Computer-aided measurements of pulmonary emphysema in chest multidetector-row spiral computed tomography: effect of image reconstruction parameters.

Objective: To evaluate the effect of different image reconstruction parameters on quantitative automated measurements of pulmonary emphysema in chest multidetector-row spiral computed tomography.

Materials And Methods: Thirty patients with known emphysema underwent multidetector-row spiral computed tomography. Retrospective reconstruction with a soft tissue kernel (Siemens B20 at 1-mm, 2-mm, and 3-mm slices) and 4 alternative kernel grades (from smooth to sharp: Siemens B30, B40, B50, B60 at 1-mm slices) was performed.

Introduction of a dedicated circulation phantom for comprehensive in vitro analysis of intravascular contrast material application.

Objectives: To develop a circulation phantom with physiologic circulation parameters, including a pulmonary and a body circulation for the evaluation of intravascular contrast material (CM) application.

Materials And Methods: The circulation phantom consists of a low-pressure venous system into which CM is injected, a pulmonary circulation, and high-pressure body circulation with an anthropometric aorta and coronary arteries. The phantom is driven by a pulsatile Harvard heart pump.

Which Iodine concentration in chest CT?--a prospective study in 300 patients.

In computed tomography (CT) several contrast media with different iodine concentrations are available. The aim of this study is to prospectively compare contrast media with iodine concentrations of 300, 370 and 400 mg iodine/ml for chest- CT. 300 consecutive patients were prospectively enrolled, under a waiver of the local ethics committee.

Computer-aided detection of pulmonary embolism: influence on radiologists' detection performance with respect to vessel segments.

The purpose was to assess the sensitivity of a CAD software prototype for the detection of pulmonary embolism in MDCT chest examinations with regard to vessel level and to assess the influence on radiologists' detection performance. Forty-three patients with suspected PE were included in this retrospective study. MDCT chest examinations with a standard PE protocol were acquired at a 16-slice MDCT.

Dose reduction during CT fluoroscopy: phantom study of angular beam modulation.

Purpose: To prospectively evaluate, in a phantom, the dose reductions achievable by using angular beam modulation (ABM) during computed tomographic (CT) fluoroscopy-guided thoracic interventions.

Materials And Methods: To enable measurement of organ doses and effective patient dose, a female Alderson-Rando phantom was equipped with thermoluminescent dosimeters (TLDs) in 41 positions, with three TLDs in each position. Additionally, the local dose was assessed in 22 locations above the phantom to estimate the radiation exposure to the radiologist's hand and the patient's skin dose during thoracic interventions.

Prospective evaluation of image quality with use of a patient image gallery for dose reduction in pediatric 16-MDCT.

Objective: The purposes of this study were to evaluate prospective adjustment of dose settings in pediatric 16-MDCT by use of computer-simulated images in a patient image gallery and to compare the dose reduction achieved with that of standard pediatric protocols.

Subjects And Methods: The image gallery consisted of images from weight-dependent sample examinations performed with varied simulated tube current-exposure time settings. The scanning parameters prospectively chosen on the basis of the image quality of the image gallery were used for 30 16-MDCT examinations (chest, n = 15; abdomen, n = 8; pelvis, n = 7) of 22 children (14 boys, eight girls; mean age, 6.

Flat panel computed tomography for non-invasive flow measurement: initial results in in-vitro studies.

The purpose was to evaluate the feasibility of flat panel computed tomography (FPCT) for quantifying flow by analyzing contrast changes along the z-axis in an in-vitro setting. Contrast material was injected in a 3-mm silicone tube at flow rates of 0.1, 0.

Value of conventional chest radiography for the detection of coronary calcifications: comparison with MSCT.

Purpose: To evaluate if computed tomography (CT) coronary calcium scoring is needed after detection of coronary calcifications on conventional chest radiographs.

Materials And Methods: One hundred and five patients (67 men; 57.2+/-12.

