Article Figures & Data
Figures
- Fig 1.
Axial DIR images in a 37-year-old healthy volunteer showing the basal cisterns (A and B) and the subarachnoid spaces at the brain convexity (C). In all the healthy volunteers scanned with the DIR sequence, the CSF appeared hypointense without CSF flow-related artifacts (B, arrowheads). Note the regional variation of gray matter signal intensity by using DIR, such as the difference between the prefrontal (C, arrows) and motor (C, arrowheads) cortices. The absence of CSF signal abnormality on DIR images in all the healthy volunteers and the strong agreement among readers suggest that the hyperintensities observed in patients with SAH by using DIR were not linked to artifacts.
- Fig 2.
Subacute SAH related to an aneurysm of the anterior communicating artery in a 42-year-old woman. No signal abnormality is visible on 3D FLAIR (A). SAH is visible by using axial SWI minimum-intensity-projection reformations in the right Sylvian fissure (B, arrows). The hypointensity visible in the left Sylvian fissure on SWI was considered a cortical vein by the 3 blinded readers by using both average and minimum-intensity-projection reformations (B, arrowhead). On the axial T2* image, SAH is bilateral, involving the Sylvian fissures (C, arrows). The DIR sequence reveals extensive SAH prevailing in the Sylvian fissures (D, arrows) and interhemispheric and occipital sulci (D, arrowheads).
- Fig 3.
Subacute SAH related to an aneurysm of the anterior communicating artery in a 63-year-old man. With 2D FLAIR (A), 3D FLAIR (B), or T2* (C) images, no subacute hemorrhage is visible. Conversely, marked subarachnoid signal abnormalities along the anterior and posterior interhemispheric sulci are observed by using DIR (D, arrows). SAH involving the parietal lobes is also visible (D, arrowheads).
- Fig 4.
Subacute SAH related to an aneurysm of the left internal carotid artery in a 25-year-old woman. With 2D FLAIR images, the detection of SAH is challenging due to potential CSF flow-related artifacts (A, arrow). With an axial average SWI reformat, a slight rim of hemorrhage is visible within the interpeduncular fossa (B, arrow). On the 3D FLAIR image, SAH is subtle due to a lack of contrast (C, arrows). With DIR images, SAH is obvious, with a marked hyperintensity within the interpeduncular fossa, vermis, and left Sylvian fissure (D, arrows). Note the marked signal intensity of SAH with DIR compared with the other MR images.
Tables
Patients Controls No. 25 20 Sex 16 M/9 F 13 M/7 F Age (yr) (mean) (range) 52 (28–71) 50 (26–69) Fisher grading (mean) 3 Grade 1 (No.) 5 Grade 2 (No.) 2 Grade 3 (No.) 6 Grade 4 (No.) 12 GCS (mean) (range) 14.1 (10–15) WFNS score (mean) (range) 1.5 (1–4) No vascular lesion (No.) 10 Brain aneurysm (No.) 15 Etiologic work-up (CTA and DSA) ACA (No.) 6 MCA (No.) (right 2, left 2) Right PcomA (No.) 2 Left vertebral artery (No.) 1 Left ICA (No.) 1 Basilar artery (No.) 1 Note:—GCS indicates Glasgow Coma Scale; WFNS, World Federation of Neurosurgical Societies; ACA, anterior communicating artery; PcomA, posterior communicating artery.
2D FLAIR 2D T2* 3D FLAIR 3D SWI 3D DIR Acquisition plane Axial Axial Sagittal Sagittal Sagittal TR/TE (ms) 11,000/125 1077/16 4800/267 13/19 5500/255 TI (ms) 2800 – 1650 – 2600/625 Acquired voxel size (mm) 0.8 × 1.4 × 4 0.9 × 1.2 × 4 1.2 × 1.2 × 1.2 1.2 × 1.2 × 1.2 1.2 × 1.2 × 1.2 Bandwidth (Hz) 271 216 1433 172 1433 Echo-train length 31 – 182 – 173 No. of sections 36 36 280 280 280 SENSE 1.4 – 2.5 2.5 2.5 CLEAR Yes Yes Yes Yes Yes Fat suppression No No SPIR No SPIR Acquisition time 3 min 3 min 3 min 20 sec 3 min 4 min Note:—SENSE indicates sensitivity encoding; CLEAR, inhomogeneity correction; SPIR, spectral presaturation with inversion recovery.
