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Biomedical subjects

N L Müller

Publications and source records attributed to N L Müller.

At least 37 records · Page 2Linked to original sources
PubMed2000

High-resolution computed tomographic characteristics in acute farmer's lung and in its follow-up.

High resolution computed tomography (HRCT) scans are increasingly used in hypersensitivity pneumonitis (HP). This study looked at HRCT findings at different phases of farmer's lung (FL), a common form of HP. A cross sectional analysis of 95 HRCT scans of FL cases (20 acute, 75 with a history of FL, 48 still in contact (Ex +) (dairy farm), and 27 who had ceased contact (Ex-)) was made. All scans were read independently by two, and if needed by three, radiologists blinded to the category. The lungs were divided into six regions (fives lobes + lingula), and read for attenuation/mosaic, ground-glass, micronodules, fibrosis, and emphysema. A score of 0-3 was given for each region and each variable: 0 = absence, 1 =<25% of the surface, 2 = 25-50%, 3 =>50%. Mediastinal lymphadenopathy was also noted. Ground glass, predominating in the lower lobes, was the most frequent feature in the acute and Ex+ cases. Other abnormalities had no preferential distribution. Ex+ had more ground-glass than the Ex- (p=0.0025). Emphysema was more frequently seen than interstitial fibrosis (p=0.004). Mediastinal lymphadenopathy was present in 26 cases (9 acute, 10 Ex+ and 7 Ex-). In conclusion, in farmer's lung: 1) ground-glass predominates in the lower lobes while the other abnormalities have no anatomic predilection; 2) contact avoidance allows a better resolution of computed tomography abnormalities than continued exposure; 3) emphysema is a more frequent finding than interstitial fibrosis; and 4) the presence of mediastinal lymphadenopathy has no negative diagnostic value.

Acute Disease↗
PubMed2000

Bronchocentric granulomatosis: computed tomographic findings in five patients.

AIM: The aim of this study was to assess the CT manifestations of bronchocentric granulomatosis. SUBJECTS AND METHODS: The CT results of five patients with bronchocentric granulomatosis were retrospectively analysed. The patients ranged from 20 to 72 years of age and included three men and two women. The diagnosis of bronchocentric granulomatosis was made at lobectomy (n = 2), open lung biopsy (n = 2), and transbronchial biopsy (n = 1). Only one of the five patients had asthma. RESULTS: The main findings consisted of a spiculated mass lesion (n = 3) or lobar consolidation with associated mild volume loss (n = 2). One of the two patients with consolidation had extensive mucoid impaction. The abnormalities involved predominantly an upper lobe in four patients and a lower lobe in one patient. In the four resected specimens, the macroscopic pathological appearance was consolidation (n = 2) and mass lesion (n = 2). Microscopically, the typical histology of airway-centred necrotizing granulomata was present in all cases. Aspergillus hyphae were identified in two cases. Nocardia sp. was cultured from the biopsy specimen in one case. CONCLUSION: The CT manifestations of bronchocentric granulomatosis consist of a focal mass or lobar consolidation with atelectasis. These reflect the presence of granuloma formation with or without associated bronchial obstruction.

Adult↗
PubMed2000

Pulmonary complications following lung transplantation.

Lung transplantation has become an accepted procedure for the treatment of end-stage lung disease, being successful in improving the quality and length of life of many patients. The recognition and early treatment of complications is important for long-term survival of lung transplant recipients. The radiologist frequently plays a central role in investigation. The radiological appearance of pulmonary complications arising in the immediate, early (within 2 months) and late (after 2 months) stages post-transplantation are reviewed.

Graft Rejection↗
PubMed2000

Pulmonary nodules in early fat embolism syndrome: a case report.

The radiologic abnormalities in a patient with mild clinical manifestations of fat embolism are reported. The findings consisted of small nodular opacities, which were shown on computed tomography (CT) scans to be located predominantly in the centrilobular and subpleural regions. The nodules presumably represented alveolar edema or hemorrhage secondary to the fat embolism syndrome.

Accidents, Traffic↗
PubMed2000

Lung nodule enhancement at CT: multicenter study.

