All articles A–Z

Diffraction contrast

Diffraction contrast is a principal contrast mechanism in transmission electron microscopy, first observed in 1956, in which dislocations and stacking faults bend or strain the crystal lattice so Bragg diffraction makes them appear dark or bright.

Diffraction contrast tomography

Diffraction contrast tomography (DCT) is an X-ray imaging technique that reconstructs the three-dimensional grain shapes and orientations of polycrystalline materials, first reported by Wolfgang Ludwig and colleagues in 2008.

Diffraction from slits

Diffraction from slits, also called diffraction formalism, is the spreading and interference of waves passing through narrow openings, the classic demonstration that light is a wave.

Diffraction grating

A diffraction grating is an optical component with many parallel grooves or slits that splits light into its component wavelengths, each emerging at a different angle.

Diffraction microscopy

Diffraction microscopy, also known as coherent diffractive imaging (CDI), is a lensless imaging method that reconstructs a specimen's image computationally from its measured diffraction pattern.

Diffraction order

A diffraction order is one of the discrete output directions in which a diffraction grating sends light, labeled by the integer m in the grating equation.

Diffraction tomography

Diffraction tomography is an inverse-scattering imaging method that reconstructs the internal structure of weakly scattering objects from diffracted waves, unlike ray-based tomography, with applications in geophysics, breast ultrasound, and cell imaging.

Oct 22, 2026

Diffraction-limited storage ring

A diffraction-limited storage ring (DLSR) is an electron storage ring x-ray source whose emittance is low enough that the emitted x-rays are nearly fully spatially coherent.

Diffraction-limited system

A diffraction-limited system, or optical diffraction limit, is an optical instrument whose imaging performance is limited by the wave nature of light rather than by flaws in its optics.

Diffractive neural network

A diffractive neural network, or diffractive deep neural network, performs machine learning inference through light passing through trained diffractive layers, introduced by UCLA researchers in 2018.

Diffractive scattering

Diffractive scattering is a class of high-energy particle collisions in which one or both incoming hadrons emerge nearly intact, separated from the produced system by a large rapidity gap.

Diffractometry

Diffractometry is a family of techniques for determining the structure, phase composition, or texture of matter by analyzing diffraction patterns from X-rays, electrons, or neutrons, a field born in 1912.

Diffuse alveolar damage

Diffuse alveolar damage (DAD), the histologic hallmark of ARDS and the pathology behind acute interstitial pneumonia, is a lung injury pattern with exudative, proliferative, and fibrotic phases, hyaline membranes, and higher mortality when present in ARDS.

Diffuse alveolar hemorrhage

Diffuse alveolar hemorrhage (DAH), bleeding from pulmonary microcirculation into alveolar spaces, presents with hemoptysis, anemia, infiltrates, hypoxemic respiratory failure; mostly autoimmune causes, over 20% in-hospital mortality.

Diffuse axonal injury

Diffuse axonal injury (DAI), also called traumatic axonal injury (TAI), is widespread white-matter axon rupture from acceleration-deceleration forces in TBI; graded by Adams system, best seen on MRI/SWI, diagnosed in 40-50% of hospitalized TBI.

Diffuse brain injury

Diffuse brain injury (ICD-11 NA07.3), chiefly diffuse axonal injury (DAI), is widespread traumatic white-matter damage from rapid rotational acceleration-deceleration, graded Adams 1-3, common in severe TBI and worsening prognosis.

Diffuse capillary malformation with overgrowth

Diffuse capillary malformation with overgrowth (DCMO), ORPHA:714737, is a rare congenital vascular anomaly syndrome with extensive pink reticulated capillary malformations, proportionate overgrowth, and foot anomalies, linked to somatic PIK3CA, GNAQ, or GNA11 variants.

Diffuse correlation spectroscopy

Diffuse correlation spectroscopy (DCS) is a noninvasive optical technique that measures a blood flow index in deep tissue, such as brain, muscle, and tumors, at the bedside.

Diffuse cutaneous mastocytosis

Diffuse cutaneous mastocytosis (DCM), the rarest and most severe cutaneous mastocytosis subtype, causes generalized erythroderma, peau d'orange thickened skin, and infantile blistering, with anaphylaxis risk and symptomatic antihistamine treatment.

Oct 20, 2026

Diffuse hemispheric glioma-H3 G34-mutant

Diffuse hemispheric glioma, H3 G34-mutant, is a rare malignant brain tumor of the cerebral hemispheres, defined by H3 G34R/V histone mutations, affecting mainly adolescents and young adults.

Oct 20, 2026

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia

DIPNECH (diffuse idiopathic pulmonary neuroendocrine cell hyperplasia) is a rare WHO pre-invasive lung lesion of proliferating neuroendocrine cells, mainly in nonsmoking women over 60, causing cough, dyspnea, nodules, and mosaic CT attenuation, sometimes progressing to carcinoid tumors.

Diffuse interface method

The diffuse interface method is a numerical modeling approach that treats the boundary between two phases as a smooth transition region described by a continuous order parameter.

Diffuse interstellar bands

Diffuse interstellar bands (DIBs) are about 500 broad absorption features in starlight passing through interstellar gas and dust, first noticed by Mary Lea Heger in 1919.

Diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, about 30% of cases, marked by rapidly growing tumors in lymph nodes or organs.

Diffuse large B-cell lymphoma associated with chronic inflammation

DLBCL associated with chronic inflammation (CI-DLBCL, pyothorax-associated lymphoma): EBV-positive aggressive large B-cell lymphoma arising after 10–35+ years in chronically inflamed body cavities or around implants; 5-year survival 20–35%.

Diffuse large B-cell lymphoma of the central nervous system

Diffuse large B-cell lymphoma of the CNS, also called secondary CNS lymphoma (SCNSL), is DLBCL spreading to brain, meninges, or spinal cord; rare (about 3% of DLBCL), mostly within two years, with median survival of months unless ASCT consolidation succeeds.