To correlate the pattern and extent of abnormalities on thin-section computed tomographic (CT) scans with pulmonary function test results in subacute and chronic hypersensitivity pneumonitis.
...Thin-section scans (1-3 mm collimation) obtained in 22 patients were assessed for pattern of abnormality and extent of disease. CT scores were correlated with functional parameters by using Spearman rank correlation and forward stepwise regression analysis.
The most common CT patterns were decreased attenuation and mosaic perfusion (n = 19), ground-glass opacification (n = 18), small nodules (n = 12), and a reticular pattern (n = 8). Areas of decreased attenuation correlated with severity of air trapping indicated by residual volume (r = .58, P < .01), whereas ground-glass opacification and reticulation correlated independently with restrictive lung function.
Areas of decreased attenuation and mosaic perfusion are an important ancillary CT finding in hypersensitivity pneumonitis, and obstructive functional abnormalities indicate that this phenomenon is caused by bronchiolitis.
Individual features of small airways disease depicted at computed tomography (CT) were correlated with functional indexes in patients with obliterative bronchiolitis.
Fifteen patients (all women) who ...fulfilled the strict criteria for diagnosis of obliterative bronchiolitis underwent thin-section CT at full inspiration and at end expiration. The CT scans were scored by two observers for extent of decreased attenuation of the lung parenchyma; end-expiration CT signs of air trapping; and bronchial dilation, wall thickening, and mucous plugging. The functional importance of each CT sign was evaluated.
Areas of decreased attenuation were present in all patients (median score at end expiration, 61%; range, 21%-83%). Bronchial wall thickening was identified in 13 of the 15 patients. Correlations of the extent of decreased attenuation and measures of air-flow obstruction were strongest between decreased attenuation at end expiration and air flow at low lung volumes (r(s) = -.70, P < .005). This relationship remained intact after correction for the severity of bronchial wall thickening.
In patients with obliterative bronchiolitis, the extent of decreased attenuation at CT was most strongly related to depression of pulmonary function tests of the small airways. Decreased attenuation is the cardinal sign for further quantitative studies of obliterative bronchiolitis.
To determine whether infiltrative lung, airway, or vascular disease can be differentiated as the cause of mosaic attenuation on thin-section computed tomographic (CT) scans of the lung.
Thin-section ...CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or clinical proof of a specific type of disease were demonstrated. Causes of the mosaic pattern included infiltrative lung disease (n = 37), airway disease (n = 22), and vascular disease (n = 11). Thin-section CT findings were assessed independently by two observers blinded to clinical findings.
The type of disease was identified correctly at CT in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by both observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease.
Infiltrative lung disease and airway disease may be differentiated reliably as the cause of mosaic attenuation on lung CT scans, whereas vascular disease is often misinterpreted as infiltrative lung disease or airway disease.
PURPOSE: To assess the ability of a semi-quantitative latex agglutination D-dimer test Accuclot™ with bedside measurements of arterial oxygen saturation, respiratory and cardiac rates to exclude ...pulmonary embolism (PE) on computed tomographic pulmonary angiography (CTPA).
MATERIALS AND METHODS: All patients referred to our CT unit for investigation of suspected acute pulmonary embolism were enrolled. Pulse oximetery, respiratory rate, heart rate and blood sampling for D-dimer testing were carried out just before CT. A high resolution CT (HRCT) of the chest was followed by a CT pulmonary angiogram (CTPA). The images were independently interpreted at a workstation with cine-paging and 2D reformation facilities by three consultant radiologists blinded to the clinical and laboratory data. If positive, the level of the most proximal embolus was recorded. Discordant imaging results were re-read collectively and consensus achieved.
RESULTS: A total of 101 patients were enrolled. The CTPA was positive for PE in 28/101 (28%). The D-dimer was positive in 65/101 (65%). Twenty-six patients had a positive CT and positive D-dimer, two a positive CT but negative D-dimer, 39 a negative CT and positive D-dimer, and 34 a negative CT and negative D-dimer. The negative predictive value of the Accuclot™ D-dimer test for excluding a pulmonary embolus on spiral CT was 0.94. Combining the D-dimer result with pulse oximetry (normal SaO2⩾90%) improved the negative predictive value to 0.97. CONCLUSION: A negative Accuclot™ D-dimer assay proved highly predictive for a negative CT pulmonary angiogram in suspected acute pulmonary embolus. If this D-dimer assay were included in the diagnostic algorithm of these patients a negative D-dimer would have unnecessary CTPA rendered in 36% of patients. Burkill, G. J. C.et al. (2002). Clinical Radiology57, 41–46.
