The role of multidetector computed tomography angiography for the diagnosis of pulmonary embolism.

From a radiological point of view, computed tomography pulmonary angiography (CTPA) has effectively become the de-facto first-line imaging test for the evaluation of pulmonary embolism (PE), as patients with a high-quality negative CTPA do not require further examination or treatment for suspected PE. We are likely to see further technical developments in CT technology in the near future. These advances will most likely further improve image quality.

Multidetector CT of thoracic aortic aneurysms.

Thoracic aortic aneurysms (TAAs) can be broadly divided into true aneurysms and false aneurysms (pseudoaneurysms). True aneurysms contain all three layers of the aortic wall (intima, media, and adventitia), whereas false aneurysms have fewer than three layers and are contained by the adventitia or periadventitial tissues. Multidetector computed tomographic (CT) angiography allows the comprehensive evaluation of TAAs in terms of morphologic features and extent, presence of thrombus, relationship to adjacent structures and branches, and signs of impending or acute rupture, and is routinely used in this setting.

Anatomy and terminology for the interpretation and reporting of cardiac MDCT: part 2, CT angiography, cardiac function assessment, and noncoronary and extracardiac findings.

Objective: In this part 2 of our two-part article, we aim to describe the evaluation and interpretation of coronary CTA, cardiac structures, and cardiac functional assessment using an approach similar to the reporting of catheter angiography and echocardiography.

Conclusion: The superb resolution and the isotropic image data acquisition of ECG-gated coronary CT angiography (CTA) enable evaluation of the coronary arteries and cardiac anatomy in any selected plane. The consistent use of standard terminology when reporting cardiac CT findings is part of a structured and comprehensive coronary CTA report.

Anatomy and terminology for the interpretation and reporting of cardiac MDCT: part 1, Structured report, coronary calcium screening, and coronary artery anatomy.

Objective: In this part one of a two-part article, we aim to illustrate our understanding of and approach to comprehensive cardiac CT reporting, cardiac CT technique, and coronary calcium scoring CT, as well as normal and anomalous coronary artery anatomy.

Conclusion: Structured cardiac CT reporting is important to effectively communicate with referring clinicians. Knowledge of cardiac CT technique, cardiac anatomy, and standard anatomic and physiologic terminology can assist the reader in creating a consistent and comprehensive cardiac CT report.

Left ventricular functional analysis with 16- and 64-row multidetector computed tomography: comparison with gated single-photon emission computed tomography.

Objective: To compare the left ventricular (LV) ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) from electrocardiogram-gated computed tomography (CT) to gated single-photon emission computed tomography (SPECT).

Methods: Fifty-seven patients underwent electrocardiogram-gated multidetector CT and SPECT examinations within a 3-month period, without interim cardiac events. The LV EF, EDV, and ESV were compared.

The prognostic value of cardiopulmonary exercise testing in idiopathic pulmonary fibrosis.

Rationale: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive dyspnea, impaired gas exchange, and ultimate mortality.

Objectives: To test the hypothesis that maximal oxygen uptake during cardiopulmonary exercise testing at baseline and with short-term longitudinal measures would predict mortality in patients with idiopathic pulmonary fibrosis.

Methods: Data from 117 patients with IPF and longitudinal cardiopulmonary exercise tests were examined retrospectively.

Assessment of radiologist performance in the detection of lung nodules: dependence on the definition of "truth".

Rationale And Objectives: Studies that evaluate the lung nodule detection performance of radiologists or computerized methods depend on an initial inventory of the nodules within the thoracic images (the "truth"). The purpose of this study was to analyze (1) variability in the "truth" defined by different combinations of experienced thoracic radiologists and (2) variability in the performance of other experienced thoracic radiologists based on these definitions of "truth" in the context of lung nodule detection in computed tomographic (CT) scans.

Materials And Methods: Twenty-five thoracic CT scans were reviewed by four thoracic radiologists, who independently marked lesions they considered to be nodules >or=3 mm in maximum diameter.

Dual left anterior descending coronary artery: CT findings.

Objective: Dual left anterior descending coronary artery (LAD) is a rare congenital anomaly with four subtypes. This anomaly has been described in the angiographic literature, but with the increasing use of coronary CT, it becomes imperative for CT interpreters to be aware of this entity, its implications, and the cross-sectional findings. We report the ECG-gated 64-MDCT coronary angiographic findings on two types of dual LAD (types 1 and 4).

