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  • 1
    Keywords: Germany ; LUNG ; PERFUSION ; DIAGNOSIS ; imaging ; INFORMATION ; VOLUME ; DISEASE ; TIME ; PATIENT ; BLOOD-FLOW ; primary ; HIGH-RESOLUTION MEASUREMENT ; MRI ; TRACER BOLUS PASSAGES ; SEQUENCE ; LUNG PERFUSION
    Abstract: Purpose: To assess the use of time-resolved parallel 3D MRI for a quantitative analysis of pulmonary perfusion in patients with cardiopulmonary disease. Materials and Methods: Eight patients with pulmonary embolism or pulmonary hypertension were examined with a time-resolved 3D gradient echo pulse sequence with parallel imaging techniques (FLASH 3D, TE/TR: 0.81 1.9 ms; flip angle: 40degrees; GRAPPA). A quantitative perfusion analysis based on indicator dilution theory was performed using a dedicated software. Results: Patients with pulmonary embolism or chronic thromboembolic pulmonary hypertension revealed characteristic wedge-shaped perfusion defects at perfusion MRI. They were characterized by a decreased pulmonary blood flow (PBF) and pulmonary blood volume (PBV) and increased mean transit time (MTT). Patients with primary pulmonary hypertension or Eisenmenger syndrome showed a more homogeneous perfusion pattern. The mean MTT of all patients was 3.3 +/- 4.7 s. The mean PBF and PBV showed a broader interindividual variation (PBF: 104-322ml/100ml/min; PBV: 8-21ml/100 ml). Conclusion: Time-resolved parallel 3D MRI allows at least a semi-quantitative assessment of lung perfusion. Future studies will have to assess the clinical value of this quantitative information for the diagnosis and management of cardiopulmonary disease
    Type of Publication: Journal article published
    PubMed ID: 14872369
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  • 2
    Keywords: measurement ; evaluation ; Germany ; LUNG ; PERFUSION ; imaging ; QUANTIFICATION ; VENTILATION ; TIME ; BLOOD-FLOW ; MR ; MRI ; SEQUENCE ; SIGNAL ; ACQUISITION ; DIFFERENCE ; REGION ; arteries ; REGIONS ; EMBOLISM ; ANGIOGRAPHY ; PULMONARY PERFUSION ; LUNG PERFUSION ; PULMONARY ; HEALTHY-VOLUNTEERS ; CINE-MRI ; perfusion,lung,phase-contrast,MRI,parallel imaging
    Abstract: Purpose: Evaluation of lung perfusion by contrast-enhanced 3D MRI using partial parallel imaging techniques. Materials and Methods: Eight healthy volunteers were examined using a contrast-enhanced dynamic FLASH 3D sequence with partial parallel imaging technique at 1.5 T MRI with a TA of 1.5 sec. The whole lung was covered by 36 coronal slices. A ventral, middle and dorsal, slice of each lung was manually segmented and signal-to-time curves were computed. For absolute quantification of blood flow through the right and left pulmonary artery, phase-contrast flow measurements were performed. Results: No significant difference was found between the signal intensity in the right (8.9 +/- 2.6) and left (8.0 +/- 3.5) lung, corresponding to a left-to-right signal intensity ratio of 0.9. A significantly higher signal intensity was found in the dorsal regions of the lungs (p = 0.01) compared to the ventral regions. The time to peak of the signal intensity was significantly shorter in the dorsal (15.3 sec) and middle (15.7 sec) regions of the lungs (p = 0.03 and p = 0.04, respectively) than in the ventral regions (16.3 sec). The ratio between blood flow through the left (2.2 L/min) and right (2.7 L/min) lung was 0.84. Conclusion: Partial parallel image acquisition can assess the perfusion of the lungs at high temporal resolution. The perfusion is slightly higher on the right than on the left. The signal increases faster and has a higher peak in the dorsal lung regions
    Type of Publication: Journal article published
