Computed tomographic abnormalities in Mycobacterium avium complex lung disease include the mosaic pattern of reduced lung attenuation.

OBJECTIVE: To describe the range and frequency of abnormalities on computed tomographic (CT) scans in patients who met the American Thoracic Society (ATS) case definition of Mycobacterium avium complex (MAC) lung disease. Further, to report the effect of time and treatment on the progression of these abnormalities. METHODS: The demographic, clinical and radiologic features of 10 patients with proven MAC lung disease (mean age 71 years, standard deviation 12 years) were described. The presence or absence of 14 CT abnormalities was recorded in each of 10 lung zones. The effects of time and treatment on the abnormalities were recorded. RESULTS: The patients' lung function was minimally impaired. Pretreatment CT scans showed small nodules in 47% of the lung zones, reduced lung attenuation in 41%, and bronchiectasis in 27%. Bronchiectasis was associated with nodules in 20 zones from 9 patients and with no nodules in 7 zones from 1 patient. Reduced attenuation was associated with bronchiectasis alone in 8 zones, with nodules alone in 25 zones and with both bronchiectasis and nodules in 8 zones. In patients without treatment, or with non-curative treatment, bronchiectasis developed or worsened in 12 of 26 zones and resolved or improved in none. In contrast, after curative treatment, small nodules disappeared completely in 10 of 21 zones and developed in none. Of 7 zones with only nodules and reduced attenuation before treatment, 6 had no abnormalities after treatment. CONCLUSIONS: Our data suggest that the 3 leading CT abnormalities in nodular-bronchiectatic MAC lung disease are small nodules, reduced attenuation and bronchiectasis. Reduced attenuation appeared to result from gas trapping and hypoxic vasoconstriction due to bronchiolocentric inflammatory nodules. Bronchiectasis appeared to be secondary to this bronchiolar disease.

Mycotic pulmonary arterial aneurysms in an intravenous drug user.

A case of mycotic pulmonary artery aneurysm (PAA) in an intravenous drug user in whom resolution occurred with conservative therapy is described. The natural history of PAA is not well described in the literature. Although PAA is potentially fatal, resolution may occur in patients who do not have hemoptysis. Clinical presentation, diagnosis and management of PAA are reviewed.

Pulmonary tuberculosis treated with directly observed therapy: serial changes in lung structure and function.

OBJECTIVES: (1) To correlate structure (CT) with function in pulmonary tuberculosis (TB), and (2) to describe the evolution of structural and functional abnormalities when pulmonary TB is treated with directly observed therapy. SUBJECTS AND METHODS: Twenty-five patients with drug-susceptible pulmonary TB, 15 cavitary and 10 noncavitary, were studied prospectively. Conventional CT and pulmonary function testing (spirometry, diffusing capacity, and arterial blood gases) were performed at baseline, and after 1 and 6 months of directly observed therapy. RESULTS: All but one patient with noncavitary miliary TB had CT evidence of endobronchial disease, and all patients with cavitary disease had coexistent reduced lung attenuation, the latter presumably a result of gas trapping, hypoxic vasoconstriction, and vascular injury. Functional impairment was minimal and in proportion to the number of diseased segments and cavitary volume. Bronchiectasis was significantly more likely to complicate cavitary than noncavitary disease (64 vs 11%; p<0.05). CONCLUSIONS: CT findings correlate well with function in pulmonary TB. Physiologic data were consistent with the concept that pulmonary TB is an endobronchial disease that causes parallel reductions in ventilation and perfusion. This concurrent involvement of both airways and contiguous pulmonary blood supply offers an explanation for the minimal respiratory limitation experienced by these patients despite often extensive lung disease. Supervised therapy of drug-susceptible disease results in minimal structural and functional residua.

Compression of the left main bronchus between a descending thoracic aortic aneurysm and an enlarged right pulmonary artery.

A man with chronic obstructive lung disease presented to the hospital with respiratory failure and a chest x-ray indicated complete radiopacity of the left hemithorax. An endobronchial malignancy was suspected, but unexpectedly left-main bronchial occlusion was found secondary to compression between a descending thoracic aortic aneurysm and an enlarged right pulmonary artery.

Evaluation of adrenal masses with gadolinium enhancement and fat-suppressed MR imaging.

A study was undertaken to determine the ability to characterize benign and malignant masses with unenhanced and contrast material-enhanced fast low-angle shot and fat-suppressed spin-echo magnetic resonance (MR) imaging. Thirty patients with adrenal masses detected at computed tomography (CT) underwent MR imaging within 14 days after CT. CT and MR images were interpreted in a prospective, blinded fashion. Sixteen patients had 20 benign adrenal masses, and 14 patients had 18 malignant masses. Quantitative measurements included percentage of contrast enhancement on immediate postcontrast dynamic images and periphery--center signal-to-noise ratio (S/N) on gadolinium-enhanced fat-suppressed images. Qualitative evaluation included determination of the regularity of lesion margins, homogeneity of signal intensity, and local extension. MR imaging depicted all adrenal masses discovered at CT examinations. Lesions ranged in diameter from 1 to 15 (mean, 4.4) cm. No significant difference was observed in percentage of contrast enhancement between benign (90.5% +/- 59.0 [standard deviation]) and malignant (110.5% +/- 116.4) masses. A difference was observed between periphery--center S/N for benign (-.05 +/- 1.5) and malignant (7.7 +/- 9.8) masses; overlap between the two, however, occurred. Qualitative evaluation allowed correct characterization of 32 of 38 masses, comparing favorably with CT, which allowed characterization of 30 lesions.

The chest roentgenogram in pulmonary tuberculosis patients seropositive for human immunodeficiency virus type 1.

To determine the impact that co-infection with HIV has on the radiographic presentation of pulmonary tuberculosis, we examined the chest roentgenograms obtained before treatment in 225 HIV-tested adult Haitians with bacillary (smear or culture or both) positive pulmonary tuberculosis. There were 67 HIV-seropositive and 158 HIV-seronegative patients. Intrathoracic adenopathy alone was more common and parenchymal infiltrates less common in HIV-seropositive patients (p less than 0.05). Although a parenchymal infiltrate was less likely to be cavitating in the HIV-seropositive group (p less than 0.05) when cavitary parenchymal disease was present, HIV seropositivity did not affect the number of cavities (single or multiple) or the size of the largest cavity. Patients with AIDS were significantly more likely to have a chest radiographic pattern consistent with primary tuberculosis (80 percent) than HIV-seropositive patients without AIDS (30 percent), and the latter were significantly more likely to have such a pattern than HIV-seronegative patients (11 percent) (p less than 0.05). The HIV-seropositive patients were equally infectious, regardless of the pattern of disease (primary vs postprimary). Even though pulmonary tuberculosis in an HIV-seropositive adult probably results from reactivation of dormant foci or reinfection, the pattern on the chest roentgenogram often suggests primary disease, especially if the patient has AIDS.