Metastatic pheochromocytoma in a parakeet

OBJECTIVE: The aim of this study was to determine the frequency of diagnostic findings of bronchiectasis on thin-section CT and the usefulness of those findings in distinguishing patients with cylindrical bronchiectasis from healthy subjects. MATERIALS AND METHODS: The study was retrospective and included 26 healthy adults, 10 consecutive patients with surgically proven cylindrical bronchiectasis, and 49 patients who had been prospectively diagnosed at three institutions as having cylindrical bronchiectasis. All patients had 1.0- to 1.5-mm-collimation CT scans obtained at 10-mm intervals through the chest. The CT scans were independently reviewed in random order by two chest radiologists. RESULTS: Findings in patients with bronchiectasis that were not seen by either observer in any of the healthy subjects included visualization of a bronchus within 1 cm of the costal pleura and visualization of a bronchus abutting the mediastinal pleura. The two observers saw these findings on 96 (81%) and 63 (53%) of 118 CT scans in the 59 patients with bronchiectasis, respectively. Lack of tapering of bronchi was seen in five (10%) of 52 reviews in healthy subjects compared with 95% of reviews in patients with bronchiectasis. Bronchoarterial ratios greater than 1 were identified in 11 (21%) of 52 reviews in healthy subjects compared with 95% of reviews in patients with bronchiectasis. We calculated good agreement between the two observers (kappa values equal to or greater than .63). CONCLUSION: In most cases, thin-section CT allows reliable distinction of patients with cylindrical bronchiectasis from healthy subjects.     

Bronchiolitis obliterans syndrome: thin-section CT diagnosis of obstructive changes in infants and young children after lung transplantation

PURPOSE: To characterize the thin-section computed tomographic (CT) appearance of bronchiolitis fibrosa obliterans syndrome in infants and young children after lung transplantation. MATERIALS AND METHODS: Thin-section CT studies in six patients with bronchiolitis obliterans syndrome (age range, 2 months to 5 1/2 years) and in 15 control patients without obstructive airway disease (age range, 2 months to 7 years) who underwent bilateral lung transplantation were retrospectively reviewed. The thin-section CT scans were obtained during quiet sleep at a median of 24 months (range, 6-36 months) after transplantation. The CT studies were evaluated for mosaic perfusion, bronchial dilatation, bronchial wall thickening, and mucous plugging Final diagnoses in all patients were based pulmonary function test results. RESULTS: Thin-section CT findings in the six patients with clinically proved bronchiolitis obliterans syndrome were mosaic perfusion in five (83%) bronchial dilation in three (50%), and bronchial wall thickening in one (17%). Of the 15 control patients with normal pulmonary function test results, six (40%) had mosaic perfusion; none had bronchial dilatation or bronchial wall thickening. Mucous plugging was not seen in either group. Only the association of bronchial dilatation with bronchiolitis obliterans syndrome was significant (P = .02). CONCLUSION: Infants and young children with bronchiolitis obliterans syndrome after lung transplantation are more likely to have CT abnormalities than those with normal pulmonary function test results.     

Uncomplicated asthma in adults: comparison of CT appearance of the lungs in asthmatic and healthy subjects

A study was undertaken to define the computed tomographic (CT) appearance of the lungs in subjects with uncomplicated asthma and to compare the prevalence of bronchial dilatation at CT in asthmatic and healthy subjects. Clinical features, pulmonary physiologic findings, chest radiographs, and high-resolution CT scans of 48 asthmatic subjects were reviewed. Forty-one (85%) of the 48 asthmatic subjects were undergoing bronchodilator therapy, 28 (58%) were undergoing steroid therapy, and 21 (44%) were cigarette smokers. Twenty-seven healthy control subjects underwent limited high-resolution CT. At selected CT levels, any bronchus with an internal diameter greater than that of the accompanying pulmonary artery was considered dilated. In the asthmatic subjects, 153 (36%) of 429 bronchi evaluated met criteria for bronchial dilatation compared with 37 (26%) of 142 bronchi in the control group (P < .05). Because bronchial dilatation demonstrated at CT did not correlate with clinical data, the authors conclude a bronchus larger in diameter than the adjacent vessel is not sufficient evidence to diagnose cylindric bronchiectasis.     

