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  • Germany  (17)
  • 11
    Keywords: Germany ; LUNG ; PERFUSION ; CT ; DIAGNOSIS ; IMAGES ; VISUALIZATION ; DISEASE ; DIFFERENTIATION ; RESOLUTION ; TIME ; PATIENT ; MR ; MRI ; MAGNETIC-RESONANCE ; arteries ; EMBOLISM ; MR-ANGIOGRAPHY ; magnetic resonance angiography ; pathology ; ANGIOGRAPHY ; HYPERTENSION ; contrast media ; MANAGEMENT ; PULMONARY ; PH ; ARTERIAL-HYPERTENSION ; ARTERIAL ; LEVEL ; IMAGE QUALITY ; CONSENSUS ; PULMONARY-ARTERIES ; TEMPORAL RESOLUTION ; HIGH-SPATIAL-RESOLUTION ; CTEPH ; IPAH
    Abstract: Differentiation between different forms of pulmonary hypertension (PH) is essential for correct disease management. The goal of this study was to elucidate the clinical impact of high spatial resolution MR angiography (SR-MRA) and time-resolved MRA (TR-MRA) to differentiate between patients with chronic thromboembolic PH (CTEPH) and idiopathic pulmonary arterial hypertension (IPAH). Ten PH patients and five volunteers were examined. Twenty TR-MRA data sets (TA 1.5 s) and SR-MRA (TA 23 s) were acquired. TR-MRA data sets were subtracted as angiography and perfusion images. Evaluation comprised analysis of vascular pathologies on a segmental basis, detection of perfusion defects, and bronchial arteries by two readers in consensus. Technical evaluation comprised evaluation of image quality, signal-to-noise ratio (SNR) measurements, and contrast-media passage time. Visualization of the pulmonary arteries was possible down to a subsegmental (SR-MRA) and to a segmental (TR-MRA) level. SR-MRA outperformed TR-MRA in direct visualization of intravascular changes. Patients with IPAH predominantly showed tortuous pulmonary arteries while in CTEPH wall irregularities and abnormal proximal-to-distal tapering was found. Perfusion images showed a diffuse pattern in IPAH and focal defects in CTEPH. TR-MRA and SR-MRA resulted in the same final diagnosis. Both MRA techniques allowed for differentiation between IPAH and CTEPH. Therefore, TR-MRA can be used in the clinical setting, especially in dyspneic patients
    Type of Publication: Journal article published
    PubMed ID: 16041529
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  • 12
    Keywords: BLOOD ; Germany ; LUNG ; SPIRAL CT ; VOLUME ; DISEASE ; POPULATION ; HEART ; TIME ; PATIENT ; BLOOD-FLOW ; blood flow ; FLOW ; MRI ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; AGE ; arteries ; PARAMETERS ; HYPERTENSION ; HEALTHY ; PULMONARY ; VELOCITY ; fibrosis ; PH ; HEALTHY-VOLUNTEERS ; CHRONIC THROMBOEMBOLISM ; CYSTIC-FIBROSIS ; ARTERIAL ; PULMONARY-ARTERIES ; early development ; bronchosystemic shunt ; cystic fibrosis
    Abstract: Cystic fibrosis (CF) leads to disabling lung disease and pulmonary hypertension (PH). The goal of this study was to assess the hemodynamics in the systemic and pulmonary arterial circulation of patients with CF using MRI. Ten patients with CF and 15 healthy volunteers were examined (1.5-T MRI). Phase-contrast flow measurements were assessed in the ascending aorta, pulmonary trunc, and the left and right pulmonary arteries (PA), resulting in the following parameters: peak velocity (PV) (centimeters per second) velocity rise gradient (VRG), time to PV (milliseconds), and the average area (centimeters squared). The blood flow ratio between the right and left lungs and the bronchosystemic shunt were calculated. For the ascending aorta and pulmonary trunc no parameter was significantly different between both populations. In the right PA a significantly lower PV (p=0.001) and VRG (p=0.02) was found. In the left PA there was a significantly (p=0.007) lower PV but no significant (p=0.07) difference between the VRG. The areas of the right (p=0.08) and left (p=0.5) PA were not significantly enlarged. For the volunteers a linear increase of PV in both PA was found with age, while it decreased in patients with CF. The blood flow distribution (right/left lung) showed no significant (p=0.7) difference between the groups. There was a significantly (p 〈 0.001) higher bronchosystemic shunt volume in patients with CF (1.3 l/min) than in volunteers (0.1 l/min). Magnetic resonance based flow measurements in the right and left PA showed first indications for early development of PH. The significant increase in bronchosystemic shunt volume might be indicative fo the extent of parenchymal changes
    Type of Publication: Journal article published
    PubMed ID: 15761712
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  • 13
    Keywords: COMBINATION ; Germany ; LUNG ; MODEL ; PERFUSION ; EMPHYSEMA ; IMAGES ; imaging ; TOOL ; VOLUME ; DISEASE ; MRI ; CYCLE ; SEQUENCE ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; REGION ; COMPUTED-TOMOGRAPHY ; MOTION ; HEALTHY ; RE ; HEALTHY-VOLUNTEERS ; CHEST-WALL ; PULMONARY-FUNCTION TESTS ; HUMAN DIAPHRAGM SHAPE ; breathing cycle ; HEALTHY-SUBJECTS ; lung motion ; SPIROMETRY ; view sharing ; volumetry ; dynamic 3D MRI ; respiration
