Understanding Subdural Collections in Pediatric Abusive Head Trauma

SDC entities in AHT cases. A, Acute SDH (nonenhanced CT): a 2-month-old boy with a small hyperdense SDC over the left frontoparietal region (arrow) and hyperdense blood components around the tentorium (arrowheads). B, SDHy (nonenhanced CT): a 2-month-old boy with wide, homogeneously hypodense (or CSF-isodense) SDCs over both frontoparietal regions; no neomembranes or septa. C, SDHy (MR imaging, T2WI, TSE, nonenhanced): a 4-month-old boy with wide, homogeneously CSF-isointense SDCs over both frontoparietooccipital regions, markedly frontal due to the supine position; no neomembranes or septa. D, SDHHy, homogeneous variant (MR imaging, T2WI, TSE, nonenhanced): a 3-month-old boy with homogeneous SDCs over both frontoparietal regions. Compared with CSF within the external and internal CSF spaces, the SDCs appear hypointense. Two intact BVs can be found next to the superior sagittal sinus (arrow shows 1 BV). E, SDHHy, heterogeneous variant (nonenhanced CT): a 19-month-old boy with an SDC in the left frontoparietal region. The SDC is composed of a thin, brain-sided, hyperdense component and a thin, dura-sided, hypodense component that runs parallel to the former component (mixed-density pattern). In this case, the study also revealed severe brain edema with a midline shift to the right side as well as hyperdense blood components within the anterior and posterior interhemispheric fissures. F, SDHHy, heterogeneous variant (MR imaging, FLAIR, nonenhanced): a 4-month-old girl with wide SDCs over both frontoparietooccipital regions. While the frontoparietal SDC proportions appear hypointense, the parietooccipital proportions are iso- to hyperintense. The transitional zone between the 2 components is almost smooth; fluid-fluid levels cannot be recognized unambiguously. G, Chronic SDH (nonenhanced CT): a 7-month-old boy with wide, hypodense SDCs over both frontoparietal regions and subtle formation of subdural neomembranes on the left side (arrows). H, Chronic SDH (MR imaging, T1WI, gradient-echo sequence, enhanced by contrast agent): same case as in G. Confirmation of the presence of subdurally located septa and chamber formations. In contrast to the nonenhanced T1WI (not shown), this contrast agent–enhanced study revealed focal signal enrichment located at the neomembranes (arrows). I, Chronic SDH (MR imaging, T2WI, TSE, nonenhanced): a 4-month-old boy with numerous subdural septa and neomembranes. Note the different signal intensities and multiple fluid-fluid levels within subdural chamber formations, especially in the right occipital region.