More on Exploiting the T1 Shinethrough and T2* Effects Using Multiecho Susceptibility-Weighted Imaging

Dual-echo Gd-SWI of a 71-year-old man with primary CNS lymphoma showing periventricular enhancing masses. The shorter echo Gd-SWI (A) produced an image with greater T1-weighting demonstrating homogenous enhancement of the periventricular masses. The enhancing area has a signal-to-noise ratio of 108:1. Perilesional brain edema in the right centrum semiovale is also clearly depicted (asterisks). Conversely, the longer echo Gd-SWI (B) also highlights the periventricular enhancing masses, but with a lower signal-to-noise ratio of 53:1, compared with the shorter echo SWI. However, the longer echo Gd-SWI (B) has greater T2* weighting and reveals the draining medullary veins (arrowheads). Note that the area of brain vasogenic edema (asterisks) seen on shorter echo Gd-SWI (A) is not visible in the longer echo Gd-SWI (B) because the background brain tissue loses the signal faster than the tissue with edema, so it appears isointense. Dual-echo Gd-SWI parameters were: TE 1 = 10 ms and TE 2 = 22 ms, TR = 29 ms, flip angle = 15°, in-plane resolution = 0.9 × 0.9 mm, and a section thickness of 2.5 mm. The data were collected from a 3T MR imaging scanner (Siemens 3.0T Skyra, Erlangen, Germany).