Answer:

Explanation
1. Aspiration of glass will produce a hyperdense lesion located in the bronchial distribution.  Although it is hyperdense, the location of the lesion is the key distinguishing feature.  [Aspiration of a foreign body (glass, metal or plastic) will result in a hyperdense lesion located within the bronchial distribution (differential table)].

2. Broncholithiasis may have a similar appearance to cement embolization on conventional radiography, but not usually on CT.  Broncholiths will be found in the bronchi rather than the pulmonary arteries.  The key is to identify the lesion in the bronchi.  Another clue that the patient may have a broncholith is that there are signs of obstruction, which are usually not seen with cement embolization.  [A broncholith is usually a solitary lesion which narrows or completely occludes the bronchial lumen (summary table)].

3. Granulomatous disease can have a varied appearance depending on the cause (histoplasmosis, silicosis, tuberculosis).  Granulomatous disease is localized to the lung parenchyma, but is usually not found isolated to the arterial distribution.  If the arterial distribution is involved, other parts of the lung parenchyma are typically involved.  Furthermore, granulomas typically will enhance with contrast administration, whereas a cement embolism will not enhance.  [These lesions are located within the lung parenchyma and typically enhance with contrast administration (summary table)].

4. IV administration of hyperdense material such as iodine-base contrast and mercury will result in a hyperdense lesion with a branching or globular pattern, which may mimic cement pulmonary embolization if the proper history regarding the patient or the type of study was not available.  [Injection of hyperdense material has a branching or globular hyperdense material in the pulmonary arterial distribution, best seen in bone windows on non-contrast chest CT (summary table)].

5. Aspiration of plastic will produce a hyperdense lesion located in the bronchial distribution.  Much like the example with glass listed earlier, the location of the lesion is the key distinguishing feature.  [Aspiration of a foreign body (glass, metal or plastic) will result in a hyperdense lesion located within the bronchial distribution (differential table)].