Diffusion-Weighted MR Imaging of Intracerebral Hemorrhage

Abstract

ObjectiveTo document the signal characteristics of intracerebral hemorrhage (ICH) at evolving stages on diffusion-weighted images (DWI) by comparison with conventional MR images.Materials and MethodsIn our retrospective study, 38 patients with ICH underwent a set of imaging sequences that included DWI, T1-and T2-weighted imaging, and fluid-attenuated inversion recovery (FLAIR). In 33 and 10 patients, respectively, conventional and echo-planar T2* gradient-echo images were also obtained. According to the time interval between symptom onset and initial MRI, five stages were categorized: hyperacute (n=6); acute (n=7); early subacute (n=7); late subacute (n=10); and chronic (n=8). We investigated the signal intensity and apparent diffusion coefficient (ADC) of ICH and compared the signal intensities of hematomas at DWI and on conventional MR images.ResultsDWI showed that hematomas were hyperintense at the hyperacute and late subacute stages, and hypointense at the acute, early subacute and chronic stages. Invariably, focal hypointensity was observed within a hyperacute hematoma. At the hyperacute, acute and early subacute stages, hyperintense rims that corresponded with edema surrounding the hematoma were present. The mean ADC ratio was 0.73 at the hyperacute stage, 0.72 at the acute stage, 0.70 at the early subacute stage, 0.72 at the late subacute stage, and 2.56 at the chronic stage.ConclusionDWI showed that the signal intensity of an ICH may be related to both its ADC value and the magnetic susceptibility effect. In patients with acute stroke, an understanding of the characteristic features of ICH seen at DWI can be helpful in both the characterization of intracranial hemorrhagic lesions and the differentiation of hemorrhage from ischemia.

Diffusion-Weighted Imaging of Traumatic Subdural Hematoma in the Subacute Stage-Five Case Reports-

“…In general, late subacute intracerebral hematoma appears as high intensity on both T 1 -and T 2 -weighted imaging, reflecting lysis of the erythrocytes and predominantly extracellular methemoglobin. [2][3][4] The mean ADC value of the extracellular methemoglobin is 0.58 ± 0.10 × 10 -3 mm 2 /sec. 4) The high intensity areas in the subacute hematoma on diffusion-weighted imaging were considered to mainly consist of extracellular methemoglobin.…”

“…[2][3][4] The mean ADC value of the extracellular methemoglobin is 0.58 ± 0.10 × 10 -3 mm 2 /sec. 4) The high intensity areas in the subacute hematoma on diffusion-weighted imaging were considered to mainly consist of extracellular methemoglobin.…”

Subdural Hyperintense Band on Diffusion-Weighted Imaging of Chronic Subdural Hematoma Indicates Bleeding From the Outer Membrane

“…3) In this study, 29 of the 31 chronic subdural hematomas showed low intensity components on diffusion-weighted imaging due to the free water molecular movement rather than the paramagnetic effect of the extracellular methemoglobin, because the ADC value (1.81 ± 0.79 × 10 -3 mm 2 /sec) of the low intensity areas was larger than the reported ADC value of extracellular methemoglobin (0.58 ± 0.10 × 10 -3 mm 2 /sec). 8) The high intensity areas in the present subdural hematomas consisted of several types: high intensity line along the dura mater (subdural hyperintense band), high intensity along the intrahematoma septum, and laminar shape along the inner membrane. The subdural hyperintense bands accounted for almost all high intensity areas in the subdural hematomas.…”

“…The high intensity bands may reflect extracellular and/or intracellular methemoglobins without the influence of water molecular diffusion because the ADC value (0.76 ± 0.24 × 10 -3 mm 2 /sec) of the high intensity areas in the chronic subdural hematomas was similar to the reported ADC values of the extracellular (0.58 ± 0.10 × 10 -3 mm 2 /sec) and/or intracellular (0.55 ± 0.23 × 10 -3 mm 2 /sec) methemoglobins. 8) Repeated hemorrhaging from the outer membrane has been considered to be a causative factor of the chronic subdural hematoma. 6,21) Intravenous infusion of 51 Cr-labeled red blood cells in patients with chronic subdural hematoma resulted in the subsequent presence of labeled cells in the subdural fluid.…”

Intra and Inter-Observer Reliability of Mobile Tablet PACS Viewer System vs. Standard PACS Viewing Station-Diagnosis of Acute Central Nervous System Events

“…All personal identifiers were removed from the data spreadsheets such that there were no links between the study sequence folders and the individual patients as shown in Figure 1. Each radiologist documented his results into positive or negative restricted diffusion for infarction via analysis of restricted DWI & ADC mapping, blooming artifact seen on gradient sequencing, perfusion deficit as determined by analysis of cerebral blood flow, cerebral blood volume, and mean transit time [38][39][40][41][42][43]. In addition, other CNS pathologic etiologies were assayed including: intracranial hemorrhage, spinal cord compression, fracture, spinal canal stenosis, neural foraminal stenoses, disk herniation, and annular fissuring [24,[44][45][46][47].…”