Factors influencing pneumothorax rate at lung biopsy: are dwell time and angle of pleural puncture contributing factors?

PURPOSE: To study factors that may influence pneumothorax and chest tube placement rate, especially needle dwell time and pleural puncture angle. MATERIALS AND METHODS: In 159 patients, 160 coaxial computed tomography (CT)-guided lung biopsies were performed. Dwell time, the time between pleural puncture and needle removal, was calculated. The smallest angle of the needle with the pleura ("needle-pleural angle") was measured. These and other variables were correlated with pneumothorax and chest tube rates. RESULTS: One hundred fifty biopsies were included. There were 58 (39%) pneumothoraces (14 noted only at CT), with eight (5%) biopsies resulting in chest tube placement. Longer dwell times (mean, 29 minutes; range, 12-66 minutes) did not correlate with pneumothoraces (P =.81). Smaller needle-pleural angles (< 80 degrees) [corrected], decreased forced expiratory volume in 1 second to vital capacity ratio (<50%), lateral pleural puncture, and lesions along fissures were associated with higher [corrected] pneumothorax rates (P <.05). Emphysema along the needle path, pulmonary function tests showing ventilatory obstruction, and lesions along fissures predisposed patients to chest tube placement (P <.05). Pleural thickening and prior surgery were associated with lower pneumothorax rates (P <.05). CONCLUSION: Longer dwell times do not correlate with pneumothorax and should not influence the decision to obtain more biopsy samples. A shallow pleural puncture angle may increase the pneumothorax rate.

Diagnostic accuracy and safety of CT-guided percutaneous needle aspiration biopsy of the lung: comparison of small and large pulmonary nodules.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy and safety of CT-guided percutaneous needle aspiration biopsy of pulmonary nodules less than or equal to 1.5 cm in diameter with those of nodules greater than 1.5 cm in diameter. MATERIALS AND METHODS: We retrospectively reviewed a consecutive series of 97 patients who underwent CT-guided percutaneous needle aspiration biopsy of a lung nodule and then surgical resection (n = 95) or autopsy (n = 2). By examining CT images, we classified 27 nodules as small ( < or = 1.5 cm) and 70 nodules as large ( > 1.5 cm). Diagnostic accuracy was calculated by comparing cytologic diagnoses based on biopsy with final diagnoses based on histologic findings from surgery or autopsy. Each case was reviewed for possible complications, including pneumothorax and chest tube placement. RESULTS: The diagnostic accuracy of CT-guided percutaneous needle aspiration biopsy of large nodules was 96%. The diagnostic accuracy for small nodules was 74%, a statistically significant difference (p < .05). The prevalences of pneumothorax in our population were nearly identical for small and large nodules (22 and 21%, respectively). The prevalence of chest tube placement in our population was approximately 2%. The prevalences of chest tube placement were 0% for small nodules and 3% for large nodules. CONCLUSION: CT-guided percutaneous needle aspiration biopsy is significantly less accurate for small pulmonary nodules than for large pulmonary nodules, but the complication rates for both are low.

Radiographic aspects of pneumothorax.

Pneumothorax is a common medical problem of varied etiology. Because pneumothorax has potentially severe acute consequences, it is important that all physicians know its radiographic appearance. Patient complaints are nonspecific, and physical examination findings are often subtle. The chest radiograph is the principal means of detecting and following a pneumothorax. Radiographic diagnosis on an upright film requires the detection of the visceral pleural line. For radiographs obtained with the patient in the supine position, pneumothorax may be manifested by increased lucency over the upper quadrant of the abdomen, an unusually sharp definition of the anterior diaphragmatic surface or a very wide and deep costophrenic angle.

Idiopathic laryngotracheal stenosis: radiologic findings.

