Impact of resistance training on core muscle strength and size

What are the muscles in the low back region? (anatomy of the muscles and studies
related to these musces) – previous studies have been done about muscle hypertrophy.
(More emphasize on muscles in the low back region, also include studies related to
other muscles such as biceps, triceps. etc) -what Kind of technologies have been used
to measure muscle cross-sectional area (GSA)? (such as MRI magnetic resonance
imaging ; computed tomography CT; x-rays ; regression models; etc) more emphasize
on MRI related studies