Carbon Nanotube Field Emitters Synthesized on Metal Alloy Substrate by PECVD for Customized Compact Field Emission Devices to Be Used in X-Ray Source Applications.

In this study, a simple, efficient, and economical process is reported for the direct synthesis of carbon nanotube (CNT) field emitters on metal alloy. Given that CNT field emitters can be customized with ease for compact and cold field emission devices, they are promising replacements for thermionic emitters in widely accessible X-ray source electron guns. High performance CNT emitter samples were prepared in optimized plasma conditions through the plasma-enhanced chemical vapor deposition (PECVD) process and subsequently characterized by using a scanning electron microscope, tunneling electron microscope, and Raman spectroscopy. For the cathode current, field emission (FE) characteristics with respective turn on (1 µA/cm²) and threshold (1 mA/cm²) field of 2.84 and 4.05 V/µm were obtained. For a field of 5.24 V/µm, maximum current density of 7 mA/cm² was achieved and a field enhancement factor ß of 2838 was calculated. In addition, the CNT emitters sustained a current density of 6.7 mA/cm² for 420 min under a field of 5.2 V/µm, confirming good operational stability. Finally, an X-ray generated image of an integrated circuit was taken using the compact field emission device developed herein.

LOGIS (LOcalization of Ground-glass-opacity and pulmonary lesions for mInimal Surgery) registry: Design and Rationale.

BACKGROUND AND PURPOSE: An optimal pulmonary localization technique for video-assisted thoracic surgery (VATS) of small lung nodules has not yet been established. The LOcalization of Ground-glass-opacity and pulmonary lesions for mInimal Surgery (LOGIS) registry aims to establish a multicenter database and investigate the usefulness and safety of localization techniques for small pulmonary lesions in individuals undergoing VATS. METHODS/DESIGN: The LOGIS registry is a large-scale, multicenter cohort study, aiming to enroll 825 patients at 10 institutions. Based on the inclusion and exclusion criteria, all study participants with pulmonary lesions indicated for VATS will be screened and enrolled at each site. All study participants will undergo preoperative lesion localization by the hook-wire or lipiodol localization methods according to site-specific methods. Within a few hours of marking, thoracoscopic surgery will be done under general anesthesia by experienced thoracoscopic surgeons. The primary endpoints are the success and complication rates of the two localization techniques. Secondary endpoints include procedure duration, recurrence rate, and all-cause mortality. Study participant enrollment will be completed within 2 years. Procedure success rates and incidence of complications will be analyzed based on computed tomography findings. Procedure duration, recurrence rate, and all-cause mortality will be compared between the two techniques. The study will require 5 years for completion, including 6 months of preparation, 3.5 years for recruitment, and 1 year of follow-up endpoint assessment. DISCUSSION: The LOGIS registry, once complete, will provide objective comparative results regarding the usefulness and safety of the lipiodol and hook-wire localization techniques.

Prognostic value of baseline carcinoembryonic antigen and cytokeratin 19 fragment levels in advanced non-small cell lung cancer.

BACKGROUND: Serum carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA 21-1) levels are prognostic predictors in non-small cell lung cancer (NSCLC). However, even in patients with the same stage of cancer, the serum levels of those markers often vary. OBJECTIVE: We investigated the association between the initial biomarker levels and prognosis. METHODS: We retrospectively reviewed 445 patients with advanced NSCLC and their baseline serum CEA and CYFRA 21-1 levels. Patients were divided into four groups according to the initial levels of those markers: the NN, HN, NH, and HH group. Kaplan-Meier survival analysis with Log-rank test and Cox proportional hazards regression analysis were performed. RESULTS: The 5-year overall survival (OS) rate in the HN group was the highest (32.2%). Multivariate analyses indicated that the HN group (HR 0.520, 95% CI 0.309-0.878, P= 0.014), female sex (HR 0.685, 95% CI 0.498-0.944, P= 0.021), serum CRP level (HR 1.057, 95% CI 1.034-1.080, P< 0.001), chemotherapy (HR 0.324, 95% CI 0.228-0.460, P< 0.001), and chemotherapy/radiotherapy (HR 0.266, 95% CI 0.171-0.414, P< 0.001) were independent prognostic factors for overall survival. CONCLUSIONS: In advanced NSCLC, patients with baseline high serum CEA but low CYFRA 21-1 level have a significant longer overall survival regardless of clinical stage.

