Cook sushi rice according to package instructions. Let cool.
In a small bowl, combine rice vinegar, sugar, and salt. Stir until sugar and salt are dissolved.
Drizzle vinegar mixture over cooled sushi rice. Gently toss to combine.
In a large bowl, combine salmon, avocado, cucumber, carrot, and green onions.
In a separate small bowl, whisk together soy sauce, sesame oil, and lime juice.
Drizzle dressing over salmon mixture. Toss to combine.
To serve, divide sushi rice mixture among plates. Top with salmon mixture and sprinkle with sesame seeds.