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  • CT  (8)
  • ANGIOGRAPHY  (7)
  • Aorta  (6)
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  • 1
    Keywords: Diagnostic Imaging ; radiology ; MULTISLICE CT ; imaging ; CT ; CT ANGIOGRAPHY ; ANGIOGRAPHY ; arteries
    Type of Publication: Book chapter
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  • 2
    Keywords: Germany ; THERAPY ; chest ; CT ; imaging ; segmentation ; TOOL ; VOLUME ; NEW-YORK ; NUCLEAR-MEDICINE ; TIME ; PATIENT ; QUALITY ; CARE ; REPRODUCIBILITY ; metastases ; MELANOMA ; VARIABILITY ; MALIGNANT-MELANOMA ; malignant melanoma ; nuclear medicine ; FEASIBILITY ; radiology ; ONCOLOGY ; RE ; THERAPIES ; monitoring ; SOFTWARE ; SOLID TUMORS ; analysis ; methods ; NUCLEAR ; CRITERIA ; USA ; lymph node metastases ; lymph nodes ; CANCER-TREATMENT ; MULTISLICE CT ; SMALL PULMONARY NODULES ; therapy monitoring ; postprocessing ; MEDICINE ; VALUES ; INTEROBSERVER ; RECIST ; RECIST CRITERIA ; RESPONSE ASSESSMENT ; volumetric analysis
    Abstract: Therapy monitoring in oncological patient care requires accurate and reliable imaging and post-processing methods. RECIST criteria are the current standard, with inherent disadvantages. The aim of this study was to investigate the feasibility of semi-automated volumetric analysis of lymph node metastases in patients with malignant melanoma compared to manual volumetric analysis and RECIST. Multislice CT was performed in 47 patients, covering the chest, abdomen and pelvis. In total, 227 suspicious, enlarged lymph nodes were evaluated retrospectively by two radiologists regarding diameters (RECIST), manually measured volume by placement of ROIs and semi-automated volumetric analysis. Volume (ml), quality of segmentation (++/-) and time effort (s) were evaluated in the study. The semi-automated volumetric analysis software tool was rated acceptable to excellent in 81% of all cases (reader 1) and 79% (reader 2). Median time for the entire segmentation process and necessary corrections was shorter with the semi-automated software than by manual segmentation. Bland-Altman plots showed a significantly lower interobserver variability for semi-automated volumetric than for RECIST measurements. The study demonstrated feasibility of volumetric analysis of lymph node metastases. The software allows a fast and robust segmentation in up to 80% of all cases. Ease of use and time needed are acceptable for application in the clinical routine. Variability and interuser bias were reduced to about one third of the values found for RECIST measurements
    Type of Publication: Journal article published
    PubMed ID: 18274757
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  • 3
    Keywords: CANCER ; INVASION ; tumor ; carcinoma ; evaluation ; Germany ; CT ; DIAGNOSIS ; FOLLOW-UP ; SPIRAL CT ; TOOL ; DISEASE ; TUMORS ; computed tomography ; RESOLUTION ; PATIENT ; primary ; NO ; METASTASIS ; adenocarcinoma ; COMPUTED-TOMOGRAPHY ; sensitivity ; specificity ; VESSELS ; QUESTIONNAIRE ; pancreatic carcinoma ; HELICAL CT ; HYDRO-CT ; methods ; ROW CT ; CURVED PLANAR REFORMATIONS ; invasion score ; MULTISLICE SPIRAL CT ; resectability ; VASCULAR INVASION
    Abstract: Objective: It was the aim of this study to evaluate a new infiltration score to determine the resectability of pancreatic carcinomas in preoperative planning. Materials and Methods: Eighty patients with suspected pancreatic tumor were examined prospectively using 16-row spiral CT. The scans were evaluated for the presence of pancreatic carcinoma, peripancreatic tumor extension and vascular invasion using a standardized questionnaire. Invasion of the surgically relevant vessels was evaluated using a new invasion score. The operative and histological findings and the clinical follow-up served as the gold standard. Results: Forty patients had a pancreatic carcinoma, 5 had metastasis of a different primary tumor, and in 35 patients, there was no malignant pancreatic disease. The sensitivity for tumor detection was 100%, with a specificity of 88% for differentiating between malignant and benign pancreatic tumors. Invasion of the surrounding vessels was evaluated correctly using the invasion score, with a sensitivity of 89% and a specificity of 99%. In evaluation of resectability, a sensitivity of 94% and a specificity of 89% were achieved. Conclusion: Using 16-row spiral CT, the invasion score is a valid tool for correctly assessing invasion in relevant vessels in cases of pancreatic carcinoma and for determining resectability. Copyright (C) 2008 S. Karger AG, Basel and IAP
    Type of Publication: Journal article published
    PubMed ID: 18434758
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  • 4
    Keywords: computed tomography ; ANGIOGRAPHY ; ABDOMINAL-AORTA ; Aorta ; Aortic pathologies ; COMPUTED-TOMOGRAPHY AN
