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

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• S

  • sacral

  • second (SI unit of time)

  • sulfur

• S1-S5: sacral vertebrae

• S₁-S₄: first, second, third, fourth heart sounds

• S100

• SA

  • semen analysis

  • sinoatrial

• SAA: serum amyloid A

• SAAG: serum ascites albumin gradient

• SAB: subacromial bursa

• SABA: short-acting beta-2 agonist (e.g. albuterol)

• SABR: stereotactic ablative radiotherapy

• SACT: systemic anti-cancer therapy

• SAD

  • seasonal affective disorder

  • short axis diameter

• SAE

  • sepsis-associated encephalopathy

  • serious adverse event

  • splenic artery embolization

• Sag: sagittal

• SAH: subarachnoid hemorrhage

• SALT: speech and language therapy/therapist

• SAM: segmental arterial mediolysis

• SAN: sinoatrial node

• SAP: superior articular process (of vertebra)

• S&S: signs and symptoms

• SAPHO: synovitis, acne, pustulosis, hyperostosis, osteitis

• SAR

  • serious adverse reaction

  • specific absorption rate

• SARS: severe acute respiratory syndrome

• SARS-CoV-1: severe acute respiratory syndrome-coronavirus-1

• SARS-CoV-2: severe acute respiratory syndrome-coronavirus-2

• SAVR: surgical aortic valve replacement

• SB

  • small bowel

  • spectral broadening

  • stillbirth

• Sb: antimony (Latin: stibium)

• SBBOS: small bowel bacterial overgrowth syndrome

• SBC: simple bone cyst

• SBE: subacute bacterial endocarditis

• SBF: small bowel follow through

• SBFT: small bowel follow through

• SBO: small bowel obstruction

• SBP

  • spontaneous bacterial peritonitis

  • systolic blood pressure

• SBPL: spontaneous bacterial pleuritis

• SBRT: stereotactic body radiotherapy

• SBS: seat belt sign

• SC

  • spinal cord

  • subcutaneous

• Sc: scandium

• SCA

  • sickle cell anemia

  • subclavian artery

  • superior cerebellar artery

• SCAD: spontaneous coronary artery dissection

• SCC

  • semicircular canal

  • spinal cord compression

  • squamous cell cancer

  • squamous cell carcinoma

• SCCD: semicircular canal dehiscence

• SCCP: small cell carcinoma of the prostate

• SCD

  • sickle cell disease

  • sudden cardiac death

  • superior canal dehiscence

• SCDO: spondylocostal dysostosis

• SCI: spinal cord injury

• SCIG: subcutaneous immunoglobulin

• SCIWORA: spinal cord injury without radiographic abnormality

• SCJ: sternoclavicular joint

• SCLC: small cell lung cancer

• SCM: sternocleidomastoid

• SCoR: Society and College of Radiographers (UK)

• SCORIF: stimulated cycle oocyte retrieval in [office] fertilisation

• SCOS: small cell osteosarcoma

• SCP-Nano: Single Cell Precision Nanocarrier Identification

• scRNA-seq: single-cell RNA sequencing

• SCS: spinal cord stimulator

• SCT: stem cell transplant

• SCV: subclavian vein

• SD

  • septal deviation

  • stable disease (malignant disease/RECIST)

  • standard deviation

  • standard drinks (alcohol)

• SDASH: shunt-dependency in symptomatic aneurysmal subarachnoid hemorrhage score

• SDD: surfactant deficiency disorder

• SDEC: same-day emergency care

• SDH: subdural hemorrhage

• SE

  • side-effect

  • spin echo

  • status epilepticus

• Se: selenium

• Sec: second

• SEE: septic-embolic encephalitis

• SEEG: stereoelectroencephalography 

• SeHCAT: selenium homocholic acid taurine

• SEMAC: slice-encoding for metal artifact correction (Siemens)

• SEMS: self-expandable metallic stent

• SEP: superior end-plate (vertebral body)

• Ser: serine

• sestamibi: sesta-methoxyisobutylisonitrile

• SFA: superficial femoral artery

• SFEMG: single-fiber electromyography

• SFH: symphyseal fundal height

• SFLC: serum free light chains

• SFN: small fiber neuropathy

• SFSS: small for size syndrome (liver graft)

• SFV: superficial femoral vein (femoral vein preferred)

