We see a high population of scale insects on the bark, mainly on the area with dark coloration. Control may be challenging and repeat treatments likely needed. Ideally, dormant oil (a slightly more concentrated type of horticultural oil) would have been applied in winter; now, you might instead try manual removal with a gentle scrub brush and high-pressure water spray (from a hose, not a pressure-washer). If this is Japanese Maple Scale (which, despite the name, feeds on a wide array of trees and shrubs and has this appearance), the first new generation ("crawlers") will emerge soon, weather-depending, and can be controlled with a target application of horticultural oil. Other insecticides are effective when used at that time as well, but need to be applied by a professional pesticide applicator.

Here is more information on armored-type scales in general: https://extension.umd.edu/resource/armored-hard-scale-trees-and-shrubs

We see buds breaking dormancy in the photo, which means the tree is not dead, though we cannot tell the extent of any overall damage. It's normal for birch to not have leafed-out quite this early yet, particularly in central MD. Depending on how long this tree has been planted here, and given the quantity of scale present, the scale may have already been on the plant at the time of planting, or colonized the plant afterwards, particularly if it was stressed due to insufficient moisture. (Incidentally, if the tree has been in the ground more than six to twelve months, the stakes should be removed, as they're either done doing their job or, at worst, weren't helping at all from the start and therefore won't be useful going forwards and may only hinder trunk growth at this point.)

Scale protective covers - their only parts visible without magnification or manipulation - don't immediately fall off the plant when they die. As such, dead scale look essentially the same as live scale for awhile. Therefore, if the scale here are already dead or dying due to a prior treatment, then other factors may have resulted in dieback if you notice branches failing to leaf-out later this spring. Birches are not very drought-tolerant, and in summer or autumn periods with insufficient rainfall, they'll need irrigating unless planted in a low-lying area that remains moist. Wounds to the trunk from mowers (see below) or buck deer rubbing antler velvet off in autumn can also result in major loss of crown growth.

To avoid additional tree stress, which can make them more vulnerable to pests, make sure the base is encircled by mulch (though not touching the trunk itself) to keep the lawn from growing too close. It may already be - we can't see the bottom of the trunk - but if not, this allows for both more root competition between the two and risks injury to the thin bark if mowing or weeding equipment contacts the trunk.

Miri