    Abstract: Current imaging of the aorta saw an improvement in terms of diversity and quality in recent years. In addition to verifying and documenting a clinical suspicion, it provides the basis for establishing an indication, choosing a therapy (conservative, surgical, interventional), as well as therapy planning and follow-up. Besides B-mode and duplex sonography, as well as transesophageal echocardiography (TEE), contrast-enhanced cross-sectional imaging, computer tomography (CT), with the option for CT angiography (CTA), and magnetic resonance tomography (MRT), with the option for MR angiography (MRA), play a significant role. The present article describes the possibilities offered by CTA and MRA for the diagnosis of aortic pathologies from the point of view of the radiologist in a maximum care hospital
    Type of Publication: Journal article published
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  • 5
    Keywords: Germany ; chest ; CT ; SYSTEM ; TOOL ; DEATH ; DISEASE ; MORTALITY ; RISK ; SURGERY ; PATIENT ; INJURIES ; MECHANISM ; IMPACT ; CONTRAST ; mechanisms ; treatment ; EXPERIENCE ; DISRUPTION ; REPAIR ; REGION ; ANGIOGRAPHY ; MANAGEMENT ; THORACIC AORTA ; HEIGHT ; wound ; STABILIZATION ; endovascular ; Cause of Death ; BLUNT ; DELAYED TREATMENT ; intracranial ; RUPTURE
    Abstract: Acute traumatic aortic tear (ATAT) is the second most common cause of deaths in trauma patients (about 8,000 deaths/year in the USA). Due to circumferential aortic disruption, up to 90% die at the scene. Responsible trauma mechanisms are: penetrating (gunshot/stab wounds), iatrogenic (interventional catheterization) and, most frequently, blunt chest trauma (high-speed motor vehicles, falls from heights, crushes, explosions) resulting in injury at the aortic isthmus region (loco typico, about 90%). Severe multiple system injuries (polytrauma), especially to intracranial and intraabdominal organs, are characteristic and prognostically predicitive. Immediate transthoracic open repair of ATAT has a mortality risk of 8% to 33% and paraplegia risk of 2% to 26%. Contrast enhanced CT scan has replaced the classical angiography as the diagnostic tool of choice. Patients with life-threatening multisystem injuries are scheduled for delayed repair after initial stabilization. Currently, the use of endovascular stent-grafts (EVAR) is being investigated. Our personal series confirms that EVAR for ATAT is a viable alternative to open repair while minimizing the morbidity and mortality of the open procedure and having a limited impact on trauma destabilization. The assessment of long-term durability of EVAR is one of the key issues to consider EVAR as the first choice of treatment
    Type of Publication: Journal article published
    PubMed ID: 16533692
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  • 6
    Keywords: ANGIOGENESIS ; CANCER ; SURVIVAL ; tumor ; Germany ; THERAPY ; DENSITY ; DIAGNOSIS ; imaging ; liver ; NEW-YORK ; SAMPLE ; SAMPLES ; TISSUE ; TUMORS ; NUCLEAR-MEDICINE ; PATIENT ; BIOMARKERS ; TISSUES ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; BREAST ; immunohistochemistry ; REGION ; REGIONS ; MUSCLE ; PARAMETERS ; NORMAL TISSUE ; SERIES ; CONTRAST-ENHANCED MRI ; nuclear medicine ; ASBESTOS ; mesothelioma ; MALIGNANT MESOTHELIOMA ; LUNG-CARCINOMA ; HETEROGENEITY ; radiology ; RE ; THERAPIES ; monitoring ; dynamic contrast enhanced MRI ; biomarker ; analysis ; methods ; SUBTYPES ; NUCLEAR ; USA ; correlation ; spleen ; Aorta ; microvascular density ; MEDICINE ; quantitative ; PHARMACOKINETIC ANALYSIS ; DCE-MRI ; neoplasm ; CD-34 ; IMAGING BIOMARKER
    Abstract: Rationale and Objectives. Malignant mesothelioma (MM) of the pleura is an aggressive and often fatal neoplasm. Because MM frequently demonstrates marked angiogenesis, it may be responsive to antiangiogenic therapy, but effective methods for selecting and monitoring of patients are further needed. We employed dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and quantitative immunohistochemistry (IHC) to characterize the microvascularity of MM using both a physiologic and ultrastructural method. Materials and Methods. Nineteen patients diagnosed with MM were enrolled and DCE-MRI was performed before antiangiogenic treatment. For each patient, tumor regions were characterized by their DCE-MRI-derived pharmacokinetic parameters (Amp, k(ep), k(el)), which were also compared to those of normal tissue (aorta, liver, spleen, and muscle). In addition, quantitative ITIC of representative samples was performed with CD-34 staining to compare the calculated microvessel density (MVD) results with DCE-MRI results. Results. MM demonstrated markedly abnormal pharmacokinetic properties compared with normal tissues. Among the parameters tested, Amp was significantly different in MM (P :5.001) compared to normal organs. Despite the observation that the MVD of mesotheliomas in this series was high compared to other tumors, DCE-MRI pharmacokinetic parameters had a moderately positive correlation with MVD (r = 0.5). Conclusions. DCE-MRI and IHC can be used in patients with MM to visualize tumor microvascularity and to characterize tumor heterogeneity. DCE-MRI and IHC results positively correlated, though moderately, but these two methods present as essential tumor biomarkers. This multimodal characterization may be useful in selecting possible tumor subtypes that would benefit from antiangiogenic therapy