Direct Synthesis of Carbon Nanotube Field Emitters on Metal Substrate for Open-Type X-ray Source in Medical Imaging.

We report the design, fabrication and characterization of a carbon nanotube enabled open-type X-ray system for medical imaging. We directly grew the carbon nanotubes used as electron emitter for electron gun on a non-polished raw metallic rectangular-rounded substrate with an area of 0.1377 cm² through a plasma enhanced chemical vapor deposition system. The stable field emission properties with triode electrodes after electrical aging treatment showed an anode emission current of 0.63 mA at a gate field of 7.51 V/µm. The 4.5-inch cubic shape open type X-ray system was developed consisting of an X-ray aperture, a vacuum part, an anode high voltage part, and a field emission electron gun including three electrodes with focusing, gate and cathode electrodes. Using this system, we obtained high-resolution X-ray images accelerated at 42-70 kV voltage by digital switching control between emitter and ground electrode.

Primary Pleural Synovial Sarcoma with Metastatic Cardiac Involvement: A Case Report.

Primary pleuropulmonary synovial sarcomas are rare soft tissue malignancies; combined metastatic involvement of the heart is extremely rare. In this case report, a 17-year-old female presented with a history of chest pain. Chest radiographs revealed a round mass in the left upper hemithorax, and computed tomography (CT) showed a well-defined heterogeneous enhancing mass abutting the pleura. A core needle biopsy revealed malignant spindle cells. Surgical resection was performed, and a final diagnosis of primary pleural synovial sarcoma, monophasic fibrous type, was made. The patient underwent radical irradiation and chemotherapy and remained stable for 28 months until a follow-up chest CT showed a poorly enhancing nodule in the left pericardial region that enlarged after 5 months. Surgical resection was performed. Histological examination confirmed metastatic cardiac involvement from a primary pleural synovial sarcoma. We report this unusual case of a primary pleural synovial sarcoma metastasis to the heart.

Impact of a vendor-specific motion-correction algorithm on image quality, interpretability, and diagnostic performance of daily routine coronary CT angiography: influence of heart rate on the effect of motion-correction.

To investigate the impact of a vendor-specific motion-correction algorithm on morphological assessment of coronary arteries using coronary CT angiography (cCTA) and to evaluate the influence of heart rate (HR) on the motion-correction effect of this algorithm. Eighty-four patients (mean age 56.3 ± 11.4 years; 53 males) were divided into two groups with a HR of ≥65 and <65 bpm during cCTA, respectively. Images were assigned quality scores (graded 1-4) on coronary segments. Interpretability was defined as a grade >1. Catheter angiography was used to determine the diagnostic accuracy of cCTA for detecting significant stenosis (≥50 %). We compared the image quality, interpretability and diagnostic accuracy between the standard and motion-correction reconstructions in both groups. The motion-correction reconstructions showed significantly (p < 0.05) higher image quality in the proximal and middle right coronary artery (RCA) in the low HR group (57.2 ± 5.0 bpm; n = 51) and proximal-to-distal RCA, posterior descending artery, and proximal and distal left circumflex artery in the high HR group (71.1 ± 4.6 bpm; n = 33). The per-segment interpretability was significantly higher using motion-correction algorithm in the middle RCA in the low HR group and in the proximal and middle RCA in high HR group. Overall, the image quality and interpretability were improved using motion-correction reconstructions in both groups (p < 0.05). Motion-correction reconstruction demonstrated higher (p < 0.05) diagnostic accuracy in 25 patients from both groups. Use of the motion-correction algorithm improves the overall image quality and interpretability of cCTA in both groups. However, it may be more beneficial to the patients with a higher HR.

Quantitative analysis of lungs and airways with CT in subjects with the chronic obstructive pulmonary disease (COPD) candidate FAM13A gene: case control study for CT quantification in COPD risk gene.

