Role of HRCT in the identification of atypical pulmonary mycobacteriosis.

AIM: 1) To identify the principal radiological signs of atypical pulmonary mycobacteriosis by means of X-rays and CT/HRCT; 2) to compare the two methods in order to evaluate their reliability with particular interest for the diagnostic role of HRCT in the identification of the disease; 3) to establish any significant differences in the pathology between AIDS and immunocompetent patients. MATERIAL AND METHODS: The chest X-rays and CT/HRCT of 28 atypical pulmonary mycobacteriosis patients (16 with AIDS and 12 immunocompetent) have been studied. The subjects were examined during the period of October 1993 to May 2000 and were found to be positive for atypical mycobacterium and consequently underwent a standard chest X-ray. Twenty cases were followed-up with a chest CT/HRCT; of these only 17 were performed within 30 days of the traditional chest X-ray which was considered to be the time limit in order to validate the comparison between the two methods. RESULTS: The significant semeiotical findings were the parenchymal consolidations observed in 25 patients (89%) by standard chest X-rays; the CT/HRCT confirmed the findings in 4 cases while in 13 it enhanced the evaluation of their extensions. In 9 cases the standard chest X-ray established the presence of cavitations which were confirmed by the CT/HRCT in only 7 cases. Lymphadenopathy was observed in 3/28 patients (10.7%) through standard X-rays and in 15/17 cases (82%) through CT/HRCT. The latter method revealed to be extremely useful in the identification of this pathology. Nodules and micronodules were seen in 5 patients with traditional X-rays and in 9 cases with CT/HRCT. Bronchogenic spread signs of disease became visible only with CT and in particular with HRCT (11/17 patients = 65%). Comparing the two groups (AIDS and immunocompetent) taken into consideration, the most frequent lesion present in both was parenchymal consolidation resulting more bilateral in the AIDS subjects. Cavitation and pleural edema were seen more often in the AIDS group while bronchiectasia, bronchogenic spread and signs of previous pleuro-parenchymal suffering were more frequent in the immunocompetent patients. Lymphadenopathy was frequently found in the total study population but appeared slightly prevalent for the group not afflicted with AIDS. CONCLUSION: Radiological study of the chest permitted the identification of signs useful in the diagnosis of mycobacteriosis in all the patients studied. The application of CT/HRCT added helpful elements in almost all of the cases examined demonstrating to be more effective than the standard chest X-ray not only in terms of improved evaluation of known lesions but also in the identification of lesions which are difficult to determine by means of traditional radiology.

Perception of methacholine-induced airway obstruction in asthmatics.

The main objective of this study was to examine the perception of the first symptom during methacholine bronchoconstriction as soon as it occurred, and in the second instance to quantify the intensity of the breathlessness by means of the Borg Scale performed at the end of challenge so to not determine any difficulties for identification of the first symptom. A methacholine challenge test was carried out in 139 symptom-free asthmatics with a normal pulmonary function. When the first symptom was reported by the subject, the forced expiratory volume in one second (FEV1) was measured immediately. FEV1 was expressed as a percentage of the best personal value (FEV1%BPV). The intensity of the breathlessness was rated using a modified Borg Scale at the end of the challenge test so as not to confuse the patient. Seven subjects felt nothing during challenge. The first symptoms varied: constriction behind the breastbone (49%), inspiratory shortness (16.5%), coughing (10%), wheezing, throat constriction, general chest tightness, pain behind the sternum, and a sensation of rheum behind the sternum. FEV1%BPV at the first symptom was 80.5 +/- 10 (range 41-99). No symptom was perceived by 42% of the subjects within the 80-100 range of FEV1%BPV. FEV1%BPV at the first symptom was related to the log of the provocative dose causing a 20% fall in FEV1 (r = 0.2, p < 0.05). An inverse correlation between Borg Score and final FEV1%BPV (r = -0.25, p < 0.01) was found at the end of challenge. A subgroup of 39 subjects with similar final FEV1%BPV values (68-72) showed a correlation between the Borg Score at end of challenge and FEV1%BPV at the first symptom (r = 0.59, p < 0.001). The first symptom of the methacholine-induced bronchoconstriction varies in asthmatics and may be atypical, the bronchoconstriction level at which it is felt also varies among individuals, highly methacholine-responsive subjects perceive the bronchoconstriction later, while late perceivers of the first symptom show less intense breathlessness at the end of challenge. The measurement of the patient's ability to perceive asthmatic symptoms during the methacholine challenge test could be used to single out poor perceivers.

Pneumoconiosis (silicosis) in the confectionery industry.

Pneumoconiosis is not reported in food industry workers, and more specifically in the confectionery industry. We diagnosed diffuse pulmonary interstitial nodular fibrosis due to inhalation of powder containing quartz in a 54 year-old asymptomatic woman. Silicosis was due to a 5-year period of talc dust exposure 35 years earlier in the confectionery industry. The diagnosis was supported by a history of exposure, transbronchial lung biopsy specimen, 67Gallium scan, and CT scan. Our patient had an unusual history of exposure, which was not readily disclosed until the patient's memories, and after consultation with an expert in confectionery techniques, indicated she had been exposed to talc powder during her employment in the confectionery industry.

Primary acute pulmonary cavitation in asymptomatic sarcoidosis.

Sarcoidosis has a large variety of chest x-ray manifestations, but primary acute cavitation is very rare. We report a case of cavitary sarcoidosis occurring in an asymptomatic 25 year-old white patient. The diagnosis was established from chest x-ray, transbronchial biopsy specimen, bronchoalveolar lavage and gallium 67 scan. The peculiarities of this case are: 1) the presence of hilar adenopathy; 2) the cavitation occurred during the decreased activity of the disease; 3) the resolution of cavity without therapy. We suggest asymptomatic sarcoidosis should be considered in the differential diagnosis of pulmonary cavitation.