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  • MAGNETIC-RESONANCE  (13)
  • 1
    Keywords: BLOOD ; Germany ; LUNG ; PERFUSION ; imaging ; QUANTIFICATION ; VOLUME ; TIME ; BLOOD-FLOW ; blood flow ; FLOW ; HIGH-RESOLUTION MEASUREMENT ; MRI ; TRACER BOLUS PASSAGES ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; AGE ; PARAMETERS ; SCINTIGRAPHY ; CONTRAST-ENHANCED MRI ; magnetic resonance imaging (MRI) ; QUANTITATIVE-ANALYSIS ; HEALTHY ; LUNG PERFUSION ; TRANSIT-TIME ; HEALTHY-VOLUNTEERS ; ARTERIAL ; INFLATION ; contrast-enhanced
    Abstract: Rationale and Objectives: The effect of breathholding on pulmonary perfusion remains largely unknown. The aim of this study was to assess the effect of inspiratory and expiratory breathhold on pulmonary perfusion using quantitative pulmonary perfusion magnetic resonance imaging (MRI). Methods and Results: Nine healthy volunteers (median age, 28 years; range, 20-45 years) were examined with contrast-enhanced time-resolved 3-dimensional pulmonary perfusion MRI (FLASH 313, TR/TE: 1.9/0.8 ms; flip angle: 40degrees; GRAPPA) during end-inspiratory and expiratory breathholds. The perfusion parameters pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time (MTT) were calculated using the indicator dilution theory. As a reference method, end-inspiratory and expiratory phase-contrast (PC) MRI of the pulmonary arterial blood flow (PABF) was performed. Results: There was a statistically significant increase of the PBF (Delta = 182 mL/100mL/min), PBV (Delta = 12 mL/100 mL), and PABF (Delta = 0.5 L/min) between inspiratory and expiratory breathhold measurements (P 〈 0.0001). Also, the MTT was significantly shorter (Delta = -0.5 sec) at expiratory breathhold (P = 0.03). Inspiratory PBF and PBV showed a moderate correlation (r = 0.72 and 0.61, P less than or equal to0.008) with inspiratory PABF. Conclusion: Pulmonary perfusion during breathhold depends on the inspiratory level. Higher perfusion is observed at expiratory breathhold
    Type of Publication: Journal article published
    PubMed ID: 15654250
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  • 2
    Keywords: Germany ; LUNG ; imaging ; SYSTEM ; SYSTEMS ; VOLUME ; SAMPLE ; COMPONENTS ; ACCURACY ; MR ; magnetic resonance ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; DIFFERENCE ; AGE ; COMPONENT ; PARAMETERS ; COMPUTED-TOMOGRAPHY ; BODY ; MR imaging ; dynamic magnetic resonance imaging ; BODIES ; CAPACITY ; OBSTRUCTION ; PULMONARY-FUNCTION TESTS ; development ; DIAPHRAGM ; HEALTHY-SUBJECTS ; CYSTIC-FIBROSIS ; SPIROMETRY ; INTERVAL ; analysis ; function ; LUNG-VOLUME ; female ; Male ; AGREEMENT ; RESONANCE ; body posture ; lung function tests ; magnetic resonance-compatible-spirometry ; nonsmokers ; pulmonary mechanics
    Abstract: The aim of this study was to assess the feasibility and accuracy of a novel magnetic resonance-compatible (MRc)-spirometer. The influence of body posture, magnetic resonance (MR)-setting and image acquisition on lung function was evaluated. Dynamic MR imaging (dMRI) was compared with simultaneously measured lung function. The development of the MRc-spirometer was based on a commercial spirometer and evaluated by flow-generator measurements and forced expiratory manoeuvres in 34 healthy nonsmokers (17 females and 17 males, mean age 32.9 yrs). Mean differences between forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were calculated and a sample paired t-test and Bland-Altman plots were generated. A total of I I subjects underwent different subsequent MRc-spirometric measurements to assess the influence of the components of the MR system on lung function. The mean (95% confidence interval) difference of FEV1 and FVC between the two systems was 0.004 (-0.04-0.04) L and 0.018 (-0.05-0.09) L, respectively. In the subgroup analysis, an influence of the MR-system on FEV1 was found. FEV1 correlated well with the dMRI measurement of the apico-diaphragmatic distance-change after the first second of forced expiration (r=0.72). In conclusion, magnetic resonance-compatible-spirometry is feasible, reliable and safe. The magnetic resonance-setting only has a small influence on simultaneously measured forced expiratory volume in one second. Dynamic magnetic resonance imaging measurements correlate well with simultaneously acquired lung function parameters