Accuracy of high-resolution CT in the diagnosis of diffuse lung disease: effect of predominance and distribution of findings.

Objective: The purpose of this study was to determine whether the predominant findings at high-resolution CT influence the accuracy of diagnosis of diffuse lung disease.

Materials And Methods: The cases of 100 patients with diffuse lung disease who underwent high-resolution CT and tissue diagnosis were studied. Three thoracic radiologists reviewed high-resolution CT images blindly and independently for patterns of abnormality, listing their three main diagnoses and level of confidence in the first choice.

Smoking-related interstitial lung disease: radiologic-clinical-pathologic correlation.

Cigarette smoking is a recognized risk factor for development of interstitial lung disease (ILD). There is strong evidence supporting a causal role for cigarette smoking in development of respiratory bronchiolitis ILD (RB-ILD), desquamative interstitial pneumonitis (DIP), and pulmonary Langerhans cell histiocytosis (PLCH). In addition, former and current smokers may be at increased risk for developing idiopathic pulmonary fibrosis (IPF).

Stent size selection using 64-detector coronary computed tomography angiography: a comparison to invasive coronary angiography.

Rationale And Objectives: Compare stent size selection using coronary computed tomography angiography (CCTA) to invasive coronary angiography (ICA). CCTA is increasingly performed before cardiac catheterization; however, the utility of incorporating these data into coronary interventions is unknown.

Methods: Retrospective study of 18 consecutive patients with 24 coronary artery lesions evaluated with 64-detector CCTA followed by ICA and resulting stent placement.

Measurements of pulmonary vein ostial diameter and distance to first bifurcation: a comparison of different measurement methods.

The purpose of this study was to evaluate the agreement between axial, multiplanar reformatted (MPR) and semi-automated software measurements of pulmonary vein ostial diameters and distance to the first bifurcation. CT examinations of the thorax were retrospectively reviewed in 150 consecutive patients. The pulmonary vein ostial diameter and distance to the first bifurcation of the four main pulmonary veins were independently measured.

Idiopathic nonspecific interstitial pneumonia: report of an American Thoracic Society project.

Rationale: The 2002 American Thoracic Society/European Respiratory Society classification of idiopathic interstitial pneumonias identified nonspecific interstitial pneumonia (NSIP) as a provisional diagnosis. Concern was expressed that NSIP was a "wastebasket" category, difficult to distinguish from other idiopathic interstitial pneumonias.

Objectives: The following questions were addressed: (1) Is idiopathic NSIP a distinct entity? 2) If so, what are its clinical, radiologic and pathologic characteristics? (3) What is the role of radiology and pathology in establishing the diagnosis? (4) To make a diagnosis of idiopathic NSIP, what other disorders need to be excluded and how should this be done?

Methods: Investigators who had previously reported cases of idiopathic NSIP were invited to submit cases for review (n = 305).

Automatic multiscale enhancement and segmentation of pulmonary vessels in CT pulmonary angiography images for CAD applications.

The authors are developing a computerized pulmonary vessel segmentation method for a computer-aided pulmonary embolism (PE) detection system on computed tomographic pulmonary angiography (CTPA) images. Because PE only occurs inside pulmonary arteries, an automatic and accurate segmentation of the pulmonary vessels in 3D CTPA images is an essential step for the PE CAD system. To segment the pulmonary vessels within the lung, the lung regions are first extracted using expectation-maximization (EM) analysis and morphological operations.

Comparison of on-call radiology resident and faculty interpretation of 4- and 16-row multidetector CT pulmonary angiography with indirect CT venography.

Rationale And Objectives: On-call radiology residents frequently interpret computed tomography (CT) pulmonary angiography and CT venography studies outside of routine working hours. The purpose of this study was to compare resident and faculty interpretation concordance rates and to see if concordance rates differed depending on the number of CT detectors used.

Materials And Methods: The study population included 122 consecutive CT pulmonary angiography (CTPA) and CT venography (CTV) examinations performed on a four-row multidetector CT (MDCT) and 125 consecutive CTPA examinations performed using a 16-row MDCT scanner with CTV performed in 124 patients.

The Lung Image Database Consortium (LIDC): a comparison of different size metrics for pulmonary nodule measurements.