OBJECTIVE: Acquired nonneoplastic laryngotracheal stenosis can be either focal or diffuse. Diffuse tracheal stenosis is caused by sarcoidosis, tuberculosis, histoplasmosis, relapsing polychondritis, tracheopathia osteoplastica, and Wegener's granulomatosis. Focal tracheal stenosis, on the other hand, usually results from placement of an endotracheal or tracheostomy tube or from previous neck trauma. At our institution, since 1971, we have seen 49 cases of focal laryngotracheal stenosis that could not be attributed clinically or histologically to any one of the aforementioned causes. The purpose of this study was to study the radiologic features of these idiopathic laryngotracheal stenoses. MATERIALS AND METHODS: A retrospective review of records showed that radiologic studies were still available in only 15 of the 49 patients with idiopathic laryngotracheal stenoses. All 15 patients had radiographs and plain tomograms, and one patient had a CT scan of the neck. Three radiologists reviewed all the images. RESULTS: The radiologic appearance was variable: the stenoses were from 2 to 4 cm long with a lumen between 3 and 5 mm in diameter at the narrowest portion. The narrowing was concentric and shaped like an hourglass in eight patients (53%) and was eccentric in the other seven (47%). The margins of the stenosis were smooth in nine patients (60%) and irregular and lobulated in six patients (40%). A dominant mass measuring approximately 1 cm in diameter was present in two patients (13%). No evidence of calcification or ossification was seen. CONCLUSION: Idiopathic laryngotracheal stenosis produces focal stenosis of the cervical part of the trachea, 2 to 4 cm long. The lumen is severely compromised, measuring no more than 5 mm in diameter at its narrowest portion. The stenosis can be concentric or eccentric and can have either smooth or lobulated margins. Special attention should be paid to the airways when chest radiographs of patients with a history of prolonged dyspnea and wheezing are reviewed. The prevalence of focal stenosis of the larynx and the upper part of the trachea due to tracheal intubation has declined since the introduction of low-pressure, high-volume retention cuffs. Therefore, idiopathic laryngotracheal stenosis should be considered in the differential diagnosis in patients with focal narrowing of the airway.

Imaging the airways. Computed tomography and magnetic resonance imaging.

Both CT and MRI are significant advances in the diagnostic imaging of the trachea and bronchi. Because of its ability to image the airways in cross section with high spatial and contrast resolution, CT has gained wide acceptance in the evaluation of tracheobronchial diseases. Although the spatial resolution of MRI is less than that of CT, MRI offers the advantages of multiplanar imaging, high contrast resolution without use of intravenous contrast agents, and absence of ionizing radiation. Although to date the role of MR in evaluating the trachea and bronchi has been limited, it may be anticipated that the list of indications will continue to expand with advancing technologic developments.

Image-guided pleural biopsies: indications, technique, and results in 23 patients.

Twenty-six pleural biopsies were performed on 23 patients over a 3-year period. Twenty-three biopsies were performed guided with ultrasound; one, with computed tomography; and two, with fluoroscopy. Indications for an image-guided pleural biopsy were (a) pleural masses or thickening that were either not seen on chest radiographs or seen only on one view and (b) small or loculated pleural effusions of unknown cause with no mass seen. If only pleural fluid was present, reverse bevel needles were used for biopsy (n = 15). If a discrete pleural mass or thickening was seen with cross-sectional imaging, standard (16-20 gauge) biopsy needles were used (n = 11). In the 23 patients, biopsy results were true positive in ten (nine with malignancy, one with tuberculous pleurisy), true negative in ten (confirmed either at subsequent thoracotomy or clinical follow-up), and false negative in three. Complications were few, with a significant pneumothorax occurring in two patients (8.7%). Image-guided biopsy of small pleural lesions and small pleural effusions can be performed by the radiologist who understands the special needles and techniques involved.

Plexiform neurofibromatosis of the mediastinum: CT appearance.

We studied the CT findings in four patients with pathologically proved thoracic plexiform neurofibromatosis. In all four patients, CT showed an infiltrative process and masses that involved the mediastinum along the distribution of the sympathetic chains, phrenic, and vagus nerves. The lesions had lower attenuation values than did chest-wall muscle. In one patient, CT revealed calcifications and peripheral enhancement of nodular components after IV infusion of contrast material. In the appropriate clinical setting, CT detection of lesions in the distribution of the mediastinal nerves strongly favors the diagnosis of plexiform neurofibromatosis.

Dynamic incremental computed tomography of the pulmonary hila using a flow-rate injector.

Dynamic incremental CT of the pulmonary hila using a flow-rate injector is a safe, reliable, and reproducible technique. The technique described allows confident distinction of hilar masses from hilar vessels, while limiting the total amount of contrast medium used and eliminating radiation exposure to the radiologist.

Computed tomography of the mediastinum.

Computed tomography is the radiographic examination of choice for evaluation of the mediastinum. Information regarding the size, shape, extent, density, and vascularity of mediastinal masses can be obtained non-invasively. Mediastinal lesions not seen on routine radiographs can be visualized by CT, allowing for earlier detection of disease.