Respiratory Therapy vs. Sonography vs. Rad Tech Prerequisites- Respiratory therapy, diagnostic medical sonography, and radiologic technology all sit in the same allied-health neighborhood, and their prerequisites share a large common core. If you are comparing respiratory therapy vs sonography prerequisites — or weighing radiologic technology alongside them — you can prepare for all three at once and specialize later. This guide shows the shared courses, the field-specific additions, and the accreditation behind each. For the RT deep dive, see the complete respiratory therapy prerequisites guide.
All three also expect a grade of C or better in prerequisites, a competitive GPA (commonly 2.5–3.0+), and reasonably recent science coursework. Many imaging programs also require documented observation or job-shadow hours before applying.
| Field | Distinctive prerequisites | Accreditor / credential |
|---|---|---|
| Respiratory Therapy | Adds microbiology and chemistry; physics for bachelor’s (BSRC) programs | CoARC / NBRC (CRT, RRT) |
| Diagnostic Medical Sonography | Physics is central and usually required; observation hours; pathophysiology at some programs | CAAHEP / ARDMS (and ARRT in ultrasound) |
| Radiologic Technology | Lighter prerequisite sciences; physics typically taught inside the program; observation hours | JRCERT / ARRT |
The clearest dividing line is physics and microbiology. Sonography treats physics as foundational, so it is almost always a prerequisite. Respiratory therapy adds microbiology and chemistry and reserves physics for its bachelor’s programs. Radiologic technology keeps its prerequisite sciences lighter and folds radiologic physics into the professional curriculum.
The prerequisite differences track the work itself. Respiratory therapists manage breathing and cardiopulmonary care — ventilators, oxygen and aerosol therapy, blood-gas analysis — often in critical-care settings, which is why microbiology and chemistry sit on their list. Diagnostic medical sonographers operate ultrasound equipment to capture and optimize images, a job built on the physics of sound waves, hence physics as a near-universal prerequisite. Radiologic technologists position patients and operate X-ray and related imaging equipment, applying radiation-safety principles the program teaches directly, which is why their prerequisite sciences tend to be lighter.
All three are commonly entered at the associate level, with bachelor’s options available. Respiratory therapy leads to the CRT and RRT through the NBRC; sonography leads to ARDMS (or ARRT) registration; radiography leads to ARRT certification. Each professional program is competitive and seat-limited, and each expects prerequisites finished before you enter — so the prerequisite stage is the lever you control regardless of which path you choose.
Strategy. Complete the shared core — A&P I and II, math, English, and medical terminology — before you commit. From there it is a short, targeted add: microbiology and chemistry for RT, or physics for sonography. You stay flexible while every credit still counts.
Start with the courses all three share: Anatomy & Physiology I (BIO 270), Anatomy & Physiology II (BIO 275), College Algebra (MATH 107), and Medical Terminology (EXSS 170). Then add the field-specific pieces — microbiology (BIO 210) and chemistry (CHEM 151) for RT, or physics for sonography — once you have chosen your direction.
Diagnostic medical sonography — physics is central to image formation, so it is almost always a required prerequisite. RT only requires physics for bachelor’s programs, and rad tech usually teaches it inside the program.
Yes — both are standard RT prerequisites, a key difference from the imaging fields.
The shared core (A&P I/II, math, English, medical terminology) does. You will add a couple of field-specific courses after you decide.
Frequently, yes. Many sonography and radiography programs ask for documented job-shadow or observation hours before you apply.
No. RT credentials through the NBRC, sonography through ARDMS (or ARRT), and radiography through ARRT — each after the appropriate accredited program.
See also RT vs. nursing prerequisites, the complete respiratory therapy prerequisites guide, and all allied health prerequisite courses. Accreditation references: CoARC, CAAHEP, and JRCERT.