    PubMed ID: 15026945
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  • 3
    Keywords: brain ; SPECTRA ; IRRADIATION ; radiotherapy ; tumor ; Germany ; THERAPY ; DIAGNOSIS ; FOLLOW-UP ; imaging ; DIFFERENTIATION ; TISSUE ; TUMORS ; radiation ; PATIENT ; MR ; SIGNAL ; MR spectroscopy ; SPECTROSCOPY ; stereotactic ; LESIONS ; PROGRESSION ; TUMOR PROGRESSION ; RECURRENCE ; PROGNOSTIC-FACTORS ; positron emission tomography ; POSITRON-EMISSION-TOMOGRAPHY ; tomography ; SPECT ; PET ; AMINO-ACIDS ; LOW-GRADE ASTROCYTOMAS ; TRACER ; GLIOMAS ; 2D ; ONCOLOGY ; brain tumor ; BRAIN-TUMORS ; GLIOMA ; FDG PET ; F-18 FLUORODEOXYGLUCOSE ; single photon emission tomography
    Abstract: Purpose: To evaluate the clinical value of 1H MR spectroscopy (1 H MRSI) for follow-up of irradiated glioma compared to posi-. tron emission tomography (PET) with [18F]-2-fluoro-deoxy-D-glucose (FDG-PET) and single photon emission tomography with [1231]-a-methyl-L-tyrosine (IMT-SPECT). Materials and Methods: Twenty-four patients with irradiated gliomas were examined using 1H MRSI (2D spectroscopic imaging; PRESS; TE=135 msec; 1.5T Magnetom Vision, Siemens; Voxel size 9 x 9 x 15 mm(3)). MR spectra (n = 233) were evaluated in areas suspicious of tumor (n = 86) as well as in healthy appearing brain tissue (n = 147). Relative signal intensity ratios of choline (Cho), creatine (Cr) and N-acetyl-aspartate (NAA) were calculated. PET. scans (n = 19) were performed with 200 - 250 MBq FDG, IMT-SPECT examinations (n = 14) with 200 - 250 mBq IMT. Based on clinical and MRI/CT, follow-up lesions were classified as either neoplastic [PIT] or non-neoplastic [nPT]. Results: True positive results for the diagnosis of PT/nPT were 88/89% (1H MRSI), 73/100 % (PET) and 100/75 % (SPECT). Cho/Cr showed highly significant changes for PT. Determinating a correlation between Cho, Cr, NAA and IMT-SPECT as well as FDG-PET was not possible because of different location of maximum tracer uptake and acquired 2D I H MRSI. Conclusion: IMT-SPECT seems to be superior to detect tumor progression in irradiated gliomas. 1 H MRSI was more suitable than FDG-PET to differentiate between recurrence and radiation-induced changes. FDG-PET plays a role as sensitive method for detecting high-grade tumors. PET and SPECT allowed the examination of the entire tumor including surrounding brain tissue with higher spatial resolution than the acquired 2D 1H MRSI. A main limitation of our study was that only 2D 1 H MRSI was used, with only parts of the tumor evaluated. The use of 3D MR spectroscopic imaging may further increase the diagnostic accuracy
    Type of Publication: Journal article published
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  • 4
    Keywords: radiotherapy ; SURVIVAL ; Germany ; THERAPY ; FOLLOW-UP ; VOLUME ; NEW-YORK ; radiation ; PATIENT ; CONTRAST ; MR ; MRI ; treatment ; stereotactic ; stereotactic radiotherapy ; RADIATION-THERAPY ; RATES ; PROGNOSTIC FACTORS ; RANDOMIZED TRIAL ; ONCOLOGY-GROUP ; POSTOPERATIVE RADIOTHERAPY ; ADULTS ; BRAIN-TUMORS ; CONTRAST ENHANCEMENT ; GLIOMA ; GRADE ; LOW-GRADE ASTROCYTOMA ; astrocytoma,MRI,prognosticator,stereotactic radiotherapy
