This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bronchiectasis, Subject name: Medicine
What is not a CT finding in bronchiectasis? 
Select and explain. 
A. Tree in bud appearance, B. Crazy paving appearance, C. Signet ring appearance, D. Traction bronchiectasis with lung fibrosis
B: Crazy paving appearance
Answer: B: Crazy paving appearance 
Explanation: While chest radiographs lack sensitivity, the presence of "tram tracks" indicating dilated airways is seen with bronchiectasis. Chest CT is more specific for bronchiectasis and is the imaging modality of choice for confirming the diagnosis. CT findings include airway dilation detected as a parallel "tram tracks" or as the "signet-ring sign"--a cross-sectional area of the airway with a diameter at least 1.5 times that of the adjacent vessel. The crazy-paving pattern is seen in pulmonary alveolar proteinosis and also can be observed in exogenous lipoid pneumonia, sarcoidosis, mucinous broncho-alveolar cell carcinoma and acute respiratory distress syndrome.