MRI Sequences

Which of the following statements accurately describes the signal characteristics of cerebrospinal fluid (CSF) on T1-weighted and T2-weighted MRI sequences?

A 45-year-old patient presents with new-onset seizures. An MRI brain is performed. Which MRI sequence is most sensitive for detecting periventricular demyelinating plaques, such as those seen in multiple sclerosis, by nulling the signal from cerebrospinal fluid (CSF)?

A 68-year-old male presents to the emergency department with sudden onset right-sided weakness and aphasia. An urgent MRI brain is performed. Which MRI sequence is most crucial for the early detection of acute ischemic stroke within minutes to hours of symptom onset?

A 55-year-old patient with a history of hypertension presents with a sudden severe headache. An MRI brain is performed to rule out intracranial hemorrhage. Which MRI sequence is most sensitive for detecting acute and chronic hemorrhage, as well as microbleeds, due to its susceptibility to magnetic field inhomogeneities caused by blood products?

A 30-year-old patient undergoes an MRI brain for evaluation of a suspected brain tumor. After the administration of gadolinium-based contrast material, which MRI sequence is typically acquired to best visualize contrast enhancement?