Assessment of global left and right ventricular function using dual-source computed tomography (DSCT) in comparison to MRI: an experimental study in a porcine model.

Objective: We sought to evaluate the ability of retrospectively ECG-gated dual-source computed tomography (DSCT) to assess left (LV) and right ventricular (RV) functional parameters in comparison to 1.5 T magnetic resonance imaging (MRI).

Materials And Methods: Ten domestic pigs (60 kg) underwent both contrast-enhanced cardiac DSCT and cardiac MRI using standardized examination protocols under general anesthesia.

Molecular MR imaging of human thrombi in a swine model of pulmonary embolism using a fibrin-specific contrast agent.

Objective: Molecular targeted MR imaging of human clots material in a model of pulmonary embolism using a fibrin-specific magnetic resonance imaging contrast agent (EP-2104R, EPIX Pharmaceuticals, Cambridge, MA).

Material And Methods: Fresh ex vivo engineered thrombi (human blood) and human clots removed from patients were delivered in 11 swine. Molecular MR imaging with a 3D gradient-echo [3D fast field echo (3DFFE)] sequence and a navigator-gated and cardiac-triggered 3D inversion-recovery black-blood gradient-echo sequence (IR) was performed before thrombus delivery, after thrombus delivery but before contrast media application, and 2 hours after i.

CT imaging of myocardial viability: experimental and clinical evidence.

Over the last decade, imaging of myocardial viability has become a well-established indication in patients suffering from myocardial infarction. Myocardial viability imaging is routinely performed using (18)F-fluorodeoxyglucose positron emission tomography, single-photon emission computed tomography or magnetic resonance imaging. Only recently have several multi-slice spiral computed tomography (MSCT) techniques been evaluated for visualisation of myocardial infarction.

Dual-source computed tomography for assessing cardiac function: a phantom study.

Purpose: To investigate the influence of heart rate and temporal resolution on the assessment of global ventricular function with dual-source computed tomography (DSCT).

Materials And Methods: A dynamic cardiac phantom was repeatedly scanned with a DSCT scanner applying a standardized scan protocol at different heart rates, ranging from 40 to 140 bpm. Images were reconstructed with monosegmental and bisegmental algorithms using data from a single source and from both sources.

MDCT detection of mitral valve calcification: prevalence and clinical relevance compared with echocardiography.

Objective: The purpose of this study was to analyze the prevalence and clinical significance of mitral valve calcification incidentally detected on chest CT scans in comparison with echocardiography.

Materials And Methods: The data of 390 patients (227 men and 163 women; mean age, 62.4 +/- 12.

Automated volumetry of solid pulmonary nodules in a phantom: accuracy across different CT scanner technologies.

Objectives: The accuracy of automated volumetry for pulmonary nodules in a phantom using different CT scanner technologies from single-slice spiral CT (SSCT) to 64-slice multidetector-row CT (MDCT) was compared.

Materials And Methods: A lung phantom with 5 different categories of pulmonary nodules was scanned using a single-slice spiral CT, a 4-slice MDCT, a 16-slice MDCT and a 64-slice MDCT. Each category comprised of 7-9 nodules each (total n = 40) with different known volumes.

Evaluation of automated attenuation-based tube current adaptation for coronary calcium scoring in MDCT in a cohort of 262 patients.

The aim of our study was to evaluate attenuation-based tube current adaptation in coronary calcium scoring using ECG-gated multi-detector-row CT (MDCT). A total of 262 patients underwent non-enhanced cardiac MDCT. Group 1 was scanned using a standard protocol with 120 kV and 150 mAs(eff).

Late-phase MSCT in the different stages of myocardial infarction: animal experiments.

The purpose of this study was to intraindividually evaluate myocardial late enhancement on multislice spiral computed tomography (MSCT) for the assessment of the different stages of myocardial infarction (MI) in comparison with magnetic resonance (MR) imaging. Reperfused MI was successfully induced in seven pigs. Delayed enhancement MR imaging and late-phase MSCT were performed on day 0 as well as 7, 28 and 90 days after the procedure.