OBJECTIVE: To investigate the relationship between a chronic obstructive pulmonary disease (COPD) candidate gene, based on a genomewide association study, and computed tomographic (CT) quantitative analysis; and to find a phenotype in the COPD candidate FAM13A gene. MATERIALS AND METHODS: This study was conducted in subclinical male smokers between 2 groups with matched age and smoking status; 162 subjects (mean age, 58 years) with risk (CTGA, n = 85) and reference (TCAG, n = 77) diplotypes replicated through genomewide association study underwent chest CT for quantitative analysis of lungs and airways. We analyzed the measures in both the risk and reference groups using a 2-sample t test. RESULTS: Subjects with the risk CTGA diplotype had significantly higher total lung volume and emphysema index than the reference TCAG diplotype (P = 0.04). Mean lung density was significantly lower (P < 0.05) in the risk group. However, in the analysis of airways, wall area, luminal area, wall and lumen area ratio, and mean lung density on expiratory and inspiratory phases, no significant differences between the 2 groups were seen. CONCLUSIONS: There is a strong relationship between CT quantitative analysis and the COPD candidate gene. Furthermore, the CTGA diplotype was associated with emphysema among the phenotypes of COPD.

A Quantitative Study of Airway Changes on Micro-CT in a Mouse Asthma Model: Comparison With Histopathological Findings.

PURPOSE: To evaluate airway changes in ovalbumin-induced asthmatic mice in terms of postmortem micro-CT images and pathological findings. METHODS: Asthma was induced in mice by intraperitoneal injection and nasal instillation of ovalbumin aluminium hydroxide into mice (experimental group, n=6), and another group of mice received intraperitoneal injection and nasal instillation of distilled phosphate-buffered saline (control group, n=6). Bronchial lumen area was measured in the main bronchial lumen of the distal third bronchial branch level (6 parts per each mouse) on axial scans of Micro-CT, using a Lucion's smart pen (semi-automated) and a curve pen (manual). Bronchial wall thickness was obtained in 4 sections (2 levels on either side) after the third bronchial branch by measuring the diameter which was perpendicular to the longitudinal axis of the main bronchus on curved Multi-planar reconstruction (MPR) images. Histologic slides were obtained from the lesion that was matched with its CT images, and bronchial wall thicknesses were determined. RESULTS: The mean bronchial lumen area was 0.196±0.072 mm(2) in the experimental group and 0.243±0.116 mm(2) in the control group; the difference was significant. Bronchial wall thickness on micro-CT images (mean, 0.119±0.01 vs. 0.108±0.013 mm) and in pathological specimens (mean, 0.066±0.011 vs. 0.041±0.009 mm) were thicker in the experimental group than in the control group; bronchial wall thickness on micro-CT images correlated well with pathological thickness (for the experimental group, r=0.712; for the control group, r=0.46). The thick bronchial wall in the experimental group demonstrated submucosal hypertrophy along with goblet cell hyperplasia and smooth muscle hyperplasia. CONCLUSIONS: The results of this study suggest that asthma may induce thickening of bronchial wall and narrowing of the lumen area on micro-CT images and that these results may significantly correlate with pathological findings.

CT signs of right ventricular dysfunction correlated with echocardiography-derived pulmonary arterial systolic pressure: incremental value of the pulmonary arterial diameter index.

To investigate and compare the potential of right to left ventricular volume (RVV/LVV) and diameter ratios (RVD/LVD) for the prediction of pulmonary arterial hypertension (PH) over 40 mmHg, and then to evaluate the incremental value of the pulmonary artery diameter index (PADi; PAD/body surface area) in the prediction of PH over 40 mHg. We correlated the followings on chest CT with same-day echocardiography-derived pulmonary arterial systolic pressure (PASP) in 139 patients (64.8 ± 15.4 years; 63 male): PADi, RVD/LVD on axial (RVD axial/LVD axial) and four chamber (RVD 4CH/LVD 4CH) views, and RVV/LVV. Those were then adjusted (multiplied) by PADi. Areas under the curves (AUC) for predicting PASP > 40 mmHg were calculated. All patients had undergone non-ECG-gated, contrast enhanced chest CT on a 64-slice multi-detector CT system. The correlation of PASP with RVV/LVV (R(2) = 0.45) was stronger than with RVD axial/LVD axial (R(2) = 0.28) and RVD 4CH/LVD 4CH (R(2) = 0.34). When adjusted by PADi, the correlation improved; R(2) = 0.55, 0.41 and 0.47, respectively. The AUC of adjusted RVV/LVV was significantly higher than those of other CT measurements (P < 0.05) excluding adjusted RVD 4CH/LVD 4CH (P = 0.08). With 18.80 as the cutoff, its sensitivity and specificity for predicting PH > 40 mmHg were 83 and 87 %, respectively. Ventricular volume is superior to ventricular diameter ratios in the prediction of PH > 40 mmHg with better correlation with PASP. PADi adds incremental value to these measurements in the prediction of PH > 40 mmHg. Of those, adjusted RVV/LVV is most reliable and predicts PH > 40 mmHg with fairly high sensitivity and specificity.

