale and Objectives: Partial liquid ventilation using Perfluorcarbon (PFC) is an innovative treatment of acute respiratory distress syndrome. However, the underlying mechanisms are not totally clear. The aim was to investigate the distribution of oxygen partial pressure within the PFC-filled lung (ppO 2 ). Methods: Nine pigs underwent partial liquid ventilation, receiving 20 mL PFC/kg bodyweight (bw). Measurements were obtained by a chemical shift selective TurboFLASH sequence at different axial lung levels. ppO 2 was calculated from 1 9 F-MRI by nonlinear curve T 1 -fitting technique after noise correction. Results: Quantification and distribution of ppO 2 was performed successfully. …

About Objective 3-D Analysis of Airway Geometry in Computerized Tomography

The technology of multislice X-ray computed tomography (MSCT) provides volume data sets with approximately isotropic resolution, which permits a noninvasive 3-D measurement and quantification of airway geometry. In different diseases, like emphysema, chronic obstructive pulmonary disease (COPD), or cystic fribrosis, changes in lung parenchyma are associated with an increase in airway wall thickness. In this paper, we describe an objective measuring method of the airway geometry in the 3-D space. The limited spatial resolution of clinical CT scanners in comparison to thin structures like airway walls causes difficulties in the measurement of the density and the thickness of these structures.…

Computertomographische Funktionsuntersuchung der Lunge nach einseitiger Lungentransplantation mit axialer und koronarer Akquisition

After single-lung transplantation in a patient suffering from obstructive emphysema lung function parameters worsened during follow-up. To complement the routine high-resolution CT (HRCT) scans acquired in inspiration, additional scans were obtained to evaluate regional lung function. The comparison of HRCT scans acquired in inspiration and in expiration revealed different ventilation conditions of both lungs, continuous acquisition in a single slice (dynamic multiscan acquisition) in the axial and coronal plane demonstrated mediastinal shifting and the movement of the diaphragm during the whole breathing cycle. Both modalities can provide important information concerning regional differenc…

Comparison of magnetic resonance imaging of inhaled SF6 with respiratory gas analysis

Magnetic resonance imaging of inhaled fluorinated inert gases ((19)F-MRI) such as sulfur hexafluoride (SF(6)) allows for analysis of ventilated air spaces. In this study, the possibility of using this technique to image lung function was assessed. For this, (19)F-MRI of inhaled SF(6) was compared with respiratory gas analysis, which is a global but reliable measure of alveolar gas fraction. Five anesthetized pigs underwent multiple-breath wash-in procedures with a gas mixture of 70% SF(6) and 30% oxygen. Two-dimensional (19)F-MRI and end-expiratory gas fraction analysis were performed after 4 to 24 inhaled breaths. Signal intensity of (19)F-MRI and end-expiratory SF(6) fraction were evaluat…

Subsecond fluorine-19 MRI of the lung

Minimal scan times in rapid fluorine-19 MRI using sulfur hexafluoride (SF6) have been on the order of 10 s. Because of the very short T1 relaxation time of SF6 (T1 = 1.65 ms), high receiver bandwidths are necessary to allow for a high number of excitations. Since high bandwidths cause high levels of electronic noise, SNR per acquisition has been too low to further reduce scan time. The purpose of this study was to investigate whether scan times could be reduced using hexafluoroethane (C2F6), a gas with a longer T1 (T1 = 7.9 ms) at a relatively low bandwidth of 488 Hz/pixel. Gradient-echo images were acquired during and after completion of the wash-in of a 70% C2F6- 30% O2 mixture. Peak SNR …

Effects of bortezomib on pro-inflammatory cytokine levels and transfusion dependency in a patient with multicentric Castleman Disease

Assessment of lung microstructure with magnetic resonance imaging of hyperpolarized Helium-3

Magnetic resonance imaging of the apparent diffusion coefficient (ADC) of hyperpolarized Helium-3 is a new technique for probing pulmonary microstructure in vivo. The aim of this study was the assessment of potential sources of systematic errors of the ADC measurement. The influence of macroscopic motion was determined by measurements at two different delays after initiating the breath-hold, and before and after cardiac arrest. An intercentre comparison was performed in two age- and lung function-matched groups of lung-healthy volunteers at two research sites. Moreover, measurements of diffusion anisotropy were performed. We found no dependency of the ADC as a function of the delay after st…

3He MRI in healthy volunteers: preliminary correlation with smoking history and lung volumes

MRI with hyperpolarized helium-3 (3He) provides high-resolution imaging of ventilated airspaces. The first aim of this 3He-study was to compare observations of localized signal defects in healthy smokers and non-smokers. A second aim was to describe relationships between parameters of lung function, volume of inspired 3He and signal-to-noise ratio. With Ethics Committee approval and informed consent, 12 healthy volunteers (seven smokers and five non-smokers) were studied. Imaging was performed in a 1.5 T scanner using a two-dimensional FLASH sequence at 30V transmitter amplitude (TR/TE/α = 11 ms/4.2 ms/<10°). Known amounts of 3He were inhaled from a microprocessor-controlled delivery device…

Hybrid segmentation and virtual bronchoscopy based on CT images1

Rationale and objectives Introduction of combination of the segmentation tool SegoMeTex and the virtual endoscopy system VIVENDI to perform virtual endoscopic inspections of the human lung. This virtual bronchoscopy system enables visualization of the tracheobronchial tree down to seventh generation. Furthermore, the modified virtual system visualizes hidden structures such as segmented vascular system or tumors. Materials and methods The segmentation is based on image data acquired by a multislice computed tomography scanner. SegoMeTex is used to segment the tracheobronchial tree by a hybrid system with minimal user action. Similarly, the complementary pulmonary arterial can be segmented, …

3D-Segmentierung des menschlichen Tracheobronchialbaums aus CT-Bilddaten

Zur Erstellung eines mathematischen Lungenmodells zur Simulation individueller inhalativer Therapien ist die genaue Geometrie des menschlichen Tracheobronchialbaums notwendig. Diese wird durch eine intelligente 3D-Segmentierung aus CT-Datensatzen gewonnen. Der hybride Algorithmus wurde umfangreich auf unterschiedlichen Bildmaterialien manuell evaluiert.

