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  • 1
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    UNI-MED
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    Keywords: measurement ; CANCER ; proliferation ; Germany ; LUNG ; THERAPY ; ALGORITHM ; ALGORITHMS ; ANATOMICAL MODEL ; AUTOMATIC DETECTION ; BAYESIAN-ANALYSIS ; cancer screening ; chest ; CLASSIFICATION ; COMMON ; computed tomography (CT),image processing ; computers,diagnostic aid ; computers,neural networks ; CT ; DENSITY ; DIAGNOSIS ; EMPHYSEMA ; FOLLOW-UP ; follow-up studies ; GENERATION ; GROUND-GLASS OPACITIES ; HIGH-RESOLUTION CT ; IMAGES ; imaging ; INFORMATION ; lung cancer ; LUNG-CANCER ; MASK ; MULTIPLE NEURAL-NETWORKS ; NETWORK ; NETWORKS ; neural networks ; QUANTIFICATION ; screening ; segmentation ; SOLITARY PULMONARY NODULES ; SPIRAL CT ; SUPPORT ; SYSTEM ; SYSTEMS ; thorax ; TOMOGRAPHY IMAGES ; TOOL ; TOTAL LUNG CAPACITY ; VENTILATION ; VISUALIZATION ; VOLUME
    Abstract: The proliferation of digital data sets and the increasing amount of images, e.g. through the use of multislice spiral CT or multiple follow-up examinations in the context of new therapies, are ideal prerequisites for computer-aided diagnosis (CAD) in chest radiology. Multiple studies have described the applications and advantages of computer assistance in performing different diagnostic tasks. More powerful computers will enable the introduction of these systems into the clinical routine and could provide an enormous increase in morphological and functional information. The commercial introduction of tools for detection and visualization of pulmonary nodules has already begun. This is one of the most widely-reported applications in view of the ongoing studies on lung cancer screening. The next generation of tools will improve the diagnosis of emphysema through detection, quantification and classification. Many more uses are being developed, for instance the detection and classification of infiltrates, volume measurements or functional pulmonary imaging (e.g. dynamic ventilation CT or (3)Helium-MRI). Grossly simplified, most systems use a three level structure consisting of segmentation/feature extraction, classification of extracted features and an output unit. The output can be mere visualization through color-coding, volume measurements or calculated probabilities. The output supports the radiologist in establishing his findings and preparing differential and final diagnoses as well as providing quantitative data for follow-up studies. Different techniques are used for segmentation of lung areas as the basis for a variety of applications. Some commonly-used techniques for this and other tasks are density masks and threshold-based algorithms. Data processing is predominantly carried out with Bayesian classifiers or neural networks. This article describes the current status of research and provides insight into the common schemes and capabilities of the systems. It focuses particularly on common topics such as segmentation, volume measurement, detection of pulmonary nodules, quantification of emphysema and analysis of ground glass opacities
    Type of Publication: Journal article published
    PubMed ID: 14610697
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    Keywords: measurement ; Germany ; LUNG ; THERAPY ; EMPHYSEMA ; IMAGES ; QUANTIFICATION ; TOOL ; VENTILATION ; RESOLUTION ; TIME ; PATIENT ; TRANSPLANTATION ; FLOW ; MRI ; SIGNAL ; magnetic resonance ; REGION ; REGIONS ; PARAMETERS ; SERIES ; MOTION ; HYPERPOLARIZED HE-3 ; PULMONARY VENTILATION ; LUNG VENTILATION ; hyperpolarized ; MAPS ; PULMONARY ; SOFTWARE TOOL ; 2D ; CLINICAL-SIGNIFICANCE ; pulmonary function ; PULMONARY-FUNCTION ; He-3 ; HE-3 GAS ; hyperpolarized gas ; LUNG MOTION CORRECTION