PURPOSE: To test the hypothesis that absence of statistically significant lung nodule enhancement (< or =15 HU) at computed tomography (CT) is strongly predictive of benignity. MATERIALS AND METHODS: Five hundred fifty lung nodules were studied. Of these, 356 met all entrance criteria and had a diagnosis. On nonenhanced, thin-section CT scans, the nodules were solid, 5-40 mm in diameter, relatively spherical, homogeneous, and without calcification or fat. All patients were examined with 3-mm-collimation CT before and after intravenous injection of contrast material. CT scans through the nodule were obtained at 1, 2, 3, and 4 minutes after the onset of injection. Peak net nodule enhancement and time-attenuation curves were analyzed. Seven centers participated. RESULTS: The prevalence of malignancy was 48% (171 of 356 nodules). Malignant neoplasms enhanced (median, 38.1 HU; range, 14.0-165.3 HU) significantly more than granulomas and benign neoplasms (median, 10.0 HU; range, -20.0 to 96.0 HU; P < .001). With 15 HU as the threshold, the sensitivity was 98% (167 of 171 malignant nodules), the specificity was 58% (107 of 185 benign nodules), and the accuracy was 77% (274 of 356 nodules). CONCLUSION: Absence of significant lung nodule enhancement (< or = 15 HU) at CT is strongly predictive of benignity.

Adult↗
PubMed2000

Hyperoxia-induced diffuse alveolar damage in pigs: correlation between thin-section CT and histopathologic findings.

PURPOSE: To determine whether lung abnormalities at thin-section computed tomography (CT) in experimental hyperoxic lung injury correlate with the pathologic phases of diffuse alveolar damage (DAD). MATERIALS AND METHODS: Eighteen juvenile pigs were exposed to more than 80% oxygen-for 24, 48, 72, 96, or 120 hours-or room air in sealed cages. Their removed lungs were inflated with air infused through the trachea and examined with thin-section CT. Two independent observers, without knowledge of the exposure times, compared 63 areas selected on the CT scans with the corresponding pathologic and histologic findings, which were evaluated independently by two pathologists. RESULTS: CT findings correlated well with histologic findings (rho = 0.86, P <.001), which corresponded to the pathologic phases of DAD. All areas of normal CT attenuation, eight of nine spared regions within areas of opacity, and two of 15 areas of ground-glass opacity corresponded to the early exudative pathologic phase of DAD. All areas that showed traction bronchiolectasis at CT corresponded to the early proliferative pathologic phase. There was good observer agreement regarding the interpretation of CT findings (kappa statistic, >0.60) and histologic results (>/=0.70). CONCLUSION: Thin-section CT findings reflect the pathologic phases of DAD, although the early exudative phase cannot be specifically depicted by thin-section CT. Traction bronchiolectasis on a CT scan suggests progression to the proliferative phase.

Animals↗
PubMed2000

Eosinophilic lung diseases: diagnostic accuracy of thin-section CT in 111 patients.

PURPOSE: To determine whether various eosinophilic lung diseases can be differentiated by means of thin-section computed tomography (CT). MATERIALS AND METHODS: Thin-section CT scans in 111 patients with eosinophilic lung diseases-40 with chronic eosinophilic pneumonia, 16 with Churg-Strauss syndrome, 16 with allergic bronchopulmonary aspergillosis (ABPA), 13 with acute eosinophilic pneumonia, 12 with simple pulmonary eosinophilia, 11 with drug-induced eosinophilic pneumonia, and three with hypereosinophilic syndrome-were assessed independently by two observers. The observers recorded the abnormalities, diagnosis, and degree of confidence in the diagnosis. RESULTS: The two observers made a correct first-choice diagnosis on average in 61% of readings. The correct diagnosis was made in 78% of cases of chronic eosinophilic pneumonia; 81%, acute eosinophilic pneumonia; 44%, Churg-Strauss syndrome; 84%, ABPA; 17%, simple pulmonary eosinophilia; 27%, drug-induced eosinophilic pneumonia; and 33%, hypereosinophilic syndrome. The two observers made a correct diagnosis with a high degree of confidence in 36% of readings. There was moderate agreement between the observers for the correct diagnosis (kappa, 0.47) and for the correct diagnosis with a high degree of confidence (kappa, 0.59). CONCLUSION: Although eosinophilic lung diseases often can be differentiated by means of thin-section CT, correlation between CT findings and careful clinical evaluation are required for a definitive diagnosis.

