case_images: PMC11808609_01
case_images: (A) Axial CT subdural window: The long, thick red arrow points to the extra-axial epidural collection. The blue arrowhead indicates subgaleal soft tissue edema. (B) Axial CT soft tissue window: The blue arrowhead indicates subgaleal soft tissue edema, appearing isodense on the axial CT soft tissue window. (C) Axial Diffusion-Weighted Imaging (DWI): The thin, long white arrows mark a region of occipital osteonecrosis. The thin, short white arrows point to the corresponding adjacent subgaleal hemorrhage. (D) Coronal T1WI Post-Contrast: The long, thin white arrows indicate calvarial heterogeneity with enhancement, suggesting areas of presumed bone infarction. The short, thick green arrows highlight pockets of subgaleal peripherally-enhancing collections with intrinsic T1 hyperintense signals. The blue arrowhead marks subgaleal soft tissue edema.
case_images: gr1.jpg
case_images: PMC11808609_01_gr1.jpg
case_images: fig0001
case_images: Tomography (CT), extending from the vertex to the foramen magnum. The CT revealed a new onset of a 2.4 x 1.6 cm lesion with intermediate attenuation measuring 50 Hounsfield Units (HU), straddling and displacing the anterior cerebral falx (Fig. 1A). Additionally, extensive soft tissue enlargement was observed in the subgaleal scalp (Fig. 1B). MRI demonstrated heterogeneous marrow signal within the calvarium, characterized by T1/T2 hypointensity with mild diffusion restriction (Fig. 1C) and superimposed enhancement (Fig. 1D). Multifocal, well-circumscribed T1/T2 heterogeneous extraosseous lesions/collections were identified, demonstrating peripheral enhancement throughout the frontal and parietal scalp bilaterally (Fig. 1D). Instead, the collections displayed increased T1 hyperintensity and susceptibility on susceptibility-weighted imaging (Fig. 1A), compatible with hemorrhagic collections within the extracranial subgaleal space and intracranial epidural space, superimposed on areas of osteonecrosis and bone infarction. T1, hyperintense on T2, with mild, ill-defined enhancement, consistent with edema (Fig. 1, Fig. 2, Fig. 3). This constellation of findings is consistent with ASHS, an exceedingly rare complication in individuals with SCD.
case_images: (A) Axial T2WI: The thick red arrow indicates an epidural collection with a T2WI hypointense signal, consistent with blood products. The thin green arrow highlights heterogeneous subgaleal collections with multiple confluent foci of susceptibility, surrounded by a T2WI hyperintense signal, consistent with blood products. The blue arrowhead marks thickened subgaleal and subcutaneous tissue with a T2WI hyperintense signal.
case_images: gr3.jpg
case_images: PMC11808609_01_gr3.jpg
case_images: fig0003
case_images: T1, hyperintense on T2, with mild, ill-defined enhancement, consistent with edema (Fig. 1, Fig. 2, Fig. 3). This constellation of findings is consistent with ASHS, an exceedingly rare complication in individuals with SCD.