Article Figures & Data
Figures
- Fig 1.
55-year-old man with right homonymous hemianopsia and right-body hemisensory loss. Admission nonenhanced CT 6 hours after symptom onset was unremarkable (both reviewers), except for an attenuated left PCA (arrowheads, one reviewer). PCT shows prolonged MTT and reduced rCBF in the left PCA territory. rCBVs are reduced only in a small part of the left thalamus but are increased in the rest of the PCA territory. The areas correspond to infarct and penumbra on the computerized automated map. Figure and legend continues.
- Fig 1.
Continued.—Admission CTA shows an occluded left P1 segment, which had recanalized but remained focally stenotic on follow-up MR angiography 3 days later. Follow-up DW image shows completed stroke in the predicted left thalamic infarct core. The penumbra did not infarct, most likely because of early recanalization; the MTT and rCBF abnormalities were however, categorized as false-positive since delayed MR imaging was selected as the criterion standard.
- Fig 2.
77-year-old woman with acute-onset left hemiparesis. Admission nonenhanced CT 2 hours after onset is normal. TTP and MTT are prolonged in the right superficial MCA territory (arrows). rCBFs are normal, but rCBVs are higher than contralateral values. TTP and MTT changes are not explained by any vascular abnormality; right carotid bifurcation (arrowhead) and intracranial arteries are normal. Final diagnosis was TIA. Follow-up CT 14 days later was normal. TTP and MTT changes were regarded as false-positive and most likely related to luxury perfusion due to TIA.
Tables
Scoring System Number (n = 26) Major arterial territory ACA 2 (7.7) MCA 17 (65.4) PCA 11 (42.3) ATLANTIS Frontal 12 (46.2) Parietal 8 (30.8) Temporal 8 (30.8) Basal ganglia 9 (34.6) ASPECTS Caudate 4 (15.4) Lenticulate 8 (30.8) Internal capsule 7 (26.9) Insula 10 (38.5) M1 5 (19.2) M2 10 (38.5) M3 7 (26.9) M4 7 (26.9) M5 14 (53.8) M6 5 (19.2) Note.—Data in parentheses are percentages. The MCA territory was involved in about two-thirds of the 26 stroke patients. Patients may have had more than one infarcted area.
- TABLE 2:
Sensitivity, specificity, accuracy, and interobserver agreement in detecting stroke
Imaging Study True-Positive False-Positive False-Negative True-Negative Sensitivity (%) Specificity (%) Accuracy (%) κ Nonenhanced CT Any sign 18 23 8 43 69.2 65.0 66.2 0.502 Lost cortical ribbon 11 5 15 61 43.4 92.3 78.5 0.528 Lost insular ribbon 7 3 19 63 26.9 95.0 75.8 0.591 Basal ganglia hypodensity 15 10 12 56 55.8 85.0 76.7 0.478 Dense artery 6 10 20 56 23.1 85.0 67.5 0.462 ATLANTIS/ASPECTS hypoattenuations 115 77 139 1141 45.2 93.7 85.3 0.594 PCT TTP review 194 298 60 920 76.5* 75.6 75.7* 0.526 MTT review 197 288 57 930 77.6* 76.3 76.5* 0.618 rCBF review 158 111 96 1107 62.2 90.9* 86.0* 0.516 rCBV review 128 89 126 1129 50.5 92.7* 85.4* 0.505 Computerized automated method 173 94 81 1124 68.2 92.3* 88.1* NA Note.—Follow-up CT or MR imaging was the criterion standard. Globally, accuracy was significantly greater with PCT than with nonenhanced CT: TTP and MTT maps are significantly more sensitive, whereas rCBF and rCBV maps were significantly more specific. NA indicates not applicable.
* Significantly superior to nonenhanced CT (any sign).
- TABLE 3:
Sensitivity, specificity, accuracy, and interobserver agreement in assessing stroke extent by ASPECTS score (>
ASPECTS)Imaging Study ASPECTS Score Sensitivity (%) Specificity (%) Accuracy (%) κ Nonenhanced CT 8.4 ± 1.9 42.9 67.6 62.8 0.446 PCT TTP review 6.9 ± 2.5 87.5* 68.4 72.2 0.716* MTT review 7.2 ± 2.3 94.4* 64.1 70.0 0.763* rCBF review 7.4 ± 2.3 85.7* 87.2* 86.9* 0.691* rCBV review 7.8 ± 2.1 62.5* 92.1* 86.3* 0.669* Computerized automated method 7.7 ± 2.3 72.2* 91.8* 87.9* NA Follow-up 7.4 ± 2.1 NA NA NA NA Note.—PCT was globally more sensitive, specific, and accurate than nonenhanced CT in correctly classifying large strokes, with significantly increased interobserver agreement. NA indicates not applicable.
* Significantly superior to nonenhanced CT.
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