Shark liver oil-induced lipoid pneumonia in pigs: correlation of thin-section CT and histopathologic findings

Early time-related course of image findings in postmortem MRI: Typical findings and observer agreement in a porcine model

PURPOSE

To assess early time-related image findings in postmortem magnetic resonance imaging (MRI) and to evaluate observer agreement in a porcine model.

MATERIAL AND METHODS

Three pigs were examined by MRI at 15 different time points in the first 36h after death. Two observers independently recorded the postmortem interval (PMI) to the appearance of fluid collection (pleural space, interlobar and interlobular pulmonary fissures and hepatic interlobar fissures), gas accumulation (intrahepatic and intracardial) and blood clotting (aorta and intrahepatic venous vessels). Cohen's Kappa statistics and intraclass correlation coefficient (ICC) were used to evaluate intra- and interobserver agreement.

RESULTS

Intrahepatic gas was evident after 12, 17 and 30h. Also, intracardiac gas was present in all animals. However, no chronological appearance has been observed. Blood clotting in the hepatic vein was observed within 3min, aortic clotting with a delay of 2-12h after death. Interlobular pulmonary fluid (median PMI: 2h, range 2-2h), pleural effusion (median PMI: 10.5h, range 9-12h) and hepatic interlobar fissure fluid (median PMI: 11.5h, range 11-12h) displayed a chronological appearance pattern. Qualitative and quantitative detection of most postmortem findings showed excellent intra- and interobserver agreement with Kappa values>0.8 or ICC>0.75.

CONCLUSION

Pulmonary and hepatic fissural fluid collection as well as intravasal gas accumulation are early time-related image findings in postmortem MRI. The chronological appearance of these findings can be assessed with excellent observer agreement in a porcine model.

Aspiration-related lung diseases

Aspiration is a common but underrecognized clinicopathologic entity, with varied radiographic manifestations. Aspiration represents a spectrum of diseases, including diffuse aspiration bronchiolitis, aspiration pneumonitis, airway obstruction by foreign body, exogenous lipoid pneumonia, interstitial fibrosis, and aspiration pneumonia with or without lung abscess formation. Many patients who aspirate do not present with disease, suggesting that pathophysiology is related to a variety of factors, including decreased levels of consciousness, dysphagia, impaired mucociliary clearance, composition of aspirate, and impaired host defenses. In this pictorial essay, we will review the different types of aspiration lung diseases, focusing on their imaging features and differential diagnosis.

Lipoid pneumonia: spectrum of clinical and radiologic manifestations

OBJECTIVE

Lipoid pneumonia results from accumulation of lipids in the alveoli and can be either exogenous or endogenous in cause based on the source of the lipid. Exogenous lipoid pneumonia is caused by inhalation or aspiration of animal fat or vegetable or mineral oil. Endogenous lipoid pneumonia is usually associated with bronchial obstruction. The purpose of this article is to review the pathogenesis and clinical and radiologic manifestations of exogenous and endogenous lipoid pneumonia.

CONCLUSION

The ability to recognize the radiologic manifestations of lipoid pneumonia is important because, in the appropriate clinical setting, these findings can be diagnostic.

Thin-section CT of the secondary pulmonary lobule: anatomy and the image--the 2004 Fleischner lecture

The secondary pulmonary lobule is a fundamental unit of lung structure, and it reproduces the lung in miniature. Airways, pulmonary arteries, veins, lymphatics, and the lung interstitium are all represented at the level of the secondary lobule. Several of these components of the secondary lobule are normally visible on thin-section computed tomographic (CT) scans of the lung. The recognition of lung abnormalities relative to the structures of the secondary lobule is fundamental to the interpretation of thin-section CT scans. Pathologic alterations in secondary lobular anatomy visible on thin-section CT scans include interlobular septal thickening and diseases with peripheral lobular distribution, centrilobular abnormalities, and panlobular abnormalities. The differential diagnosis of lobular abnormalities is based on comparisons between lobular anatomy and lung pathology.

Squalene aspiration pneumonia in children: radiographic and CT findings as the first clue to diagnosis

BACKGROUND

The diagnosis of squalene aspiration pneumonia in children is often difficult because of minimal non-specific symptoms.

OBJECTIVE

To investigate the radiological findings of squalene aspiration pneumonia in children.

MATERIALS AND METHODS

We reviewed the chest radiographs (n = 8) and CT scans (n = 7), including high-resolution CT (n = 3), of eight patients (four boys, four girls; age 3 months to 6 years) with squalene aspiration pneumonia. All patients presented minimal symptoms.

RESULTS

Chest radiographs showed right-sided predominantly parahilar infiltrations. The extent and the opacity of the lesions decreased slowly during the follow-up period (mean 5.4 months) after halting the exposure. On CT, affected areas appeared as dense consolidations surrounded by ground-glass opacities showing a crazy-paving pattern in a geographic lobular distribution in all patients. The lesions were predominantly in the right lung and dependent areas in all patients and extensively involved all pulmonary lobes in five patients.

CONCLUSIONS

These radiological findings, although non-specific, can lead to an appropriate diagnosis, particularly when patients present few symptoms.