Expression of bcl-2 protein and APO-1 (Fas antigen) in the lung tissue from patients with idiopathic pulmonary fibrosis

Between 1974 and 1995 we encountered 19 cases of bronchial stricture or obliteration caused by endobronchial tuberculous lesions. In 11 the involvements were located at the right bronchus (including involvements of segmental and middle lobe bronchi) and in 8 at the left bronchus. On bronchoscopic biopsy of the stenosed bronchus, 7 patients showed histopathologic findings of tuberculous bronchitis, but 12 patients showed nonspecific inflammatory granular tissue. Five patients were kept under conservative observation because of mild subjective symptoms or refusal to undergo operation. Two patients underwent stent procedures but had poor outcomes. Twelve patients underwent operation. As the bronchial lesions in four of them were confined to the lobar or segmental bronchus, lobectomy was performed. One patient with a history of infantile tuberculosis had developed complete obliteration of the left main bronchus and cystic bronchiectasis in the entire lung parenchyma; pneumonectomy was essential. Seven patients who had strictures involving the main bronchus underwent bronchoplastic surgery with right (n = 4) or left (n = 3) upper sleeve lobectomy. None of the patients treated surgically showed any postoperative complication or recurrence of the tuberculosis. These surgical results for endobronchial tuberculosis indicate the need for early detection and operation. Bronchoscopy and computed tomography are the methods of choice for accurate diagnosis of bronchial involvement and assessment of the surgical indications. It is emphasized that bronchoplastic surgery is the best treatment for bronchial stricture involving bilateral main bronchi.     

A morphologic study of nodular lung carcinomas and their possible pathogenesis from a cluster of non-obstructive bronchiectasis

A very simple procedure has enabled us to show that nodular lung carcinomas correspond, to a high degree, to neoplasias arising in a cluster of bronchiectasis of the non-obstructive type. This pathogenesis explains their peculiar features: the round shape with a sharp borderline on the surrounding lung, the frequent cavitation, the prevailing histologic type of epidermoid carcinomas. At present, when thin-section CT allows discovery of bronchiectasis with no need for bronchography, this interpretation suggests the possibility of carrying out a prevention program which should consist of identifying the high-risk group of patients with bronchiectasis, 'sputum producers' and smokers, in which an early diagnosis of nodular lung carcinoma might be realized by periodical diagnostic cytology.     

A novel procedure for mediastinal vagotomy inhibits neurogenic inflammation in rat bronchial tree

Tachykinin-containing sensory axons originating from the cervical vagal nerves and the first several pairs of thoracic spinal nerves are involved in neurogenic inflammation evoked by capsaicin in the bronchial tree. Unilateral degeneration of the cervical vagal trunk by surgical lesion inhibits neurogenic inflammation in the ipsilateral bronchial airways. The vagal trunk has two main branches, the thoracic vagus nerve and recurrent laryngeal nerve in the thorax. The main purpose of this study was to determine whether the thoracic vagus nerve or recurrent laryngeal nerve was significantly involved in the neural control of bronchial inflammation in the rat. A novel and safe surgical procedure was used for selectively cutting the right thoracic vagal trunk, thoracic vagus nerve, or recurrent laryngeal nerve by introducing the surgical instrument through an aperture between the first and second ribs in the ventral wall of the rostral mediastinum. This surgical operation could be completed without causing a pneumothorax. After 2 postoperative weeks, the effects of denervation on capsaicin-induced plasma extravasation in the respiratory tract were tested. Either right thoracic vagal trunk transection or thoracic vagus section significantly decreased plasma extravasation in the right bronchial tree. Thoracic vagus section was obviously more effective. Evans blue extravasation in the right lobar bronchi was reduced by 44-78% after thoracic vagal trunk transection, while that in the right mainstem and lobar bronchi was reduced by 58-81% after thoracic vagus section. Area densities of India ink-labeled leaky blood vessels in the right lobar bronchi were reduced by 40-65% after thoracic vagal trunk transection, and those in the right mainstem and lobar bronchi were reduced by 83-88% after thoracic vagus neurectomy. Recurrent laryngeal neurectomy did not change the plasma extravasation induced by capsaicin in the trachea and bronchi. These results suggest that capsaicin-sensitive fibers running in the vagal trunk, which largely mediated neurogenic inflammation in the bronchial tree, were projected into the thoracic vagus nerve which, in turn, sent these nerve fibers to the ipsilateral bronchial tree. For the trachea, the remaining sensory fibers surviving denervation might provide sufficient tachykinins to trigger neurogenic inflammation.     

