Q fever pneumonia: CT findings.

PURPOSE: To evaluate the computed tomographic (CT) features of Q fever pneumonia. MATERIALS AND METHODS: The authors retrospectively reviewed the chest radiographs and CT scans obtained in 12 patients, who were selected on the basis of chest CT availability from a group of patients with a definite diagnosis of acute Q fever infection during an 8.5-year period. RESULTS: In all cases, CT depicted lesions indicative of airspace involvement, which was expressed as lobar (n = 3), segmental (n = 3), patchy (n = 3), or a combination of these patterns (n = 3). Involvement of more than one lobe was observed in seven (58%) patients. In one patient with multiple patchy areas of consolidation, nodular lesions with a vascular connection and a halo of ground-glass opacity, which were suggestive of an angioinvasive process, were demonstrated. In addition, CT performed in a patient with acute Coxiella burnetii infection who abused alcohol revealed necrotizing pneumonia. Pleural effusions were seen at both CT and radiography in three patients, and mild lymph node enlargement in isolated regions was seen at CT in four patients. Chest radiography was less accurate than CT in the detection of segmental and patchy areas of consolidation. CONCLUSION: The typical CT findings of Q fever pneumonia consisted mainly of multilobar airspace consolidation. A nodular pattern accompanied by a halo of ground-glass opacification and vessel connection, and necrotizing pneumonia in the setting of impaired immunity were less frequent.

HRCT in miliary lung disease.

PURPOSE: To analyze high resolution CT (HRCT) features of a miliary pattern in different diseases. MATERIAL AND METHODS: Eight HRCT studies with a miliary lung pattern were retrospectively reviewed with the diagnoses tuberculosis (n=3), Candida albicans (n=1), sarcoidosis (n=3), and metastatic adenocarcinoma (n=1). RESULTS: In all cases, HRCT showed diffusely disseminated nodules up to 3 mm. In 2 cases of tuberculosis and 1 of sarcoidosis, the lesions predominated in the upper/middle lung zones. In the case of metastatic adenocarcinoma the nodules were more sparse in the lung periphery while in 1 case of sarcoidosis, HRCT revealed a predominance of the lesions in the outer third of the lungs. Cyst-like lesions of 12 mm were observed in 2/3 cases of tuberculosis and in metastatic adenocarcinoma. Notably thickened interlobular septa and interlobar fissures were each seen in 2/3 cases of sarcoidosis. In general, a random relationship of miliary nodules to secondary lobular structures and bronchovascular bundles was observed, despite the co-existence of centrilobular, subpleural and paraseptal nodules. CONCLUSION: HRCT features that potentially contribute in making a differential diagnosis are: a) A peripheral distribution of nodules, an increased number of thickened interlobular septae, and a notable thickening of interlobar fissures, all of which are indicative of sarcoidosis; and b) Multiple cyst-like lesions which should direct attention to tuberculous or metastatic origin. The predominance of miliary nodules in relation to cephalocaudal axis, their margin and size are not helpful features to the differential diagnosis of diseases presenting a miliary pattern.

Sacroiliac joints: anatomical variants on CT.

The purpose of this work was to examine the type and prevalence of anatomical variants of the sacroiliac joints (SJs) in patients without SJ disease on CT examinations. The study comprised 534 consecutive patients undergoing pelvic CT with various indications not related to diseases that could involve the SJ. Images printed on bone window settings were evaluated with reference to any deviation from the usual appearance of the SJ. Physical data and history of low back pain were recorded in each patient. Six types of anatomical variants were observed: accessory joints in 102 patients (19.1%), "iliosacral complex" in 31 (5.8%), bipartite iliac bony plate in 22 (4.1%), crescent-like iliac bony plate in 20 (3.7%), semicircular defects at the sacral or iliac side in 16 (3%), and ossification centers in 3 patients (0.6%). Accessory joints were more common in obese than in normal-weight individuals (p < 0.05) and in older than younger (<60 years) patients (p < 0.001) and presented degenerative alterations especially in patients with episodes of low back pain. Three of these variants (iliosacral complex, bipartite iliac bony plate, and crescent-like iliac bony plate) had higher incidence in women than in men (p < 0.05) and were not associated with degenerative changes. Knowledge of the normal variations in the SJ appearance broadens the understanding of SJ anatomy, facilitating image interpretation.

Crescentic and ring-shaped opacities. CT features in two cases of bronchiolitis obliterans organizing pneumonia (BOOP).

Two cases of idiopathic bronchiolitis obliterans organizing pneumonia (BOOP) with unusual CT findings are presented. On CT both cases exhibited crescentic and ring-shaped opacities, surrounding areas of groundglass attenuation, and associated with a nodular pattern in one patient and airspace consolidations in the second patient. CT-pathologic correlation disclosed that the central areas of groundglass attenuation corresponded to alveolar septal inflammation, in contrast to the denser periphery where granulomatous tissue in peripheral airspaces predominated. In the broad spectrum of CT findings, BOOP can exhibit specific CT features with regard to the crescentic or ring-shaped opacities with a central groundglass attenuation area. Since these features have not been described in any other disease, they might be characteristic features for the diagnosis of BOOP.

Emphysematous cystitis after orchiectomy.

A 59-year-old man developed emphysematous cystitis 3 weeks after undergoing left orchiectomy because of suppurative epididymitis. The case is presented because of its unusual cause and to emphasize the high degree of suspicion required for the diagnosis.