This article contains a list of commonly used medical abbreviations and acronyms that start with the letter C and may be encountered in medicine and radiology (please keep both the main list and any sublists in alphabetic order).

A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z - misc

• C

  • cesarean (C-section)

  • carbon

  • Celsius/centigrade

  • cervical

  • coulomb (SI unit of charge)

  • cysteine (single letter amino acid code)

  • cytosine (DNA nucleotide)

  • hundred (Roman numeral)

• c: speed of light in a vacuum (always lowercase)

• C1-C3: cruciate pulleys

• C1-C7

  • cervical spinal nerve roots

  • cervical vertebrae

• C2H5OH: ethanol

• C8: eighth cervical nerve root

• CA

  • calcification

  • cancer

  • carcinoma

  • coronary angiography

• Ca: calcium

• CA 15-3: cancer antigen 15-3

• CA 19-9: cancer antigen 19-9

• CA 27-29: cancer antigen 27-29

• CA-125: cancer antigen 125

• CAA

  • cerebral amyloid angiopathy

  • coronary artery aneurysm

• CABG: coronary artery bypass graft

• CAC: coronary artery calcification

• CACG: chronic angle-closure glaucoma

• cACLD: compensated advanced chronic liver disease

• CAD

  • computer-aided diagnosis

  • coronary artery disease

• CADASIL: cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

• CAE: coronary artery ectasia

• CAG: coronary artery graft

• CAGS: coronary artery graft surgery

• CAH: congenital adrenal hyperplasia

• CAI: chronic ankle instability

• CAIPIRINHA: controlled aliasing in parallel imaging results in higher acceleration (Siemens)

• CAK: cumulative air kerma

• CAKUT: congenital abnormality of the kidneys and urinary tracts

• CAM: comprehensive arthroscopic management

• CANVAS: cerebellar ataxia with neuropathy and vestibular areflexia syndrome

• CAP

  • chest-abdomen-pelvis (as in CT scan of CAP)

  • community-acquired pneumonia

• CAPD: continuous ambulatory peritoneal dialysis

• CAPS: catastrophic antiphospholipid syndrome

• CAR: chimeric antigen receptor (as in CAR T-cell)

• CARASAL: cathepsin A-related arteriopathy with strokes and leukoencephalopathy

• CARASIL: cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy

• CAS: carotid artery stenosis

• CASA: computer-assisted semen analysis

• CASH: chemotherapy-associated steatohepatitis

• CAT

  • computed axial tomography or computer-aided tomography

  • critically-appraised topic

• c/b: complicated by

• CB: ciliary body

• CBAVD: congenital bilateral absence of vas deferens

• CBC: complete blood count

• CBCT: cone beam CT

• CBD

  • cannabidiol

  • common bile duct

  • corticobasal degeneration

• CBF: cerebral blood flow

• CBH: change in bowel habit

• CBI: continuous bladder irrigation

• CBS

  • Charles Bonnet syndrome

  • corticobasal syndrome

• CBV: cerebral blood volume

• cc: with correction (ophthalmology)

• CC

  • caudocranial or caudocraniad

  • chief complaint

  • copy to (letters/email)

  • corpus callosum

  • craniocaudad or craniocaudal

  • Creative Commons

  • cubic centimeter (cm³ preferred)

• CCA

  • cholangiocarcinoma

  • common carotid artery

  • copper chrome arsenic

• CCAM: congenital cystic adenomatoid malformation

• CCC: continuous curvilinear capsulorrhexis

• CCCT: clomiphene citrate (Clomid) challenge test

• CCD

  • caput-collum-diaphyseal (angle)

  • charge-coupled device

  • crossed cerebellar diaschisis

• CCF

  • caroticocavernous fistula

  • congestive cardiac failure

• ccfRNA: circulating cell-free ribonucleic acids

• CCL: corpus callosum lipoma

• CCMx: continue current management

• CCP

  • central chest pain

  • cyclic citrullinated peptide (antibody, in rheumatoid arthritis)

• CCS

  • chronic coronary syndrome

  • combined conduit score

  • clear cell sarcoma

• CCST: Certificate of Completion of Specialist Training (UK)

• CCT

  • cardiac CT

  • Certificate of Completion of Training (UK)

• CCTA: cardiac computed tomography angiography

• CCU

  • coronary care unit

  • critical care unit

• CD

  • clinical director

  • Clostridioides difficile

  • cluster of differentiation (immunology, e.g. CD4, CD8, etc.)