Practical application of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) imaging in minimizing metallic artifacts.

Iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) is a recently developed method for robust separation of fat and water with very high signal-to-noise-ratio (SNR) efficiency. In contrast to conventional fat-saturation methods, IDEAL is insensitive to magnetic field (B0 and B1) inhomogeneity. The aim of this study was to illustrate the practical application of the IDEAL technique in reducing metallic artifacts in postoperative patients with metallic hardware. The IDEAL technique can help musculoskeletal radiologists make an accurate diagnosis particularly in musculoskeletal imaging by reducing metallic artifacts, enabling the use of contrast enhancement, improving SNR performance, and providing various modes of MR images with one scan parameter.

Treatment of a recurrent chest wall desmoid tumor using a CT-guided steroid injection.

We report on a 41-year-old woman with a chest wall desmoid tumour who was successfully treated with a computed tomography (CT)-guided steroid injection. She presented with a palpable mass in the right upper chest wall and was treated by surgical excision and postoperative radiation therapy due to recurrence of the mass at the surgical site. At 20 months after the second operation, a recurrent mass was again detected in the anterosuperior portion of the previous surgical site on CT. We performed a CT-guided steroid injection weekly for 4 weeks by applying a mixture of 3 mL of triamcinolone acetonide (40 mg/mL) and 3 mL of 1% Lidocaine, administering 4-6 mL of the mixture, to the lesion. Six months later, CT showed a marked decrease in the size of the mass.

Apical-sparing variant of stress cardiomyopathy: Integrative analysis with multidetector row cardiac computed tomography in dual-energy mode.

Stress cardiomyopathy is a unique reversible cardiac syndrome that is frequently precipitated by a physical or emotionally stressful event and has a clinical presentation that is indistinguishable from a myocardial infarction. We describe the case of a patient with apical sparing variant of stress cardiomyopathy in whom dual energy cardiac CT identified characteristic regional wall motion abnormality without concomitant coronary artery disease and myocardial perfusion defects.

The bright rim sign on MRI for anterior talofibular ligament injury with arthroscopic correlation.

OBJECTIVE: The purpose of this article is to determine whether bright rim lesions on MRI are a marker for anterior talofibular ligament injury. MATERIALS AND METHODS: The study included 34 patients who had an ankle injury and underwent arthroscopic surgery. All patients underwent 3-T MRI for the diagnosis of anterior talofibular ligament injury. If MRI revealed nonvisualization of the ligament, ligament discontinuity, and unusual ligament thickening (criterion 1) or the bright rim sign (criterion 2), the injury was considered to be a ligament disruption. After MRI, ankle arthroscopy was performed in all patients for a definitive diagnosis. RESULTS: Arthroscopy showed anterior talofibular ligament disruption in 33 patients. When the MRI diagnosis was based on criterion 1, anterior talofibular ligament disruption was diagnosed with a sensitivity of 60.6-66.7% and an accuracy of 58.8-67.6%. When the MRI diagnosis was based on both criteria 1 and 2, anterior talofibular ligament disruption was diagnosed with a sensitivity of 90.9-97.0% and an accuracy of 88.2-94.1%. By adding criterion 2 to the diagnosis, the sensitivity for anterior talofibular ligament injury was increased significantly (p < 0.01), and 8-12 additional patients with anterior talofibular ligament injury were diagnosed, most of whom exhibited a partial tear of the anterior talofibular ligament on arthroscopy. The interobserver agreement rate for the presence of anterior talofibular ligament disruption using criterion 1, both criteria, and the bright rim sign was fair to excellent. CONCLUSION: A cortical defect with bright dotlike or curvilinear high-signal-intensity lesions on T2-weighted MRI may be an additional morphologic feature to increase the diagnostic performance of detecting anterior talofibular ligament injuries, including those with partial tears.

Successful treatment of malignant superior vena cava syndrome using a stent-graft.