    Type of Publication: Journal article published
    PubMed ID: 18423312
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  • 7
    Keywords: THERAPY ; CT ; QUANTIFICATION ; VOLUME ; REPRODUCIBILITY ; malignant melanoma ; SOLID TUMORS ; CRITERIA ; lymph nodes ; SMALL PULMONARY NODULES ; therapy monitoring ; PRECISION ; RECIST ; volumetric analysis ; COMPUTER-AIDED VOLUMETRY ; INTEROBSERVER-VARIABILITY ; VIVO PORCINE LUNGS
    Abstract: OBJECTIVE: Quantification of tumour burden in oncology requires accurate and reproducible evaluation. The current standard is RECIST measurement with its inherent disadvantages. Volumetric analysis is an alternative for therapy monitoring. The aim of this study was to evaluate the feasibility of volumetric analysis of lymph node metastases using a software prototype in a follow-up setting. METHODS: MSCT was performed in 50 patients covering the chest, abdomen and pelvis. A total of 174 suspicious lymph nodes were evaluated by two radiologists regarding short axis diameters and volumetric analysis using semi-automated software. Quality of segmentation, time, maximum diameter and volume were documented. Variability of the derived change rates was computed as the standard deviation of the difference of the obtained respective change rates. RESULTS: The software performance provides robust volumetric analysis. Quality of segmentation was rated acceptable to excellent in 76-79% by each reader. Mean time spent per lesion was 38 s. The variability of change in effective diameters was 10.6%; for change rates of RECIST maximum diameter variability was 27.5%. CONCLUSION: Semi-automated volumetric analysis allows fast and convenient segmentation of most lymph node metastases. Compared with RECIST the inter-observer-variability in baseline and follow-up is reduced. This should principally allow subtle changes to be subclassified within the RECIST stable range as minor response [-15% to +10%].
    Type of Publication: Journal article published
    PubMed ID: 20953870
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  • 8
    Keywords: MODEL ; VISUALIZATION ; DISEASE ; BLOOD-FLOW ; MAGNETIC-RESONANCE ; magnetic resonance imaging ; SURVEILLANCE ; ANGIOGRAPHY ; endovascular repair ; endovascular ; ANEURYSM REPAIR ; Aorta ; stent graft ; phase-contrast flow ; blood flow velocity
    Abstract: PURPOSE: To validate flow measurements within an aortic nickel-titanium (nitinol) stent graft using velocity-encoded cine magnetic resonance imaging (VEC MRI) and to assess intraobserver agreement of repeated flow measurements. MATERIALS AND METHODS: An elastic tube phantom mimicking the descending aorta was developed with the possibility to insert an aortic nitinol stent graft. Different flow patterns (constant, sinusoidal and pulsatile aortic flow) were applied by a gear pump. A two-dimensional phase-contrast sequence was used to acquire VEC perpendicular cross-sections at six equidistant levels along the phantom. Each acquisition was performed twice with and without stent graft, and each dataset was analysed twice by the same reader. The percental difference of the measured flow volume to the gold standard (pump setting) was defined as the parameter for accuracy. Furthermore, the intraobserver agreement was assessed. RESULTS: Mean accuracy of flow volume measurements was -0.45+/- 1.63% without stent graft and -0.18+/- 1.45% with stent graft. Slightly lower accuracy was obtained for aortic flow both without (-2.31%) and with (-1.29%) stent graft. Accuracy was neither influenced by the measurement position nor by repeated acquisitions. There was significant intraobserver agreement with an intraclass correlation coefficient of 0.87 (without stent graft, p〈0.001) and 0.80 (with stent graft, p〈0.001). The coefficient of variance was 0.25% without stent graft and 0.28% with stent graft. CONCLUSION: This study demonstrated high accuracy and excellent intraobserver agreement of flow measurements within an aortic nitinol stent graft using VEC MRI. VEC MRI may give new insights into the haemodynamic consequences of endovascular aortic repair.