    Abstract: Aim of this study was to evaluate the role of pre-therapeutic and follow-up MRI in the clinical treatment and outcome in patients with astrocytoma WHO grade II after fractionated stereotactic radiation therapy (FSRT). One hundred thirty-nine patients with histologically proven astrocytoma WHO grade II were treated with FSRT and retrospectively evaluated. All patients had follow-up MRI studies (Gd-DTPA-enhanced T1- and T2-weighted MR images). Progression-free survival (PFS) and overall survival (OS) rates were calculated using the Kaplan-Meier method. Multivariate analysis was performed on five potential MRI related prognosticators. Median follow-up was 3.8 years. Positive contrast enhancement (CM+) prior to FSRT proved to be a significant prognosticator for PFS and OS (p〈0.01). Pre-therapeutic oedema on T2-weighted images and multifocality of contrast medium (CM) enhancement did not prove to be significant prognosticators. Also, diameter and volume of CM enhancement showed no significance on clinical outcome. Negative contrast enhancing (CM-) patients developing a de novo CM enhancement during follow-up showed a significantly worse clinical outcome compared with generally CM- patients (p〈0.05). Pre-therapeutic CM enhancement and the development of CM-enhancing areas during follow-up are negative prognosticators for PFS and OS. They must be interpreted as signs of secondary malignity
    Type of Publication: Journal article published
    PubMed ID: 14610685
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  • 5
    Keywords: evaluation ; Germany ; LUNG ; MODEL ; CT ; EMPHYSEMA ; imaging ; TOOL ; DISEASE ; MRI ; CYCLE ; SEQUENCE ; INVIVO ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; PARAMETERS ; MOTION ; PULMONARY ; TRUEFISP ; HEALTHY-VOLUNTEERS ; EXPIRATION ; HUMAN DIAPHRAGM SHAPE ; INSPIRATORY PUMP ; lung dynamic,magnetic resonance imaging,respiration,model,spirometry ; LUNG-VOLUMES ; WALL MECHANICS
    Abstract: Rationale and Objectives: To investigate diaphragm and chest wall motion during the whole breathing cycle using magnetic resonance imaging (MRI) and a volumetric model in correlation with spirometry.Materials and Methods: Breathing cycles of 15 healthy volunteers were examined using a trueFISP sequence (5 slices in 3 planes, 3 images per second). Time-distance curves were calculated and correlated to spirometry. A model for vital capacity (VC), continuous time-dependent vital capacity (tVC), and investigating the influence of horizontal and vertical parameters on tVC was introduced.Results: Time-distance curves of the breathing cycle using MRI correlated highly significant with spirometry (P 〈 0.0001). VC calculated by the model was similar to VC measured in spirometry (5.00 L vs. 5.15 L). tVC correlated highly significantly with spirometry (P 〈 0.0001). Vertical parameters had a more profound influence on tVC change than horizontal parameters.Conclusions: Dynamic MRI is a simple noninvasive method to evaluate local chest wall motion and respiratory mechanics. It widens the repertoire of tools for lung examination with a high temporal resolution
    Type of Publication: Journal article published
    PubMed ID: 15021323
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  • 6
    Keywords: measurement ; tumor ; Germany ; LUNG ; CT ; IMAGES ; DISEASE ; NEW-YORK ; TUMORS ; PATIENT ; REDUCTION ; CONTRAST ; MRI ; CYCLE ; SEQUENCE ; NO ; DIFFERENCE ; REGION ; LOCALIZATION ; LENGTH ; COMPUTED-TOMOGRAPHY ; CURVES ; 3-DIMENSIONAL RECONSTRUCTION ; MOTION ; HEALTHY ; ORIENTATION ; LOCATION ; dynamic MRI ; ADULT ; ADULTS ; STRENGTH ; TRUEFISP ; HEALTHY-VOLUNTEERS ; PULMONARY-FUNCTION ; HEART-FAILURE ; EXPIRATION ; LUNG-VOLUMES ; breathing cycle ; diaphragmatic function