• SGA​

  • small for gestational age

  • supraglottic airway

• SGC: Swan-Ganz catheter

• SGHL: superior glenohumeral ligament

• SGRT: surface guided radiation therapy

• SH

  • Salter-Harris

  • social history

• SHG: sonohysterogram

• SHO: senior house officer

• SHORT syndrome: short stature, hyperextensibility and/or inguinal hernia, ocular depression, Rieger anomaly, teething delay

• SHx: social history

• SI

  • sacroiliac

  • secondary infertility

  • serious incident

  • sexual intercourse

  • signal intensity

  • situs inversus

  • small intestine

  • Systeme Internationale (d'unites) (SI units)

• Si: silicon

• SIADH: syndrome of inappropriate antidiuretic hormone secretion

• SIBGP: sent in by GP (general practitioner)

• SIBO: small intestinal bacterial overgrowth

• SICRET: small infarctions of cochlear, retinal and encephalic tissue = Susac syndrome

• SIDM: steroid-induced diabetes mellitus

• SIDS: sudden infant death syndrome

• SIJ: sacroiliac joint

• SIM: simulation

• SIMV: synchronised intermittent mechanical ventilation

• SINS: spinal instability neoplastic score

• SIRT: selective internal radiotherapy

• SIRVA: shoulder injury related to vaccine administration

• SISCOM: subtraction ictal single photon emission computed tomography (SPECT) coregistered to magnetic resonance imaging (MRI)

• SIT: situs inversus totalis

• SJS: Stevens-Johnson syndrome

• SKA: simultaneous pancreas and kidney transplant

• SkM: skeletal muscle

• SLAC: scapholunate advanced collapse

• SLAP: superior labral anterior-posterior (tear)

• SLE

  • Saint Louis encephalitis

  • systemic lupus erythematosus

• SLEC: spinal longitudinal epidural collection

• SLG: sublingual gland

• SLGA: superior lateral genicular artery

• SLGB: single lumen gastric bypass

• SLIG: single live intrauterine gestation

• SLIP: single live intrauterine pregnancy

• SLIPPERS: supratentorial lymphocytic inflammation with parenchymal perivascular enhancement responsive to steroids

• SLIUG: single live intrauterine gestation

• SLIUP: single live intrauterine pregnancy

• SLJ: Sinding-Larsen-Johansson disease

• SLL: scapholunate ligament

• SLN: sentinel lymph node

• SLNBx: sentinel lymph node biopsy

• SLT: speech and language therapy

• SLYM: subarachnoid lymphatic-like membrane

• SM

  • smooth muscle

  • submucosa

• SMA

  • smooth muscle actin (immunohistochemistry)

  • spinal muscular atrophy

  • superior mesenteric artery

  • supplementary motor area

• SMART

  • specific, measurable, achievable, relevant, timely

  • stroke-like migraine attacks after radiation therapy syndrome

• SMAS: superficial musculoaponeurotic system

• SMEI: severe myoclonic epilepsy of infancy

• SMG: submandibular gland

• SMGA: superior medial genicular artery

• SMR: stable metabolic response

• SMS: sonographic Murphy sign

• SMV

  • submentovertical

  • superior mesenteric vein

• SN: sentinel node

• Sn

  • sensitivity

  • tin (Latin: stannum)

• SNAC: scaphoid nonunion advanced collapse

• SNBx: sentinel node biopsy

• SNHL: sensorineural hearing loss

• SNiP: single nucleotide polymorphism

• SNOH: surgical neck of humerus

• SNP: single nucleotide polymorphism

• SNpc: substantia nigra pars compacta

• SNR: signal-to-noise ratio

• SNRI: serotonin and norepinephrine reuptake inhibitors

• SNS

  • sacral nerve stimulator

  • sympathetic nervous system

• SNT: soft, non-tender

• SOA: swelling of ankles

• SOAP: subjective, objective, assessment, plan (medical notes)

• SOB: shortness of breath (difficulty in breathing, dyspnea)

• SOBAR: shortness of breath at rest

• SOBOE: shortness of breath on exertion

• SOD: septo-optic dysplasia

• SOF: superior orbital fissure

• SOFS: superior orbital fissure syndrome

• SOL: space-occupying lesion

• SONK: spontaneous osteonecrosis of the knee

• SOP: standard operating procedure

• SoR: Society of Radiographers (UK)

• SOS

  • satisfaction of search (error)