We report successful outcomes after endovascular placement of a stent graft in a 74- and a 77-year-old men, both of whom had malignant superior vena cava syndrome caused by squamous cell carcinoma. In each patient, successful palliation of the malignant superior vena cava syndrome was achieved by placement of a stent graft. No procedure-related complications were observed. The patients were asymptomatic until their deaths, seven and 14 months after stent graft placement, respectively.

Role of neutrophils in persistent airway obstruction due to refractory asthma.

BACKGROUND AND OBJECTIVE: One of the clinical manifestations of refractory asthma (RA) in a certain group of patients is persistent airway obstruction (PAO), despite treatment with high doses of inhaled and/or systemic corticosteroids. Airway neutrophilic inflammation is frequently observed in RA; however, the relationship between neutrophilic inflammation and PAO has not been evaluated in this group of patients. The aim of this study was to compare the clinical parameters and patterns of inflammatory cells between patients with or without PAO due to RA, and to identify the factors associated with PAO. METHODS: Seventy-seven patients with RA were recruited from a cohort of 2298 asthmatic patients. Sputum differential cell counts were performed at initial presentation. Clinical and physiological parameters were compared between patients with (n = 19) or without PAO (n = 58). RESULTS: The group with PAO had a longer duration of asthma and a higher frequency of near-fatal asthma than the non-PAO group, although higher doses of inhaled corticosteroids were used in the PAO group (P = 0.037). Neutrophilic inflammation was predominant in the group with PAO, whereas eosinophilic inflammation was predominant in the non-PAO group (P = 0.003). When both groups were stratified according to smoking status, the non-smoking PAO group had the longest duration of asthma, with early onset of asthma (P < 0.05). The non-smoking PAO group tended to have the highest percentage of sputum neutrophils. Irrespective of smoking status, the percentage of sputum eosinophils was significantly higher in the non-PAO group than in the PAO group. CONCLUSIONS: Patients with PAO due to RA show different clinical manifestations when compared with those without PAO and have neutrophil-dominant airway inflammation.

Utility of postmortem autopsy via whole-body imaging: initial observations comparing MDCT and 3.0 T MRI findings with autopsy findings.

OBJECTIVE: We prospectively compared whole-body multidetector computed tomography (MDCT) and 3.0 T magnetic resonance (MR) images with autopsy findings. MATERIALS AND METHODS: Five cadavers were subjected to whole-body, 16-channel MDCT and 3.0 T MR imaging within two hours before an autopsy. A radiologist classified the MDCT and 3.0 T MRI findings into major and minor findings, which were compared with autopsy findings. RESULTS: Most of the imaging findings, pertaining to head and neck, heart and vascular, chest, abdomen, spine, and musculoskeletal lesions, corresponded to autopsy findings. The causes of death that were determined on the bases of MDCT and 3.0 T MRI findings were consistent with the autopsy findings in four of five cases. CT was useful in diagnosing fatal hemorrhage and pneumothorax, as well as determining the shapes and characteristics of the fractures and the direction of external force. MRI was effective in evaluating and tracing the route of a metallic object, soft tissue lesions, chronicity of hemorrhage, and bone bruises. CONCLUSION: A postmortem MDCT combined with MRI is a potentially powerful tool, providing noninvasive and objective measurements for forensic investigations.

Primary pulmonary T-cell lymphoma: a case report.

Primary pulmonary T-cell lymphoma is an extremely rare malady, and we diagnosed this in a 52-year-old male who was admitted to our hospital with cough for the previous two weeks. The chest CT demonstrated multiple variable sized mass-like consolidations with low density central necrosis in the peripheral portion of both the upper and lower lobes. Positron emission tomography (PET) showed multiple areas of hypermetabolic fluorodeoxyglucose (FDG) uptake in both lungs with central metabolic defects, which correlated with central necrosis seen on CT. The histological sample showed peripheral T-cell lymphoma of the not otherwise specified form. The follow-up CT scan showed an increased extent of the multifocal consolidative lesions despite that the patient had undergone chemotherapy.

Interleukin-13 and its receptors in idiopathic interstitial pneumonia: clinical implications for lung function.