The purpose of this work was to investigate thin section CT image enhancement of subtle areas of decreased attenuation of the lung parenchyma in suspected airways disease.
Forty-seven consecutive ...patients with chronic sputum production underwent pulmonary function tests and high resolution CT (HRCT). Single section inspiratory (INSP), expiratory (EXP), and minimum intensity projection (MINIP) images through the lower lobes were acquired. A histogram stretch was applied to the INSP and MINIP images, generating two further image formats. The five image types were compared for the extent of decreased attenuation, observer confidence, and correlations with pulmonary function tests.
Interobserver variation was lowest with MINIP images (mean weighted K: MINIP 0.70, INSP sections 0.65, other image formats < or =0.48). Observers were most confident with EXP and MINIP images. EXP sections identified more disease than MINIP images (p<0.001). Correlations with pulmonary function tests were similar for each image format.
The HRCT changes of small airways disease are enhanced with image postprocessing. MINIP images are associated with increased observer confidence and agreement as compared with HRCT alone.
To evaluate the manifestations of chronic hypersensitivity pneumonitis at radiography and high-resolution computed tomography (HRCT), findings in 16 patients with this disease were reviewed. To ...ensure objectivity, 50 patients with other chronic infiltrative lung diseases (fibrosing alveolitis n = 29, sarcoidosis n = 16, and miscellaneous conditions n = 5) were included. All patients had chronic disease with evidence of fibrosis at HRCT, as indicated by irregular linear areas and architectural distortion. Radiographs and HRCT scans were reviewed separately, in random order, and without knowledge of diagnosis. On radiographs and HRCT scans, the fibrosis in cases of hypersensitivity pneumonitis was situated predominantly in the middle lung zones or showed no zonal predominance. Lung apices and bases were relatively spared in all cases. The distribution of fibrosis in the transverse plane was random in seven cases, subpleural in six, and peri-bronchovascular in three. The distribution of fibrosis can allow distinction of chronic hypersensitivity pneumonitis from other causes of fibrosis in many cases.
AIM: To evaluate the use of ultrasound-guided percutaneous injection of thrombin for treatment of femoral artery pseudoaneurysms.
METHOD: Nine patients with a confirmed femoral false aneurysm were ...included in the study. 0.5–1ml of a 2000U/ml solution of activated bovine thrombin was injected under ultrasound visualization into the neck of the aneurysm to induce thrombosis. The parent artery and adjacent major vessels were checked during and after the procedure to exclude propagation of thrombus. A check ultrasound examination was undertaken on the following day.
RESULTS: Eight patients were successfully treated by a single injection. One patient required a second injection due to recurrence of their pseudoaneurysm 4 days after the initial treatment. The procedure was well tolerated in all cases and no complications were encountered.
CONCLUSION: This small series provides further evidence that ultrasound-guided thrombin injection is a promising new method for the treatment of femoral false aneurysms.Hughes, M. J. et al. (2000). Clinical Radiology55, 749–751.
OBJECTIVES: Biliary tract abnormalities are well recognised in AIDS, most frequently related to opportunistic infection with Cryptosporidium, Microsporidium, and cytomegalovirus. We noted a high ...frequency of pancreatic abnormalities associated with biliary tract disease. To define these further we reviewed the clinical and radiological features in these patients. METHODS: Notes and radiographs were available from two centres for 83 HIV positive patients who had undergone endoscopic retrograde cholangiopancreatography for the investigation of cholestatic liver function tests or abdominal pain. RESULTS: 56 patients had AIDS related sclerosing cholangitis (ARSC); 86% of these patients had epigastric or right upper quadrant pain and 52% had hepatomegaly. Of the patients with ARSC, 10 had papillary stenosis alone, 11 had intra- and extrahepatic sclerosing cholangitis alone, and 35 had a combination of the two. Ampullary biopsies performed in 24 patients confirmed an opportunistic infection in 16. In 15 patients, intraluminal polyps were noted on the cholangiogram. Pancreatograms were available in 34 of the 45 patients with papillary stenosis, in which 29 (81%) had associated pancreatic duct dilatation, often with associated features of chronic pancreatitis. In the remaining 27 patients, final diagnoses included drug induced liver disease, acalculous cholecystitis, gall bladder empyema, chronic B virus hepatitis, and alcoholic liver disease. CONCLUSION: Pancreatic abnormalities are commonly seen with ARSC and may be responsible for some of the pain not relieved by biliary sphincterotomy. The most frequent radiographic biliary abnormality is papillary stenosis combined with ductal sclerosis.
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