This article contains a list of commonly used medical abbreviations and acronyms that start with the letter R and may be encountered in medicine and radiology (please keep 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

• R

  • reproductive number

  • right

  • roentgen (unit)

• RA

  • rheumatoid arthritis

  • right atrium

  • right auricle

  • room air

• Ra: radium

• RAA: right atrial appendage

• RAAS: renin-angiotensin-aldosterone system 

• RACF: residential aged-care facility

• RAD

  • right axis deviation

  • radiation absorbed dose

• Rad: cgs unit of absorbed radiation dose

• RAI: radioactive Iodine

• RALP: robot-assisted laparoscopic prostatectomy

• RAMC: Royal Army Medical Corps (UK)

• RANK: receptor activator of nuclear factor-Kappa B

• RANZCR: Royal Australian and New Zealand College of Radiologists

• RAO: right anterior oblique

• RAPD: relative afferent pupillary defect

• RAPN: robot-assisted partial nephrectomy

• RAR: renal-to-aortic ratio

• RARP: robot-assisted radical prostatectomy

• RAS

  • renin-angiotensin system

  • renal artery stenosis

  • reticular activating system

• RAZ: right apical zone

• Rb: rubidium

• RBBB: right bundle branch block

• RBC: red blood cells

• RB-ILD: respiratory bronchiolitis-interstitial lung disease

• RC: rotator cuff

• RCA

  • right colic artery

  • right coronary artery

  • root cause analysis

  • rotator cuff arthropathy

• RCC

  • Rathke cleft cyst

  • red cell count

  • renal cell carcinoma

• RCCA: right common carotid artery

• RCH: remote cerebellar hemorrhage

• R-CHOP: rituximab, cyclophosphamide, doxorubicin (hydroxydaunomycin), oncovin (vincristine), prednisolone

• RCJ: radiocarpal joint

• RCL: radial collateral ligament complex of the elbow

• RCM: restrictive cardiomyopathy

• RCR: Royal College of Radiologists (UK)

• RCT

  • randomized control trial

  • rotator cuff tear

• RCVS: reversible cerebral vasoconstriction syndrome

• Rd: rutherford

• RDC: rapid diagnostic center

• RdRp: RNA-dependent RNA polymerase gene 

• RDS: respiratory distress syndrome

• RDW: red cell distribution width

• RE: right eye

• Re: rhenium

• ReA: reactive arthritis

• REBOA: resuscitative endovascular balloon occlusion of the aorta

• RECIST: response evaluation criteria in solid tumors

• Recons: reconstructions

• Reg: registrar

• Rem: roentgen equivalent man

• Rems: radiofrequency echographic multispectrometry

• RES: reticuloendothelial system

• Resus: resuscitation

• RF

  • radiofrequency

  • rheumatoid factor

  • ring finger

  • risk factor

• RFA: radiofrequency ablation

• RFB: rectal foreign body

• RFT: right ventricular false tendon

• RFTs: respiratory function tests

• RGA: right gastric artery

• Rh

  • rhesus

  • rhodium

• RHA: right hepatic artery

• RHD

  • right hand dominant

  • right hepatic duct

• RHS: right hand side

• RHV: right hepatic vein

• RI

  • ramus intermedius

  • resistive index

  • retention index

• RIF: right iliac fossa

• RIG: radiologically inserted gastrostomy

• RIGS: radioimmuno-guided surgery

• RIH: right inguinal hernia

• RIHD: radiation-induced heart disease

• RIJ: right internal jugular

• RIJV: right internal jugular vein

• RIMA: right internal mammary artery

• RIRS: retrograde intrarenal surgery

• RIS

  • radiologically-isolated syndrome

  • radiology information system

• RITA: right internal thoracic artery

• RK: right kidney

• RL: Ringer's lactate

• RLE: right lower extremity

• RLL

  • right lobe of liver

  • right lower limb

  • right lower lobe (of the lung)

• RLN: recurrent laryngeal nerve

• RLQ: right lower quadrant

• RLZ: right lower zone

• RMB: right main bronchus

• RML: right middle lobe

• RMO: resident medical officer

• RMS: 

  • Ramsay Hunt syndrome

  • rhabdomyosarcoma

  • root mean square

• RMT: retromolar trigone

• RMZ: right middle zone

• RN: registered nurse

• Rn: radon

• RNA: ribonucleic acid

• RNFL: retinal nerve fiber layer

• RNS: repetitive nerve stimulation

• RO: right ovary

• R/O

  • removal of

  • rule out

• ROC: receiver operating characteristic curve

• ROI: region of interest

• ROLL: radioguided occult lesion localization 

• ROM: range of motion

• ROP: retinopathy of prematurity

• ROS

  • reactive oxygen species

  • removal of sutures

  • review of systems

• ROSC: return of spontaneous circulation

• RP

  • retinopathy of prematurity

  • retroperitoneal

  • retropharyngeal

• RPA: right pulmonary artery

• RPOC: retained products of conception

• RPL: recurrent pregnancy loss

• RPLND: retroperitoneal lymph node dissection

• RPLS: reversible posterior leukoencephalopathy syndrome

• RPP: radical perineal prostatectomy

• RR: respiratory rate

• RRA: right renal artery

• RRMS: relapsing remitting multiple sclerosis

• RRP: radical retropubic prostatectomy

• RRT: renal replacement therapy

• RS: respiratory system

• RSBI: rapid shallow breathing index

• RSCA: right subclavian artery

• RSI: repetitive strain injury

• RSM

  • recurrent spontaneous abortion

  • Royal Society of Medicine (UK)

• RSNA: Radiological Society of North America

• RSO: resident surgical officer

• RSW: right-sided weakness

• RSWP: radial-sided wrist pain

• RSX: radiosurgery

• RT

  • radiotherapy

  • right

• RTA

  • renal tubular acidosis

  • road traffic accident

• RTC: road traffic collision

• RTT: return to theater

• RTI: respiratory tract infection

• RTX

  • radiotherapy

  • rituximab

• Ru: ruthenium

• RUE: right upper extremity

• RUL

  • right upper limb

  • right upper lobe (of the lung)

• RUO: right ureteric orifice

• RUQ: right upper quadrant

• RUZ: right upper zone

• RUSH: rapid ultrasound in shock

• RV

  • residual volume

  • right ventricle

• RVA: right vertebral artery

• RVAD: right ventricular assist device

• RVCL-S: retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations

• RVD

  • retroviral disease (euphemism for HIV)

  • right ventricular dilatation

• RVF: right ventricular failure

• RVH: right ventricular hypertrophy

• RVOT: right ventricular outflow tract 

• RVR: rapid ventricular rate/response (in atrial fibrillation)

• RVSP: right ventricular systolic pressure

• RVT: renal vein thrombosis

• RWMA: regional wall motion abnormalities or regional wall motion abnormality

• Rx: prescription (originally, and strictly, ℞, shorthand for recipe, in Latin = take thou)