摘要:

The purpose of this study was to evaluate a large-area, flat-panel X-ray detector, which uses cesium-iodide (CsI) and amorphous silicon (a-Si). Conventional images were compared with digital images acquired with equal dose (2.5&mgr;Gy) and with 50% dose reduction. Fifteen consecutive patients were studied prospectively using an asymmetric screen–film system (detector dose, 2.5&mgr;Gy). Digital images were taken from the same patients in a posteroanterior view with detector doses of 2.5 and 1.25&mgr;Gy, respectively. The CsI/a-Si active-matrix imager had a panel-size of 43 × 43 cm, a matrix of 3 × 3k, and a pixel-pitch of 143&mgr;m. Hard copies were presented in a random order to eight independent observers, who rated image quality according to six subjective quality criteria. Statistical significance of differences was evaluated with Student'sttest for paired samples (confidence level, 95%). Digital radiographs with 2.5 and 1.25&mgr;Gy were superior to conventional images regarding all quality criteria. Statistically significant differences were observed for five of six criteria at a detector dose of 2.5&mgr;Gy and for only one quality feature at 1.25&mgr;Gy. Flat-panel digital imagers based on CsI/a-Si technique have the potential to replace conventional systems and might allow a reduction of radiation dose by 50% without loss of image quality.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The aim of the present study was to assess the evolution of various computed tomographic (CT) findings of lymphocytic interstitial pneumonia (LIP) with determination of potentially reversible or irreversible features. The study included 14 patients with biopsy-proved LIP who had serial thin-section CT examination 4 to 82 months (median 13 months) apart. Initial and follow-up CT scans were evaluated independently and then directly compared with each other by two observers. The main parenchymal abnormalities on the initial CT scan consisted of ground-glass attenuation (n = 14), thickening of interlobular septa (n = 13), centrilobular nodules (n = 12), cystic airspaces (n = 10), and airspace consolidation (n = 4). On follow-up CT, nine patients improved, one showed no change, and four showed increased extent of disease. With the exception of cysts, the parenchymal opacities were reversible. On follow-up CT, new cysts were seen in three patients; these developed mainly in areas with centrilobular nodules on initial CT. Honeycombing was seen on follow-up CT in four patients; in three patients it developed in areas of airspace consolidation and in one patient it developed in an area with ground-glass attenuation on initial CT. The majority of patients with LIP improved on follow-up. However, airspace consolidation may progress to honeycombing and centrilobular nodules may precede cystic formation.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Seventeen patients with lung transplants were evaluated with inspiratory, postexpiratory, and low-dose, dynamic expiratory thin-section computed tomography (CT). Region of interest measurements were performed on inspiration and expiration images with both techniques, and mean lung attenuation changes between inspiration and expiration images were calculated and compared. Dynamic expiratory thin-section CT resulted in a significantly greater increase in lung attenuation than postexpiratory thin-section CT. Dynamic expiratory thin-section CT may prove useful in the evaluation of patients with lung diseases characterized by air flow obstruction with little increase in patient radiation dose.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The authors assess clinical and radiographic findings of pulmonary nodules and masses after lung and heart-lung transplantation. One hundred and fifty nine patients who survived at least 3 months after lung and heart-lung transplantation were followed by serial chest radiographs for a median of 27 months. Single or multiple lung nodules or masses were noted at chest radiography in 15 (9.4%) of 159 patients. Imaging findings and causes of these nodules and masses were reviewed retrospectively. Infection was found in 10 (6%) of 159 patients. Specific pathogens (11 pathogens in 10 patients) wereAspergillus(n = 4),Mycobacteria(n = 4), and other bacteria (n = 3). Noninfectious causes were found in 5 (3%) of patients and included B-cell lymphoma (n = 2), bronchogenic carcinoma (n = 2), and pulmonary infarcts (n = 1). Nodules and masses appeared a median of 11 months after transplantation (range: 0.2 to 36 months). Five patients (33%) had single lesions; the other 10 (67%) patients had multiple lesions (range 2 to 50).Aspergilluslesions were most commonly located in the upper lobes, were cavitary in three of four patients, and all were fatal. Nodules and masses arose in the transplanted lung in 12 (80%) of the patients, and in the native lung in 3 (20%) of the patients (2 bronchogenic carcinoma, 1M. tuberculosissimulating bronchogenic carcinoma). Nodules and masses detected by chest radiography are not uncommon (9.4%) after lung and heart-lung transplantation. Infections are more common than noninfectious causes of posttransplant nodules and masses. Specific clinical and imaging characteristics may provide clues to etiology.