  • sinusoidal obstruction syndrome

• SOV: superior ophthalmic vein

• SOVA: sinus of Valsalva aneurysm

• SP

  • sacral promontory

  • speech pathology/pathologist

  • spinous process

• Sp

  • species

  • specificity

• SPTTL: superficial posterior tibiotalar ligament

• S/P: status post (i.e. post-procedure/surgery)

• SPACE

  • sampling perfection with application optimized contrasts using different flip angle evolution (Siemens)

  • spatial and chemical-shift encoded excitation

• SpaceOAR: space organ at risk

• SPAIR: spectral attenuated inversion recovery

• SPC: suprapubic catheter

• SPECIAL: spectral inversion at lipid

• SPECT: single photon emission computed tomography

• SPET: single photon emission computed tomography

• SPGR: spoiled gradient recalled

• SPIR: spectral presaturation with inversion recovery

• SPMS: secondary progressive multiple sclerosis

• SPN: solitary pulmonary nodule

• Spp: species (plural)

• SPS

  • single point stick

  • stiff person syndrome

• SQ

  • status quo

  • subcutaneous

• SR: sinus rhythm

• Sr: strontium

• SREAT: steroid responsive encephalopathy associated with autoimmune thyroiditis

• SRM

  • small renal mass

  • solitary renal mass

• SRO: sagittal ramus osteotomy

• SROM: spontaneous rupture of membranes

• SRS

  • Silver-Russell syndrome

  • somatostatin receptor scintigraphy

  • stereotactic radiosurgery

• SS

  • serotonin syndrome

  • signs and symptoms

  • situs solitus

  • Sjögren syndrome

  • straight sinus

  • supraspinatus muscle

  • systemic sclerosis

• SSc: systemic sclerosis

• SSCC: superior semicircular canal

• SSD

  • solid state drive

  • source skin distance

• SSFP: steady state free precession

• SSG: split skin graft

• SSI: surgical site infection

• SSN: suprasternal notch

• ssp: subspecies

• SSPE: subacute sclerosing panencephalitis

• SSR: spontaneous splenic rupture

• SSRF: surgical stabilization of rib fractures

• SSRI: selective serotonin reuptake inhibitors

• SSS

  • sick sinus syndrome

  • superior sagittal sinus

• SST: short Synacthen test

• SSTR: somasostatin receptor

• ST

  • speech therapy

  • ST segment on ECG

• STA: superficial temporal artery

• STAMCA: superficial temporal artery to middle cerebral artery anastomosis

• Staph: Staphylococcus spp.

• stat: immediately (Latin: statim)

• STD

  • sexually transmitted disease

  • ST depression

• STE: ST elevation

• STEMI: ST segment elevation myocardial infarct

• STI

  • sexually transmitted infection

  • soft tissue injury

• STIR

  • short tau inversion recovery

  • short TI inversion recovery

• STJ

  • sinotubular junction (of the ascending aorta)

  • subtalar joint

• STN: subthalamic nucleus

• STOP: selective tubal occlusive procedure

• STP: standard temperature and pressure

• Strep: Streptococcus spp.

• STT

  • scaphotrapeziotrapezoid joint

  • Schirmer tear test

  • serial thrombin time

  • straight to test

• STUMP: stromal tumor of uncertain malignant potential

• SUA: single umbilical artery

• Sub: subiculum

• subcut: subcutaneous

• subsp: subspecies

• SUDEP: sudden unexplained death in epilepsy

• SUDI: sudden unexpected death in infancy

• SUI: serious untoward incident

• SUIB: sitting up in bed

• SUL: standardized uptake value corrected for lean body mass

• SUO: syncope of unknown origin

• supraclav: supraclavicular

• SUSAR: suspected unexpected serious adverse reaction

• SUV: standardized uptake value

• SV: stroke volume

• Sv: sievert

• SVC: superior vena cava

• SVD: spontaneous vaginal delivery

• SVG: saphenous vein graft

• SVI: stroke volume index

• SVR: sustained virologic response

• SVT

  • subdural venous thrombosis

  • superficial venous thrombosis

  • supraventricular tachycardia

• SWAN

  • susceptibility weighted angiography

  • syndrome without a name

• SWI: susceptibility weighted imaging

• SWOT analysis: strengths, weaknesses, opportunities, threats

• SWS: Sturge-Weber syndrome

• SWU: sepsis workup

• Sx: signs

• SXR: skull x-ray

• Sy: symptoms

• Symp: symptoms

• Symph: symphysis pubis

• Sys: systems review