Idiopathic interstitial pneumonia (IIP) is characterized by varying degrees of interstitial fibrosis. IL-13 and IL-4 are strong inducers of tissue fibrosis, whereas IFN-gamma has antifibrotic potential. However, the roles of these substances in IIP remain unknown. IL-13, IL-4, and IFN-gamma were measured in the BAL fluid of 16 idiopathic pulmonary fibrosis (IPF) patients, 10 nonspecific interstitial pneumonia (NSIP) patients, and 8 normal controls. The expression of IL-13 and IL-13Ralpha1/alpha2 in lung tissues was analyzed using ELISA and immunohistochemistry. IL-13 levels were significantly higher in IPF patients than the others (P<0.05). IL-4 levels were higher in both IPF and NSIP patients than in normal controls (P<0.05), and IFN-gamma levels were lower in NSIP patients than in normal controls (P=0.047). IL-13 levels correlated inversely with FVC% (r=-0.47, P=0.043) and DLCO% (r=-0.58, P=0.014) in IPF and NSIP patients. IL-13 was strongly expressed in the smooth muscle, bronchial epithelium, alveolar macrophages and endothelium of IPF patients. IL-13Ralpha1, rather than IL-13Ralpha2, was strongly expressed in the smooth muscle, bronchial epithelium, and endothelium of IPF patients. IL-13 and its receptors may contribute to the pathogenesis of fibrosis in IIP and appear to be related to the severity of the disease.

Comparison of high-resolution ultrasonography and computed tomography in the diagnosis of nasal fractures.

OBJECTIVE: The purpose of this study was to compare the value of high-resolution ultrasonography (HRUS) and computed tomography (CT) in the diagnosis of nasal fractures. METHODS: Facial CT and HRUS examinations performed on 140 consecutive patients (103 male and 37 female; age range, 2-74 years; mean, 26 years) with nasal trauma between October 2004 and April 2007 were retrospectively evaluated. Sonograms were obtained with a hockey stick probe (15-7 MHz linear array transducer). All patients also underwent facial CT and conventional radiography. The nasal fracture detection rates for HRUS, CT, and conventional radiography were compared with the clinical and surgical diagnosis. Nasal fractures were classified into high- and low-grade groups according to severity. They were also compared with the CT findings of all 280 lateral nasal bones and with HRUS findings as the reference standard. RESULTS: The accuracy rates for HRUS, CT, and conventional radiography in detecting nasal fractures were 100%, 92.1%, and 78.6%, respectively. Compared with HRUS, CT revealed only 196 of 233 lateral nasal bone fractures; its accuracy was 80%. In high-grade fractures, the accuracy of CT was 87%, but it decreased to 68% in low-grade fractures. CONCLUSIONS: Compared with HRUS, CT had lower accuracy, especially in low-grade nasal fractures. Thus, HRUS is a reliable diagnostic tool for the evaluation of nasal fractures.

Digital tomosynthesis of the chest for lung nodule detection: interim sensitivity results from an ongoing NIH-sponsored trial.

The authors report interim clinical results from an ongoing NIH-sponsored trial to evaluate digital chest tomosynthesis for improving detectability of small lung nodules. Twenty-one patients undergoing computed tomography (CT) to follow up lung nodules were consented and enrolled to receive an additional digital PA chest radiograph and digital tomosynthesis exam. Tomosynthesis was performed with a commercial CsI/a-Si flat-panel detector and a custom-built tube mover. Seventy-one images were acquired in 11 s, reconstructed with the matrix inversion tomosynthesis algorithm at 5-mm plane spacing, and then averaged (seven planes) to reduce noise and low-contrast artifacts. Total exposure for tomosynthesis imaging was equivalent to that of 11 digital PA radiographs (comparable to a typical screen-film lateral radiograph or two digital lateral radiographs). CT scans (1.25-mm section thickness) were reviewed to confirm presence and location of nodules. Three chest radiologists independently reviewed tomosynthesis images and PA chest radiographs to confirm visualization of nodules identified by CT. Nodules were scored as: definitely visible, uncertain, or not visible. 175 nodules (diameter range 3.5-25.5 mm) were seen by CT and grouped according to size: < 5, 5-10, and > 10 mm. When considering as true positives only nodules that were scored definitely visible, sensitivities for all nodules by tomosynthesis and PA radiography were 70% (+/- 5%) and 22% (+/- 4%), respectively, (p < 0.0001). Digital tomosynthesis showed significantly improved sensitivity of detection of known small lung nodules in all three size groups, when compared to PA chest radiography.