    Type of Publication: Journal article published
    PubMed ID: 20888719
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  • 9
    Keywords: POPULATION ; magnetic resonance imaging ; AGE ; NECK ; COMPUTED-TOMOGRAPHY ; ANGIOGRAPHY ; physiology ; CONFORMATIONAL-CHANGES ; THORACIC AORTA ; endovascular repair ; endovascular ; ANEURYSMS ; stent graft ; ARTERIAL STIFFNESS ; WAVE REFLECTION
    Abstract: PURPOSE: To test our hypothesis that distension and displacement in various segments of the healthy thoracic aorta are significant and can be predicted based on clinical characteristics. MATERIALS AND METHODS: Sixty-one Caucasian volunteers without cardiovascular disease (49 +/- 16 years, range 19-82; 28 men, 33 women) divided into two age groups (A: 〈50, B: 〉/= 50 years) underwent 1.5-T MRI. ECG-gated dynamic data sets were acquired at five locations perpendicular to the thoracic aorta. Aortic distension and Centre of Mass (CoM) displacement were determined as percentages of diastolic aortic diameter. A multiple linear regression model including age group, gender, location, mean arterial blood pressure, heart rate and body mass index was tested. RESULTS: Mean aortic distension averaged over all locations was 11.2 +/- 4.1% (age group A) and 6.7 +/- 3.3% (age group B), mean displacement 15.1 +/- 8.3% (A) and 11.0 +/- 6.2% (B). Systolic and diastolic aortic diameter and CoM position significantly differed at all locations (p〈0.001). Distension and displacement could be predicted based on the regression model (p〈0.001). Age group A and women exhibited significantly greater distension and displacement compared to age group B (p〈0.001) and men (p〈0.01), respectively. Distension increased, displacement decreased from proximal to distal. CONCLUSION: Distension and translational displacement are significant at all levels of the thoracic aorta and can be predicted based on clinical characteristics.
    Type of Publication: Journal article published
    PubMed ID: 20850234
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  • 10
    Keywords: CT ; QUANTIFICATION ; echocardiography ; DISSECTION ; INSIGHT ; ROOT MOTION ; STENT-GRAFT TREATMENT
    Abstract: Previous analyses of aortic displacement and distension using computed tomography angiography (CTA) were performed on double-oblique multi-planar reformations and did not consider through-plane motion. The aim of this study was to overcome this limitation by using a novel computational approach for the assessment of thoracic aortic displacement and distension in their true four-dimensional extent. Vessel segmentation with landmark tracking was executed on CTA of 24 patients without evidence of aortic disease. Distension magnitudes and maximum displacement vectors (MDV) including their direction were analyzed at 5 aortic locations: left coronary artery (COR), mid-ascending aorta (ASC), brachiocephalic trunk (BCT), left subclavian artery (LSA), descending aorta (DES). Distension was highest for COR (2.3 +/- A 1.2 mm) and BCT (1.7 +/- A 1.1 mm) compared with ASC, LSA, and DES (p 〈 0.005). MDV decreased from COR to LSA (p 〈 0.005) and was highest for COR (6.2 +/- A 2.0 mm) and ASC (3.8 +/- A 1.9 mm). Displacement was directed towards left and anterior at COR and ASC. Craniocaudal displacement at COR and ASC was 1.3 +/- A 0.8 and 0.3 +/- A 0.3 mm. At BCT, LSA, and DES no predominant displacement direction was observable. Vessel displacement and wall distension are highest in the ascending aorta, and ascending aortic displacement is primarily directed towards left and anterior. Craniocaudal displacement remains low even close to the left cardiac ventricle.
    Type of Publication: Journal article published
    PubMed ID: 24135852
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