Identification of the aberrant hepatic artery with axial spiral CT

PURPOSE: To determine whether axial spiral computed tomography (CT) allows detection of the replaced hepatic artery as part of preoperative planning for pancreatic tumor resection. MATERIALS AND METHODS: Axial spiral CT scans (8-mm section thickness, 4-mm overlapping reconstructions) were obtained in 50 patients with periampullary tumor and were examined by three radiologists. Readers' interpretations were compared with angiographic results. RESULTS: Eight patients had an aberrant hepatic artery. Two of the three readers detected or suspected all of these abnormalities (100% sensitivity), and one reader identified seven of eight aberrant arteries (88% sensitivity). However, readers requested angiographic confirmation in 14 of 24 tests. Sensitivity, specificity, and accuracy were 96%, 87%, and 88%, respectively, for all readers. CONCLUSION: Axial spiral CT may simplify preoperative evaluation of periampullary tumors. However, angiographic support was necessary in most cases in this study. Improvements in CT techniques may eventually allow spiral CT to replace angiography in the examination of these patients.     

Diagnosis of disease of the common carotid artery bifurcation: CT angiography vs catheter angiography

OBJECTIVE: The purpose of this prospective study was to compare CT angiography with conventional catheter angiography for imaging the bifurcation of the common carotid artery in patients with signs and symptoms of atherosclerotic disease. SUBJECTS AND METHODS: Ten symptomatic patients (20 bifurcations of the common carotid artery) underwent contrast-enhanced spiral CT of the neck. The images were preprocessed and postprocessed by using a commercially available volume-rendering technique and a maximum-intensity-projection algorithm. All patients subsequently underwent conventional catheter angiography. RESULTS: CT angiographic findings matched those on conventional angiograms in only 50% of cases. Two nearly occluded internal carotid arteries were missed with CT angiography. Four internal carotid arteries were interpreted as occluded on the basis of CT angiograms but were shown as patent on catheter angiograms. Of five severe stenoses shown by CT angiography, only two were confirmed by conventional angiography. CONCLUSION: The results indicate that CT angiography as used in this study cannot replace catheter angiography. With CT angiography, both overestimation and underestimation of stenoses occur.     

The hepatopulmonary syndrome: radiologic findings in 10 patients

OBJECTIVE: The purpose of this study was to review the radiologic manifestations of the hepatopulmonary syndrome. MATERIALS AND METHODS: We retrospectively reviewed clinical records, chest radiographs, 99m Tc-macroaggregated albumin (MAA) perfusion lung scans, chest CT scans, and pulmonary angiograms of 10 patients with proven hepatopulmonary syndrome. RESULTS: Chest radiographs showed basilar, medium-sized (1.5-3.0 mm) nodular or reticulonodular opacities in all cases. CT was done in eight cases and showed basilar dilatation of lung vessels with a larger than normal number of visible branches. The vascular basis for these opacities was best appreciated on conventional CT scans of 10-mm sections. No individual arteriovenous malformations were seen on CT scans. High-resolution CT scans showed no evidence of interstitial fibrosis. 99mTc-MAA perfusion lung imaging, done in seven patients, showed pulmonary arteriovenous shunting in five. Contrast echocardiography confirmed intrapulmonary shunting in these five patients. Pulmonary angiography, done in four cases, showed subtle distal vascular dilatation in two and moderate dilatation with early venous filling in two but did not reveal any individual arteriovenous malformations. CONCLUSION: Chest radiographs in hepatopulmonary syndrome usually show bibasilar nodular or reticulonodular opacities. Conventional CT shows that these opacities represent dilated lung vessels. High-resolution CT is useful in excluding pulmonary fibrosis or emphysema as the cause of these opacities. 99mTc-MMA perfusion imaging or contrast echocardiography can be used to confirm intrapulmonary arteriovenous shunting.     