Rationale And Objectives: The goal was to investigate the effects of choosing between different metrics in estimating the size of pulmonary nodules as a factor both of nodule characterization and of performance of computer aided detection systems, because the latter are always qualified with respect to a given size range of nodules.

Materials And Methods: This study used 265 whole-lung CT scans documented by the Lung Image Database Consortium (LIDC) using their protocol for nodule evaluation. Each inspected lesion was reviewed independently by four experienced radiologists who provided boundary markings for nodules larger than 3 mm.

The Lung Image Database Consortium (LIDC) data collection process for nodule detection and annotation.

Rationale And Objectives: The Lung Image Database Consortium (LIDC) is developing a publicly available database of thoracic computed tomography (CT) scans as a medical imaging research resource to promote the development of computer-aided detection or characterization of pulmonary nodules. To obtain the best estimate of the location and spatial extent of lung nodules, expert thoracic radiologists reviewed and annotated each scan. Because a consensus panel approach was neither feasible nor desirable, a unique two-phase, multicenter data collection process was developed to allow multiple radiologists at different centers to asynchronously review and annotate each CT scan.

The Lung Image Database Consortium (LIDC): ensuring the integrity of expert-defined "truth".

Rationale And Objectives: Computer-aided diagnostic (CAD) systems fundamentally require the opinions of expert human observers to establish "truth" for algorithm development, training, and testing. The integrity of this "truth," however, must be established before investigators commit to this "gold standard" as the basis for their research. The purpose of this study was to develop a quality assurance (QA) model as an integral component of the "truth" collection process concerning the location and spatial extent of lung nodules observed on computed tomography (CT) scans to be included in the Lung Image Database Consortium (LIDC) public database.

The Lung Image Database Consortium (LIDC): an evaluation of radiologist variability in the identification of lung nodules on CT scans.

Rationale And Objectives: The purpose of this study was to analyze the variability of experienced thoracic radiologists in the identification of lung nodules on computed tomography (CT) scans and thereby to investigate variability in the establishment of the "truth" against which nodule-based studies are measured.

Materials And Methods: Thirty CT scans were reviewed twice by four thoracic radiologists through a two-phase image annotation process. During the initial "blinded read" phase, radiologists independently marked lesions they identified as "nodule >or=3 mm (diameter)," "nodule <3 mm," or "non-nodule >or=3 mm.

CT and MRI of acute thoracic cardiovascular emergencies.

A wide spectrum of acute cardiovascular disorders is seen in patients who are hospitalized in a critical care setting. Imaging plays a central role in the diagnosis and management of these conditions. The most frequently used imaging remains chest radiography; however, more advanced modalities, including coronary angiography, echocardiography, and radioisotope scintigraphy, have well established roles in the assessment of patients in the critical care setting.

Reliability of MDCT measurements of pulmonary vein ostial diameter and distance to first bifurcation: an interobserver study comparing radiologists with a semiautomated software.

The purpose of this study was to evaluate agreement between radiologists and semiautomated software measurements of pulmonary vein ostial diameters and distance to the first bifurcation. Computed tomography (CT) examinations of the thorax were retrospectively reviewed in 50 consecutive patients. The pulmonary vein ostial diameter and distance to the first bifurcation of the four major, and the middle lobe pulmonary veins, were measured independently by two experienced cardiothoracic radiologists, and using CardEP semiautomated software.

Case 116: lymphangioleiomyomatosis.

A 49-year-old premenopausal woman presented with acute onset of lower abdominal pain. Physical examination revealed her abdomen was distended and nontender. Her white blood cell count and serum markers for ovarian cancer were normal (alpha-fetoprotein level, 1.

Metastatic shoulder liposarcoma to the right ventricle: CT findings.

Metastatic cardiac liposarcoma is rare. A right ventricular liposarcoma metastasis is described in a 46-year-old man, who was admitted with significant shortness of breath and fatigue, and in whom a large lobulated low attenuation mass occupying most of the right ventricular cavity, with extension through the right ventricular apex and a small-to-moderate pericardial effusion was detected by electrocardiogram-gated cardiac computed tomography. The patient had an antecedent history of a left upper arm liposarcoma treated with surgical resection, chemotherapy, and postoperative radiotherapy 3 years earlier.