In February 145, when the two-year-old Emperor Chong died, he had no close male relative to inherit his throne.
His stepmother Empress Dowager Liang (the wife of Emperor Shun) therefore summoned two of his third cousins—Liu Suan (劉蒜), the Prince of Qinghe, and Liu Zuan, then seven-years-old, to the capital, to examine them as potential heir to the throne.
Liu Suan was apparently an adult (although history did not record his age) and was described as solemn and proper, and the officials largely favored him.
Empress Dowager Liang served as Emperor Zhi's regent, and while she overly trusted her brother Liang Ji, who was violent and corrupt, she herself was diligent and interested in governing the country well—in particular, entrusting much of the important matters to the honest official Li Gu (李固, who was Grand Commandant).
For example, the agrarian rebellions that started during Emperors Shun and Chong's reigns were largely quelled in 145, after she selected the right generals to lead the armies.
The officials were again largely in favor of Prince Suan, but Liang Ji was still concerned about how he would be difficult to control.