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

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• F

  • farad

  • female

  • fluorine

  • French gauge

  • phenylalanine (single amino acid code)

• FA

  • fibroadenoma

  • facet asymmetry

• FABER: flexion, abduction, and external rotation maneuver

• FACR: Fellow of the American College of Radiology

• FAF: fissula ante fenestram

• FAI: femoroacetabular impingement

• FAIR: flow sensitive alternating inversion recovery

• FAMMM: familial atypical multiple mole melanoma syndrome​

• FAS

  • fetal alcohol syndrome

  • focal aware seizure

• FASD: fetal alcohol spectrum disorders

• FASI: focal areas of signal intensity

• FAST

  • focused assessment with sonography for trauma

  • Fourier-acquired steady state

• Fat sat: fat saturation

• FAVA: fibroadipose vascular anomaly

• Fax: facsimile

• FB: foreign body

• FBC: full blood count

• FBG: fasting blood glucose

• FBOA: foreign body obstructed airway

• FBMS: fasting metabolic bone studies

• FCC: fibrocystic change

• FCD

  • fibrocystic disease (of the breast)

  • fibrous cortical defect

  • fibrous cortical dysplasia

• FCL: fibular collateral ligament

• FCMD: Fukuyama congenital muscular dystrophy

• FC Rad Diag(SA): Fellowship of the College of Radiologists of South Africa

• FCRB: flexor carpi radialis brevis vel profundus

• FCS: furin cleavage site

• FCSEMS: fully covered self-expanding metal stent

• FD

  • fibrous dysplasia

  • found down (unconscious)

• FDA: Food and Drug Administration (a federal agency of United States)

• FDG: fluorodeoxyglucose

• FDL: flexor digitorum longus

• FDP

  • fibrin degradation product

  • flexor digitorum profundus

• FDS: flexor digitorum superficialis

• FE: flexion-extension

• Fe: iron (Latin: ferrum)

• FEP: first ever psychosis

• FES: fat embolism syndrome

• FESS: functional endoscopic sinus surgery

• FEV1: forced expiratory volume in 1 second

• FEVAR: fenestrated endovascular aortic repair

• FFA: free fatty acids

• FFD: fixed flexion deformity

• FFG - F-encoding plasmid DNA and virus-like particles containing RSV fusion (F) and attachment (G) glycoproteins

• FFI: focal fatty infiltration

• FFL: fabellofibular ligament

• FFP: fresh frozen plasma

• FFS: focal fatty sparing

• FGC: fibreglass cast

• FGI: fluoroscopically guided intervention

• FGR: fetal growth restriction

• FH: family history

• FHM: fetal heart motion

• FHR: fetal heart rate

• FHS: fetal heart sounds

• FHx: family history

• FI: for investigation

• FIAS: focal impaired aware seizure

• FID: free induction decay

• FIESTA: fast imaging employing steady state acquisition

• FIF: forced inspiratory flow

• FiNA: fine needle aspiration

• FiO₂: fraction of inspired oxygen

• FIRES: febrile infection-related epilepsy syndrome

• FISP: fast imaging with steady-state precession

• FIT: fecal immunochemical test

• FJ: facet joint

• FL: femur length (obstetric USS)

• FLAIR: fluid-attenuated inversion recovery

• FLAMES: FLAIR-hyperintense lesions in anti-MOG associated encephalitis with seizures

• FLASH: fast low angle shot

• FLC: fibrolamellar carcinoma

• FLCN-S: folliculin gene-associated syndrome

• FLI: flu-like illness

• FLR: future liver remnant

• Fluoro: fluoroscopy

• FLUS: follicular lesion of undetermined significance

• FMD

  • fibromuscular dysplasia

  • functional movement disorder

• FMF: familial Mediterranean fever

• fMRI: functional magnetic resonance imaging

• FN

  • false negative

  • febrile neutropenia

• FNA: fine needle aspiration

• FNAB: fine needle aspiration biopsy

• FNAC: fine needle aspiration cytology

• FND: functional neurological disorder

• FNE: fiberoptic nasoendoscopy

• FNH: focal nodular hyperplasia

• FNMR: Fédération Nationale des Médecins Radiologues (French radiologists' union)

• FO: foramen ovale

• FOB: fecal occult blood

• FOBT: fecal occult blood test

• FOLFOX: Fluorouracil, leucovorin (fOLinic acid), OXaliplatin

• FOM: floor of mouth

• FONAR: field focussing nuclear magnetic resonance

• FOOSH: fall on outstretched hand

• FOSIT: feeling of something in the throat

• FOV: field of view

• FP

  • false positive

  • fetal pole

• FPCT: flat panel CT

• FPIES: food protein-induced enterocolitis syndrome

• fPSA: free prostate specific antigen

• FPS-R: faces pain scale-revised

• Fr: French gauge

• FRANZCR: Fellow of the Royal Australian and New Zealand College of Radiologists

• FRC: functional residual capacity

• FRCR: Fellow of the Royal College of Radiologists

• FRI: fracture-related infection (osteomyelitis)

• FROEM: full range of eye movements

• FROM: full range of movement

• FS

  • fat saturation/suppression

  • febrile seizure

  • foramen spinosum

  • functional seizure

• F/S: frames/second

• FSE: fast spin echo

• FSH: follicle-stimulating hormone

• FSHD: facioscapulohumeral muscular dystrophy

• FT

  • follow-through

  • Fourier transform

  • full-time

• fT₃: free tri-iodothyronine

• fT₄: free thyroxine

• FTD: frontotemporal dementia

• FTS: first trimester screening

• FU: fluorouracil

• F/U: follow-up

• FUEL: FLAIR-variable unilateral enhancement of the leptomeninges

• FUO: fever of unknown origin

• FURS: flexible ureteroscopy

• FV: femoral vein

• FVC: forced vital capacity

• FVL: factor V Leiden (V=5, Roman numeral)

• FWHM: full width at half maximum

• FWT: full ward test (urine)

• Fx: fracture