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.

Pulmonary complications of liver transplantation: radiological appearance and statistical evaluation of risk factors in 300 cases.

The aim of this study was to evaluate the incidence, radiographic appearance, time of onset, outcome and risk factors of non-infectious and infectious pulmonary complications following liver transplantation. Chest X-ray features of 300 consecutive patients who had undergone 333 liver transplants over an 11-year period were analysed: the type of pulmonary complication, the infecting pathogens and the mean time of their occurrence are described. The main risk factors for lung infections were quantified through univariate and multivariate statistical analysis. Non-infectious pulmonary abnormalities (atelectasis and/or pleural effusion: 86.7%) and pulmonary oedema (44.7%) appeared during the first postoperative week. Infectious pneumonia was observed in 13.7%, with a mortality of 36.6%. Bacterial and viral pneumonia made up the bulk of infections (63.4 and 29.3%, respectively) followed by fungal infiltrates (24.4 %). A fairly good correlation between radiological chest X-ray pattern, time of onset and the cultured microorganisms has been observed in all cases. In multivariate analysis, persistent non-infectious abnormalities and pulmonary oedema were identified as the major independent predictors of posttransplant pneumonia, followed by prolonged assisted mechanical ventilation and traditional caval anastomosis. A "pneumonia-risk score" was calculated: low-risk score ( < 2.25) predicts 2.7% of probability of the onset of infections compared with 28.7% of high-risk (> 3.30) population. The "pneumonia-risk score" identifies a specific group of patients in whom closer radiographic monitoring is recommended. In addition, a highly significant correlation (p < 0.001) was observed between pneumonia-risk score and the expected survival, thus confirming pulmonary infections as a major cause of death in OLT recipients.

[Clinical role of CT-guided transthoracic needle biopsy in the diagnosis of solitary pulmonary nodules]. / Ruolo clinico dell'agobiopsia transtoracica guidata con tomografia computerizzata nella diagnostica dei noduli polmonari solitari.

PURPOSE: The aim of this prospective study was to assess the overall diagnostic accuracy of CT-guided transthoracic biopsy of solitary pulmonary nodules, to compare the reliability of the diagnosis of malignancy made at prebiopsy CT and to investigate the final clinical impact of cyto-histologic results. MATERIALS AND METHODS: A prospective study was carried out on 128 CT-guided transthoracic biopsies performed in 119 subjects with a solitary pulmonary nodule to assess the diagnostic accuracy of the method. The cyto-histologic diagnosis was then compared to the previous radiologic and CT diagnosis and to clinical outcome, to define the reliability of the previous CT diagnosis and the clinical impact of lung biopsy in relation to its risk. For each needle biopsy, the lesion site, diameter and depth, the number of punctures and needle size were related to the complications, their latency and treatment. The cyto-histologic diagnosis was compared with the results of the macro- and microscopic examination of the surgical specimens in the surgical patients (no. 44). RESULTS: As for the drawbacks of our approach, 40 patients (31%) developed pneumothorax which required thoracic drainage in 10% of cases. A self-resolving, clinically asymptomatic blood effusion was observed around the lesion site or adjacent to the needle path in 21 patients. All the complications were only related to the number of needle punctures and to perilesional emphysema. 113 of 128 (88%) needle biopsies of isolated pulmonary nodules were diagnostic, with 88 malignant and 25 benign lesions. All malignant diagnoses had surgical (42 cases) of follow-up confirmation. No false positives were observed in our series but we had 4 false negatives; specificity was 100%, sensitivity 95%, PPV 100% and NPV 84% and overall diagnostic accuracy 96%. The CT diagnosis of malignancy was correct in 68% of cases and we had 16 false positives and 20 false negatives. Thus, CT had 77% sensitivity and 36% specificity in malignant characterization and particularly in identifying benign lesions (9 of 25 cases). The results of biopsy had an unquestionable impact on diagnosis and treatment in 44% of patients: the previous CT diagnosis was modified in 32% and treatment planning changed accordingly. In the other 14 patients whose CT diagnosis was correct (4 lymphomas, 3 small cell carcinomas, 3 mesotheliomas, 4 benign lesions), biopsy was the cornerstone of subsequent treatment planning. CONCLUSIONS: CT-guided thoracic biopsy, allowing an accurate histologic diagnosis, is confirmed as a safe procedure with a strong impact on the diagnostic protocol of the solitary pulmonary nodule.