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Intermediate Technical IVT

LAO

Also written as: LAO — Left Anterior Oblique

Angiographic projection angle positioning the image intensifier to the patient's left side and anteriorly.

Full Definition

Left Anterior Oblique refers to a standard angiographic projection where the image intensifier is positioned to the patient's left side and moved anteriorly, typically at angles ranging from 30 to 60 degrees. This projection is fundamental in coronary angiography for optimal visualization of specific coronary segments. LAO projections are particularly useful for evaluating the left anterior descending artery, circumflex system, and right coronary artery. The angle is often combined with cranial or caudal angulation to eliminate vessel overlap and provide clear delineation of coronary anatomy.

Usage

Usage note: Always specify the degree of angulation (e.g., LAO 45°) in procedural reports.

In Context

  • "The LAO 30° cranial view provided excellent visualization of the left main bifurcation." — Angiography report
  • "Additional LAO projections were obtained to better delineate the marginal branches." — Procedural documentation

Contrasted with

RAO right anterior oblique

Don't confuse with

RAO lateral projection

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