Human health and medicine

Intratumoral injection

Intratumoral injection is an oncology drug delivery method injecting agents directly into a tumor for high local concentrations and low systemic exposure, used chiefly for immunotherapies like oncolytic viruses and T-VEC.

Intratympanic injection

Intratympanic injection is an ear procedure in which drugs such as steroids or gentamicin are injected through the eardrum into the middle ear, diffusing into the inner ear.

Intrauterine device

Intrauterine device (IUD, coil): small T-shaped device placed in the uterus; copper and levonorgestrel types; over 99% effective, lasting 3–12 years, also emergency contraception.

Intrauterine growth restriction

Intrauterine growth restriction, also called fetal growth restriction (FGR), is a fetus failing to reach its growth potential, usually from placental insufficiency; defined as estimated fetal weight below the 10th percentile, monitored by Doppler, with delivery timing tied to severity.

Intrauterine growth retardation-micrognathia-short stature-facial dysmorphism-rhizomelic shortening syndrome

Intrauterine growth retardation-micrognathia-short stature-facial dysmorphism-rhizomelic shortening syndrome, or ARCN1-related syndrome (OMIM 617164), is a rare autosomal dominant COPI transport disorder with IUGR, severe micrognathia, short stature, and microcephaly.

Oct 20, 2026

Intrauterine hypoxia

Intrauterine hypoxia (ICD-11 KB20, ICD-10 P20), also called intrauterine distress, is fetal oxygen deprivation before birth, caused by cord prolapse or occlusion, placental infarction, or maternal smoking, and can cause neonatal encephalopathy.

Intrauterine insemination

Intrauterine insemination (IUI) is a fertility treatment that places washed, concentrated sperm directly into the uterus around ovulation, used for unexplained infertility, mild male factor, and donor-sperm treatment.

Intrauterine resuscitation

Intrauterine resuscitation is a set of measures applied during labor when fetal heart monitoring shows distress, including maternal repositioning, stopping oxytocin, IV fluids, tocolysis, and amnioinfusion, to improve fetal oxygenation and often avoid cesarean delivery.

Intrauterine transfusion

Intrauterine transfusion, also known as fetal transfusion, is an ultrasound-guided fetal therapy that injects donor red cells into the umbilical vein to treat severe fetal anemia, introduced in 1963.

Intravaginal administration

Intravaginal administration is a route of drug delivery in which medication is placed directly into the vagina, treating it locally or reaching the bloodstream while bypassing the liver.

Intravascular lymphoma

Intravascular lymphoma (IVLBCL, angiotropic large cell lymphoma) is a rare aggressive extranodal B-cell lymphoma growing almost exclusively inside small blood vessels, without masses or lymphadenopathy, affecting mainly elderly patients and treated with rituximab-chemotherapy plus CNS prophylaxis.

Intravascular papillary endothelial hyperplasia

Intravascular papillary endothelial hyperplasia (IPEH), or Masson's tumor, is a benign reactive endothelial proliferation within an organizing thrombus, first described by Pierre Masson in 1923. It accounts for about 2% of vascular tumors, mimics angiosarcoma, and is cured by complete excision.

Intravascular ultrasound

Intravascular ultrasound (IVUS) is a catheter-based imaging technique using a miniature 20–60 MHz transducer to image artery walls from inside, quantifying plaque burden that angiography cannot measure.

Intravenous anesthesia

Intravenous anesthesia is general anesthesia from drugs injected or infused into a vein, usually induced with propofol; without any anesthetic gas it is called TIVA.

Intravenous iron therapy

Intravenous iron therapy delivers elemental iron into a vein as iron–carbohydrate nanoparticles, rapidly replenishing iron stores when oral iron is slow, poorly absorbed in inflammation, or causes gastrointestinal side effects.

Intravenous leiomyomatosis

Intravenous leiomyomatosis (IVL), a rare benign uterine smooth muscle tumor growing within veins toward the inferior vena cava and right heart; first described 1896, treated by complete resection, recurs in 10-31%.

Intravenous sugar solution

Intravenous sugar solution (dextrose or glucose IV infusion, e.g. D5W): sterile 5% glucose in water supplying calories and water, first infused in 1896; physiologically hypotonic after metabolism, with hyponatremia and hyperglycemia as key risks.

Intravenous therapy

Intravenous therapy, also known as IV therapy or an intravenous drip, is a medical technique that delivers fluids, medications, nutrition, or blood products directly into a vein, bypassing the gut.

Intravenous urography

Intravenous urography, also called intravenous pyelography or IVP, is a radiological technique in which iodinated contrast injected into a vein outlines the kidneys, ureters, and bladder on X-rays.

Intraventricular hemorrhage

Intraventricular hemorrhage (IVH), also called ventricular bleeding, is blood within the brain's ventricular system, usually extending from intracerebral or subarachnoid hemorrhage in adults or from germinal matrix bleeding in premature infants, and commonly causing hydrocephalus.

Intraventricular infusion

Intraventricular infusion, also called intracerebroventricular (ICV) administration, delivers drugs directly into the brain's cerebrospinal fluid through a catheter and reservoir, bypassing the blood–brain barrier for chemotherapy, antibiotics, enzyme replacement, and gene therapy.

Intraventricular injection

Intraventricular injection, also called intracerebroventricular (ICV) injection, delivers a drug directly into the brain's ventricular cerebrospinal fluid, bypassing the blood-brain barrier, often through an Ommaya reservoir.

Intravesical administration

Intravesical administration is a drug delivery method in which liquid medication is instilled into the bladder via catheter, chiefly to treat non-muscle-invasive bladder cancer with mitomycin C or BCG.

Intravesical chemotherapy

Intravesical chemotherapy is a bladder cancer treatment in which a cytotoxic drug, such as mitomycin C, is instilled through a catheter to treat non-muscle invasive tumors.

Intravitreal injection

An intravitreal injection delivers a drug, most often an anti-VEGF agent, directly into the vitreous humor of the eye to treat retinal disease such as age-related macular degeneration.

Intravoxel incoherent motion imaging

Intravoxel incoherent motion (IVIM) imaging is a diffusion-weighted MRI technique, introduced by Le Bihan in 1986, that separates microvascular perfusion from true water diffusion without contrast agents.

Intrinsic factor

Intrinsic factor (gastric intrinsic factor, GIF) is a parietal-cell glycoprotein that binds vitamin B12 for cubam-receptor absorption in the terminal ileum; its loss causes pernicious anemia, first demonstrated by Castle in 1928.

Intrinsic primary afferent neuron of myenteric plexus

Intrinsic primary afferent neuron (IPAN), also called enteric primary afferent neuron or intrinsic sensory neuron: a sensory neuron with cell bodies in the myenteric and submucosal plexuses that transduces gut mechanical and chemical stimuli, has Dogiel type II morphology and AH electrophysiology, initiates local enteric reflexes, and does not project to the CNS.