Adolescent↗
PubMed2000

Nonspecific interstitial pneumonia: variable appearance at high-resolution chest CT.

PURPOSE: To describe the computed tomographic (CT) findings in patients with nonspecific interstitial pneumonia (NSIP) and to compare these with the CT findings of other chronic infiltrative lung diseases. MATERIALS AND METHODS: Findings in 50 patients with biopsy-proved NSIP and a CT scan were reviewed by two thoracic radiologists in consensus. After the findings were described, the observers judged whether the findings were compatible with previously published descriptions of NSIP or whether the findings would support the diagnosis of a different chronic infiltrative lung disease. RESULTS: Eleven (22%) of the 50 patients had CT findings that were compatible with previous descriptions of NSIP. Sixteen (32%) patients had CT findings that were more compatible with usual interstitial pneumonia. The other 23 (46%) patients had findings that were nondiagnostic or most compatible with the diagnosis of another chronic infiltrative lung disease. CONCLUSION: Contrary to previously published articles, there are a wide variety of CT findings in cases of NSIP.

Adult↗
PubMed2000

An analysis algorithm for measuring airway lumen and wall areas from high-resolution computed tomographic data.

High-resolution computed tomography (HRCT) has been used to examine airway narrowing. We developed an automated computed tomographic image analysis algorithm (computed tomographic airway morphometry; CTAM) to measure airway lumen area (Ai ), airway wall area (Awa), and airway angle of orientation. Tubes of varying size were embedded in Styrofoam and then scanned at angles between 0 degrees and 50 degrees to assess the accuracy of measurements made with CTAM. Two excised pig lungs were fixed in inflation, sectioned, and scanned. Ai and Awa were measured planimetrically from the cut surfaces to optimize CTAM measurement parameters. In CTAM, Ai was defined according to an airway-size-dependent threshold value, and total Awa was determined through a score-guided erosion method. Results were compared with measurements made through a previously validated method (manual method). CTAM provided accurate measurements of the tubes' Ai values at all angles; Awa was overestimated in direct relation to airway size. The manual method underestimated Ai and overestimated Awa in a manner directly related to airway size as well as to airway angle of orientation. In the excised lung, the mean errors of Ai and Awa measurements made with CTAM were 0.52 +/- 0.24 mm(2) and 0.17 +/- 0.32 mm(2) (mean +/- SEM), respectively. Ai errors with the manual method were similar, but Awa was overestimated to a greater degree (6.3 +/- 0.38 mm(2); p < 0.01) and the error was proportional to Awa (r = 0.64; p < 0.01). CTAM allows accurate measurements of airway dimensions and angle of orientation.

Airway Resistance↗
PubMed2000

Spiral computed tomography is comparable to angiography for the diagnosis of pulmonary embolism.

The use of spiral computed tomography (CT) for the diagnosis of pulmonary embolism has been compared to angiography, the current gold standard. However, the accuracy of pulmonary angiography has never been evaluated against an independent gold standard. The aim of this study was to compare contrast-enhanced spiral CT to pulmonary angiography for the detection of subsegmental-sized pulmonary emboli by using a methacrylate cast of porcine pulmonary vessels as an independent gold standard. We studied 16 anesthetized, juvenile pigs and injected colored methacrylate beads (3.8 mm, small; 4.2 mm, large) via the jugular vein. After embolization spiral CT (3 mm and 1 mm collimation), and pulmonary angiography were performed. Pigs were killed and the pulmonary arterial tree was cast using methacrylate. Spiral CT and angiography were interpreted independently by two radiologists. Sensitivity and 95% confidence intervals for 3 mm and 1 mm collimation CT and angiography, respectively, were: 82% (73 to 88%), 87% (79 to 93%), 87% (79 to 93%) (p = 0.42). Positive predictive values and 95% confidence intervals for 3 mm and 1 mm collimation CT and angiography, respectively, were: 94% (86 to 94%), 81% (73 to 88%), and 88% (80 to 93%). There was no difference between spiral CT and angiography for detection of subsegmental-sized pulmonary emboli. We conclude that spiral CT is comparable to angiography for detection of pulmonary emboli.

