Molecular, Pathological, Clinical, and Therapeutic Aspects of Perihematomal Edema in Different Stages of Intracerebral Hemorrhage

Figure 1

The imaging characteristics of PHE at different stages after ICH. (a) Cranial CT images on days 1, 2, 4, and 7 after acute ICH in a patient. PHE (a rim around the hematoma indicated by yellow arrows) was not prominent on day 1 after ICH and gradually increased from days 1 to 7 after ICH. (b) MRI characteristics of PHE at 8 hours, 27 hours, day 4, and day 10, respectively, after the onset of symptoms in 4 patients with ICH. The red arrows in the T1WI images indicate the location of the hematoma. The signal characteristics of the hematomas changed over time in the T1WI and T2WI images after ICH, with PHE presented as a thin or wide rim with a strong signal in the T2WI and FLAIR images in the areas surrounding the hematoma. A strong signal on the DWI image but a weak signal on the ADC map appeared in the perihematomal area 8 hours after ICH. It may represent the appearance of ionic edema or cytotoxic edema in the perihematomal area. However, typical imaging characteristics of vasogenic edema in the perihematomal region were observed at 27 hours, day 4, and day 10 after the onset of the symptom. Vasogenic edema presented as a normal signal on the DWI images, and a strong signal surrounds the hematoma on the ADC map at 27 hours, day 4, and day 10 after ICH in 3 patients. Abbreviations: CT: computed tomography; PHE: perihematomal edema; ICH: intracerebral hemorrhage; T1WI: T1-weighted MRI; T2WI: T2-weighted MRI; FLAIR: fluid-attenuated inversion recovery; DWI: diffusion-weighted imaging; ADC: apparent diffusion coefficient.

(a)

(b)