Figure 1.
An MRI performed on a healthy subject using spin-echo T1-weighted imaging.
We obtained axial slices of the normal brain. The anatomical structures of the subarachnoid space were labeled according to the following method. The subarachnoid area of each cerebral hemisphere was divided into 5 regions (frontal lobe, temporal lobe, occipital lobe, parietal lobe, and Sylvian fissure), and the subarachnoid areas of the cerebellum and the brainstem were divided into two relatively independent regions. Then, the number of regions, ranging from 0 to 12, of the subarachnoid area of the entire brain, excluding the ventricular system, was determined.
Figure 2.
CT and enhanced gradient echo T2 star-weighted angiography (ESWAN) images of the brain of a 54-year-old man who experienced a traumatic brain injury.
An axial head CT image displays right frontotemporal SAH (Fisher grade 4) with bilateral frontal contusions and intracerebral hematoma (A). A follow-up CT image 26 weeks after the brain injury indicates that the hemorrhages were completely resolved and the lateral ventricles were mildly enlarged (B). A follow-up MRI (1.5T) image was obtained 26 weeks following the head injury (C,D). The axial ESWAN image displays a rim of hypointensity (arrowheads), with hemosiderin deposits forming along the cerebral convexity (C, D).
Figure 3.
Chi-square contingency table analysis reveals a correlation between the number of regions exhibiting tSAH (%) based on CT images and the number of regions exhibiting SS-CNS (%) based on ESWAN images in 31 patients (χ2 = 17.73, P<0.05).
Figure 4.
CT and ESWAN images of the brain of a 50-year-old man (A, B) and a 59-year-old man (C, D).
The Fisher grades of the SAH based on the CT images were grade 2 (A) and grade 4 (C), respectively. Follow-up MR (1.5T) images were obtained at 34 weeks (B) and 177 weeks (D) after the head injury. The arrows denote areas of SS-CNS, which is indicated by a rim of hypointensity on the surface of the brain. Note the extent of deposition in each case. The CT and ESWAN images display a degree of correlation, patients with a higher Fisher grade exhibit more regions containing SS-CNS deposits.
Table 1.
Univariate analyses of factors associated with extent of SS-CNS deposition based on ESWAN in 31 patients.