Performance of Automated ASPECTS Software and Value as a Computer-Aided Detection Tool

BACKGROUND AND PURPOSE

ASPECTS quantifies early ischemic changes in anterior circulation stroke on NCCT but has interrater variability. We examined the agreement of conventional and automated ASPECTS and studied the value of computer-aided detection.

MATERIALS AND METHODS

We retrospectively collected imaging data from consecutive patients with acute ischemic stroke with large-vessel occlusion undergoing thrombectomy. Five raters scored conventional ASPECTS on baseline NCCTs, which were also processed by RAPID software. Conventional and automated ASPECTS were compared with a consensus criterion standard. We determined the agreement over the full ASPECTS range as well as dichotomized, reflecting thrombectomy eligibility according to the guidelines (ASPECTS 0-5 versus 6-10). Raters subsequently scored ASPECTS on the same NCCTs with assistance of the automated ASPECTS outputs, and agreement was obtained.

RESULTS

For the total of 175 cases, agreement among raters individually and the criterion standard varied from fair to good (weighted κ = between 0.38 and 0.76) and was moderate (weighted κ = 0.59) for the automated ASPECTS. The agreement of all raters individually versus the criterion standard improved with software assistance, as did the interrater agreement (overall Fleiss κ = 0.15-0.23; P < .001 and .39 to .55; P = .01 for the dichotomized ASPECTS).

CONCLUSIONS

Automated ASPECTS had agreement with the criterion standard similar to that of conventional ASPECTS. However, including automated ASPECTS during the evaluation of NCCT in acute stroke improved the agreement with the criterion standard and improved interrater agreement, which could, therefore, result in more uniform scoring in clinical practice.

Haemodynamic changes associated with atropine/neostigmine administration. A non-invasive investigation

Stroke volume, systolic time intervals and related index variations induced by atropine/neostigmine (AN) (0.75 mg/l mg) decurarization mixture were investigated by non-invasive methods (ECG, phonocardiogram, thoracic impedance) in 15 anaesthetized normocapnic patients in a stable state after induction of anaesthesia and prior to surgical stimulation. Data showed decrease in mean heart rate (HR) (initial value: 82 beats/min; after 10 min: 57 beats/min; P less than 0.001) accompanied by an increase in stroke volume (SV) (initial value: 75 ml, after 10 min: 100 ml; P less than 0.001). No alterations in myocardial contractility were noted with the systolic time intervals (PEP, PEP/LVET, 1/PEP2). Under the conditions of the study, the negative chronotropic effect of AN mixture was not accompanied by a negative inotropic state.