Angiography, Digital Subtraction↗
PubMed2000

Mycoplasma pneumoniae pneumonia: radiographic and high-resolution CT features in 28 patients.

OBJECTIVE: The aim of the study was to compare the radiographic and the high-resolution CT findings of Mycoplasma pneumoniae pneumonia. MATERIALS AND METHODS: The chest radiographs and 1.5-mm collimation CT scans obtained in 28 patients with serologically proven M. pneumoniae pneumonia were retrospectively reviewed. The radiographs and CT scans were analyzed independently by two observers. RESULTS: The most common finding on radiography was the presence of air-space opacification (n = 24), which was patchy and segmental (n = 9) or nonsegmental (n = 15) in distribution. On high-resolution CT, areas of ground-glass attenuation were seen in 24 patients (86%) and air-space consolidation in 22 (79%). In 13 patients (59%), the areas of consolidation had a lobular distribution evident on CT. Nodules were seen more commonly on high-resolution CT (25 of 28 patients, 89%) than on radiography (14 patients, 50%) (p < 0.01, chi-square test). In 24 (86%) of the 28 patients, the nodules had a predominantly centrilobular distribution on CT. Thickening of the bronchovascular bundles was identified more commonly on CT (23 of 28 patients, 82%) than on radiography (five patients, 18%) (p < 0.01, chi-square test). CONCLUSION: The lobular distribution, centrilobular involvement, and interstitial abnormalities in M. pneumoniae pneumonia are often difficult to recognize on radiography but can usually be seen on high-resolution CT.

Adolescent↗
PubMed2000

Semiinvasive pulmonary aspergillosis in chronic obstructive pulmonary disease: radiologic and pathologic findings in nine patients.

OBJECTIVE: The purpose of this study is to assess the radiographic, thin-section CT, and histologic findings of semiinvasive aspergillosis in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: The study included nine patients with COPD seen at the Hospital de Sant Pau during a 3-year period who had histopathologically proven aspergillosis with tissue invasion. Chest radiography and thin-section (2-mm collimation) CT of the chest were available in all cases. RESULTS: Nine patients had semiinvasive aspergillosis proven at autopsy (n = 7) or by thoracoscopically guided lung biopsy (n = 2). The radiologic findings consisted of parenchymal consolidation (n = 6) and nodules larger than 1 cm in diameter (n = 3). Parenchymal consolidation involved the upper lobes in five patients and was bilateral in four. Cavitation was present in two of the patients with consolidation and in two of the patients with nodular opacities. Adjacent pleural thickening was revealed by CT in four patients. Histologically, the areas of consolidation represented active inflammation and intraalveolar hemorrhage containing Aspergillus organisms. In the three patients with multiple cavitated nodules, a variable degree of central necrosis was observed. The inflammatory infiltrate extended into the surrounding lung parenchyma, and adjacent areas of hemorrhage were also seen. Aspergillus colonies were identified within the lung tissue. CONCLUSION: Upper lobe consolidation or multiple nodules in patients with COPD should raise the possibility of semiinvasive aspergillosis.

Aged↗
PubMed2000

Talcosis associated with IV abuse of oral medications: CT findings.

