J. Broncano

Relationship between coronary artery disease and epicardial adipose tissue quantification at cardiac CT: comparison between automatic volumetric measurement and manual bidimensional estimation.

RATIONALE AND OBJECTIVES The aim of this study was to compare the reproducibility of bidimensional and volumetric quantification of epicardial adipose tissue (EAT) on cardiac computed tomography (CT) and evaluate their relationship with the extent of coronary artery disease (CAD). MATERIALS AND METHODS Forty-five individuals underwent cardiac dual-source CT and conventional coronary angiography for suspicion of CAD. Nonenhanced images acquired to assess calcium score were used to quantify EAT. Coronary stenosis grading was performed on conventional coronary angiograms using Gensini scores. Two independent observers manually measured right ventricular EAT thickness at three different levels and in two different planes (four chamber and short axis) to obtain mean values. Additionally, EAT volume was automatically determined using a commercially available software tool. RESULTS Conventional coronary angiography demonstrated nonstenotic coronary arteries in 22 subjects and significant coronary artery stenosis in 23. Significant correlations were observed between volumetric estimation of EAT and body mass index, coronary artery calcification, and Gensini score. On automatic volumetry, patients with significant coronary artery stenosis had significantly greater EAT volumes (154.58 +/- 58.91 mL) than those without significant CAD (120.94 +/- 81.85 mL) (P = .016). The manual bidimensional approach based on thickness measurements failed to show a significant difference between the two groups. Reproducibility and interobserver agreement for EAT quantification were higher when the automatic volumetric method was used (concordance-correlation coefficient, 0.96) compared to manual measurements (concordance-correlation coefficients, 0.37 for four-chamber EAT, 0.53 for short-axis EAT, and 0.58 for average EAT). CONCLUSIONS For the quantification of EAT on cardiac CT, automated volumetry is more reproducible and correlates better with the extent of CAD than manual bidimensional measurements.

Dual-source CT in heart transplant recipients: quantification of global left ventricular function and mass.

Objective To evaluate reliability of global left ventricular (LV) function and mass quantification in heart transplant recipients undergoing cardiac dual-source computed tomography examinations by means of manual contour tracing and using a region-growing–based semiautomatic segmentation analysis software tool. Materials and Methods Twenty-six consecutive heart transplant recipients undergoing cardiac dual-source computed tomography examinations with tube current modulation were included. Double-oblique short-axis 8-mm slice thickness multiphase image reconstructions were used for manual contouring and axial 0.75 mm slices were used for the semiautomated segmentation. LV ejection fraction, end-diastolic volume, end-systolic volume, stroke volume, cardiac output, and myocardial mass were assessed by both segmentation methods. Length of time needed for manual contour tracing and for the semiautomated software was recorded. Contrast-to-noise ratio was calculated in end-diastolic and end-systolic images. Results No statistically significant differences were observed in LV functional parameters derived from semiautomatic contour detection algorithm as compared with manual contouring, with excellent agreement (concordance-correlation coefficient ≥0.80). The semiautomated contour detection algorithm overestimated LV mass (mean difference 12.84±3.39) (P<0.001). The evaluated software allowed to quantify LV parameters in a significantly shorter period of time (mean difference 201.68±121.98 s, P<0.001). Contrast-to-noise ratio in end-systole and end-diastole statistically differed (mean difference 5.29±2.94 Hounsfield units; P<0.01) but did not significantly hamper the semiautomated segmentation. Conclusions Objective quantification of LV volumes using the evaluated semiautomated segmentation software is precise, reproducible, and time effective.

Ergonomía del puesto de trabajo en radiología

The replacement of conventional films and view boxes with digital images and computer monitors managed by PACS has clearly improved the diagnostic imaging workplace. The new setup has many advantages, including increased productivity brought about by decreased overall time required for image interpretation. On the other hand, the implementation of the digital workplace has increased the importance of factors like background lighting and the position of the chair, work table, mouse, keyboard, and monitor to prevent lesions that can disable the radiologist. The influence of these factors is often undervalued in the design and implementation of the radiological workplace. This article provides recommendations for the design of the radiological workplace based on ergonomics, which is the science that studies interactions among humans and other elements of a system.

Coronariografía mediante tomografía computarizada de doble fuente: calidad de imagen e intervalo de reconstrucción óptimo

OBJECTIVE To evaluate the effect of average heart rate on the quality of images of the coronary arteries and to determine the optimal reconstruction interval in nonselected patients undergoing DSCT coronary imaging. MATERIALS AND METHODS We studied 28 consecutive subjects (26 men, 2 women; mean age 60+/-12 years) undergoing contrast-enhanced DSCT (Somatom Definition, Siemens) coronary angiography. Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent readers assessed the image quality of the whole coronary tree and of each coronary artery using a four-point scale (1: impossible to evaluate, 4: excellent quality). RESULTS Mean heart rate during scanning was 73.1+/-14.8 bpm (range, 49-107 bpm). In the best reconstruction interval, excellent diagnostic image quality (score 4) was achieved for 98.8% (83/84) of coronary arteries. Very good interobserver agreement was observed for image quality rating (kappa=0.77) and for selection of the optimal reconstruction interval (kappa=0.86). Mean image quality score for the whole coronary tree was 2.84+/-0.31. No significant correlation was found between the average heart rate and the mean quality scores (r=0.108). No significant differences were found in the quality of images of the coronary arteries in systolic and diastolic reconstructions in each patient. CONCLUSIONS DSCT makes it possible to obtain excellent coronary angiograms independent of the heart rate. Reconstructions can be obtained in either the diastolic or systolic phase without significant differences in image quality, even at high heart rates.

Multidetector Computed Tomography Findings of Dense Pulmonary Emboli in Oncologic Patients

Pulmonary embolism is a frequent condition for which multidetector computed tomography (MDCT) plays an important role in its detection. Occasionally, on MDCT studies, dense linear branching opacities may be found within the pulmonary vessels. They represent dense emboli within the pulmonary arteries (DEPA). These may occur in oncologic patients that undergo specific treatments or interventional procedures, such as cement embolus from vertebroplasty, catheter or coil migration after embolization procedures, radioactive seed embolus in patients treated with local brachytherapy for prostate, lung, or liver cancer, and also in chronic pulmonary embolism. Usually DEPA does not have any clinical significance but may be fatal when massive or when in patients with impaired cardiopulmonary function. Being familiar with their radiologic appearance and knowing about the good clinical outcome of these patients will avoid unnecessary imaging testing. In this article, we describe some examples of DEPA. Based on the MDCT imaging findings, these emboli have very few or no side effects on the underlying lung parenchyma. We would like to stress the need for using bone window values for identifying these emboli. We provide examples of dense linear nonvascular images (pulmonary calcification secondary to tuberculosis (TBC) or radiotherapy, calcified mucous plugs, lung sutures, etc) that may mimic DEPA.

Migrating Azygos Vein and Vanishing Azygos Lobe: Mdct Findings

OBJECTIVE The purpose of this study was to describe six cases of migrating azygos vein and to explain the etiologic factors that contribute to the migration. Six patients with migrating azygos vein were studied by MDCT before and after migration. Five patients had right pneumothorax. All patients had repeated episodes of cough, vomiting, and a short mesoazygos. CONCLUSION Pneumothorax, increased intrathoracic pressure, and a short mesoazygos, in combination or alone, are the main factors in azygos vein migration.