v3.26.1
Note 6 - Stock-based Compensation - Option Activity (Details) - $ / shares
12 Months Ended
Apr. 30, 2026
Apr. 30, 2025
Apr. 30, 2024
Outstanding, options (in shares) 173,659 18,659  
Outstanding, weighted average exercise price (in dollars per share) $ 17 $ 121  
Outstanding, remaining contractual term (Year) 9 years 9 years 6 months 8 years 10 months 24 days
Options granted (in shares) 604,000 155,000  
Granted, weighted average exercise price (in dollars per share) $ 4.36 $ 3.35  
Granted, remaining contractual term (Year) 9 years 8 months 12 days 10 years  
Options forfeited (in shares) (466)    
Forfeited, weighted average exercise price (in dollars per share) $ 0    
Outstanding, options (in shares) 777,193 173,659 18,659
Outstanding, weighted average exercise price (in dollars per share) $ 6.64 $ 17 $ 121
Non-vested, options (in shares) 651,126    
Non-vested, weighted average exercise price (in dollars per share) $ 4.23    
Non-vested, remaining contractual term (Year) 9 years 1 month 6 days    
Vested, options (in shares) 126,067    
Vested, weighted average exercise price (in dollars per share) $ 19.08    
Vested, remaining contractual term (Year) 8 years 8 months 12 days    
Performance Shares [Member]      
Outstanding, options (in shares) 2,787 5,456  
Outstanding, weighted average exercise price (in dollars per share) $ 320 $ 502  
Outstanding, remaining contractual term (Year) 4 years 3 months 18 days 5 years 1 month 6 days 5 years 10 months 24 days
Options forfeited (in shares) (159) (73)  
Forfeited, weighted average exercise price (in dollars per share) $ 0 $ 249  
Outstanding, options (in shares) 2,628 2,787 5,456
Outstanding, weighted average exercise price (in dollars per share) $ 286 $ 320 $ 502
Non-vested, options (in shares) 758    
Non-vested, weighted average exercise price (in dollars per share) $ 335    
Non-vested, remaining contractual term (Year) 4 years 6 months    
Vested, options (in shares) 1,870    
Vested, weighted average exercise price (in dollars per share) $ 267    
Vested, remaining contractual term (Year) 4 years 3 months 18 days    
Options cancelled (in shares)   (2,596)  
Options cancelled, weighted average exercise price (in dollars per share)   $ 704