OBJECTIVE: Our objective was to evaluate the CT appearance of talcosis associated with IV abuse of oral medications and to compare the findings of talcosis related to methylphenidate with those findings seen with other drugs. MATERIALS AND METHODS: The CT scans of 12 patients with talcosis (seven men, five women), 33-54 years old (mean age, 44 years), were analyzed retrospectively. Seven patients had abused methylphenidate; five patients had no history of abuse. The diagnosis of talcosis was made histologically in 11 patients and at funduscopy in one patient. CT was performed with 1- to 1.5-mm collimation (n = 10 patients) or 5- to 10-mm collimation (n = 2). RESULTS: The predominant abnormalities seen on CT consisted of a diffuse fine nodular pattern (n = 2), a combination of nodules and lower lobe panacinar emphysema (n = 3), and ground-glass attenuation (n = 2). Emphysema was the only abnormality seen in the remaining five patients (lower lobe panacinar, n = 4; upper lobe centrilobular, n = 1). No significant difference in the prevalence of nodules and ground-glass attenuation was seen between the methylphenidate and non-methylphenidate groups. Lower lobe panacinar emphysema was more common in methylphenidate abusers (six [86%] of seven patients) than in non-mnethylphenidate drug abusers (one [20%] of five, p<0.05, Fisher's exact test). CONCLUSION: The CT manifestations of talcosis consist of a fine micronodular pattern, ground-glass attenuation, and emphysema. A significantly increased prevalence of lower lobe panacinar emphysema is seen in IV drug addicts who abuse methylphenidate.

Adult↗
PubMed2000

Acute parenchymal lung disease in immunocompetent patients: diagnostic accuracy of high-resolution CT.

OBJECTIVE: The purpose of this study was to determine whether acute parenchymal lung diseases can be differentiated on the basis of the pattern and distribution of abnormalities revealed on high-resolution CT. MATERIALS AND METHODS: High-resolution CT scans of 90 patients with acute parenchymal lung diseases (19 with bacterial pneumonia, 13 with mycoplasmal pneumonia, 21 with acute interstitial pneumonia, 18 with hypersensitivity pneumonitis, 10 with acute eosinophilic pneumonia, and nine with pulmonary hemorrhage) were independently assessed by two observers who had no knowledge of clinical or pathologic data. The observers recorded abnormalities, their first-choice diagnosis, and their degree of confidence in their first-choice diagnosis. RESULTS: The two observers made a correct first-choice diagnosis in an average of 55 (61%) of 90 cases. Correct first-choice diagnosis was made in 50% of cases of bacterial pneumonia, 62% of mycoplasmal pneumonia, 90% of acute interstitial pneumonia, 72% of hypersensitivity pneumonitis, 30% of acute eosinophilic pneumonia, and 28% of pulmonary hemorrhage. CT findings allowed distinction between infectious and noninfectious causes in 81 (90%) of 90 cases. CONCLUSION: High-resolution CT is helpful in the differential diagnosis of infectious from noninfectious acute parenchymal lung disease. However, high-resolution CT is of limited value in making a specific diagnosis.

Acute Disease↗
PubMed2000

CT findings of pneumonia after lung transplantation.

OBJECTIVE: The purpose of this study was to describe the CT findings of pneumonia in patients who had undergone lung transplantation and to determine if specific imaging features existed for the different infectious organisms. MATERIALS AND METHODS: The authors retrospectively reviewed the medical records of 262 patients with transplanted lungs at two lung transplantation centers. Patients with a documented pneumonia and correlating abnormal findings on CT (39 patients with 45 pneumonias) were included in the study. RESULTS. Of 45 pneumonias, Cytomegalovirus (n = 15), Pseudomonas (n = 7), and Aspergillus (n = 8) organisms were the most common single responsible infectious agents. The most common CT findings of pneumonia consisted of consolidation (n = 37; 82%), ground-glass opacification (n = 34; 76%), septal thickening (n = 33; 73%), pleural effusion (n = 33; 73%), and multiple (n = 25; 56%) or single (n = 2; 4%) nodules. No significant difference in the prevalence of findings was revealed among bacterial, viral, and fungal pneumonias (p >.05, chisquare test). Of 25 pneumonias in patients with a single transplanted lung, parenchymal abnormalities involved both lungs in 12 (48%), only the transplanted lung in 11 (44%), and only the native lung in two (8%). CONCLUSION: The manifestations revealed on CT of bacterial, viral, and fungal pneumonia after lung transplantation are similar, consisting of a combination of consolidation, ground-glass opacification, septal thickening, pleural effusion, or multiple nodules. Therefore, these findings cannot be used to suggest the infectious organisms in this patient population.

Adolescent↗