99mTc-HMPAO SPECT of the brain in mild to moderate traumatic brain injury patients: compared with CT--a prospective study

Single photon emission computed tomography (SPECT) with Technetium-99m hexamethyl propylenamine oxime (Tc-99m-HMPAO) was used in 20 patients with mild to moderate traumatic brain injury (TBI) to evaluate the effects of brain trauma on regional cerebral blood flow (rCBF). SPECT scan was compared with CT scan in 16 patients. SPECT showed intraparenchymal differences in rCBF more often than lesions diagnosed with CT scans (87.5% vs. 37.5%). In five of six patients with lesions in both modalities, the area of involvement was relatively larger on SPECT scans than on CT scans. Contrecoup changes were seen in five patients on SPECT alone, two patients with CT alone and one patient had contrecoup lesions on CT and SPECT. Of the eight patients (50%) with skull fractures, seven (43.7%) had rCBF findings on SPECT scan and five (31.3%) demonstrated decrease in rCBF in brain underlying the fracture. All these patients with fractures had normal brain on CT scans. Conversely, extra-axial lesions and fractures evident on CT did not visualize on SPECT, but SPECT demonstrated associated changes in rCBF. Although there is still lack of clinical and pathological correlation, SPECT appears to be a promising method for a more sensitive evaluation of axial lesions in patients with mild to moderate TBI.     

Angiographic evaluation of chronic pulmonary embolism

In some patients acute pulmonary emboli may fail to resolve normally, resulting in chronic pulmonary embolism. This may lead to pulmonary hypertension, respiratory insufficiency, cor pulmonale, and death. The angiographic evaluation in nine patients with chronic pulmonary embolism who underwent embolectomy is presented. Particular emphasis on the predictive value of selective bronchial arteriography in four of these patients is considered. In chronic pulmonary embolism, pulmonary arteries distal to obstructed areas may remain patent and be supplied by hypertrophied bronchial arteries. Since back-bleeding of arterial blood from the bronchial circulation at surgery may predict the success of embolectomy, preoperative bronchial arteriography may be useful for predicting potential surgical success.     

Early detection of pneumonia in febrile neutropenic patients: use of thin-section CT

OBJECTIVE: The purpose of this study was to evaluate the usefulness of thin-section CT for early detection of pneumonia in neutropenic patients with an unknown site of infection and normal or nonspecific findings on chest radiographs. SUBJECTS AND METHODS: Eighty-seven patients with febrile neutropenia that persisted for more than 2 days despite empiric antibiotic treatment underwent 146 prospective examinations. If findings on chest radiographs were normal (n = 126) or nonspecific (n = 20), thin-section CT (1-mm collimation, 10-mm increment) was done. If thin-section CT scans showed opacities, bronchoalveolar lavage was recommended. RESULTS: Findings on chest radiographs were nonspecific for pneumonia in 20 (14%) of 146 cases, and CT findings in those cases were suggestive of pneumonia. Microorganisms were detected in 11 of those 20 cases. Seven of the 11 cases were not optimally treated before CT diagnosis, the other four were sufficiently treated. Findings on chest radiographs and thin-section CT scans were normal in 56 (38%) of 146 cases. In 70 (48%) of 146 cases, findings on chest radiographs were normal, whereas findings on thin-section CT scans were suggestive of pneumonia. Microorganisms were detected in 30 of the 70 cases. Nineteen of 30 cases were not optimally treated before CT, whereas the other 11 cases were sufficiently treated before CT. In 22 (31%) of these 70 cases, an opacity was observed on the chest radiograph during the 7 days after the CT study. Only three (5%) of 56 pneumonias occurred during the first 7 days after thin-section CT studies with normal findings (p < .005). Additional risk factors for pneumonia occurring later that were detectable on chest radiographs were poorly defined nodules (p < .05), consolidation (p < .05), and younger age (p < .05). CONCLUSION: Thin-section CT scans show findings suggestive of pneumonia about 5 days earlier than chest radiographs show suggestive findings. When thin-section CT scans show findings suggestive of pneumonia, the probability of pneumonia being detected on chest radiographs during the 7-day follow-up is 31%, whereas the probability is only 5% when the findings on the prior thin-section CT scan were normal (p < .005). All neutropenic patients with fever of unknown origin and normal findings on chest radiographs should be examined with thin-section CT.     

