BT is a UK-based communication services provider since 1969. Company serves nearly 20 million customers globally. Name changed three times: Post Office Telephones, Telecommunications, British Telecom
Imaging appearances of liver metastases are generally nonspecific. CT is preferred imaging modality due to dual blood supply effects. MRI may be superior for small lesions and fatty liver changes
Begins at left ventricle base, 6 cm behind sternum. Passes upward, forward, and to right, reaching second right costal cartilage. Total length about 5 centimeters. Contains aortic sinuses between valve commissures
CNR measures contrast between tissue of interest and background. SNR measures image signal relative to background noise. Optimal images have reasonable noise level. Quantum noise (mottle) is inherent in x-ray and CT imaging
Found behind intact tympanic membrane without infection. Middle ear congenital cholesteatomas represent 2% of all cases. Can occur in petrous bone near geniculate ganglion. Usually asymptomatic, discovered incidentally. Treatment requires complete surgical removal
Shows hyperintense signal on T1-weighted images due to proteinaceous content. Appears hypointense on T2-weighted images due to low water content. Demonstrates restricted diffusion on diffusion-weighted imaging. Typically has thin, smooth capsule without contrast enhancement