Composition

Cell Debris in Fluid

Areflective fluid spaces with hyperreflective coarse granular deposits Static fluid, no flow from perfusion as seen in vessels Observed in areas of liquifactive necrosis Pus filled bulla

Fluid

Areflective well defined pools for localised edema or diffuse hyporeflective areas for inflammatory edema/erythema Representative of both tissue fluid, water and other non-scattering fluids in the absence of blood Fluid pools from an intradermal saline injection

Dense Keratin

Hyperreflective upper surface getting more hyporeflective with depth Homogenous smooth texture Distinct vertical shadow cast by structure Epidermal inclusion cysts/keratinised cysts

Layered Keratin

Hyporeflective, coarse texture with areas of hyperreflectivity Parallel keratin filaments in a mesh structure, spaces between fibres limit scattering causing darker appearance Hyperreflective areas inside plaque indicate disruption to keratin organisation Hyperkeratotic layering on an invasive squamous cell carcinoma

Loose Keratin

Hyperreflective, smooth homogenous texture Diffuse/Undefined border Amorphous arrangement of keratin fibrils in a seborrheic keratosis Can appear brighter or darker depending on how compressed the keratin is

Dense Collagen

Hyperreflective, smooth mottled texture Small hyporeflective areas due to capillaries Small collagen bundles closely packed together Follicular skin papillary dermis

Loose Collagen

Hyporeflective, smooth mottled texture. Large collagen bundles loosely packed due to vessels and tissue fluid pockets. Follicular skin reticular dermis

Normal Epidermal Keratinocytes

Stratum Spinosum of glabrous skin, also main component of epidermis visible on follicular skin. Hyperreflective, coarse grain texture Scattering due to cell cytoskeleton arrangement and intracellular keratin  

Basal Cells

Hyporeflective, coarse grain texture Due to nucleus size, arrangement of cytoskeleton and lack of intracellular keratin deposits Observed in thickened DEJ and basal nests