Comparison of 1.5 and 8 Tesla High-Resolution Magnetic Resonance Imaging of Lacunar Infarcts

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Abstract
We present a case report comparing 1.5 fast spin-echo (FSE) and high-resolution 8 Tesla (T) gradient echo (GE) MRI of a patient with multiple lacunar infarcts. A 51-year-old man with a history of previous lacunar infarctions was studied with two-dimensional Fourier transform axial 8 T GE MRI using the following parameters: 3 mm thick slices skip 3 mm, flip-angle approximately 20 degrees, TR 800 milliseconds, TE 12 milliseconds, 1024 × 1024 matrix, field of view (FOV) 20 cm, and bandwidth 50 kHz. These images were then compared with routine clinical 1.5 T T2-weighted FSE images with 5 mm thick sections, 256 × 256, FOV 20, TR 5650, TE 102, and 16 echo train length. The majority of the infarctions were seen as areas of high signal intensity on both the 1.5 and 8 T images. They were seen in the corona radiata or the basal ganglia. More lesions were seen on the 8 T images. Low intensity signal was best demonstrated on the 8 T images at segments of the periphery of a few of the larger infarcts. There were a few small punctate low signal intensity regions localized at the termination of some of the microvessels on the 8 T images only. The foci of decreased signal intensity in regions of chronic hemorrhage appeared larger on the 8 T images compared with the 1.5 T images. The 8 T images demonstrated direct visualization of many small vessels, primarily in the deep white matter, which were not visible on the 1.5 T images. On the 8 T images, some of the infarcts appeared to be located between the medullary veins of the deep white matter. This case report indicates that GE 8 T images demonstrate more infarctions compared with the FSE 1.5 T images. It is possible to simultaneously identify the microvessels of the brain, small foci of hemorrhage, and lacunar infarctions using 8 T MRI.