Design of practical T 2 ‐selective RF excitation (TELEX) pulses

Traditional T 2 ‐based imaging techniques are geared toward imaging long‐ T 2 , species. Traditional techniques are, therefore, not optimal in clinical situations where the information of interest lies in the short‐ T 2 species. T 2 ‐selective RF excitation (TELEX) is a technique for obtaining a T 2 ‐based contrast that highlights short‐ T 2 values while suppressing long‐ T 2 values‐opposite to traditional T 2 contrast. Previously, TELEX has been demonstrated qualitatively to highlight only very short‐T 2 values ( T 2 = 0.001 s). When applied to longer T 2 values ( T 2 ≈ 0.01 s), TELEX becomes sensitive to ΔB o non‐uniformities. This restricts its application to problems in which the T 2 of interest is very short. In this study, TELEX is characterized quantitatively. Furthermore, a bandwidth broadening scheme is developed that reduces the Δ B o sensitivity of TELEX. This permits the technique to be applied to longer T 2 values. The capabilities and limitations of a practical implementation of TELEX are discussed.