    Type of Publication: Journal article published
    PubMed ID: 17715166
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  • 3
    Keywords: LUNG ; PERFUSION ; imaging ; SYSTEM ; SYSTEMS ; VENTILATION ; NUCLEAR-MEDICINE ; TIME ; AIR ; MRI ; SIGNAL ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; DIFFERENCE ; NUMBER ; AGE ; WOMEN ; MEN ; DELIVERY ; motion correction ; nuclear medicine ; OXYGEN ; PULMONARY BLOOD-FLOW ; FEASIBILITY ; radiology ; methods ; NUCLEAR ; technique ; USA ; THICKNESS ; DIFFUSING-CAPACITY ; MEDICINE ; VALUES ; SECONDS ; RESPIRATORY SYNCHRONIZATION
    Abstract: Objective: The clinical feasibility of oxygen-enhanced magnetic resonance imaging (MRI) of the lung may benefit from the use of a simple gas delivery method. In this study, the oxygen-induced T1 change of the lung obtained using a closed O-2 delivery system was compared with that obtained by a conventional nontight face mask. Material and Methods: Twenty-three healthy subjects (15 men, 8 women, mean age = 25 years, age range = 20-35 years) underwent oxygen-enhanced MRI of the lung using a closed 02 delivery system composed by a tightly fitting face mask and a 60-L reservoir bag (equipment type A: n = 13, 9 men, 4 women, mean age = 24.4 years, age range = 20-32 years), or a clinically available nontight face mask (equipment type B: n = 10; 6 men, 4 women, mean age = 25.8 years, age range = 20-35 years). The effect of 100%-oxygen inhalation was assessed using a Snapshot FLASH T1-mapping technique (repetition time/echo time 1.5-1.6/0.56 milliseconds; matrix 128 X 90; acquisition time 3.3-3.7 seconds; slice thickness 15-20 mm; number of images = 40). By nonlinear curve fitting, the mean T1 values of the left and right lung at room air and 100%-oxygen ventilation were calculated (T1(room air, right); T1(oxygen, right); T1(room air, left); T1(oxygen, left)). The average T1 differences (Delta T1 = T1(room air) - T1(oxygen)) of the 2 volunteer groups were compared (Wilcoxon signed rank test, Mann-Whimey U test). Results: The mean T1 values obtained using the 2 respiratory equipments at room air or oxygen ventilation were not significantly different (A vs. B at room air ventilation: P = 0.85 for the right lung, P = 0.27 for the left lung; A vs. B at oxygen ventilation: P = 0.55 for the left lung, P = 0.29 for the right lung). With both systems, the mean T1 values decreased significantly after oxygen inhalation (P = 0.03-0.0002). For both lungs, the AT I obtained using the equipment type A was statistically equivalent to that obtained using the equipment type B: Delta T1(A), (right) = 96 +/- 19 milliseconds versus Delta T1(B), (right) = 97 +/- 34 milliseconds (P = 0.82); Delta T1(A), (left) = 74 +/- 47 milliseconds versus Delta T1(B), (left) = 68 +/- 63 milliseconds (P = 0.85). Conclusion: Gas delivery in oxygen-enhanced MRI of the lung can be performed with a clinically available standard face mask, without the need for closed sophisticated equipments
    Type of Publication: Journal article published
    PubMed ID: 18496048
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  • 4
    Keywords: CANCER ; tumor ; carcinoma ; Germany ; LUNG ; imaging ; lung cancer ; LUNG-CANCER ; VOLUME ; TUMORS ; RESOLUTION ; PATIENT ; MRI ; SEQUENCE ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; REGION ; LOCALIZATION ; LENGTH ; PARAMETERS ; FUNCTION TESTS ; 3-DIMENSIONAL RECONSTRUCTION ; MOTION ; HEALTHY ; COMPLICATIONS ; dynamic MRI ; STAGE-I ; HEALTHY-VOLUNTEERS ; PULMONARY-FUNCTION ; HUMAN DIAPHRAGM SHAPE ; breathing cycle ; HEALTHY-SUBJECTS ; SPIROMETRY ; parallel imaging ; TEMPORAL RESOLUTION ; IA ; FEV1 /VC ; INTRATHORACIC TUMOR
