Phu Tho Provincial General Hospital was the first hospital in to Vietnam introduce RAPID AI technology for the diagnosis and treatment of stroke patientsThis study presents the results of the diagnosis and treatment of stroke patients for whom RAPID AI combined with neuroimaging was used for the detection, characterization, and prognostication of acute strokes. AI technology is a rapidly developing field and represents a promising avenue for fast and efficient imaging analysis . RAPID AI has been approved and certified by the FDA for perfusion imaging and is currently used in 50 countries. RAPID AI software can be used for perfusion imaging in stroke. The RAPID AI software was validated in the DEFUSE 2 study in 2012 and received FDA approval in 2013 . RAPID software analyzes CT and MRI perfusion within 3 minutes and generates colorimetric perfusion maps of stroke penumbra as well as the core mismatch volume and mismatch ratio . The penumbra mismatch sensitivity is 100% and specificity is 91% [10–13]. RAPID AI technology was used in the recent large LVO ET trials EXTEND IA, SWIFT PRIME, CRISP, DEFUSE 2 and 3, and DAWN [8, 10, 14–16].
Stroke incidence increases with age and is more common in males . The analysis of this cohort of 54 patients’ electronic medical records were the first to be assessed using AI in Phu Tho Provincial General Hospital, Vietnam from October 2019 to June 2020. The results of our study agree with those of previous studies in terms of demographic characteristics conducted by Albers et al. in Gondar University Hospital , Tirschwell et al. in Danang Hospital , and Yue in China  21].
The time from symptom onset to hospital arrival (time to hospital) is a key factor for delivering effective treatment and improved outcomes of stroke patients, especially for patients with ischemic stroke. Our results for time to hospital showed that about half of patients arrive after six hours and are therefore less likely to be eligible for reperfusion treatment. If outcomes are to improve in Vietnam the systems for prehospital care in terms of patient and population awareness of the symptoms of stroke and emergency medical services need to improve. The patients who do present are predominantly very severe stroke with over half having reduced levels of consciousness. These results were similar to those of a study in Hong Kong  and Shanghai , which showed that 56.3% and 51.9% of patients arrived at a hospital within 6 h after the first symptom of stroke. Previous studies have presented a median arrival time that varied from 2.51 to 15 h . However, studies on the time to hospital of patients in European countries reported that the majority of patients arrived within 3 h of onset, earlier than in Asian countries, which is due to the higher rate of ambulance transport of stroke patients and better stroke awareness knowledge in these countries .
In our study, we found that the most common risk factor was hypertension, identified in 75.9% of patients, followed by atrial fibrillation in 24.1% of patients, and diabetes in 20.4% of patients. These results align with previous studies indicating that uncontrolled hypertension is the most important risk factor for stroke in developing and developed countries . This may reflect the fact that hypertension has been identified as the most prevalent modifiable risk factor and is a powerful modifiable risk factor. On the other hand, the numbers of stroke patients with smoking and alcohol habits in this study were lower (< 15%) than in other studies, .
Hemiparesis and dysarthria were two of the most common clinical presentations of stroke in our study, at 75.9% and 50% of the total, respectively. This is similar to cohorts reported from Egypt  and India , which showed that 76.1% of patients had hemiparesis and 60% of patients had dysarthria. Memory loss commonly occurs as a result of stroke and was observed in 27.8% of patients in our study. Other investigators have reported a dementia incidence of approximately 25% at 3 months after ischemic stroke. In the current study, a small number of patients suffered from dizziness and headache (7.4%), and unconsciousness and near death (5.6%). These results also agree with the results of El Tallawy .
There was a variety in the laboratory tests requested as this depends on the stroke clinicians rather than a formal protocol In our study, the laboratory tests included BP, RBC, BG, cholesterol, PC, INR, and triglyceride. These tests were examined to evaluate patients before the administration of tPA. Some of the tests are necessary to determine suitability for intravenous thrombolysis but some are often unnecessary and just delay commencement of acute treatments. .
The application of RAPID AI to read CT perfusion images was first applied in Phu Tho Provincial General Hospital, Vietnam, in June 2019. RAPID AI technology processing takes within 3 minutes to send the results of ASPECTS, infarct core volume, mismatch volume, and mismatch ratio to PACS and RAPID mobile apps. This application was developed by an experienced neurologist, Greg Alber . The ASPECTS is a 10-point quantitative topographic CT scan score used for patients with middle cerebral artery (MCA) stroke . Our study showed the ASPECTS score was good in 44.4% of patients, compared with 31.5% showing a bad score and 24.1% showing the worst possible score. The assessment of the ASPECTS score has been used to direct therapies. Those with a low ASPECTS score, suggesting a large MCA infarction, can be excluded from futile intra-arterial treatments, which are unlikely to result in patients gaining functional independence and increase the risk of hemorrhage . The infarct core volume shows the part of the AIS which was already infarcted or was irrevocably destined to infarct regardless of reperfusion . The inclusion criteria used to select patients eligible for interventional thrombectomy in the case of patients admitted to hospital within or beyond 6 h onset include an initial infarct volume of < 70 mL, a ratio of ischemic penumbra to infarct core of ≥ 1.8, and an absolute mismatch of ≥ 15 mL [36, 37]. Our results showed that the majority of patients had an infarct core volume of < 70 mL, at 50 (92.6%) patients; a mismatch volume of > 15 mL was observed in 31 (54.7%) patients, and 22 (40.7%) patients had a mismatch ratio of > 1.8. Previous studies have indicated that the automated RAPID AI system is sufficiently accurate and fast to be used for routine care as well as in clinical trials [11, 38]. The evidence of using RAPID showed the diffusion–perfusion mismatch identified by RAPID was in agreement with the observation of a human reader in 60 cases (95.2%) and in disagreement in 3 cases (4.8%, 3 false positives) . RAPID was able to identify mismatches with 100% sensitivity and 91% specificity (false positive rate = 9.1%, false negative rate = 0%) in analyses with the observations of the human reader as a ground truth .
The RAPID software enabled information about the location, size, and whether there was any potentially salvageable brain enabling the physicians to make decisions on the suitable treatment, whether thrombolysis or thrombectomy . The diagnostic evaluation of occlusive thrombi on noninvasive studies now constitutes an integral component of acute stroke management . In a hospital with limited access to neuroradiology 24 hours a day, seven days a week, such a facility is of critical importance and has huge potential to improve the quality of clinical care in hospitals and countries with limited resources. Clearly, this needs to be combined with improving public awareness that stroke is a treatable condition if they get to hospital quickly after the onset of symptoms, and an improved emergency medical service. The current poor outcomes with a 50% mortality and only 10% making a full recovery are unacceptable. Using modern technology such as RAPID or similar artificial intelligence systems will be important to improve outcomes.