Evaluation of aortocoronary bypass stents with cardiac MDCT compared with conventional catheter angiography.

Objective: The objective of our study was to determine the accuracy of 16-MDCT for evaluation of stent patency and in-stent stenosis in venous coronary bypass grafts.

Subjects And Methods: Fourteen patients who had previous stent placements in stenosed venous coronary bypass grafts underwent contrast-enhanced MDCT of the heart (collimation, 16 x 0.75 mm; 120 kV; 550 mAs(eff)) and invasive coronary angiography.

Low tube voltage improves computed tomography imaging of delayed myocardial contrast enhancement in an experimental acute myocardial infarction model.

Objective: We sought to evaluate the influence of tube voltage on the visualization of acute myocardial infarction (MI) in cardiac multislice spiral computed tomography (MSCT).

Materials And Methods: Acute MI was induced in 12 domestic pigs by a 45-minute balloon occlusion of the left anterior descending artery. Delayed enhancement magnetic resonance imaging was performed 15 minutes after the injection of 0.

Accuracy of automated volumetry of pulmonary nodules across different multislice CT scanners.

The purpose of this study was to compare the accuracy of an automated volumetry software for phantom pulmonary nodules across various 16-slice multislice spiral CT (MSCT) scanners from different vendors. A lung phantom containing five different nodule categories (intraparenchymal, around a vessel, vessel attached, pleural, and attached to the pleura), with each category comprised of 7-9 nodules (total, n = 40) of varying sizes (diameter 3-10 mm; volume 6.62 mm(3)-525 mm(3)), was scanned with four different 16-slice MSCT scanners (Siemens, GE, Philips, Toshiba).

Active breathing control (ABC): determination and reduction of breathing-induced organ motion in the chest.

Purpose: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility.

Methods And Materials: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system.

Quantitative prediction of contrast enhancement from test bolus data in cardiac MSCT.

The purpose of this study was to evaluate a new algorithm for the prediction of contrast enhancement from test bolus data in cardiac multislice spiral computed tomography (MSCT). An algorithm for the prediction of contrast enhancement using test bolus data was developed. A total of 30 consecutive patients (15 male, 69.

Cardiac CT: coronary arteries and beyond.

Multi-detector-row computed tomography (MDCT) has emerged as a rapidly developing method for non-invasive imaging of the heart. An understanding of ECG synchronization, contrast material administration, patient preparation and image post-processing is needed to optimize image quality. The basic technical principles and essentials of these technical basics are described here.

Small pulmonary nodules: effect of two computer-aided detection systems on radiologist performance.

Purpose: To prospectively compare the effects of two computer-aided detection (CAD) systems on the detection of small pulmonary nodules at multi-detector row computed tomography (CT) by using a consensus panel decision as the reference standard.

Materials And Methods: Institutional review board approval and informed consent were obtained. Multi-detector row CT scans were randomly chosen and prospectively evaluated in 25 patients.

Asbestos Surveillance Program Aachen (ASPA): initial results from baseline screening for lung cancer in asbestos-exposed high-risk individuals using low-dose multidetector-row CT.

The purpose of this study was to assess the prevalence of lung cancer in a high-risk asbestos-exposed cohort using low-dose MDCT. Of a population of 5,389 former power-plant workers, 316 were characterized as individuals at highest risk for lung cancer according to a lung-cancer risk model including age, asbestos exposure and smoking habits. Of these 316, 187 (mean age: 66.

Radiofrequency ablation of osteoid osteoma: initial results with a bipolar ablation device.

Purpose: To report the initial results with percutaneous radiofrequency (RF) ablation of osteoid osteomas with a bipolar ablation device.

Materials And Methods: Twelve patients (seven male patients and five female patients; mean age, 17.3 years; age range, 6-36 y) with clinically and radiologically suspected osteoid osteoma were treated with computed tomography-guided percutaneous bipolar RF ablation.