    Abstract: Purpose: He-3-MRI is able to visualize the regional distribution of lung ventilation with a temporal and spatial resolution so far unmatched by any other technique. The aim of the study was the development of a new software tool for quantification of dynamic ventilation parameters in absolute physical units. Materials and Methods: During continuous breathing, a bolus of hyperpolarized He-3 (300 ml) was applied at inspiration and a series of 168 coronal projection images simultaneously acquired using a 2D FLASH-sequence. Postprocessing software was developed to analyze the He-3 distribution in the lung. After correction for lung motion, several ventilation parameters (rise time, delay time, He-3 amount and He-3 peak flow) were calculated. Due to normalization of signal intensities, these parameters are presented in absolute physical units. The data sets were analyzed on a ROI basis as well as on a pixel-by-pixel basis. Results: Using the developed software, the measurements were analyzed in 6 lung-healthy volunteers, in one patient after lung transplantation, and in one patient with lung emphysema. The volunteers' parameter maps of the pixel-based analysis showed an almost homogeneous distribution of the ventilation parameters within the lung. In the parameter maps of both patients, regions with poor ventilation were observed. Conclusion: The developed software permits an objective and quantitative analysis of regional lung ventilation in absolute physical units. The clinical significance of the parameters, however, has to be determined in larger clinical studies. The software may become valuable in grading and following pulmonary function as well as in monitoring any therapy
    Type of Publication: Journal article published
    PubMed ID: 15383970
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    Keywords: evaluation ; Germany ; LUNG ; chest ; CT ; FOLLOW-UP ; follow-up studies ; IMAGES ; SUPPORT ; VENTILATION ; VOLUME ; RESOLUTION ; PATIENT ; MRI ; helium ; HEALTHY ; HYPERPOLARIZED HE-3 ; motion correction ; MR imaging ; PULMONARY ; VOLUMES ; RECIPIENTS ; BRONCHIOLITIS ; bronchiolitis obliterans ; lung transplantation ; pulmonary function ; PULMONARY-FUNCTION ; TRANSPLANT RECIPIENTS
    Abstract: The aim of this study was to evaluate the possible contribution of He-3-MRI to detect obliterative bronchiolitis (OB) in the follow-up of lung transplant recipients. Nine single- and double-lung transplanted patients were studied by an initial and a follow-up He-3-MRI study. Images were evaluated subjectively by estimation of ventilation defect area and quantitatively by individually adapted threshold segmentation and subsequent calculation of ventilated lung volume. Bronchiolitis obliterans syndrome (BOS) was diagnosed using pulmonary function tests. At He-3-MRI, OB was suspected if ventilated lung volume had decreased by 10% or more at the follow-up MRI study compared with the initial study. General accordance between pulmonary function testing and He-3-MRI was good, although subjective evaluation of He-3-MRI underestimated improvement in ventilation as obtained by pulmonary function tests. The He-3-MRI indicated OB in 6 cases. According to pulmonary function tests, BOS was diagnosed in 5 cases. All diagnoses of BOS were also detected by He-3-MRI. In 2 of these 5 cases, He-3-MRI indicated OB earlier than pulmonary function tests. The results support the hypothesis that He-3-MRI may be sensitive for early detection of OB and emphasize the need for larger prospective follow-up studies
    Type of Publication: Journal article published
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    Keywords: evaluation ; Germany ; THERAPY ; CLASSIFICATION ; CT ; DIAGNOSIS ; FOLLOW-UP ; imaging ; SPIRAL CT ; DISEASE ; NEW-YORK ; RISK ; computed tomography ; BLOOD-FLOW ; primary ; RISK-FACTORS ; MR ; MRI ; treatment ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; risk factors ; RISK FACTOR ; tomography ; SCINTIGRAPHY ; COMPUTED-TOMOGRAPHY ; ORGANIZATION ; BREATH-HOLD TECHNIQUE ; MR imaging ; HELICAL CT ; DIFFERENTIAL-DIAGNOSIS ; ARTERIAL-HYPERTENSION ; LEFT-VENTRICULAR DYSFUNCTION ; CHEST-X-RAY ; CHRONIC THROMBOEMBOLISM ; pulmonary hypertension,computed tomography,magnetic resonance imaging,echocardiography,angiography,E ; RADIOLOGIC FEATURES
    Abstract: 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 tomography (CT) and magnetic resonance imaging (MRI) became more important in the evaluation and for differential diagnosis of pulmonary arterial hypertension. Both modalities are reviewed and recommendations for clinical use are given
    Type of Publication: Journal article published
    PubMed ID: 14740163