An in vitro model to study mesenchymal-epithelial transformation

PURPOSE: To determine if the lower milliampere second setting and shorter acquisition time of subsecond spiral computed tomography (CT) affects the image quality of thoracic CT scans. MATERIALS AND METHODS: In 92 consecutive outpatients referred for thoracic CT, spiral CT (120 kV, 292 mA) was performed with 1-second (n = 45) or 0.75-second (n = 47) scanning time. An equal percentage of patients (70%) in each group received intravenous contrast medium. At six mediastinal and six lung zones, degradation due to motion and noise, respectively, were graded independently on a four-point scale by three blinded radiologists. Statistically significant differences were determine with a two-tailed test. RESULTS: Mediastinal image quality was significantly better on 0.75-second scans than on 1-seconds scans (P < .001). Regions with the greatest improvement in image quality were around the aortic root, cardiac ventricles, and aortic arch. Lung image quality was also better on 0.75-second scans than on 1-second scans (P = .04). On 0.75- and 1-second scans, respectively, motion-related artifacts were found to degrade image quality 6.2 and 8.7 times more than noise-related artifacts in the mediastinum and 2.6 and 3.9 times more in the lungs. CONCLUSION: Subsecond spiral CT is associated with improved clarity and diminished motion artifacts on mediastinal and pulmonary images when compared with 1-second spiral CT.     

Prevalence of acute pulmonary embolism in central and subsegmental pulmonary arteries and relation to probability interpretation of ventilation/perfusion lung scans

PURPOSE: The purpose of this investigation is to determine the prevalence of acute pulmonary embolism (PE) limited to subsegmental pulmonary arteries. BACKGROUND: Contrast-enhanced helical (spiral) and electron-beam CT, in the hands of experienced radiologists who are skillful with this modality, are sensitive for the detection of acute PE in central pulmonary arteries, but have a low sensitivity for the detection of PE limited to subsegmental pulmonary arteries. The potential for CT to diagnose PE, therefore, is partially dependent on the prevalence of PE limited to subsegmental pulmonary arteries. METHODS: Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). The largest pulmonary arteries that showed PE, as interpreted by the PIOPED angiographic readers, were identified in 375 patients in PIOPED with angiographically diagnosed PE. RESULTS: Among all patients with PE, 6% (95% confidence interval [CI], 4 to 9%) had PE limited to subsegmental branches of the pulmonary artery. Patients with high-probability ventilation/ perfusion (V/Q) scans had PE limited to subsegmental branches in only 1% (95% CI, 0 to 4%). Among patients with low-probability V/Q lung scans, 17% (95% CI, 8 to 29%) had PE limited to the subsegmental branches. Patients with low-probability V/Q scans and no prior cardiopulmonary disease had PE limited to the subsegmental pulmonary arteries in 30% (95% CI, 13 to 53%), whereas patients with low-probability V/Q scans who had prior cardiopulmonary disease had PE limited to subsegmental pulmonary arteries in 8% (95% CI, 2 to 22%) (p < 0.05). CONCLUSION: Based on data from all patients with PE in PIOPED, the prevalence of PE limited to subsegmental pulmonary arteries is low, 6%. PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability V/Q scans, particularly if they had no prior cardiopulmonary disease.     

Primary bronchial amyloidosis. A case report

A case of primary bronchial amyloidosis in a 58-year old patient, with haemoptysis, cough, purulent sputum and fever, is described. Bronchoscopy showed nodules and yellow wax plaques in the lower lobar bronchi. Histology of bioptic specimens showed the amyloidosic nature of the lesions. The search of other localizations was negative.     