    Abstract: 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
    Type of Publication: Journal article published
    PubMed ID: 15714092
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  • 14
    Keywords: Germany ; DISEASE ; PATIENT ; MRI ; CYCLE ; MOBILITY ; REPRODUCIBILITY ; FUNCTION TESTS ; THIN-SECTION CT ; MOTION ; HYPERTENSION ; dynamic MRI ; BREATH-HOLD ; DIAPHRAGM ; LEVEL ; INTERVAL ; INTRATHORACIC TUMOR ; healthy subjects ; LUNG-VOLUME ; primary pulmonary hypertension
    Abstract: To assess the stability and reproducibility of different breath-hold levels in healthy volunteers and patients using dynamic MRI (dMRI). In ten healthy volunteers and ten patients with pulmonary hypertension (PH) and normal lung function craniocaudal intrathoracic distances (CCD) were measured during inspiratory and expiratory breath-hold (15 s) (in healthy volunteers additionally at a self-chosen mid-inspiratory breath-hold) using dMRI (trueFISP, three images/s). To evaluate stability and intraobserver reproducibility of the different breath-hold levels, CCDs, time-distance curves, confidence intervals (CIs), Mann-Witney U test and regression equations were calculated. In healthy volunteers there was a substantial decrease of the CCD during the inspiratory breath-hold in contrast to the expiratory breath-hold. The CI at inspiration was 2.84 +/- 1.28 in the right and 2.1 +/- 0.68 in the left hemithorax. At expiration the CI was 2.54 +/- 1.18 and 2.8 +/- 1.48. Patients were significantly less able to hold their breath at inspiration than controls (P 〈 0.05). In patients CI was 4.53 +/- 4.06 and 3.46 +/- 2.21 at inspiration and 4.45 +/- 4.23 and 4.76 +/- 3.73 at expiration. Intraobserver variability showed no significant differences either in patients or in healthy subjects. Reproducibility was significantly lower at a self-chosen breath-hold level of the healthy volunteers. DMRI is able to differentiate stability and reproducibility of different breath-hold levels. Expiratory breath-hold proved to be more stable than inspiratory breath-hold in healthy volunteers and patients
    Type of Publication: Journal article published
    PubMed ID: 15968516
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  • 15
    Keywords: Germany ; LUNG ; chest ; CT ; FOLLOW-UP ; imaging ; INFORMATION ; SYSTEM ; TOOL ; DEATH ; POPULATION ; computed tomography ; RESOLUTION ; PATIENT ; IMPACT ; CONTRAST ; MRI ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; COMPUTED-TOMOGRAPHY ; CHILDREN ; LUNG PERFUSION ; ADULTS ; PHASE ; cystic fibrosis
    Abstract: Cystic fibrosis (CF) is the most frequent inherited disorder leading to premature death in the Caucasian population. As life expectancy is limited by pulmonary complications, repeated imaging [chest X-ray, multislice high-resolution computed tomography (MS-HRCT)] is required in the follow-up. Magnetic resonance imaging (MRI) of the lung parenchyma is a promising new diagnostic tool. Its value for imaging lung changes caused by CF compared with CT is demonstrated. MRI performs well when compared with CT, which serves as the gold standard. Its lack in spatial resolution is obvious, but advantages in contrast and functional assessment compensate for this limitation. Thus, MRI is a reasonable alternative for imaging the CF lung and should be introduced as a radiation-free modality for follow-up studies in CF patients. For further evaluation of the impact of MRI, systematic studies comparing MRI and conventional imaging modalities are necessary. Furthermore, the value of the additional functional MRI (fMRI) information has to be studied, and a scoring system for the morphological and functional aspect of MRI has to be established
    Type of Publication: Journal article published
    PubMed ID: 16941092
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  • 16
    Keywords: evaluation ; Germany ; LUNG ; chest ; CT ; FOLLOW-UP ; imaging ; DISEASE ; EXPOSURE ; computed tomography ; NUCLEAR-MEDICINE ; radiation ; PATIENT ; MRI ; magnetic resonance ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; AGE ; DAMAGE ; tomography ; COMPUTED-TOMOGRAPHY ; CHILDREN ; nuclear medicine ; COMPLICATIONS ; LUNG PERFUSION ; radiology ; ADULTS ; LIFE ; CHEST-X-RAY ; CYSTIC-FIBROSIS ; RADIATION-EXPOSURE ; methods ; NUCLEAR ; USA ; correlation ; cystic fibrosis ; female ; Male ; MEDICINE ; multidetector computed tomography ; - ; comparison ; RESONANCE ; MDCT ; chest x-ray ; cystic fibrosis (CF) ; morphologic MRI ; RADIOGRAPH ; SCORING SYSTEMS