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    Keywords: evaluation ; Germany ; IN-VIVO ; LUNG ; CT ; DENSITY ; EMPHYSEMA ; imaging ; VOLUME ; DISEASE ; computed tomography ; PATIENT ; INDEX ; TRANSPLANTATION ; CONTRAST ; FLOW ; MRI ; magnetic resonance imaging ; FORM ; GAS ; tomography ; COMPUTED-TOMOGRAPHY ; HEALTHY ; HYPERPOLARIZED HE-3 ; DIFFUSION ; AIRWAY ; HRCT ; resonance imaging ; HIGH-RESOLUTION ; OBSTRUCTION ; lung transplantation ; FUNCTIONAL-CHARACTERIZATION ; AIRWAYS DISEASE ; apparent diffusion coefficient ; COEFFICIENT ; hyperpolarized (3)Helium ; lung function ; PULMONARY-FUNCTION TESTS
    Abstract: Purpose: To assess the emphysematous enlargement of distal airspaces and concomitant large and small airway disease using diffusion-weighted (3)Helium-magnetic resonance imaging (MRI), high-resolution computed tomography (HRCT), and lung function tests (LFT). Methods: Seven patients were examined after single lung transplantation (LTx) and 1 before double LTx for various forms of emphysema. Five patients after double LTx served as controls. Patients were assessed by (3)Helium-MRI (apparent diffusion coefficient [ADC]), HRCT (mean lung density [MLD], emphysema index [EI]), and LFT. Results: Transplanted lungs: mean ADC = 0.17 cm(2)/s, MLD -848 H, EI 22%. Emphysematous lungs: mean ADC = 0.33 cm(2)/s, MLD -922 H; EI = 54%. Good correlations were found between ADC and MLD (r = 0.6), EI (r = 0.8), intrathoracic gas volume (r = 0.7), forced expiratory volume in 1 second (r = 0.7), and forced expiratory flows (r = 0.7). In contrast, HRCT only provided moderate correlations with LFT (EI: r = 0.5; MLD: r [1e] 0.4). Conclusion: In this initial study, He-3-MRI yield good correlations with HRCT and agrees better than HRCT with the functional characterization of emphysema regarding hyperinflation, large and small airway disease as provided by LFT
    Type of Publication: Journal article published
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    Keywords: Germany ; IN-VIVO ; LUNG ; MODEL ; EMPHYSEMA ; IMAGES ; imaging ; TIME ; PATIENT ; MRI ; SEQUENCE ; MAGNETIC-RESONANCE ; REPRODUCIBILITY ; GAS ; PARAMETERS ; Jun ; helium ; FUNCTION TESTS ; HEALTHY ; DIFFUSION ; STANDARD ; SINGLE ; hyperpolarized gas ; COEFFICIENT ; BM ; lung microstructure ; RICIAN DISTRIBUTION
    Abstract: 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/cm(2)). Five patients with pulmonary emphysema, and six healthy-lung volunteers were included in the study. Images were acquired after inspiration of He-3 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)l analysis and global lung ADC histograms. Results: The mean ADC of a ROI varied by 5.1% between two measurements for volunteers and by 6.1% for patients. In the global evaluation, the 75th percentile demonstrated the best reproducibility (2%), while other parameters showed variations up to 12%. Only the variation of the standard deviation (SD) and the measure of homogeneity of the ADC map showed a significant difference between patients and volunteers. Conclusion: Diffusion-weighted imaging (DWI) is a well-reproducible method for assessing the lung microstructure
    Type of Publication: Journal article published
    PubMed ID: 15906344
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    Keywords: EXPRESSION ; TUMORS ; GENETIC POLYMORPHISMS ; CELL-LINES ; PHARMACOKINETICS ; DRUG-RESISTANCE ; MULTIDRUG-RESISTANCE ; SINGLE NUCLEOTIDE POLYMORPHISMS ; PHARMACOGENETICS ; PROTEIN GENE
    Abstract: ATP-binding cassette (ABC) transporter expression and genetic heterogeneity have been implicated in response to anticancer therapy. This study characterized genetic variability of the ABCB1 (also known as MDR1), ABCC2 (MRP2) and ABCG2 (BCRP) genes, which are key players in the metabolism of many chemotherapeutic agents including those used in the treatment of lung cancer. We genotyped 53 polymorphisms in the candidate genes in genomic DNA samples of 171 cases of small cell lung carcinoma (SCLC) and 206 cases of non-small cell lung carcinoma (NSCLC), and studied their impact on early response to chemotherapy, progression-free survival and overall survival. SNP rs717620 in ABCC2 was moderately associated with a poor response to chemotherapy but strongly with shorter progression-free survival and overall survival in SCLC but not NSCLC patients, indicating that ABCC2 genetic variation is an important factor in SCLC survival after chemotherapy.