    Abstract: The purpose of this study was to assess diaphragmatic length and shortening during the breathing cycle in healthy volunteers and patients with a lung tumor using dynamic MRI (dMRI). In 15 healthy volunteers and 28 patients with a solitary lung tumor, diaphragmatic motion and length were measured during the breathing cycle using a trueFISP sequence (three images per second in the coronal and sagittal plane). Time-distance curves and maximal length reduction (= shortening) of the diaphragm were calculated. The influence of tumor localization on diaphragmatic shortening was examined. In healthy volunteers maximal diaphragmatic shortening was 30% in the coronal and 34% in the sagittal orientation, with no difference between both hemithoraces. Tumors of the upper and middle lung region did not affect diaphragmatic shortening. In contrast, tumors of the lower lung region changed shortening significantly (P〈0.05). In hemithoraces with a tumor in the lower region, shortening was 18% in the coronal and 19% in the sagittal plane. The ratio of diaphragmatic length change from inspiration to expiration changed significantly from healthy subjects (inspiration length &MGT; expiratory length, P〈0.05) to patients with a tumor in the lower lung region (inspiratory length = expiratory length). dMRI is a simple, non-invasive method to evaluate diaphragmatic motion and shortening in volunteers and patients during the breathing cycle. Tumors of the lower lung region have a significant influence on shortening of the diaphragm
    Type of Publication: Journal article published
    PubMed ID: 15127220
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  • 7
    Keywords: CANCER ; IRRADIATION ; radiotherapy ; Germany ; LUNG ; MODEL ; CT ; DENSITY ; FOLLOW-UP ; DISEASE ; MORTALITY ; computed tomography ; MICE ; MOUSE ; NO ; MOBILITY ; PARAMETERS ; tomography ; leukocyte ; MOUSE MODEL ; COMPUTED-TOMOGRAPHY ; THIN-SECTION CT ; HIGH-RESOLUTION ; WEIGHT ; lung function ; AMIFOSTINE ; INDUCED PULMONARY FIBROSIS ; lung fibrosis ; MOUSE LUNG ; STRAIN-DEPENDENT DIFFERENCES
    Abstract: Rationale and Objectives: To identify characteristics of lung fibrosis in a mouse model after radiotherapy (RT) using thin-section computed tomography (CT), histology and clinical parameters. Materials and Methods: Using a multislice CT-scanner, follow-up chest CT scans of 10 out of 72 included mice (C57BL/6J, 36 control mice, 36 mice (20Gy)) were performed every 2 weeks until week 26 after RT. Hounsfield units (HU) and cardiothoracic ratio (CTR) were measured, and a multireader analysis on characteristic lung changes was performed and correlated with histology and clinical parameters. Results: From weeks 4 to 8 after RT changes in histology (leukocyte count, extraalveolar edema, P 〈 0.01) and from week 12 changes in CT were detected (increase in HU, intralobular opacity and fibrotic strandings, P 〈 0.05). From week 14 clinical manifestations occurred (loss of weight, mobility, breathing, increased mortality, P 〈 0.01). CTR showed no significant changes. Three readers showed excellent interobserver agreement (kappa 〉 0.84). Conclusion: Thin-section CT in a mouse model is capable of detecting the development of lung fibrosis after RT prior to the onset of clinical deterioration
    Type of Publication: Journal article published
    PubMed ID: 15377939
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  • 8
    Keywords: measurement ; CANCER ; radiotherapy ; tumor ; Germany ; LUNG ; IMAGES ; lung cancer ; LUNG-CANCER ; TISSUE ; TUMORS ; PATIENT ; MRI ; CYCLE ; SEQUENCE ; STAGE ; RADIATION-THERAPY ; MOBILITY ; REGION ; REGIONS ; WALL ; CURVES ; MOTION ; FUTURE ; LINEAR-ACCELERATOR ; LOCATION ; dynamic MRI ; TRUEFISP ; PULMONARY-FUNCTION ; EXTERNAL-BEAM RADIOTHERAPY ; breathing cycle ; CT SCANS ; DIAPHRAGM ; HEALTHY-SUBJECTS ; lung MRL radiotherapy ; tumor diameter
