“在囚禁中”可以翻译为 "in confinement" 或 "in imprisonment"，其中“in confinement”是更为常用和自然的表达。例如：
He has been in confinement for several years.（他已被囚禁数年。）
The prisoner remained in confinement until his trial.（这名囚犯一直被囚禁到接受审判。）