256 Slice Multi-detector Computed Tomography Thoracic Aorta Computed Tomography Angiography: Improved Luminal Opacification Using a Patient-Specific Contrast Protocol and Caudocranial Scan Acquisition.

CLINICAL RELEVANCE STATEMENT: Caudocranial scan direction and contrast injection timing based on measured patient vessel dynamics can significantly improve arterial and aneurysmal opacification and reduce both contrast and radiation dose in the assessment of thoracic aortic aneurysms (TAA) using helical thoracic computed tomography angiography (CTA). OBJECTIVES: To investigate opacification of the thoracic aorta and TAA using a caudocranial scan direction and a patient-specific contrast protocol. MATERIALS AND METHODS: Thoracic aortic CTA was performed in 160 consecutive patients with suspected TAA using a 256-slice computed tomography scanner and a dual barrel contrast injector. Patients were subjected in equal numbers to one of two contrast protocols. Patient age and sex were equally distributed across both groups. Protocol A, the department's standard protocol, consisted of a craniocaudal scan direction with 100 mL of contrast, intravenously injected at a flow rate of 4.5 mL/s. Protocol B involved a caudocranial scan direction and a novel contrast formula based on patient cardiovascular dynamics, followed by 100 mL of saline at 4.5 mL/s. Each scan acquisition comprised of 120 kVp, 200 mA with modulation, temporal resolution 0.27 seconds, and pitch 0.889:1. The dose length product was measured between each protocol and data generated were compared using Mann-Whitney U nonparametric statistics. Receiver operating characteristic analysis, visual grading characteristic (VGC), and κ analyses were performed. RESULTS: Mean opacification in the thoracic aorta and aneurysm measured was 24 % and 55%, respectively. The mean contrast volume was significantly lower in protocol B (73 ± 10 mL) compared with A (100 ± 1 mL) (P<0.001). The contrast-to-noise ratio demonstrated significant differences between the protocols (protocol A, 18.2 ± 12.9; protocol B, 29.7 ± 0.61; P < 0.003). Mean effective dose in protocol B (2.6 ± 0.4 mSv) was reduced by 19% compared with A (3.2 ± 0.8 mSv) (P < 0.004). Aneurysmal detectability demonstrated significant increases by receiver operating characteristic and visual grading characteristic analysis for protocol B compared with A (P < 0.02), and reader agreement increased from poor to excellent. CONCLUSIONS: Significant increase in the visualization of TAAs following a caudocranial scan direction during helical thoracic CTA can be achieved using low-contrast volume based on patient-specific contrast formula.

High-pitch Helical Dual-source Computed Tomographic Pulmonary Angiography: Comparing Image Quality in Inspiratory Breath-hold and During Free Breathing.

PURPOSE: The purpose of this study was to compare qualitative and quantitative image parameters of dual-source high-pitch helical computed tomographic pulmonary angiography (CTPA) in breath-holding (BH) versus free-breathing (FB) patients. MATERIALS AND METHODS: Ninety-nine consented patients (61 female individuals; mean age±SD, 49±18.7 y) were randomized into BH (n=45) versus FB (n=54) high-pitch helical CTPA. Patient characteristics and CTPA radiation doses were analyzed. Two readers assessed for pulmonary embolism (PE), transient interruption of contrast, and respiratory and cardiac motion. The readers used a subjective 3-point scale to rate the pulmonary artery opacification and lung parenchymal appearance. A single reader assessed mean pulmonary artery signal intensity, noise, contrast, signal to noise ratio, and contrast to noise ratio. RESULTS: PE was diagnosed in 16% BH and 19% FB patients. CTPAs of both groups were of excellent or acceptable quality for PE evaluation and of similar mean radiation doses (1.3 mSv). Transient interruption of contrast was seen in 5/45 (11%) BH and 5/54 (9%) FB patients (not statistically significant, P=0.54). No statistically significant difference was noted in cardiac, diaphragmatic, and lung parenchymal motion. Lung parenchymal assessment was excellent in all cases, except for 5/54 (9%) motion-affected FB cases with acceptable quality (statistically significant, P=0.03). No CTPA was considered nondiagnostic by any of the readers. No objective image quality differences were noted between both groups (P>0.05). CONCLUSIONS: High-pitch helical CTPA acquired during BH or in FB yields comparable image quality for the diagnosis of PE and lung pathology, with low radiation exposure. Only a modest increase in lung parenchymal artifacts is encountered in FB high-pitch helical CTPA.

Computed tomography correlation of airway disease with bronchoscopy--part II: tracheal neoplasms.

This pictorial essay illustrates, describes, and correlates computed tomographic findings of tracheal neoplasms with fiberoptic bronchoscopy findings. Corresponding computed tomography (CT) and bronchoscopy findings of common primary tracheal neoplasms; squamous cell papilloma, papillomatosis, squamous cell carcinoma, adenoid cystic adenoma, non-Hodgkin׳s lymphoma, and a secondary malignant neoplasm of the trachea; and renal cell carcinoma were correlated.

Computed tomography correlation of airway disease with bronchoscopy: part I--nonneoplastic large airway diseases.

To illustrate and describe computed tomographic large airway pathology and correlate with fiberoptic bronchoscopy findings. Commonly encountered diseases of the large airway include tracheobronchial amyloidosis, tracheobronchopathia osteochondroplastica, tracheobronchomegaly, laryngotracheobronchial papillomatosis, relapsing polychondritis, Wegener granulomatosis, sarcoidosis, and tracheal stenosis. Computed tomography manifestations and bronchoscopic findings of these selected large airway diseases are discussed.

Middle East respiratory syndrome coronavirus (MERS-CoV) infection: chest CT findings.

OBJECTIVE: The purpose of this study was to describe the chest CT findings in seven patients with Middle East respiratory syndrome coronavirus (MERS-CoV) infection. CONCLUSION: The most common CT finding in hospitalized patients with MERS-CoV infection is that of bilateral predominantly subpleural and basilar airspace changes, with more extensive ground-glass opacities than consolidation. The subpleural and peribronchovascular predilection of the abnormalities is suggestive of an organizing pneumonia pattern.

Dendriform pulmonary ossification: Report of two cases.

Dendriform pulmonary ossification is a rare form of diffuse pulmonary ossification that is usually detected incidentally on chest radiographs or chest computed tomography (CT) imaging. In this article, we present two patients who were incidentally found to have dendriform pulmonary ossification on chest imaging. The article will present the history and imaging findings of these two cases and then review the clinical, histological, and radiographic manifestations of dendriform pulmonary ossification.