- Table 3:
Interobserver agreement among readers 1, 2, and 3 for each set of images according to the area considered
CT MRI 2D FLAIR 3D FLAIR 2D T2* 3D SWI 3D DIR Total R1 vs R2 (95% CI) 1 (1–1) 0.85 (0.77–0.93) 0.79 (0.69–0.89) 0.84 (0.76–0.91) 0.79 (0.72–0.87) 0.94 (0.91–0.97) R1 vs R3 (95% CI) 0.94 (0.85–1) 0.68 (0.57–0.79) 0.65 (0.53–0.76) 0.74 (0.65–0.83) 0.64 (0.55–0.73) 0.90 (0.87–0.93) R2 vs R3 (95% CI) 0.94 (0.85–1.02) 0.70 (0.60–0.81) 0.70 (0.59–0.80) 0.72 (0.63–0.81) 0.73 (0.65–0.81) 0.93 (0.91–0.96) Subarachnoid Interhemispheric R1 vs R2 (95% CI) 1 (1–1) 0.91 (0.74–1) 0.83 (0.60–1) 0.76 (0.54–0.98) 0.68 (0.44–0.92) 1 (1–1) R1 vs R3 (95% CI) 1 (1–1) 0.83 (0.60–1.06) 0.76 (0.50–1.02) 0.87 (0.70–1.05) 0.44 (0.11–0.77) 1 (1–1) R2 vs R3 (95% CI) 1 (1–1) 0.91 (0.74–1.08) 0.76 (0.50–1.02) 0.77 (0.56–0.99) 0.63 (0.39–0.88) 1 (1–1) Sylvian fissures R1 vs R2 (95% CI) 1 (1–1) 1 (1–1) 1 (1–1) 0.94 (0.83–1) 0.82 (0.63–1) 0.95 (0.88–1) R1 vs R3 (95% CI) 1 (1–1) 0.88 (0.66–1.11) 1 (1–1) 1 (1–1) 0.59 (0.31–0.86) 0.90 (0.81–1) R2 vs R3 (95% CI) 1 (1–1) 0.88 (0.66–1.11) 1 (1–1) 0.94 (0.83–1.06) 0.73 (0.50–0.96) 0.95 (0.89–1.02) Convexity R1 vs R2 (95% CI) 1 (1–1) 0.83 (0.68–0.98) 0.56 (0.27–0.84) 0.73 (0.57–0.89) 0.63 (0.43–0.84) 0.90 (0.85–0.95) R1 vs R3 (95% CI) 0.83 (0.60–1.07) 0.61 (0.42–0.81) 0.48 (0.23–0.73) 0.60 (0.42–0.78) 0.63 (0.44–0.83) 0.87 (0.81–0.92) R2 vs R3 (95% CI) 0.83 (0.60–1.07) 0.60 (0.40–0.79) 0.56 (0.33–0.80) 0.56 (0.37–0.74) 0.70 (0.55–0.86) 0.90 (0.85–0.95) Basal cisterns R1 vs R2 (95% CI) 1 (1–1) 0.33 (−0.33–0.98) 0.70 (0.41–0.99) 0.74 (0.39–1) 0.64 (0.36–0.92) 0.94 (0.88–1) R1 vs R3 (95% CI) 1 (1–1) 0.43 (−0.07–0.92) 0.25 (−0.20–0.70) 0.45 (−0.01–0.98) 0.25 (−0.13–0.62) 0.89 (0.82–0.97) R2 vs R3 (95% CI) 1 (1–1) 0.39 (−0.29–1.07) 0.30 (−0.17–0.77) 0.74 (0.39–1.10) 0.41 (0.09–0.73) 0.95 (0.90–1) Intraventricular R1 vs R2 (95% CI) 1 (1–1) 1 (1–1) 1 (1–1) 1 (1–1) 0.95 (0.85–1) 1 (1–1) R1 vs R3 (95% CI) 1 (1–1) 0 (−1.12–1.12) 0 (−1.95–1.95) 0.66 (0.19–1.13) 0.86 (0.70–1.02) 0 (−1.38–1.38) R2 vs R3 (95% CI) 1 (1–1) 0 (−1.12–1.12) 0 (−-1.95–1.95) 0.66 (0.19–1.13) 0.82 (0.64–1) 0 (−1.38–1.38) Note:—R1–R3 indicate readers 1–3; Total, all the subarachnoid and ventricular areas; Convexity, bilateral frontal, parietal, temporal, and occipital convexity areas; Basal cisterns, perimesencephalic and prepontine cisterns and cisterna magna.
- Table 4:
Number of patients with at least 1 subarachnoid and/or ventricular signal abnormality (diagnosis of SAH and IVH, respectively) for each imaging modality after consensus among readers
CT MRI 2D FLAIR 3D FLAIR 2D T2* 3D SWI 3D DIR Patients with SAH 7 12 15 14 15 25 Interhemispherica 0 6 7 13 15 25 Sylvian fissuresa 4 4 4 9 8 17 Convexitya 3 8 8 10 11 19 Basal cisternsa 0 1 5 4 7 23 Patients with IVH 0 0 0 3 5 0 ↵a Number of patients with at least 1 subarachnoid signal abnormality.