    Abstract: Purpose: To assess relative forced expiratory volume in one second (FEV1/vital capacity (VQ in healthy subjects and patients with a lung tumor using dynamic magnetic resonance imaging (dMRI) parameters. Materials and Methods: In 15 healthy volunteers and 31 patients with a non-small-cell lung carcinoma stage I (NSCLC 1), diaphragmatic length change (LEI) and craniocaudal (CC) intrathoracic distance change within one second; from maximal inspiration (DEI) were divided by total length change (LEtotal, DEtotal) as a surrogate of spirometric FEV 1 /VC using a true fast imaging with steady-state precession (trueFISP) sequence TE/TR = 1.7/37.3 msec, temporal resolution = 3 images/second). Influence of tumor localization was examined. Results: In healthy volunteers FEV I /VC showed a highly significant correlation with LE1/LEtotal and DE1/DEtotal (r 〉 0.9. P 〈 0.01). In stage IB tumor patients, comparing tumor-bearing with the non-tumor-bearing hemithorax, there,was a significant difference in tumors of the middle (LE1 /LEtotal= 0.63 +/- 0.05 vs. 0. 73 +/- 0.04, DE1/DEtotal= 0.66 +/- 0.05 vs. 0.72 +/- 0.04; P 〈 0.05) and lower (P 〈 0.05) lung region. Stage IA tumor patients showed no significant differences with regard to healthy subjects. Conclusion: dMRI is a simple noninvasive method to locally determine LE1 /LEtotal and DE1 /DEtotal as a surrogate of FEV1/VC in volunteers and patients. Tumors of the middle and lower lung regions have a significant influence on these MRI parameters
    Type of Publication: Journal article published
    PubMed ID: 15723381
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  • 5
    Keywords: Germany ; LUNG ; PERFUSION ; THERAPY ; CT ; imaging ; PATIENT ; MRI ; SEQUENCE ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; AGE ; STATISTICAL-ANALYSIS ; MORPHOLOGY ; PULMONARY PERFUSION ; BODY ; CHILDREN ; SEGMENTS ; FEASIBILITY ; BREATH-HOLD ; LUNG PERFUSION ; fibrosis ; WEIGHT ; IMPAIRMENT ; CYSTIC-FIBROSIS ; cystic fibrosis ; SMALL AIRWAYS ; DEFECT ; GRAPPA ; CIRCULATION ; lung morphology
    Abstract: This paper is a feasibility study of magnetic resonance imaging (MRI) of lung perfusion in children with cystic fibrosis (CF) using contrast-enhanced 3D MRI. Correlation assessment of perfusion changes with structural abnormalities. Eleven CF patients (9 f, 2 m; median age 16 years) were examined at 1.5 T. Morphology: HASTE coronal, transversal (TR/TE/alpha/ST: 600 ms/28 ms/180 degrees/6 mm), breath-hold 18 s. Perfusion: Time-resolved 3D GRE pulse sequence (FLASH, TE/TR/alpha: 0.8/1.9 ms/40 degrees), parallel imaging (GRAPPA, PAT 2). Twenty-five data sets were acquired after intravenous injection of 0.1 mmol/kg body weight of gadodiamide, 3-5 ml/s. A total of 198 lung segments were analyzed by two radiologists in consensus and scored for morphological and perfusion changes. Statistical analysis was performed by Mantel-Haenszel chi-square test. Results showed that perfusion defects were observed in all patients and present in 80% of upper, and 39% of lower lobes. Normal lung parenchyma showed homogeneous perfusion (86%, P 〈 0.0001). Severe morphological changes led to perfusion defects (97%, P 〈 0.0001). Segments with moderate morphological changes showed normal (53%) or impaired perfusion (47%). In conclusion, pulmonary perfusion is easy to judge in segments with normal parenchyma or severe changes. In moderately damaged segments, MRI of lung perfusion may help to better assess actual functional impairment. Contrast-enhanced 3D MRI of lung perfusion has the potential for early vascular functional assessment and therapy control in CF patients
    Type of Publication: Journal article published
    PubMed ID: 16673092
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  • 6