Pneumonia in Febrile Neutropenic Patients and in Bone Marrow and Blood Stem-Cell Transplant Recipients: Use of High-Resolution Computed Tomography

PURPOSE: To obtain statistical data on the use of high-resolution computed tomography (HRCT) for early detection of pneumonia in febrile neutropenic patients with unknown focus of infection. MATERIALS AND METHODS: One hundred eighty-eight HRCT studies were performed prospectively in 112 neutropenic patients with fever of unknown origin persisting for more than 48 hours despite empiric antibiotic treatment. Fifty-four of these studies were performed in transplant recipients. All patients had normal chest roentgenograms. If pneumonia was detected by HRCT, guided bronchoalveolar lavage was recommended. Evidence of pneumonia on chest roentgenograms during follow-up and micro-organisms detected…

Adenovirus-mediated wild-type p53 gene transfer in patients receiving chemotherapy for advanced non-small-cell lung cancer: results of a multicenter phase II study.

PURPOSE: To study the additional benefit from adenoviral p53 gene therapy in patients undergoing first-line chemotherapy for advanced non–small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Twenty-five patients with nonresectable NSCLC were enrolled in an open-label, multicenter phase II study of three cycles of regimen A, carboplatin (area under the curve, 6; day 1) plus paclitaxel (175 mg/m2, day 1), or regimen B, cisplatin (100 mg/m2, day 1) plus vinorelbine (25 mg/m2, days 1, 8, 15, and 22) in combination with intratumoral injection of 7.5 × 1012 particles of SCH 58500 (rAd/p53, day 1). Responses of individual tumor lesions were assessed after each cycle, and gene transfer was examin…

Dynamic19F-MRI of pulmonary ventilation using sulfur hexafluoride (SF6) gas

A new method for dynamic imaging of pulmonary wash-in and wash-out kinetics of inhaled sulfur hexafluoride (SF6) gas was developed. Measurements at the fluorine-19 Larmor frequency were performed in pigs using a gradient echo pulse sequence with 0.5 ms echo time and a measurement time of 9.1 s per image. Dynamic MRI was performed during wash-in and wash-out of SF6 gas in mechanically ventilated porcine lungs. A postprocessing strategy was developed for quantitative determination of wash-out time constants in the presence of noise. Mean wash-out constants were 4.78 ± 0.48 breaths vs. 4.33 ± 0.76 breaths for left and right lung when ventilation was performed with low tidal volume, and 1.73 ± …

19F-MRI of perflubron for measurement of oxygen partial pressure in porcine lungs during partial liquid ventilation

A method for in vivo measurement of oxygen partial pressure (pO2) in porcine lungs during partial liquid ventilation (PLV) with perflubron (PFOB) was developed. A pulse sequence for high-resolution MRI of the distribution of PFOB in the lung after intratracheal administration was developed as well. Moreover, quantitative measurements of longitudinal relaxation time T(1) of (19)F resonances for assessment of regional pO2 are described. Due to the need to acquire data during a single expiratory breathhold, only low SNRs were achieved in vivo. Therefore, simulations were performed to investigate the influence of background noise on T(1) values calculated from data with low SNR. Based on these …

Ventilation-Perfusion Ratio in Perflubron During Partial Liquid Ventilation

BACKGROUND: Functional magnetic resonance imaging (fMRI) of fluorine-19 allows for the mapping of oxygen partial pressure within perfluorocarbons in the alveolar space (Pao(2)). Theoretically, fMRI-detected Pao(2) can be combined with the Fick principle approach, i.e., a mass balance of oxygen uptake by ventilation and delivery by perfusion, to quantify the ventilation-perfusion ratio (Va/Q) of a lung region: The mixed venous blood and the inspiratory oxygen fraction, which are equal for all lung regions, are measured. In addition, the local expiratory oxygen fraction and the end capillary oxygen content, both of which may differ between the lung regions, are calculated using the fMRI-detec…

Diffusion-weighted MRI of the lung with hyperpolarized helium-3: A study of reproducibility

Purpose To determine the reproducibility of several parameters of the ADC measurement by calculating the scan-to-scan intrasubject variability. Materials and Methods Measurements were performed using a gradient-echo sequence with a bipolar gradient for diffusion weighting (b = 3.89 sec/cm2). Five patients with pulmonary emphysema, and six healthy-lung volunteers were included in the study. Images were acquired after inspiration of 3He during a single inspiratory breath-hold. To assess the reproducibility, the measurement was performed twice (time between measurements = 20 minutes) without repositioning the subjects. Analysis was performed on the basis of region-of-interest (ROI) analysis an…

Analyse von Bronchien in der Multislice-CT

Es wird eine Methode zum objektiven Bestimmen der Wanddicke und des Gesamt durchmessers von Bronchien in der 3-dimensionalen Computertomographie vorgestellt. Die Methode wurde erfolgreich an Phantomen evaluiert. Erste Studien sowohl an tierischen als auch an menschlichen Bronchien verliefen erfolgversprechend.