  • common duct

  • compact disc

  • Cotrel-Dubousset

  • Crohn disease

  • cystic duct

• Cd: cadmium

• cd: candela (SI unit of luminous intensity)

• CDC: Centers for Disease Control and Prevention (US federal agency)

• CDE: complete dental evaluation

• CDH

  • congenital diaphragmatic hernia

  • congenital dislocation of the hip

• C.diff: Clostridioides difficile

• CDI: Color Doppler imaging

• CDR: clinical decision rules

• CD-ROM: compact disc - read only memory disc

• CDS

  • carotid duplex study

  • clinical decision support

• CDT

  • catheter-directed therapy

  • catheter-directed thrombolysis

  • Clostridioides difficile  toxin 

• CE

  • cataract extraction

  • contrast-enhanced

• Ce: cerium

• CEA

  • carcinoembryonic antigen

  • carotid endarterectomy

• CECT: contrast-enhanced computed tomography

• CEMR: contrast-enhanced magnetic resonance

• CEMRI: contrast-enhanced magnetic resonance imaging

• CERAB: covered endovascular reconstruction of the aortic bifurcation

• CES: cauda equina syndrome

• CESM: contrast-enhanced spectral mammography

• CEUS: contrast-enhanced ultrasound

• CF: cystic fibrosis

• cf: compare with (Latin: confer)

• CFA: common femoral artery

• CFC: cardiofaciocutaneous syndrome

• CFDM: cystic fibrosis - related diabetes mellitus

• CFL: calcaneofibular ligament

• CFR: case fatality rate

• CFS: chronic fatigue syndrome

• CFTR: cystic fibrosis transmembrane conductance regulator

• CFTS: combined first trimester screening

• CFV: common femoral vein (strictly does not exist)

• cgs: centimeter-gram-second (superseded system of units)

• Ch: Charrière (unit)

• CHALICE: children’s head injury algorithm for prediction of clinically important event

• CHANTER: cerebellar, hippocampal, and basal nuclei transient edema with restricted diffusion syndrome

• CHAOS: congenital high airway obstruction syndrome

• CHB: complete heart block

• CHD

  • common hepatic duct

  • congenital heart disease

  • coronary heart disease

• chem: chemistry

• CHESS: chemical shift selective pulses (all vendors)

• CHF: congestive heart failure

• CHILD syndrome: congenital hemidysplasia with ichthyosiform erythroderma and limb defects

• CHL

  • conductive hearing loss

  • coracoacromial ligament

• CHO: carbohydrate

• Chol: cholesterol

• CHOP: cyclophosphamide, doxorubicin (hydroxydaunomycin), Oncovin^® (vincristine), prednisolone

• CI

  • cardiac index

  • compound imaging

  • confidence interval

  • contraindication

  • cord insertion

• Ci: curie (non-SI unit of radioactivity)

• CIDP: chronic inflammatory demyelinating polyneuropathy

• C/I: contraindication

• CIA: common iliac artery

• CID: concealed interstitial delamination

• CIDP: chronic inflammatory demyelinating polyneuropathy

• CIED: cardiac implantable electronic device

• CIN

  • cervical intraepithelial neoplasia

  • contrast-induced nephropathy

  • contrast-induced neurotoxicity

• CIRS: chronic inflammatory response syndrome

• CIRSE: Cardiovascular and Interventional Radiology Society of Europe

• CIS: clinically isolated syndrome

• CISS: constructive interference in steady state (Siemens)

• CIV: common iliac vein

• CJD: Creutzfeldt-Jakob disease

• CK: creatine kinase

• CKD: chronic kidney disease

• CKD-EPI: Chronic Kidney Disease-Epidemiology Collaboration

• Cl: chlorine

• CLABSI: central line-associated bloodstream infection

• CLAHE: contrast-limited adaptive histogram equalization

• CLD

  • chronic liver disease

  • chronic lung disease (of infancy)