    Keywords: Germany ; LUNG ; chest ; CT ; DIAGNOSIS ; FOLLOW-UP ; imaging ; DISEASE ; EXPOSURE ; RESOLUTION ; radiation ; PATIENT ; IMPACT ; prognosis ; MRI ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; MORPHOLOGY ; COMPUTED-TOMOGRAPHY ; FUNCTION TESTS ; magnetic resonance imaging (MRI) ; CHILDREN ; HRCT ; fibrosis ; ADULTS ; LIFE ; CYSTIC-FIBROSIS ; TESTS ; technique ; function ; cystic fibrosis ; RADIATION EXPOSURE ; lungs ; improvement of ; gold ; mucoviscidosis
    Abstract: Cystic fibrosis (CF) is a multi-systemic disease with major impact on the lungs. Pulmonary manifestation is crucial for the prognosis and life expectancy of patients. Imaging modalities and lung function tests reflect the pulmonary status in these patients. The standard imaging modality for diagnosis and follow-up of pulmonary changes is chest x-ray. The gold standard for the detection of parenchymal lung changes remains high resolution computed tomography (HRCT), but this is not used routinely for CF-patients due to radiation exposure. Magnetic resonance imaging (MRI) used to be of no importance in monitoring cystic fibrosis lung disease, as shown in studies from the 1980s and early 1990s. The continuing improvement of MRI techniques, however, has allowed for an adequate application of this non-radiation method in diagnosing the major pulmonary findings in CF, in addition to the assessment of lung function
    Type of Publication: Journal article published
    PubMed ID: 16437239
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  • 7
    Keywords: Germany ; LUNG ; DIAGNOSIS ; segmentation ; DISEASE ; RESOLUTION ; TRANSPLANTATION ; MRI ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; prevention ; MOTION ; dynamic MRI ; MANAGEMENT ; MOVEMENT ; SCIENCE ; breathing cycle ; HEALTHY-SUBJECTS ; SPIROMETRY ; volumetry ; RESPIRATORY MOTION ; MR-compatible spirometry ; respiratory mechanics ; GLOBAL STRATEGY
    Abstract: Rationale and Objectives: Most lung disease is inhomogeneously distributed but diagnosed by global spirometry. Regional lung function might allow for earlier diagnosis. Dynamic two-dimensional magnetic resonance imaging (2D-MRI) can depict lung motion with high temporal resolution. We evaluated whether measurement of lung area on dynamic 2D-MRI has sufficient agreement with spirometry to allow for lung function testing of single lungs. Material and Methods: Ten healthy volunteers were examined in a 1.5 T MRI scanner with a Flash 2D-sequence (8.5 images per second, sagittal and coronal orientation) with simultaneous spirometry. The lung area was segmented semiautomatically and the area changes were compared with spirometric volume changes. Results: Segmentation of one time series took 191 seconds on average. Volume-time and flow-volume curves from MRI data were almost congruent with spirometric curves. Pearson correlation of MRI area with spirometry was very high (mean correlation coefficients 〉0.97). Bland-Altman plots showed good agreement of lung area with spirometry (95% limits of agreement below 11% in each direction). Differences between lung area and spirometry were significantly smaller for sagittal measurement of the right lung than sagittal measurement of the left lung and coronal measurement. The relative forced expiratory volume in the first second differed less than 5% between MRI and spirometry in all but one volunteer. Conclusions: Measurement of lung area on 2D-MRI allows for functional measurement of single lungs with good agreement to spirometry. Postprocessing is fast enough for application in a clinical context and possibly provides increased sensitivity for lung functional measurement of inhomogeneously distributed lung disease
    Type of Publication: Journal article published
    PubMed ID: 20138554
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  • 8
    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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  • 9
    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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  • 10
    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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