CTA
Abbreviation with 8 meanings
| Stands for | Call to action |
|---|---|
| Meanings | 8 |
| Categories | Business & Finance, Medical, Transportation & Travel, Government & Politics, Organizations & Companies, Law & Legal |
| Also written | c.t.a. |
CTA has eight meanings. The most common are Call to action (marketing & advertising) and Clear to auscultation (patient assessment); it can also stand for Computed tomography angiography, Chicago Transit Authority, Clinical trial agreement, Corporate Transparency Act and Consumer Technology Association, plus 1 more listed below.
Meanings of CTA at a glance
| # | CTA stands for | Context |
|---|---|---|
| 1 | Call to action | Business & Finance › Marketing & Advertising |
| 2 | Clear to auscultation | Medical › Patient Assessment |
| 3 | Computed tomography angiography | Medical › Medical Imaging |
| 4 | Chicago Transit Authority | Transportation & Travel › Rail and Transit |
| 5 | Clinical trial agreement | Medical › Medical Research |
| 6 | Corporate Transparency Act | Government & Politics › US Law |
| 7 | Consumer Technology Association | Organizations & Companies › Professional Association and Labor Union |
| 8 | Cum testamento annexo (with the will annexed) | Law & Legal › Latin Legal |
1. Call to action
Business & Finance · Marketing & Advertising Abbreviations
Prompt telling the audience what to do next, such as "Buy now," "Start free trial," "Call today" or "Subscribe," usually as a button or link. A clear CTA is considered essential on landing pages, ads, emails and sales letters.
Example: Move the CTA above the fold and make the button text say "Get my quote."
Copywriters advise using a single primary CTA per page, specific action verbs and a reason to act now, such as a deadline. CTA buttons are among the most frequently A/B-tested page elements because small wording or color changes can measurably affect conversion. Outside marketing, CTA is the Chicago Transit Authority and, in Canada, the Canadian Transportation Agency. Plural: CTAs.
2. Clear to auscultation
Medical · Patient Assessment Abbreviations
Lung exam finding that breath sounds are normal, with no crackles, wheezes or rhonchi heard through the stethoscope. It is often written with B for bilaterally.
Example: Lungs CTA, no increased work of breathing, SpO2 98% RA.
In radiology the same letters mean CT angiography, a contrast scan of blood vessels, so a note reading "CTA chest" means imaging, not a lung exam. Listening to the back as well as the front, comparing side to side, is part of a complete lung exam.
3. Computed tomography angiography
Medical · Medical Imaging Abbreviations
CT scan performed during a rapid intravenous injection of iodinated contrast, timed to capture arteries at peak enhancement. It diagnoses aortic dissection and aneurysm, pulmonary embolism, large vessel occlusion in stroke, coronary artery disease and peripheral artery disease.
Example: CTA head and neck: left M1 occlusion; thrombectomy team activated.
Modern scanners cover the head and neck in seconds, making CTA central to emergency stroke pathways. Coronary CTA (CCTA) requires slowing the heart rate, often with beta-blockers. Kidney function and any previous contrast reaction are checked beforehand. In research administration CTA instead means clinical trial agreement.
4. Chicago Transit Authority
Transportation & Travel · Rail and Transit Abbreviations
Chicago's transit operator, running the elevated and subway rail system known as the 'L' and one of the largest bus networks in the US, serving the city and some suburbs.
Example: Take the CTA Blue Line to O'Hare; it runs 24 hours and costs a fraction of a cab.
Formed in 1947 by consolidating private operators. The Loop elevated, completed in 1897, gave downtown Chicago its name. The 'L' has eight color-coded lines, two of which run around the clock. In marketing, CTA also means "call to action," an unrelated meaning.
5. Clinical trial agreement
Medical · Medical Research Abbreviations · also used in law
Contract between a sponsor and a research site, or between collaborating institutions, setting terms for conducting a clinical trial: budget, payment schedule, confidentiality, publication rights, intellectual property, subject injury coverage and indemnification. A signed CTA is usually required before a site is activated.
Example: Site activation delayed while legal negotiates the publication clause in the CTA.
Contract negotiation is a frequent bottleneck in trial startup, prompting standardized templates. In the EU and UK, CTA also means clinical trial application or authorization, the regulatory approval needed to run a trial. In radiology CTA means CT angiography.
6. Corporate Transparency Act
Government & Politics · US Law Abbreviations
Law enacted in 2021 requiring many companies to report their "beneficial owners", the people who own or control them, to FinCEN to combat anonymous shell companies. A March 2025 interim final rule exempted US-formed companies and US persons, limiting reporting to certain foreign companies.
Example: Our law firm emailed clients that CTA filings are no longer required for domestic LLCs.
It was enacted on January 1, 2021 as part of the annual defense authorization law, passed over a presidential veto. Reporting began in January 2024 and was disrupted by nationwide injunctions in late 2024 before the 2025 rule narrowed it. Supporters argued anonymous companies help conceal money laundering.
7. Consumer Technology Association
Organizations & Companies · Professional Association and Labor Union Abbreviations
Trade association for the consumer technology industry, which owns and produces CES, the large technology trade show held in Las Vegas each January, and develops technical standards.
Example: Gadget makers unveiled new televisions at CES, organized by the CTA.
It was founded in 1924 as the Radio Manufacturers Association and was known as the Consumer Electronics Association before adopting its current name in 2015. In transit, CTA means the Chicago Transit Authority.
8. Cum testamento annexo (with the will annexed) (c.t.a.)
Law & Legal · Latin Legal Abbreviations
Designation for an administrator appointed to settle an estate that has a valid will but no executor able or willing to serve, as when the named executor has died or declined. An administrator c.t.a. carries out the will's terms much as an executor would.
Example: The court issued letters of administration c.t.a. after the named executor renounced.
Distinct from an ordinary administrator, who handles the estate of someone who died without a will. Many states now use the general title "personal representative" for every estate fiduciary, but c.t.a. still appears on probate petitions and letters.
Related abbreviations
More marketing & advertising abbreviations
- CPQ – Configure, price, quote
- CPV – Cost per view
- CRM – Customer relationship management
- CSAT – Customer satisfaction score
- CTOR – Click-to-open rate
- CTR – Click-through rate
- CTV – Connected TV
- CVR – Conversion rate
See all 111 marketing & advertising abbreviations →
More patient assessment abbreviations
- CMS – Circulation, motion, sensation
- COWS – Clinical Opiate Withdrawal Scale
- CPOT – Critical-Care Pain Observation Tool
- CRT – Capillary refill time
- CTAB – Clear to auscultation bilaterally
- CVAT – Costovertebral angle tenderness
- EOMI – Extraocular movements intact
- FLACC – Face, Legs, Activity, Cry, Consolability
See all 65 patient assessment abbreviations →
This entry is for general education and is not medical or legal advice. Abbreviation use varies between institutions; always confirm in context.