  • congenital lactase deficiency

  • congenital limb deficiency

  • cystic lung disease

• CLE: congenital lobar emphysema

• CLEAR: constant level appearance

• CLI: critical limb ischemia

• CLIPPERS: chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids

• CLO: congenital lobar overinflation

• CLTI: chronic limb-threatening ischemia

• cm: centimeter

• CMB: cerebral microbleed

• CMCJ: carpometacarpal joint

• CMD: coronary microvascular dysfunction

• CME

  • continuing medical education

  • cystoid macular edema

• CMF: chondromyxoid fibroma

• CMH: cerebral microhemorrhage

• CMP: cardiomyopathy

• CMR: complete metabolic response

• CMT

  • Charcot-Marie-Tooth disease

  • celiacomesenteric trunk

• CMV: cytomegalovirus

• CN: cranial nerve

• CNA: chronic necrotizing aspergillosis

• CNLD: chronic neonatal lung disease

• CNN: convolutional neural network

• CNR: contrast-to-noise ratio

• CNS: central nervous system

• CNV: choroidal neovascularization

• CNVM: choroidal neovascular membrane

• CO

  • carbon monoxide

  • cardiac output

• Co

  • cobalt

  • coccygeal vertebrae (Co1, Co2, etc)

• C/O: complaining of

• CoA: coarctation of aorta

• COAD: chronic obstructive airways disease

• COAG: chronic open-angle glaucoma

• COBH: change of bowel habit

• COCP: combined oral contraceptive pill

• COD: cause of death

• CODNYD: cause of death not yet determined

• COH: controlled ovarian hyperstimulation

• COHb: carboxyhemoglobin

• COLD: Cowden-Lhermitte-Duclos syndrome

• COM: chronic otomastoiditis

• COMARE: Committee on Medical Aspects of Radiation in the Environment (UK)

• COP

  • combined oral contraceptive pill

  • cryptogenic organizing pneumonia

• COPD: chronic obstructive pulmonary disease

• Cor: coronal

• CoR: College of Radiographers (UK)

• COVID-19: CoronaVirus Disease-2019

• CoV: coronavirus

• COW: circle of Willis

• CP

  • ceruloplasmin

  • cerebral palsy

  • cervical position

  • chest pain

  • cross-polarization

• CPA

  • cerebellopontine angle

  • Child-Pugh A cirrhosis

  • costophrenic angle

• CPAM: congenital pulmonary airway malformation

• CPAP: continuous positive airway pressure

• CPB

  • cardiopulmonary bypass

  • Child-Pugh B cirrhosis

• CPC

  • Child-Pugh C cirrhosis

  • choroid plexus cyst

  • cyclophotocoagulation

• CPD: continuing professional development

• CPE

  • carbapenem-producing enterobacteriaceae

  • chronic pulmonary embolism

  • congenital peritoneal encapsulation

• CPFE: combined pulmonary fibrosis and emphysema

• CPFI: chest pain for investigation

• CPK: creatine phosphokinase

• CPR

  • cardiopulmonary resuscitation

  • cerebroplacental ratio

  • curved planar reformation

• CPS: complex partial seizure

• CQC: Care Quality Commission (UK)

• CR: complete response (RECIST)

• Cr

  • chromium

  • creatinine

• CRA: coral reef aorta

• CRAB: carbapenem-resistant Acinetobacter baumannii

• CRAO: central retinal artery occlusion

• CRC: colorectal cancer or colorectal carcinoma

• CRE: carbapenem-resistant Enterobacteriaceae

• Creat: creatinine

• CREST: calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia

• CRF

  • chronic renal failure

  • corticotropin-releasing factor

• CRFD: clinically ready for discharge

• CRIF: closed reduction internal fixation

• CRION: chronic relapsing inflammatory optic neuropathy

• CRISPR: clustered regularly interspaced short palindromic repeats

• CRL: crown-rump length

• CRLM: colorectal liver metastases

• CRM: circumferential resection margin

• CRMD: cardiac rhythm management device

• CRP: C-reactive protein

• CRPC: castration-resistant prostate cancer

• CRPS: complex regional pain syndrome

• CRRT: continuous renal replacement therapy

• CRS

  • caudal regression syndrome

  • chronic rhinosinusitis

  • colorectal surgery

  • cytoreductive surgery

  • cytokine release syndrome

• CRT

  • capillary refill time

  • cardiac resynchronisation therapy

  • cathode ray tube

• CRT-D: cardiac resynchronisation therapy device

• CRT-P: cardiac resynchronisation therapy pacemaker

• CRTX: chemoradiotherapy

• CRUK: Cancer Research UK (charity)