    Type of Publication: Journal article published
    PubMed ID: 22473764
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    Abstract: Recently, a novel classification system based on tumour architecture and with high prognostic impact has been proposed for pulmonary adenocarcinomas (ADCs). For imaging-based prediction of histological ADC subtypes and, thus, prognosis, it is of paramount importance to investigate the correlations of radio- and histomorphological parameters. Associations between histomorphological ADC growth patterns (lepidic, acinar, papillary, micropapillary and solid) and data from pre-operative assessment by computed tomography (CT) imaging of 174 resected pulmonary ADCs were analysed. Margin configuration as well as solidity/ground glass opacity of an ADC was associated with distinct histomorphological ADC growth patterns. Solid-predominant ADCs usually had smooth margins and were also solid in CT scans, while lepidic-predominant ADCs had no predominant margin pattern, were located in the periphery, showed a positive bronchogram and were frequently associated with solidity/ground glass opacity. In addition, nonspherical tumour growth was a negative predictor of overall and disease-specific patient survival. We defined CT morphological parameters that were associated with histomorphological growth patterns of pulmonary ADCs. These data may form the basis for the development of future prognostic algorithms in the palliative setting, which include an integrated evaluation of biopsy histomorphology and CT scan morphology of nonresectable pulmonary ADC.
    Type of Publication: Journal article published
    PubMed ID: 22835610
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  • 10
    Keywords: QUANTIFICATION ; COMPUTED-TOMOGRAPHY ; OBSTRUCTIVE PULMONARY-DISEASE ; SMOKERS ; multidetector CT ; SEX-DIFFERENCES ; SHORT-TERM ; COPD ; VOLUME-REDUCTION SURGERY ; AIR-FLOW OBSTRUCTION
    Abstract: Purpose: The change of emphysema distribution with increasing COPD severity is not yet assessed. Especially, involvement of the upper aspect of the lower lobe is unknown. The primary aim was to quantitatively determine regional distribution of emphysema in anatomically (lung lobes) and non-anatomically defined lung regions (upper/lower lung halves as well as core and rind regions) in a cohort covering equally all COPD severity stages using CT. Material and Methods: Basically 100 CT data sets were quantitatively evaluated for regional distribution of emphysema. Emphysema characteristics (emphysema index, mean lung density and 15th percentile of the attenuation values of lung voxels) were compared (t-test) in: upper lobes vs. upper halves, lower lobes vs. lower halves, core vs. rind region. Results: In patients with 〈= GOLD II, a significantly higher emphysema burden was found in the upper lobes as compared to upper halves. In subjects with GOLD III/IV the differences were not significant for all emphysema characteristics. A high difference between lobes and halves in subjects with 〈= GOLD II was found, in contrast to low difference in higher GOLD stages. Conclusions: Lobar segmentation provides improved characterization of cranio-caudal emphysema distribution compared to a non-anatomic approach in subjects up to GOLD stage II.
    Type of Publication: Journal article published
    PubMed ID: 25230093
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