Lung volumes before and after lung volume reduction surgery: quantitative CT analysis.

The volume and severity of pulmonary emphysema in individual lungs were measured by means of quantitative computed tomography (CT) studies in 28 patients (14 women, 14 men, median age 65 yr) who underwent either bilateral (n = 15) or unilateral (n = 13) lung volume reduction surgery (LVRS). Spirometric, total body plethysmographic, and CT data (at TLC and RV) were correlated before and after LVRS. Lung volumes determined by CT correlated well with volumes obtained by total body plethysmography (p < 0.0001). For individual lungs after LVRS, CT-derived mean lung capacity decreased 13% and residual volume 20% (p < 0.00001 for each), while mean total functional lung volume (TFLV, defined as the volume of lung with CT attenuation greater than -910 Hounsfield units) increased 9% (p < 0.01), and the mean ratio of the air space to tissue space volume (V(AS)/V(TS)) decreased more at RV (23%) than at TLC (14%) (p < 0.0005 for each). In contrast, unilateral LVRS did not affect exhalation from the unoperated lung (2% reduction in RV, p = NS). The magnitude of the postoperative response (CT-derived TLC, RV, TFLV, V(AS)/V(TS)) of each operated lung was comparable for unilateral and bilateral LVRS. Thus, a lung's response to LVRS was independent from that of the contralateral lung. Moreover, postoperative alterations in TFLV and FEV1 correlated significantly (r = 0.80, p < 0.0001), which suggests that the expansion of functioning tissue may contribute to the mechanism by which LVRS palliates airway obstruction.

Incidental lung carcinoma detected at CT in patients selected for lung volume reduction surgery to treat severe pulmonary emphysema.

PURPOSE: The authors present their experience with previously unsuspected carcinoma of the lung detected at preoperative computed tomography (CT) in patients with severe pulmonary emphysema who were scheduled to undergo lung volume reduction surgery. MATERIALS AND METHODS: Preoperative chest CT was performed in 148 patients (84 men, 64 women; mean age, 65 years +/- 8 [standard deviation]) with advanced pulmonary emphysema before lung volume reduction surgery. At surgery, an attempt was made to excise any pulmonary nodule considered suspicious for carcinoma at CT. RESULTS: Eighteen pulmonary nodules suspicious for lung cancer were found at CT in 17 (11%) of the 148 patients. Sixteen of these 148 nodules were resected at lung volume reduction surgery. Nine non-small cell carcinomas (adenocarcinoma, n = 4, including three with bronchioloalveolar differentiation; poorly differentiated, n = 3; squamous cell carcinoma, n = 2) were found in eight (5%) patients. Eight of the cancers were stage I, and one was unstaged surgically. Maximum diameters of the cancers ranged between 1.0 and 3.8 cm (median, 1.6 cm). The seven (5%) other resected nodules were all benign. CONCLUSION: A 5% rate of stage I primary lung cancer in patients selected for lung volume reduction surgery suggests that performance of chest CT in candidates for lung volume reduction surgery is appropriate not only to identify patterns of pulmonary parenchymal destruction but also to search for stage I lung cancer.

Primary carcinoma of the lung overlooked at CT: analysis of findings in 14 patients.

PURPOSE: To describe the appearances of overlooked lung cancer at computed tomographic (CT) examination and to analyze the reasons for failure to diagnose these lesions. MATERIALS AND METHODS: Fourteen patients with 15 overlooked lung cancers were identified by radiologists at three institutions. Location, shape, and cell type of each cancer were reviewed, and other relevant findings of CT examinations were assessed. RESULTS: The missed tumors manifested as endobronchial lesion (n = 10), solitary parenchymal nodule (n = 2), area of focal peripheral air-space disease (n = 2), or pleural-based thickening (n = 1). Eleven (73%) of the 15 lesions were located in a lower lobe. In six (43%) of 14 patients, major distracting findings were present elsewhere in the thorax. CONCLUSION: Endobronchial location and lower lobe predominance were the most common characteristics of overlooked lung cancer at CT. The presence of unrelated major abnormalities at CT may also have contributed to failure to diagnose the tumor.

Rhodococcus equi endobronchial mass with lung abscess in a patient with AIDS.

An endobronchial lesion with lung abscess in a patient with AIDS was due to Rhodococcus equi. The patient responded to triple chemotherapy.

Missed bronchogenic carcinoma: radiographic findings in 27 patients with a potentially resectable lesion evident in retrospect.

Eighteen radiologists failed to detect 27 potentially resectable bronchogenic carcinomas revealed retrospectively on serial chest radiographs. Most of the cancers were in an upper lobe (n = 22 [81%]), especially the right upper lobe (n = 15 [56%]). More of the cancers were in women (n = 18 [67%]) than in men (n = 9 [33%]). The mean diameter of the missed lesions was 1.6 cm +/- 0.8 (range, 0.6-3.4 cm). Only two lesions (7%) were well defined around their entire extent. A lateral radiograph (available for 23 patients) revealed the missed lesion better than the posteroanterior radiograph in four patients (17%). Six consultant radiologists, who were biased by knowledge that the cases were of missed bronchogenic carcinoma, were individually shown the radiographs in 22 of the cases. Each consultant missed a mean of 26% (5.8 +/- 1.7) of the lesions. At least one of the six consultants missed the lesion in 16 (73%) of the cases. The predominant characteristics of radiographically missed and potentially resectable bronchogenic carcinomas were difficulty in radiographic detection, female gender, and location in an upper lobe, especially on the right side.

Bronchogenic cyst: a case report emphasizing the role of magnetic resonance imaging.

The article describes a patient with a right paratracheal bronchogenic cyst in whom the preoperative diagnosis was unclear. The fluid component of the cyst was not readily apparent by CT or T1-weighted MR images. Very intense signal on T2-weighted MR images suggested a cystic lesion. Inhomogeneities evident on MR but not CT images provided further soft tissue characterization. These soft tissue elements correlated with a macroscopic ring of hyaline cartilage in the resected specimen. The usefulness of MRI for the differential diagnosis of mediastinal tumors is discussed.

Pulmonary atelectasis associated with relative hyperperfusion.

Perfusion is usually diminished to areas of the lung that are poorly ventilated. A case is presented which demonstrates not only preservation of perfusion, but also an apparent increase in relative perfusion to an atelectatic lobe.

Radionuclide administration to nursing mothers: mathematically derived guidelines.

We determined a formula to establish objective guidelines for the administration of radionuclides to nursing mothers. The formula is based on the maximum permissible dose to the infant's critical organ, serial measurements of breast milk activity, milk volume, and dose to the critical organ per microcurie in milk. Using worst-case assumptions, we believe that cessation of nursing for 24 hours after administration of technetium labeled radiopharmaceuticals is sufficient for safety. Longer-lived agents require greater delays. Iodine-123 radiopharmaceuticals are preferable to iodine-131 agents and should always be used when studying the unblocked thyroid.