• CRVO: central retinal vein occlusion

• Cryo: cryotherapy

• CS

  • Cesarean section

  • cavernous sinus

  • chemical shift

  • compressed sensing (MRI)

  • coronary sinus

  • corticospinal

• Cs: cesium

• C&S: culture and sensitivity

• C/S: cesarean section

• cSAH: convexal subarachnoid hemorrhage

• cSCC: cutaneous squamous cell carcinoma

• CSCR: central serous chorioretinopathy

• CSD: cortical spreading depression 

• cSDH: chronic subdural hemorrhage

• CSE: convulsive status epilepticus

• CSF: cerebrospinal fluid

• CS-MRI: chemical shift MRI

• CSNT: calves soft and non-tender

• CSOM: chronic serous otitis media

• CSR: central serous retinopathy

• CSS: Churg-Strauss syndrome

• cSS: cortical superficial siderosis

• CST: cervical screening test

• CSU: catheter specimen of urine

• CSW: commercial sex worker

• CT

  • chemotherapy

  • computed tomography

• CTA

  • computed tomography angiography

  • computed tomography aortogram

• CTAP: computed tomography of abdomen and pelvis

• CTAVN: cystic tumor of the atrioventricular node

• CTB: computed tomography brain

• CTC: computed tomography colonography / colonoscopy

• CTCA

  • computed tomography of chest and abdomen

  • computed tomography coronary angiogram

• CTCAP: computed tomography of chest, abdomen and pelvis

• CTEV: congenital talipes equinovarus

• CTD: connective tissue disease

• CTDI: CT dose index

• ctDNA: circulating-tumor DNA

• CTED: chronic thromboembolic disease

• CTEPH: chronic thromboembolic pulmonary hypertension

• CTEV: congenital talipes equinovarus

• CTG

  • cardiotocography

  • caudothalamic groove

• CTH: computed tomography head

• CTIVC: computed tomography intravenous cholangiography

• CTIVP: computed tomography intravenous pyelography

• CTM: computed tomography myelography

• CTO: chronic total occlusion

• CTP: computed tomography perfusion

• CTPA: computed tomography pulmonary angiogram/angiography

• CTPE: computed tomography pulmonary embolus study

• CTR: cardiothoracic ratio

• CTS: carpal tunnel syndrome

• CTSI: CT severity index 

• CTTAP: computed tomography of the thorax, abdomen and pelvis

• CTU: computed tomography urography

• CTV

  • clinical target volume

  • computed tomography venography

• CTX: chemotherapy

• CTZ: chemosensitive trigger zone  

• Cu: copper (Latin: cuprum)

• CUMS: chronic ultramild stress

• CUP: cancer of unknown primary (or carcinoma of unknown primary)

• CUS: cranial ultrasound

• CV: curriculum vitae

• CVA: cerebrovascular accident (the term stroke is preferred)

• CVAD: central venous access device

• CVC: central venous catheter

• CVE: cerebrovascular event (the term stroke is preferred)

• cVEMP: cervical vestibular-evoked myogenic potentials

• CVID: common variable immune deficiency

• CVL: central venous line

• CVP: central venous pressure

• CVS

  • cardiovascular system

  • chorionic villus sampling

• CVVHDF: continuous venovenous hemodiafiltration

• CWD: continuous wave Doppler

• CWP: coal workers' pneumoconiosis

• Cx

  • cervix

  • circumflex artery

  • coccygeal vertebra (Cx1, Cx2, etc.)

  • complication

• CXR: chest x-ray

• Cys: cysteine

• CZ: central zone (prostate)