Jeffrey S. Klein

PURPOSE: To determine the utility of coaxial transthoracic needle biopsy (TNB) with use of a 20-gauge automated cutting biopsy needle in the diagnosis of thoracic lesions. MATERIALS AND METHODS: A retrospective review was performed in 122 patients. Computed tomography was used to guide coaxial TNB, which was performed with aspirating (n = 87) and automated cutting (n = 99) needles. The sensitivities for malignant and benign lesions were determined, with a comparison of the relative yields from the two techniques. RESULTS: The overall diagnostic yield for coaxial TNB was 88%. For malignancy the sensitivity was 95%, whereas a specific benign diagnosis was obtained in 91%. Although no difference was found for fine-needle aspiration versus core biopsy of malignant lesions (92% vs 86%), a statistically significant difference was found for benign lesions (44% vs 100%, P<.05). Pneumothorax occurred in 54%. CONCLUSION: Coaxial TNB performed with an automated cutting needle helps provide a diagnosis in the majority of patients with focal chest disease and is particularly useful in the diagnosis of benign lesions.

To determine the prevalence of "nonobstructive" (impairment of gas transfer) emphysema in a select population of smokers with dyspnea, a retrospective study of patients with emphysema evident at high-resolution computed tomography (HRCT) was undertaken. Four hundred seventy HRCT studies were reviewed. In 47 cases, centrilobular emphysema was the dominant or sole parenchymal abnormality. Concomitant chest radiographs were available in 41 of these cases; 16 of the 41 lacked radiographic findings of emphysema. Among these 16 patients, pulmonary function testing revealed 10 to have normal flow rates (ratio of forced expiratory volume in 1 second to forced vital capacity and forced expiratory volume in 1 second greater than 80% predicted) and impaired gas transfer (single-breath carbon monoxide diffusing capacity [DLCOSB] less than 80% predicted). With the exclusion of one patient with congestive heart failure from the group of 10, the severity of emphysema at HRCT correlated inversely with DLCOSB (r = -.643). These results indicate that HRCT allows detection of emphysema in symptomatic patients when chest radiographs and pulmonary function tests are nondiagnostic.

Cardiac tamponade is a life-threatening condition that results from slow or rapid heart compression secondary to accumulation of fluid, pus, blood, gas, or tissue within the pericardial cavity. This condition can be associated with multiple causes including trauma, inflammation, scarring, or neoplastic involvement of the pericardial space among others. The main pathophysiologic event leading to tamponade is an increase in intrapericardial pressure sufficient to compress the heart with resultant hemodynamic impairment, which leads to limited cardiac inflow, decreased stroke volume, and reduced blood pressure. These events result in diminished cardiac output, which manifests clinically as a distinctive form of cardiogenic shock. Although cardiac tamponade is a clinical diagnosis, imaging studies play an important role in assessment and possible therapeutic intervention. Computed tomographic (CT) findings associated with cardiac tamponade include pericardial effusion, usually large, with distention of the superior and inferior venae cavae; reflux of contrast material into the azygos vein and inferior vena cava; deformity and compression of the cardiac chambers and other intrapericardial structures; and angulation or bowing of the interventricular septum. Familiarity with the clinical and pathophysiologic features of cardiac tamponade and correlation with the associated CT findings are essential for early and accurate diagnosis.