Spiral CT angiography in the diagnosis of central pulmonary embolism: comparison with pulmonary angiography and scintigraphy

PURPOSE: To evaluate the accuracy of spiral CT angiography in the diagnosis of central pulmonary embolism (PE). MATERIAL AND METHODS: A retrospective study was undertaken in a population of 90 patients who were evaluated with spiral CT angiography (acquisition: 12 to 24 s with or without strict apnea; injection of 90 cm3 of 12, 20 or 30% contrast material at a rate of 4 to 7 cm3, selective pulmonary angiography of each lung (n = 55) and/or ventilation-perfusion (VP) scanning (n = 35). RESULTS: Among the 55 patients evaluated with both spiral CT and angiography, central pulmonary embolism was excluded in 19 patients (34%), assessed in 29 patients (53%) whereas CT examination was considered as inconclusive in 7 patients (13%) due to interpretive difficulties at the level of obliquely oriented arteries and/or presence of hilar lymph nodes (sensitivity: 90.5%; specificity: 82.6%). With spiral CT, the finding of 95 central emboli (3 main, 61 lobar and 31 segmental) corresponded exactly to the angiographic findings; spiral CT enabled direct visualization of intraluminal filling defects (n = 95) whereas the angiographic recognition of PE was based on direct (n = 57) and indirect (n = 38) signs. Spiral CT angiography was more sensitive and specific than VP scanning. CONCLUSION: Spiral CT angiography appears as a sensitive and specific noninvasive method for the diagnosis of central PE.     

Accuracy of computed tomographic scanning in assessment of the mediastinum in bronchial carcinoma

We believe that malignant involvement of mediastinum is a contraindication to attempted resection of bronchial carcinoma. It was hoped that computed tomographic (CT) scanning might improve our ability to assess the mediastinum prior to thoracotomy. The accuracy of CT scanning, performed with modern techniques, in assessment of the mediastinum of 22 patients with bronchial carcinoma has therefore been determined. In all the patients CT scan impressions have been correlated with the histologic findings at thoracotomy or mediastinoscopy. In detection of malignant involvement of the mediastinum, the CT scan had a sensitivity of 80% and a specificity of 76%. There was only one false negative CT scan report, and in this case the mediastinum was involved at a site which could not have been inspected at anterior cervical mediastinoscopy. We conclude that a negative CT scan makes mediastinoscopy an unnecessary screening procedure in determining resectability. Since there was a significant number of false positive CT scans, we feel that such a report necessitates tissue confirmation before the decision to withhold thoracotomy is made. The CT scan may help to determine the best test to achieve this tissue confirmation.     

Bronchial carcinoid tumors

Bronchial carcinoid tumors, termed (incorrectly) "bronchial adenomas" in the past, are uncommon pulmonary neoplasms. These tumors are currently classified as neuroendocrine in origin because of their potential to form and sometimes secrete a variety of chemical substances. Overall, approximately 75% of bronchial carcinoid tumors arise in the lobar bronchi, 10% occur in the main-stem bronchi, and 15% originate in the periphery of the lung. Well-differentiated carcinoid tumors constitute almost 90% of all bronchial carcinoids. Atypical carcinoid tumors have a higher malignant potential than do typical bronchial carcinoids. The carcinoid syndrome is rarely, if ever, associated with carcinoids limited to the tracheobronchial tree. Occasionally, Cushing's syndrome due to ectopic hormone production is caused by bronchial carcinoid tumors. More than 75% of bronchial carcinoids are detected on conventional posteroanterior chest roentgenograms. Computed tomography may help disclose small neoplasms that are occult on conventional roentgenography, particularly in the assessment of patients who have Cushing's syndrome due to ectopic hormone production. Pulmonary resection is the treatment of choice for bronchial carcinoids. The prognosis is related to the pathologic grade and stage of the tumor.     

Three-dimensional display of the bronchi using helical CT

The purpose of this study was to evaluate the clinical usefulness of three-dimensional (3D) images of the bronchi obtained using helical CT. Thirteen patients with lung cancer, one with tracheal diverticulum, and one with bronchial amyloidosis were examined. The CT scanner employed was the Toshiba Xforce. The helical CT scan cycle consisted of 20 continuous rotations, each requiring 1.5 sec, for a total scanning time of 30 sec. Scans were obtained using a 5-mm X-ray beam width, a 5-mm/1.5 sec couchtop sliding speed, and a 2-mm reconstruction interval. 3D images were reconstructed using a CEMAX VIPstation. The optimal lower and upper threshold CT values for 3D images of the bronchi were -650 and -100 HU, respectively, and 3D images clearly depicted endobronchial lesions. Cartilage crescents were also demonstrated, but longitudinal and circular mucosal folds could not be visualized. In conclusion, 3D images of the bronchi acquired using helical CT were useful in evaluating endobronchial lesions.