    Abstract: Background and purpose: To assess the influence of tumor diameter on tumor mobility and motion of the tumor bearing hemithorax during the whole breathing cycle in patients with stage I non-small-cell lung cancer (NSCLC) using dynamic MRI. Patients and methods: Breathing cycles of thirty-nine patients with solitary NSCLCs were examined using a trueFISP sequence (three images per second). Patients were divided into three groups according to the maximal tumor diameter in the transverse plane ( 〈3, 3-5 and 〉5 cm). Continuous time-distance curves and deep inspiratory and expiratory positions of the chest wall, the diaphragm and the tumor were measured in three planes. Motion of tumor-bearing and corresponding contralateral non-tumor bearing regions was compared. Results: Patients with a tumor 〉3 cm showed a significantly lower diaphragmatic motion of the tumor bearing compared with the non-tumor bearing hemithorax in the craniocaudal (CC) directions (tumors 3-5 cm: 23.4 +/- 1.2 vs 21.1 +/- 1.5 cm (P 〈0.05); tumors 〉5 cm: 23.4 +/- 1.2 vs 20.1 +/- 1.6 cm (P 〈0.01). Tumors 〉5 cm in the lower lung region showed a significantly lower mobility compared with tumors 〈3 cm (1.8 +/- 1.0 vs 3.8 +/- 0.7 cm, P 〈0.01) in the CC directions. Conclusions: Dynamic MRI is a simple non-invasive method to differentiate mobility of tumors with different diameters and its influence on the surrounding tissue. Tumor diameter has a significant influence on tumor mobility and this might be taken into account in future radiotherapy planning, (C) 2004 Elsevier Ireland Ltd. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 15588881
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  • 9
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    Radiologe 44 (2), 177-179 
    Keywords: CANCER
    Type of Publication: Journal article published
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  • 10
    Keywords: radiotherapy ; tumor ; carcinoma ; CELL LUNG-CANCER ; Germany ; LUNG ; THERAPY ; IMAGES ; imaging ; SYSTEM ; TUMORS ; PATIENT ; MRI ; CYCLE ; STAGE ; RADIATION-THERAPY ; MOBILITY ; metastases ; REGION ; REGIONS ; VARIABILITY ; SAFETY ; MOTION ; TARGETS ; LINEAR-ACCELERATOR ; LUNG-CARCINOMA ; LOCATION ; dynamic MRI ; THERAPIES ; EXTERNAL-BEAM RADIOTHERAPY ; breathing cycle ; CT SCANS ; DIAPHRAGM ; lung motion
    Abstract: Purpose: To assess diaphragm, lung region, and tumor mobility during the whole breathing cycle using dynamic MRI. A generalized safety margin concept for radiotherapy planning was calculated and compared with an individualized concept. Methods and Materials: The breathing cycles of 20 patients with solitary lung tumors (15 Stage I non-small-cell lung carcinoma, 5 small solitary metastases) were examined with dynamic MRI (true Fast imaging with steady precision, three images per second). The deep inspiratory and expiratory positions of the diaphragm, upper, middle, and lower lung regions, and the tumor were measured in three dimensions. The mobility of tumor-bearing and corresponding tumor-free regions was compared. Tumor mobility in quiet respiration served as an MRI-based safety margin concept. Results: The motion of the lung regions was significantly greater in the lower regions than in the upper regions (5 +/- 2 cut vs. 0.9 +/- 0.4 cm, p 〈 0.05). Tumor-bearing lung regions showed a significantly lower mobility than the corresponding noninvolved regions (p 〈 0.05). In quiet respiration, tumor mobility showed a high variability; a safety margin of 3.4 mm in the upper, 4.5 mm in the middle, and 7.2 mm in the lower region was calculated. Conclusion: Dynamic MRI is a simple, noninvasive method to evaluate intrathoracic tumor mobility for therapy planning. Because of the high variability of tumor mobility, an individual safety margin is recommended. (C) 2004 Elsevier Inc
    Type of Publication: Journal article published
    PubMed ID: 15234028
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