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The authors set out to determine how histologic variability in bronchioloalveolar cell carcinoma impacts dominant radiographic patterns shown by computed tomography (CT). Thoracic CT's of all patients with pathologically confirmed bronchioloalveolar cell carcinoma diagnosed over a 36-month period were reviewed without knowledge of underlying histologic type. The dominant CT pattern was recorded as 1) air space consolidation; 2) focal nodule or mass; and 3) multicentric nodules or masses. Nodules and masses were further characterized according to borders, distribution, and associated findings, including spiculations and air bronchograms. Histology was independently reviewed. Twenty-seven patients, 16 women and 11 men, mean age 60 years, were diagnosed with bronchioloalveolar cell carcinoma. In 6 (22%) of the 27 cases, the histology was mucinous, with malignant goblet cells identified. Five (83%) of the six mucinous neoplasms manifested as air space consolidation and three (50%) of the six presented with multiple nodules, in which two had coexisting air space consolidation. Of the remaining 21 cases (78%) with nonmucinous histology, the primary malignant cells of origin included Clara cells (n = 8), tall columnar epithelial cells (n = 7) and alveolar type II pneumocytes (n = 6). Sclerosis was a dominant histologic feature in 14 (67%) of the 21 cases. Seventeen (81%) of the nonmucinous neoplasms presented as isolated nodules or masses and four (19%) presented as multiple nodules or masses. Of these four patients with multifocal disease and nonmucinous histology, multiple bronchioloalveolar adenomas accounted for multicentricity in two of the patients. Significant correlations included air space consolidation with mucinous histology (p= 0.001) and focal nodule or mass with nonmucinous histology (p= 0.001). At CT of bronchioloalveolar cell carcinoma, the patterns of air-space consolidation correlate with mucinous histology and isolated nodules or masses with nonmucinous histology. The pattern of multiple nodules or masses, however, did not correlate with histology. Coexisting bronchioloalveolar adenomas can contribute to apparent multicentric disease in patients with nonmucinous histology.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Unilateral absence of the pulmonary artery and bronchial-to-coronary-artery anastomosis are rarely described congenital vascular anomalies. The authors report a case of a 49-year-old female presenting with both anomalies. The presenting symptoms and pertinent diagnostic imaging are described, including conventional radiographs, angiography, computed tomography, and magnetic resonance imaging, and the therapeutic options available are discussed.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The authors evaluate paradoxical diaphragmatic motion using magnetic resonance (MR) imaging in patients with emphysema. The subjects were 12 healthy volunteers and 10 male patients with moderate to severe air flow obstruction. With subjects in the supine position, 30 sequential sagittal images of the bilateral lungs were obtained during quiet and forced breathing using a 1.5T MR unit with a body coil. The sequence was single shot fast spin echo (SSFSE) with half Fourier transformation. Subtraction images were made from the original images (by subtracting a given image from the preceding image), which visualized the chest wall motion as white or black bands on the edge of the lung fields. The authors evaluated both the original and subtraction images. MR imaging showed abnormal hemidiaphragmatic motion during forced breathing: the ventral portion of the hemidiaphragm moved downward while the dorsal part moved upward like a seesaw in 6 patients. MR images also revealed abnormal ribcage motion; the ventral ribcage moved anteriorly when the hemidiaphragm moved upward in 7 patients. No abnormal motion was observed in healthy volunteers. MR is a noninvasive and useful tool for evaluating the asynchronous respiratory motion in patients with emphysema.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Pulmonary dirofilariasis can produce a noncalcified solitary nodule and therefore be mistaken for a lung cancer. Careful analysis of the imaging findings in this disease can suggest the proper evaluation and management in affected patients.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

18Fluorine-2-Fluoro-2-Deoxy-D-Glucose positron emission tomography (18FDG PET) allows imaging of sites with increased metabolic activity. Increased metabolic activity in mediastinal nodes in sarcoidosis has been described. We report the prospective diagnosis of thoracic sarcoidosis on18FDG PET based on extensive, peripheral, upper lobe parenchymal, and mediastinal nodal tracer uptake.

ISSN:0883-5993    

出版商:OVID    

年代:2000

数据来源: OVID