    Abstract: Objectives: As pulmonary complications are life limiting in patients with cystic fibrosis (CF), repeated chest imaging [chest x-ray, computed tomography (CT)] is needed for follow up. With the continuously rising life expectancy of CF patients, magnetic resonance imaging (MRI) as a radiation-free imaging modality might become more and more attractive. The goal of this study was to prospectively assess the value of MRI for evaluation of morphologic pulmonary CF-changes in comparison to established imaging modalities. Materials and Methods: Thirty-one CF patients (19 female, 12 male; mean age 16.7 years) with stable lung disease were examined by MRI: HASTE, coronal/transversal (TR/TE/alpha/TA: infinite/28 ms/180 degrees/18 s), multi-detector computed tomography (MDCT) (30 patients): 120 kV, dose modulated mAs, and chest x-ray (21 patients). Image evaluation: random order, 4 chest radiologists in consensus; chest x-ray: modified Chrispin-Norman score; CT and MRI: modified Helbich score. The maximal attainable score for chest x-ray was 34, for MRI and CT 25. Median scores, Pearson correlation coefficients, Bland-Altman plots, and concordance of MRI to CT on a lobar and segmental basis were calculated. Results: The median MRI and MDCT scores were 13 (min 3, max 20) respectively 13.5 (min 0, max 20). The median chest x-ray score was 14 (min 5, max 32). Pearson correlation coefficients: MRI/CT = 0.80, P 〈 0.0001; MRI/chest x-ray = 0.63, P 〈 0.0018; chest x-ray/CT = 0.75, P 〈 0.0001. The median lobe related concordance was 80% for bronchiectasis, 77% for mucus plugging, 93%, for sacculation/abscesses, and 100% for collapse/consolidation. Conclusions: Morphologic MRI of the lung in CF patients demonstrates comparable results to MDCT and chest x-ray. Because radiation exposure is an issue in CF patients, MRI might have the ability to be used as an appropriate alternative method for pulmonary imaging
    Type of Publication: Journal article published
    PubMed ID: 17984769
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  • 17
    Keywords: SPECTRA ; Germany ; LUNG ; PERFUSION ; chest ; imaging ; DISEASE ; DISEASES ; DISTINCT ; RESOLUTION ; NUCLEAR-MEDICINE ; TIME ; MECHANISM ; CONTRAST ; LYMPH-NODES ; MR ; MRI ; SEQUENCE ; SEQUENCES ; SUSCEPTIBILITY ; magnetic resonance ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; ECHO ; LESIONS ; EXPERIENCE ; arteries ; MORPHOLOGY ; EMBOLISM ; sensitivity ; MOTION ; MR-ANGIOGRAPHY ; pathology ; ANGIOGRAPHY ; MR angiography ; nuclear medicine ; MR imaging ; LUNG PERFUSION ; pulmonary embolism ; radiology ; SINGLE ; IMPAIRMENT ; analysis ; NUCLEAR ; technique ; parallel imaging ; TEMPORAL RESOLUTION ; function ; LYMPH-NODE ; SPECTRUM ; PULMONARY-HYPERTENSION ; perfusion scintigraphy ; MEDICINE ; HOLD ; RESONANCE ; PRECESSION ; STEADY-STATE ; DYSFUNCTION ; CONTRAST-MEDIA ; PRIMARY MEDIASTINAL TUMORS
    Abstract: Magnetic resonance imaging (MRI) is capable of imaging infiltrative lung diseases as well as solid lung pathologies with high sensitivity. The broad use of lung MRI was limited by the long study time as well as its sensitivity to motion and susceptibility artifacts. These disadvantages were overcome by the utilisation of new techniques such as parallel imaging. This article aims to propose a standard MR imaging protocol at 1.5 T and presents a spectrum of indications. The standard protocol comprises non-contrast-enhanced sequences. Following a GRE localizer (2D-FLASH), a coronal T2w single-shot half-Fourier TSE (HASTE) sequence with a high sensitivity for infiltrates and a transversal T1w 3D-GRE (VIBE) sequence with a high sensitivity for small lesions are acquired in a single breath hold. Afterwards, a coronal steady-state free precession sequence (TrueFISP) in free breathing is obtained. This sequence has a high sensitivity for central pulmonary embolism. Distinct cardiac dysfunctions as well as an impairment of the breathing mechanism are visible. The last step of the basic protocol is a transversal T2w-STIR (T2-TIRM) in a multi-breath holds technique to visualize enlarged lymph nodes as well as skeletal lesions. The in-room time is approximately 15 min. The extended protocol comprises contrast-enhanced sequences (3D-GRE sequence (VIBE) after contrast media; about five additional minutes). Indications are tumorous lesions, unclear (malignant) pleural effusions and inflammatory diseases (vaskulitis). A perfusion analysis can be achieved using a 3D-GRE in shared echo-technique (TREAT) with a high temporal resolution. This protocol can be completed using a MR-angiography (3D-FLASH) with high spatial resolution. The in-room time for the complete protocol is approximately 30 min. (c) 2007 Elsevier Ireland Ltd. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 17900843
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